UNITED STATES ATOMlC ENERGY CUMMISSiON
-F - - 71013 BOILING RUBIDIUM A8 A REACTOR : COOLANT. PREPARkTION OF RUBDIUM adETAL, PHYBICAL AND 33PBER.MO~AMIcC PROFERTLES, AND COMPATIBILITY WITH INCONEL
, technical Infor~ionEx?snsion, Oak Ridgs, Timnessee DISCLAIMER
This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency Thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. DISCLAIMER
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*. .I. I *** .* ** ...... : :: . :*:. *::: /f- 8. .* .*** . . e.. 0.. .* 0.. * *. 0... 0.. *I *to.. 0 *a ** . ..a . .a* .* - -8 OPSE RIDCE SCHOOL OF REACTOR TECHNOUXY
''BOI~RUBIDIUM AS A BEACTOR.COOLANT : , PREPAMTION OF RUBIDIUM METALg PHYSICAL AND THERMJDYNAMIC PROPERTIESg AND COMPATIBILI!PY WII"H INCONEX"
This report cont~insinformaticg. geiierated by E. group of @$SORT students under .the leadershim df S; Reed Nixon aa part of an assigned summer project. Although .)ther members of the group contributed in, varying degrees to the effort described herein, the @uses reported on were the respowibillty of: 8.
August 1954 In September, 3.953, a group of men representing various scie~tificand engineering fields embarked on the twelve months of study whieh culminated in this repork. For nine of these months, formal claeeroom and etudent laboratory work occupied their Lime. At the end of that period, MA student; group wae presented with a problem in reactor design,
This is a summary report of the study, the research, the problem and the eolutions which de~~Qopdduricd 'the :final ten weeks period of the echo02 ,term, It must be realized that, in so shod a tie, a sl;u.dy of this Beope ca? not be guaranteed eompl&e or free of error, This '%heels is aaot offered a8 a poxshed engineering report but rather as a record of the work done by the group under the leaderehip of the group leader. It is reproduced for uee by those persona competent to assess the uncertainties inherent in the results obtained in term of the prebieeneee of the t.ecbnica1 data md analytical met hods employed in the study. fn the opinion of the student 8 and f acul%,y of OBSCWT, the problem has served +,,he pedagogical purpose for ,wkieh i.t vaa . intended.
Ae a matter of hiwtorieal fact and pride we point out ,that similar investigations by stude~tgroups of previous ORSOEF classes have led to sufficiently encouraging results to warrant more exhaustive studiee; in at least one instance, a reactor first investigated by a.s%udentgroup is soon to become a physical reality, There is also recorded & instance in whieh calculations contafned in a similar report were uncritically abstracted alad applied to a atudy for whi.ch they were never intended, It is to avoid the recurrence of the latter experience that we have .taken some pains to acquaint the reader with ,the character of this report,
The famltv wishes to Join the,authors ,in an expression of appreciatf on for the aseistance which various members of the Oak Ridge National laboratory have eo generously contributed. In particular, ,the guidance of the group consultant, E, It. ddann, is gratefully achwledged.
F. C. BonderLage for The Faculty of CRSOEi! Section Descrf~tio~
0.1 Introducticn 0.1. Initiationof the Project . 0.1, 2 Scope of the Report O0lO3 Organization of the Report 0.1.4 Acknowledgement
002 Smxqy 0.2.1 Conclusfons 002,2 Recomendationa
Preparation of Rubidium Metal Introduction Chromtography of Alkali Metals 1.2.1 Inorganic Exchanger
1,2,2 Qmthetic Resin Cation Exchanger " 1.2.3 1-1/2 Inch Diameter Resin Column 1.2.4 3 - Inch ,Diameter Resin Column 1.2.5 . Resin Column Operating Procedure . Conversion of Rubidium Carbonate to Rubidium Fluoride
Reduction of Rubidium Fluoride, by calcium 1,4,B Chemical R,eaction 1.4.2 Quartz Reduction Unit . 1,4,3 'Stainless Steel Reduction Unit
Purification of Rubidium Metal b:, Vacuum Distillation Analytical Procedures for Alkali Metals 6 Oxygen in Alkali Metals 106,2 Determination of Na, K, Rb, and Cs by Flame Photometer 1.6,3 Iron, Chromiun and Nickel Impurtieg 1n6n/, Fused Sal%s
Manufacturing Cost Estimate for Rubidium Metal 1 7, 1 Introduction9 1.7, 2 Rough hnufacturf ng Cost
References
Physical Properties of Rubidium Introduction 2.2 Summary of Data gj 2,3 Density 53
...... Sectf on
Specf f ic Heat Viscosity Thermal Conductivity Vapor Pressure 2070% ORIJL 2,'7,2 BatteUe DhrContent of Vapor Surface Tension Coef fiefent of Cubical Expansion Heat Transfer Properties References
300. Thermodynamic Diagrams for Rubidium 77 3,1 Introduction 77 302 Temperature - Entropy Diagram '78 3020% Entropy of the saturated Liquid, S1 78 3.2.2 Entropy of Vaporization, Sh as 3.2,3 Entropy of Saturated Vapor % 79 3,2,4 Entropy of Superheated Vapor, SSB 79 303 Temperature - Enthalpy Diagram 81 3.3.1 Enthalpy of Saturated Liquid, HI 82 3?302 Enthalpy of Vaporization 82 30303 Enthalpy of Vapor Due to Superheat Hsg 82 3.3.4 'Enthalpy of Saturated Vapor, 82 30305 Total Enthalpy, H 82
304 References .91
40 0 Cmpatfbflf ty of Ineonel and Rubidium at
1 Elevated Tempe~ature s
401 Handling of Rubidium 402 Corrosion of Ineonel 40201 htr0dU~tf0g 40202 1540Q F Capsule Test 4,2,3 1650°F Capsule Test 4,2,4 Boiling Rubidium Loop 4.2,5 Quar+,z Capsule Test
403 References Appendix 132 This report contains a portion of the informtion obtaiced during the course of an investigation to determine the merits of a vapor cycle for aircraft propulsion by use of a nuclear reaetor employing a boiling . liquid metal as a coolant, . .
There are certain advantages inherent in a power system utflizing. a coolant which undergoes a ghange of state to transfer the heat energy8
1, Low mass flow of vapor coolant
2, An isothermal system can be approached,
If the change of state is a vaporization or boiling i.socess, these are accompanying. disadvantages s
1, The coolant must experience a'considerable change in
specific volume'and the sizes of both equipment. and
piping become large,
2, Dangers of flow instability and wburnoutwof reactor
components are'present,
Dr, A, Po F'raas', ANP General Design 'Groazp, suggested tias possibility of using a liquid-=pop cykle with rubidium aB the coolant fok an power plant and recommended its study as an ORSORT project,
Rubidium was selected because it is.a coolant with a high latent heat of vaporization having an atmospheric boiling point in the temperature range of the current reactor designs for aircraft apl;lie;.j.tfon,. It als~.
\ has a low melting point which obviates the problem of maintaining a molten coolant, Other physical properties are as might 'be expertid for an ilkali metal,
...... I...... On Jme l.4, 1954 eight students of the 953-54 session of ORSORT were Ikc.t I .I I assigned this,pro,ject as a 10-week summer assignment, Do Lo Stockton and
M, J, Whitmaw were assigned the portions of the investigation 'described
in this report, Dr. E, R. Mann, ORNL inst~ntationand Control Division,
was designated as the advisor.
The overall investigation as described in a preliminary report,
"Rubidium Vapor Aircraft Reactorn ORNL CF-55-6-49 was devoted primarily
to determidng the feasibility of using rubidium metal as a heat transfer
medium in an aircraft.reactor,
The lack of reliable data concerAng borrosiora, heat transfer, and
nuclear properties of rubidium necessitated the expenditure of most of
the effort on these subjects, In addition, the ua9aflabilfty of reasonably
pure rubidium metal presented a serious problem,
To overcome these difficultiee in order to meet the project objectives,
the following programs were initiated:
. 1, The preparation of rubidium metal, 2, Determination of the physical properties of rubidium, 3, Preparation of thermodynamic diagrams for rubidium,
4. Determination of the compatibility of Inconel and Rubidium , .
, at elevated temperatures,
5. A pebble bed boiling experiment, .*.' 6, A comparison of sodium and mbidi-rn activationd
7, A power cycle study
8, A reactor study
' -. This report contains the. ixaf"omtion obtained as the result of efforts
to complete the firs? four programs listed, . >. :- .-. .,."...... -...... ,:..' . +,,,{,
It is ho'pd that the remaining f 6% 'ph'e:&s of the investigation d~l."- ' ' ' ,.-...... , v.. I . . . , <, '*,: . ,:, . I. -. .. , is.., - . .,'! be published infinal f,&n the in hear future. . . ..
.. . ,.. . . . i . ./,...... :J; ...... ; , . . .I.: .". : &.' . :.
0.1.3 Organization' of Ithe Re~ort . :. . .A ,. , . . . I ... ' !: .! '; .!, ,I ' .Since the "a.rws, covered in this project are . diversified , it is ' . ., ..C ...... -- . ..; . . - . . necessary t.6 report the results of each sepa~te.,sectiono. . It is believed ...... ' that, . thi.b will result in :a suitable presentation: of the material; .!ys, .,'- . . . . report :therefore is a cgqpilation of several reports. The order... in which .
the subjects are presented does not represent their relative importance, but was selected to give a logical arrangement. of the results.
J 0.1.4 Ackn6wledgement. . . . Sincere appreoiation is exten8ed.to the many persons who assisted I us in' this project. Ewrone \.ontacted for assistance was cordial and cooperative. without the cooperation of these ORK personnel Bhe . . imrestigation and experiments could not have been accomplished. Our
thanks are extended to the follo~iXg8
Personnel
Eo .Ro. . Mann Advisor
A, Po Fraas Chief Consultant Me Laverne Physics
Chem. Tech, X-10 I. Ro Higgins Ion Exchange Process ' J, T. Robrts
Materials. Cbem, Y-12 R. Grimes Supply of Rubidium J, Barton, Sr. halides,. fusion of RbF
E, Moore ' and dry-box facilities associates . . Stable Isotopes, Y-12 P, S. Baker Reduction to metal by I a special %eeMque r' H. Bo Greene Boyd Weaver
Analytf cal Chem. Y-12 3. 6, white Assays of ~oimeluates, Ho Pa House . fused salt and metal a Miss Jeanne Rogers samples ..... Division Personnel
Glass Blower Y-12 Fabrication of quartz and pykex apparatus
Metallurgy x-10 we D. Mnly Fabrication of loops, E. Eo Hoffban p$rification of. mbidf um, J. Cathcart corrosion tests, metallo- Ro J. Grey . graphic examination,. and R. M. Steele X-ray analysis ' * and associates
Eng'g H. F, Poppendick. Physical Properties .Expo-. 1-12 .S. M. Cohen Density Detedmtion W. D. Powers Specif fc Heat DeteranBxs tion . . 0,2,1 Conclusions: .:. , ...... _, ...... ? ..'i.!;,. .
1, The sepa.ration',of .rubidium from the ,other .,alkali-.m e$ls. Q ,. ,
ion exchange has been. demons.trated.. . .On the basis,, of experience_ .>......
gained while extracting:.rubidium metal of hfgh:.purity .....from ccm-. ..
.wrcial rubidium fluoride., it.is c,oncluded.,that 'rubidium .metal.,. *- . . I.. ' . .
can be. produced in quantity. at-:a cost of $50 per.pound 'as. corny .
pared to .the current price ;of $500 ,per poU&a...... 2. It is concluded on the basis of imperial fo&&e that ' ' more heat can be transferred in a boiling rubidium system
that in a comparable boiling water system.
3. It is tentat,ively concluded that the corrosion of Inconel . . by circulating, and static, boiling rubidium can be dismissed as insignificant for operating lifetimes of the order likely to be encountered in aircraft nuclear reactors. This con-
clusion applies through the temperature range in which Inconel
warrants consideration as a structural material.
0,2,2 Recomnerndations
. 1, - It is recommended that research be' initiated to determine the nature of the. .binary .and ternary phase diagrams of' rubidium
and the other alkali metals. This information wqd prove useful
selecting a reactor coolant composition molten at roam temperature in which the desirable physical and nuclear pro- . . perties would be optimized. 2. A bqiling heat transfer system .can be operated to transfer
heat under essentially isothermal conditions. The constant . , temperature. . and ,liquid-to-vapor transformation .should wevent . the' transpert of dissolved container metal from the region of heat input to regions where heat.is-extracted. It is recommended that many more boiling loops filled .wfth rubidium : and ath other alkali metala be operated to determine whether boiling systems are inherently less subjec't to corrosion than circulating liquid heat transfer systems, 1.0 PREPARATION OF RUBIDIUM METAL
1.1 Introduction -. ,, It was decided to prepare about 100 grams bf hiih' purity rubidium
metal for physical property measurements by Dr. H.' Fo Poppendi'ck8s grdup.
In addition, it was desired tohave a small amount of metal avaihble ' - ... . . for preliminary corrosion tests. . . . . Essentially, the process co*sisted of removing th& 'major cation
contaminants, other alkali metals, from a crude rubidium halide .by an .. * .
ion-exchange process. The cut or ' fraction of the resin colukm eluate . . b . containing nibid& carbbite was converted to the fluorid6 by,neutrali-
. s zation uith aqueous hYdkigen fluoride. ~f ter c6ncentrati& anQ fusion, ... the anhydrous fluoride was reacted 'with calcium metal under high vac . . vacuum distillation mm Hg) in a' Pyrexglass @tern and the product . ., sealed-off under vacuum A. . . After completing the preparation of about' 100 grams of metal, it was necessary to continue this program for two reasons: . . 1. the vendor under contract to supply rubidium rnetai for corrosion tests'was unable to meet his schedule 'so that ehphasis'was ...placed on .... ',' ' ' obtgining0.atleast 200 grams of metal' at' Om. 2, A shipment of rubidium fluoride for the ANP f'uels program did . . not meet specifications making it necessary t~.'~urif~t;o kilos of , crude salt fdr continuation of current B.w laboratory projehts. We wish to acknowledge the fine spirit of codperation- - which was dis- played :by all the ORNL personnel who. contrib&ed to the development of this process. Their valuable assistance, guidance and knowledge were required ,/'- to make this process successful.. . . , . . . . 1,2 Chromatography of Alkali Netals It was suggested by Dr. E. 2. Taylor, as an alterate to the older methods of fractional crystallization of ~hloroplatinates, oxala tes, and tartrates, that chromatography processes be discussed with Dr. Kurt 8, Kraus for the separation of rubidium from other alkali metals, Dr,.Ksaus pointed out that the geometrical similarity of the rubidium ion to the . . potassium ion would. make their separation a difficult one by a cation exchanger, The use of anion exchanger was dismissed because the alkali metals do not have a strong tendency to form complex ions. The extraction s s of potassium from sea water by a dipicrylamine salt (1) was mentioned as ' ' an example of selective removal of alkali metals from a solution, During a discussion with W, R. Grimes, it was suggested that Boyd . , Weaver of the Staple Isotopes . Division. . be contacted be cause Dovex-50 resin (2) had been used to isolate pure fractions of alkali metal compounds suitable for Calutron targets, With the help of ,Dr, I. Ro Higgihs a 1-1/2 inch diameter colh was set up in Building 4500 for a trial :. . . run with a 2.0 liter bed of Dowex-50, When this resin was found to give insufficient separation of rubidim, Dr. Higgins recommended Amberlite IR-105 resin which had been reported by the ORNL Analytical Chemistry ~ivisibn(3) as giving an excellent sepsration of alkali metal radioisotopes in tracer amounts. A "purew rubidium salt usually8contains potassium as the major con- taminant, It was found, however, that cesium, at times, also is present in signiffcant amounts,. Thus, the original assumption that a process was ... needed fpr separating one- part of potassium from 100 parts of rubiddm . ,. , , , r ' ; - '" . i had to be changed to ihclude 10-30 parti of cesium. - ~he*.f&strun with ' , . .. * , hberlite IR-105 shoved that cesium was easi'ly separated for both'.rubidih . . ... * ...... and potassium' by a fixed-bed ion exchange column. It .&s then decided ... -.. . ,,r...... ,. . to remove the cesium and 'take the entire cut of rtibidi*, uith the <... . .. , ' ; . , associated pbtassiumi as the product,-. . his was oonsihetkh &itisfactory :'- - .. ,. .-. .- , for both ,the initial physical measurements and the prd&krf corrosi6n 'kestso .* , . Subsequent &xpe&imenta1work was perf orm6.d to analytical ? standards of rubidium and cedum. ~ighpurity salts, containing less . . , ., . than 10-100 of contamirknts, were not available from industry' , . .,. . either as a stock item or in ipecitil order. During the early phase of the rubidium work it cas nece $sary tot ake tvb cuts near the. end 6 of the,kbidim' elution, c6hining about 100 pornO of potasa.i~,:for?,:the . . , . ~nalyticalDivision at Y-12' to use as 'a standard. ~11'of the cesium eluates, called "tail cutsw from 'hberlite IRA05 eiutidns, were held and reworked ' to prepare about 50 grams of cesium standard. A similar rubidii standard was prepred by rewbrking the idtermediate IR-1.05 cuts, which contained rubidium with appreciable ceh, and the rework batches of various .. I residues contaf ning rubidium. It was hoped that time might allow use df a njarked-bedn(4) 06aatLnuous . . ion exchange column in order ' to ob&ib a rubidi&n'stream as a product, free of both potassium and cesium.. alternate fixid-bed exchanger of a . , synthetic zeolite was tried, hokekr, and found to give excellent separation of potassium from rubidium. Thus, a process has been demonstrated by -- . . which pure rbidium can be produced for experimentel purposes. e his was , the primary objective of the groip in attacking thi's 'problem. Future .r' 1 groups shobld be able to prepare adequate rubidium me^' fo; more physical property meakureients , f br he'at transfer expe&nts ,. and for corrosion ' loops so that reliable estimate of the power plant system using the rubidium vapor cycle can be made. I' . 2 Inorganic Exchanger ' A fixed-bed column was set up to experiment with the rubidium product . . containing about one per cent potassium from... the Amberlite IR-105 r.mso .... PrelimO'nary experiments with a feed containing... equal-. parts of rubidium and potassium had indicated that a zeolite-type. . exchanger might have application. The extruded cylindrical pellets of Nolecular Sieve 4A . . ' from ~indeAir Products have a 1/16 inch diameter, a 1/4 inch height and a bulk density of 0.6 gm/cc. These pellets were crushed and screened to obtain a particle size less than 30-mesh. The fines were removed by washing with distilled water and decanting the supernatant liquid after allowing one minute for sedimentation. This cycle of operations was repeated six times before the particles were suitable for charging to the column. The column consisted of a piece of heavy wall Pyrex tubing four feet high (15/16 inch G.D. with a 1/8 inch wall), A stopcock was attached to the bottom for' control of the effluent flotr rate. A * layer of glass rjool served as a support for a one-inch lag-er of 1/8 inch diemeter Pyrex beads. . . These were covered with two inches of 10-20 mesh Ottawa sand. The 25 inch high bed, about 200-cc nominal bed volume, of the Molecular Sieve 4A exchanger was covered by about nine inches of liqtzor which overflowed continuously through an 8 rnm side arm located six inches down from the top of the column. The feed pump was connected so that it could be used to backwash the exchanger bed when necessary. This permitted fluidization of the bed so ,that the colloidal fines could be removed while converting the sodium form of the exchanger to the ammonium f orrn. The elutriant, O,5 'molar (M) 1. . . . ,, ammonium carbonate, was fed upflow at a .rat* bf 2j'cc/min for 12-24 hburs ... .t ~ until the sodium in the effluent- was reduced to 3 ppm,'b . The conditioned or /enerated particles weke then allowed to settle to I I. form a bed free of channels. T he elutriant was fed dokflow at 50 co/min lht fo 2-6 hours to check the flow, rate and the' rem&al of sodium. T6e bed . . was then washed, downflow, with five bed volum~sof distilled uater. The uater was drained until only '1/4 inch coveied the bed and then the alkaiinb feed so1i;ltion of rubidium carbonate (about 0,5 M Rb +) has- added: The I '. r feed liquor was allowed to percolate slowly, about one cc/min. through the ixchanger until only 1/4 inch remained above the' bed, ' The column was then washed at a rate of 25 cc/min with two bed volumes of distilled water - before the elution was started, . - .. The 0.5 M ammonium carbonate solution is. prepared by mixing 15 pounds of reagent (NA~)~CO~with 135 liters of distilled water and agitating until all of the salt is-dissolved, It was pumped by a "fingerw Sigma Motor % pump using heavy wall plastic tubing., The elutriant entered the top of %he column .and overflowed to the make-up storage tank. The discharge rate of the eluate was measured by ixliection in a graduated cylinder for a . . i period of one minute, ' . , The elution was carried out at 25 cc/ml.n. which is a nominal contact time of eight minutes for'a 200 cc bed, The forerun was colleete'd in a , . 500 uu bottle until a positive test for sol.fds was' found by evaporation of a 0.2 ce sample of the eluate on an evaporating di-sh under a 300 watt lamp, At this point, the eluate was collected for 10 x 100 cc rich cuts and then 2 x 500 cc tail cuts before 2 x 4000 cc of regeneration liquor was collected. The column is now ready for a water wash and another batch of feed. The various cuts were sampled for analysis of the alkali metals (Rb, K, Cs, and ~a) . . A summary of before they were selected for concentration to total solids. . . the data for Run 4-Ajj3 f s given in Table 1.1, .... - , 1'- .'-. . . . - The mechanism of the separation by the synthetic zeolite appears to ,' .,. * ... . . ,. 8 . . be exclusion of the cesium and rubidium ions from the pores of the exchanger - whi193,he~-~b-'tassium ions pass through the interst jces because of their ...... -- smaller diameter. The ammonium ions displace the adsorbed a+li metal .....; . ions by the mass action effect during the elution as in the case of an organic resin exchanger. The MO-UCULAR SIEVE allowed the purity of rubidium with respects to potassium to be increased from a ratio of 100/1.. . to 3500/1 as shown by the results: FEED FEGD' FEED .... ,PRODUCT7 -RUN Vol .cc e3n,Rb- R~/Kra.tio R~/Kratio With an Amberlite IR-105 resin the purity of rubidium with respect to cesium can be made 3000/1 from results in the. piepaFatian pf a rubidium I , - standard. These results indicate the purity that 'can be expected of a commercial process using the method cove,red in this report,: first, remove cesium by the .Amberlite IR-105 resin column; second, remove potassium by the MOLECUW SIEVE 48 exchange column. ... TABLE 1,l- -- MOLECULAR SIEVE DATA SUMMARY OF RUM L-8-3. '. , . - , . .. . . ~nal~sfs Sample Vol, cc K Cs Na L Wash 500 26 506 3.0 7.1' Forerun ,500 7.8 1.1 . 1.2 7,O ' ?' Rich cut 1 106 ' 8,100 40 0 904 7eO 2 100 * 19,600 3.1 400 308 3 100 21,000 7.0 21, 40 7 4 100 23,000 - 60 4 20 300 5 loo 22,000 6.6 16 2.8 I Tail Cut 1 500 . 1,780 - . !jOO, 2.6 3.2 1 Regeneration 1 2000 - Not Sampled - . . I , Feeds Cut 21-F containing 20 gm Rb in 75 cc solution Elutriant: 0.5 Molar (~lfl~)~CO?.. , Elution: 25 cc/min for a nominal contact time of 8 minutes in the 200 cc bed (25" height]. l,&zo 'Synthetic Reain Cation Exchanger The equatiun which repreeent~the reversl>le equilibrium between the rubidium and anmoxaium lone in aqueous solution witla the cation exchaqer . . ,' :. 9 .. 'form of a emthetie reein is: Adeorgticm , ,, .' 0.5- Pl R'b+ \ Rb Resin + UH4+ RE4 Resin + Rbf izzG-. The equilibrium ie shifted in either directim bg adjusting the concentration , of the respctive ion species. 'PPhw, the water-washed monium form of the reain is hontacted irith 0,5M rubidium ballde and Rb -t di~slaceem4+ from the reefn intereticee, This procee ie relereed when the rubidium ion is atripped off %he rain by feeding 0.5 brl curmonium earbonqte solution.. . . There are ~imllesequilibrium rcactiona which can be written'for the . other allraU nt al iolle present. , The equilibrium connt ant s can be evaluated fh each came, Tlhe differences in 'thk equi~f~rfkcomtmte account for , the ability of the resin to separate the variour~epeeies of the alkali cations, The development of the individual. baaria OQ.the resain shows I .. rodium to Be eluted first, then potasitam eaad rubidiun which almost o~rlap each other, folluwed by cesium which ita the moat etrong%g. adeorbed meniber of thie family, The selection of a mitable resin for a given &separation isbaied . ' upon o characteristie called the SepaB)ation ~act6r. This is usuallJ determined experimxrta3J.y by the we of radiomtivc tracere, me msqy for each conrponer& implotted qainet the mluk of eluat6 to obt.in o probability like curve for each ion ogeeiee. The ~e~a.rati~nFactor is defined the ratio of the eluate mlyw &rreiponding to the ....hoicentrat ion for one corrpsw& to that. for a second component. A Separatf OA Fact or, of lo00 indicates no separation, It was estimated that the separation factor for the rubidium/potassi& &stem would be ' in the 'range 1; 0-1.1, which reprekehts a difficult separation. An experiment with Dowex-50 resin using kitable I that tracers indicated the separation factors were ,about 1,l* for rubidium/ potassim and 2.0 for ceisum/rubidium. When macro amount; were used, however, , . . - , . the Dovex-50 resin was foqd to be unsuitable, with actual values of 1.1 for ' . , ... rubidi~m/~otassimand 1.1 for cesium/rubidium. ' These data are plotted in Figure 1.1 (Y-12 Photo 22423), , . Amberlite IR-105, which ,?as been successfully. - used for separation of '. . . I alkali metal tracers (3) was then substituted 'for $he Dowex-50 resin? , ... . ' The results of a typical run tire givan in Table 1.2 with a plot of the data in ,Figure . 1,2 (22424). !ll~edifficulty ... of separating potassium is . . shown by the low ratio of Rb/K =. 1.1. , The ease of removing cesium. is , . shown by the separation factor of 2.9 for, ..Cs/Rb0 Thus, a convenient method for removing cesium can be seen in Figure 1,2 that there is bnly a few ppm of' potassium near the end of the rirbidium curve, The area under the far side of the curve for this fraction represents the small amount of pure rubidium which might be recovered. A cut was taken in this region to serve as a standard for the analytical laboratory. , . The irony of the satisfactory perfo.rmance, . of the Amberlite IR-105 ...... resin is that it has been discontinued from th,e line by Rohm and Baas. Vorbal dfscusulon with Ho Kunin of Rohm and Haas disclosed that IR-105 is quite sensitive to attack by strong alkali. It was noticed during the resin , . column work that a yellow color was always present. . in the eluates. The organic material.,darkens upon charring and it is difficult to remove by carbon , , ... treatment. Thus, IR-105 resin would not be suitable over a prolonged period of time for ,a commercial process because .of.attack by the hydroxyl ion . ./' reeulting, from hydrolyef e of,the alkali metal. carbonate:., - . . , , . . . ,' ...... . If More eddenci of attack ita that there ie 2 s&~abwnt of rubidium' .?. ., d ceeiupn irreraeibm'&orbed br the resin liecause niaterial bilmces are about 90-95 per aknt- As a reeult, Dr. I, IR. Higgine ha^ conducted a few experim~cntsin an . . effort to find a aatisiactory iubetitut6 for merlite IR-'10.05.R&& -.. ezprinnts ham aham hiblite cL~to hake appllcstion b& with s poor H.T.U. DuoUte C-10 ie better than.C-3 but iaf,&riorto Merlite IR-105, ' ~hua, . considerable ecreening and d&velopzent work -t be do& before a conmirclal proceee can. be establlehed for the manufacture of rubidium ueiw this , . technique. EmgBaeis will be plaked upon the continuous f on 'exchaxge colunm ' aa other reeine are tried out in the labora~ory. ~kntually,the procea. might Be wed to prepare each of,the alkali m?tala as a pure product .stream containing lee6 tha,n'5-&0 ppm of adjacent fanday menibera. ~tis felt that the -mum oarbkte =iutriant hae several advantages over &her amonlaan ealte of weak acids8 1. It 'is eat3il.y decoxngoeed by boiling 'in the isb6aiory 60' that a . . water eolutf on reaul-tee' For example, concentrated acetic acid reeulte when eumonlun acetate, Is used., 2, '~t,can 'be &covered by the use of carbon steel equigment, since it 1' ie non-corrosive, so that it is ecdndkical. 3. ' It produces a rubidid salt which can lie ' c6'+&ed ea~i3$to the desired halide by neutraliization with the reepeetf ve hydrogen haJ.Ide. The elrolutf on of carbon dioxide serves a "a-good indicator for the ' end -goink of thie neutralfzation. ? t UNCLASSIFIED RESIN-: P.HOTO 22423 12 % CROSS LINKAGE,; STRIP I I.OM (NH4)L COS; FEED rn12ogm Rbcl , 1 I I 1 .' I I I I . SEPARATION FACTORS 8 Rb . . - 1.0s- K - ',ELEMENT-. . CONC. FACT OR ..: . . 1000 : Lk . . - . VOLUME OF ELUATE, LITERS RUN I - DOW.EX 50-W Fig. 1.1 - - .. IOE EXCRNGE SZPAEATIQE - Run 4 2,O liter resin bed of AmberUte ,IR-105 (50-100 mesh) C UNCLASSIFIED RESIN : PHOTO 22424 STRIP : 0.5 M (N ~4)~C03 ASSAY, X R b.X K X. cs X FEED IOOgm Rbcl 86.5 0.8 12.7 PRODUCT 75gm RbF 99.0 0.9-1 0.09 I- I 1 1 1 1 1 I I 1 I SEPARATION FACTORS : . . . R .b C8 . . - =1.2 - 2.9. . . K. R b , . . - ELEMENT CONC. FACTOR . . ,.. I VOLUME OF ELUATE, LITERS RUN 19 - AMBERLITE IR-105 Fig. 1.2 I It ie convenient to inoculate the crude. mbiBfum balide .feed soluti& . , . . with about five drops 0% a etock solrrtiae of ceeritm 137 tracer. The progreks of the cesium band duwn the resin bed can then be followed by ~eeiBeof a stsnd8;rd SeaJth Physics survey meter, 'By camparing the position of the cesium band on the bed &th flame teats of the column effluent, the beginning and end of the cesflua taAl ctrt can be. sgatted. Since 10-12 bed volumes of eluate are required before the cesium is etrippd aPf, the tracer Uars operation to proceed. without constant '&tention. A stock solution of cesium 237 tracer frs prepared by obtaining 5.trdllicuries (2,4 units) from the X-10 Radiofsotopes Di8fsione This consists of abo~'2 bops of solution in a 25 cc glass battle with' 1s then diluted to about 20 cc. The diluted tracer ~"eo~~fon. muat be stored inside an adequate shield of lead bria, Rubber be worn while luring a rubber bulb topipette out about 0.5 cc - \-.:L.\ .... '.., -... -, for sdbiq'Y'%$.'-i&ops to the feed solutiono An aasay sample of the rubidium .\ ....-9.- feed eolutic& $hould be taken before the cesium 137 tracer Is added, The . \-'. usual safety precautions are also obaened in handliq the effluent , . .. .. coneemtratee, from the resin column because of the.hazard from ,the cesimtt-437 tracer ... I cernpdete sepation of ceaium fmm both the rubidium and potaselm' is poaefble only when the resin column loading of ceeium ion is lese than that wuch resulte in3break-through." Bom the data it appears th~ta nomiw Poadi ng of aboat 10 gm cesium per liter 0% resin bed, volume is the maxinnun - Saw valuable theory aPld methods for analyzing the ion exchange column . . data are gf8en In a booklet from the Dow ChemicaS Cowtitled, Tablee -for &edfctln& Performance of Fixed Bed Ion Exchange _and Similar Wee- Traxlsfer ProeesajeleOv The authors are Ascher Opler of DQW Chemical Company .s . . . ,' -28- and Nevin KO Hiester of Stanford Research Institute, 1,2,3, -.&1/2 inch Diameter Resin Column The first six runs were mde in Building 4500 wfth a glass column of '1-1/2 inch Pyrex pipe, eight feet long, The two liters of resin formed a bed ~5tha height of about six feet, The column was feed by a 0-200 cc/min variable speed Sigma motor "fingern pump driven by a 1/6 HP motor, At the pump the feed line was 1/4 inch Tugon tubing (heavy wall) with 1/4 inch Saran tubing (thin wall) running, to the top of the column, The feed line entered the top of the Pyrex pipe through a rubber stopper which.was held in position by' a triangular Purex pipe flange,. The resin bed was supported by 1/4 inch cylinders of Polyethylene plastic packed to a height . -of two inches at the bottom of the column. A 100-mesh Vinyon plastic screen was over the l/4 inch outlet line underneath the support of the resin to retain any fines. The effluent stream from the column had a 12-inch section of rubber tubing which could be clamped off when not in operation, The ?. resin bbd was kept flooded with an aqueous medium at all times. The nominal load was.. 120- grams of crude rubidium halide containing 10 per cent cesium for a resin bed volume of 2.0 liters. , 1 2, 3-i nch Diameter Resin Column -, When the processing of larger amounts of crude rubidium halide became necessary, it was decided to set up a larger column in Building 9733-2 of the Y-12 area. Essentially? there was no basic change in the arrangement of the column. A cork float was installed at the top of the column through which an off-on liquid level controller was operated, This device , obviated constant attention to the balancing of the pump feed rate and the withdrawal rate through a partially opened plug-cock valve at the bottom. The pumping rate could be set at a constant value, but the swelling and , - . . contraction of the resin bed within the column changed the flow rate of eluate markedly, The liquid level controller avoided flooding as well as drainage of the liquid inside the column during an absence of a few hourso It allowed the.stripping of cesium to be done at night with only an occasional check to change the eluate collection bott3eo A 30 second timer was included with the eontrol3er which was. connected to the feed pump, The timer elimf- nqted a series of starts and stops which overheated. . the motor during the first ,week of operation, A 50-gal stainless steel dmwith a Q.5 horsepower Ligh$nin9 mixer was used to prepare and to hold about 180 liters of 005 M (NR: ) CO as elutriant. A sketch of this apparatus is shown in 42 3 Figure 1,3, It should be pointed out thzt adequate head room is seeded to insert a 1/4 inch diameter tube the full length of the eight-foot.column when it is necessary to degas the resin bed by agitation for resuspension of the resin particles, 1,2,5, Resin Column berating Procedure 1, The crude rubidium halide is dissolved in water to give a Od25- 0050 molar solution, It is neutralized to a pH 8,O -0 005 with concentrated a~oniawater using alkacid gaper as an indicator, The volume is measured in a graduate and then a 5 ml sample is taken for analysis of all alkali metals except lithium, ' 2. The s$%ghtly alkaline feed solutt6n is inoculated with five drops .. of cesium-137 tracer solution as described p~eviously,, The resin should be washed with water to remove the fines before charging to the column and also generated batch-wise on the ammonium cycle by contacting with 3,O.M . . ammonim carbonate. There is.eonside~ablesodipam %on present in the resin which should be displaced completely before operation is begun. The resin S EC RET ORNL-LR-Dwg. 9640 , -. I Fig. 1.3 FEED TANK COLLECTION (NHg I2CO3 BOTTLES 3-INCH DIAMETER. RESI'N COLUMN swePfs upm eontact with weer, end ehraeshs when feed or e%o%f;uantf e added. !Fhe bed becomes after about six runs 4require8 fluidization . . and reeettllng tb avoid chennellng bur* op~-at ion. This is best dam by back warahing with water. 9 3. The feed is then amped to the top of the resin bed which haa been .I . water wmhed after agdn converting the resin to %he ~~umform. A feed rate which aUme a nominal retent3 on time in the eolm of 20-30 minutes 9s adequate. A small water ?i&e is given the feed kesel and then a water wash of' 50 per cent bed volume is appliedo The position of the cesium bad ' dam' from the top of the bed is .%hen checked bg a survey rrueter, 4. The elutriant of .0.5 M ammium ca??b'o&te, . p?epecred by Ul&i'ng five , . pomb of the salt to each 45 mere of' solution, ifl then fed to the column . a% a rate to give a nominal retention tie of 60-120 minutes, Thus, the flow r. . rate for a 2,O liter reefn bed waa 13-30 ec/mln. ' 1 ... . I . . 5 . An accurate log should 'be' klpt wfth 8.11 the pertinent data as shown 2- by T6&&9-&&3 Regular readirgs of feed Whm~,eluate voluppc, flame te&, .': . . . distance nf cesium trakkr from top ~f bed, a&. the samgles taken mat be tabulated on .a batch sheet, . . 6, Stream samples axe taken in, 54.0 ec .~f& at the bottom of the column. Theee are best taken at regular sintervaU of about 1/10bed vol- until the ribidium has. been stripped off, Then the frequency of stream samples can be every 112 bed voPune wtil the cesium is remwed. The eon- ' centration of each f~i~@Eg~\>~:~W\ib%~~~~QBIP,~:?~~:ih~!@@b@. ,., .,. . - vol- of eluate to obtain the distribution curves illustratedl in Fis L:2 _-I 7 , During the eaut ion .it is meessarrg to eoUeet 'colurma holaup I unt iP a .positive trace of rubidium is observed bg %he %- test. The Bore- run cut ' is them std'ed & '~coratinut?eunrtil the stream. sample shm~sno sip . . . ,: * *; ' of' soditpa and definite indication. . , of ~tasbium-mbidib. The prcbict a . , .'*. ,. ... * cuts are then made until the flan:teat shows negative; . 6r. low concentration 'Phe tailcut is then started'@ continues until the cesiun , of rubidium. . - . -. .. tracer is off the column after having paased through a. definite ~XIWK~in ,, . color. 'Phe isin is then waehed with,'vater.. . to diaplace'the &p~poxbiwncar- '. . . bOQite solhion d.:~-~~:~~~inl~: on the 'amm~n$umcy ele, It should be I eiomdth& there j.e no visible difference in the blue-dolet color of the potassitmi, rubidium and cesiqp flames. A. 'knigh guide for the collection of cute is: . . -Eluate Bad-'Volumes . JJ Hold-UP . 0.5 - 100 9. Forerug 0.5 - 1.0 , . Product 200 r 3.0 . . Tail Cut . .. 6.0 -.'8,0 ...... Water Wetsh. O;?...... - :l0(j ...... ' .:. ... These cuts are best c.ollected in,calib'rated~yrex bot5les. The cuts are I .. , labeled after the forem in alphapetical order. The cute are well nixed end a 25 cc sample of each.. is- taken for'aaqay to determine the compositikm of abthe alkali metala except lithium. A materiel balance can theB be - made based on the asseyse , 8. Each of the cuts LEI saved f OT conce&ration. and thoae cuts not . . to be %&en for &e accmlat;d for future disposition. . he' cesium tall cuts were saved in the hope of reprocessing to obtain an enalytical stan&d of cegiq. A sumwry of a tppical set of assays is given in Table &i2' for Run 84. c &eayersim ....of. Rubiaium - Carbonate... to ~ubidiknFluoride 1.' The column eluate rich cuts, contaLning the rubidi& Fmd C potassium, &e concentrated to drynesa in4.0liter. stainless steel beakers on a hot plate. It is convenient to tare the beaker so that the weight of . . . . dried darbonate can be determined immizdhtely upon removal from hot plate . before moisture has been absorbed from the air, 2. The carbonate is dissolved in 100-200 ci of water, heated to 50°. C and decolorized by adding a suitable carbon equal. to 25 per cent by weight of the rubidium present, After agitating for one hour, some Super-Cel admix is added to the carbon slurry and the solution filtered by vacuum through a Super-Cel pad on a medium-pore, sintered glass funnel, The filter cake is saved for recovery of the adsorbed -rubidium car.bonate. Only the analytical grade of ,Johns-Manville Supe'r-Cel can be used without int~oducingcation impurities, especially sodium. 3. The clear filtrate is then transferred to a Polyethylene of Fluoro- thene beaker for neutralization with aqueous hydrogen , .fluorido . The standard I 60 per cent HF reagent is diluted Is1 with water before it is used. The amount of HI? required is calculated frorc the alkali metal assay and cheeked \ by the weight of carbonate isolated in the cut. ,- 4, The dil~teHF is added slowly from a polyethylene wash bottle while stirring the carbonate solution with a plastic rod or tube. The pH is checked with alkacid paper as the .'end. . point is approached. Care is taken not to add an excess of HF be&use it foma a complex with RbF. After about 90 per cent of the HF required has been added, the rate .of additLon is slowed' ' down and time is allo&d for evolution of carbon dioxide. A copious libera- I -, tion of gas is a good -s'ign that the end pnint io mar. .The neutral solution is checked with alkacid paper after standing for 30 minutes to make certain that it is slightly acid - pH 6.5, - 7,O. ., ., 5. The aqueous solution OF-R~F is then concentrated down in a Fluoro- c thene beaker under a 350 watt lamp or in 300 cc Nickel crucible on a hot plate. The heavy magma is then transferred to 'a. 50 cc platinum crucible and dried at 180° C in an oven. 6, The anhydrous RW is then .&reatedlin the fu.qed..state to remove as much as possible' of the excess Hl?.. An all .nickel 'iaaeitf on .ve?sel was , used in the ANg Fuels'Laboratory for the fusion at 800°. - 900° C, Thes melt is treated for one hour by paaaiag helim over the surface .to remove the exces.s HF. This groeedure.resetlts in about one per cent of the RbF,HF I a&iew$heing. . present in the f lnal product acpordibg to.a petrographic ' examfnati on by Dr. MeVey 0% the Ceramics Gr10li.p~ '7, The system Ss allowed t,o cool to a. temperat-us of about P50° C becore it is placed in a dry box using phosphorous pentodde as a desie,cant. The vessel is opened after it has cooled and the fused mass removed by using I 'a small chisel and hammer to fracture khe crys4ia1so 'The crystals are broken up, if necessary, before they are packaged into a bottled sealed against moisture by scotch &sking tape.. A 50-100 milligram sample is also packaged into a weighing bottle for assay of the alkali metals, 1 : 1.4. Reduction of Rubidium ~luoride_by Cu ' 1,4,% Chemical Reas%= Heat Formatf on . (5) - 2 (-133,23 Kg. ~al) (-290 Kg call. 4H = Heat of Reactor = -290 + 266.46 = -U.$ .- a@'.K gm mole Rb and aud Boyd Weamr. . Phil Baker chechd. the. heat of reaction for this equation reported it.to be favorable. By taking the heats .of fqtion end babncing...... , .... the icttha&i side against the right hand side, it ik found that the be& .. , ...... of reaction is -~.8Kg Cal pr gran Wl of ribidium infavor of the deeired - . . . . reaction. . I The granular calcium meta$, which is stable in air, is charged in excess . . have br 25 per pest of theory. The feu runs. which . . been made did not pet ...... a study of this variable for maximum ' ' ': P. S. B&er an& H. B, Greepe of the Stable Isotopes Dlvieim at Y-12 .. . . I designed an experimental. glass . system. capable. of. .reacting. . . about 90 gm . , . . . . ,' rubidium fluoride. he '&t cbmists .e.s,aerlbially of a 45-nrm diametei quart= , : , . . jacket surrounding 6 f&i-inch long stainless atedl reactor of 1 112inch :. tubing euapended from a,,glasa .hook by a glrtes'tage.6 ' The rubidium vapor flais:' ' out: .of 'the reactor through a 114-inch diameter downcomer into the 25-cc Pyrex cold zone collector. This system is evacuated at the top vla'a 10-ium , diameter side arn& The initial design was modified to permit equalization of the reactor and receiver pressure &ng with allowance to seal off the receiver under vacuum at the end of the run. The modified deals te GI-. in Pig. a;;,& he induct ion. . heating coil coneisted of a 3-inch diameter hem . . wlth nine tkna of 318 inch copper tubing throughkhicd cooling water flows . A 20-k$lowatt Megathem unit wm the source of parer for induction heating. The empty system is assenibled and tested for leaks under high vacuum) I thia is equivalent to mmHg being maintained on the sptem by an oil lo3 . . . . diffusion gump using a $ir)ney mcuum pump as the roughing stage. The system . . is degassed by heating the s .so (stainless steel) pot to drive off all . . absorbed gaees. A branch is rug off the vacuum 11ne to a tank of argon which ... senciu as a muppu of inert gaa bpri@ .hutdo& shd opeaing to the atmosphere. . . A Tiew of the entire. ssserPbly, snd it. coq~~nerstsla ebovn ih Flg. wY The actual oprations are cerried out behind .a --length, clear- plastic shield because of the hazar~iuhnature of.rubidium metal. 'c. An outline of the procedure for operatian of tine .quartz unit is: 1. me dry syetem is tested for leak6 after assenibly using Silicone greaee on Pyrex standard taper Jointa at room temperature and then at a I. . . temperature for which the stainless ' steel pot: Pa at red' heat (600~-800~~). . i . . 1. 2. Argon was. used' to vent the evacuated sptem to atmospheric .pressure ' after obtaining 0001microns Hg in a Leak-teet. The cool S.S. pot wm then charged in a dry-box containing @oephoroua pentoxide to hold the mositure content of the air to a. minimrmb Tlae reepeetive weighed amunts of rubidium .than were fluorid. crystal8 (less 1/4-inch in,size) &d the calcium... mtal -. . '. then chmged to the etaSn3.ess steel pot. A @ma31cork was 'used to plug the . . ragor 'downcaner line and the screwed idp was ~ealcdmound the edge with Scotch DreLfting Tape. 3. The S.Ss pot wae then hung $mid; the quartz jacket after remop- the &$-moisture seals. The system was tersted agtifn for 'leaks at room temperature, After reaching a pressure of O,O$ micron I&, the system wae heated s&owlyto dzy'aod degas thoroughly. Thie required about one hour before a pressure less than 0002 micron ia obtained. 4* The reaction is then 'started by heating up the sttxinless steel pot to 600-800°~. TUB is accomp~shedin a few mimtes by alternately appwng the kgtgatherm unit power f?r about 5-10 seconds in both the "onn and "offn coa3dition. The Pirani vacuum gage ir observed carefully during thia period to xmk6 certain that a preseure les~than 0.04 microns Hg is Being - lo. ~lr s- > 84 3 i3 "? 0, 513e w if.s.s. !TUBING x 4" "8 -9 & - Zu PYREX TT 29/4229/42 WmA . 8 ~ , ., =W-._. REDUCTION-DISTILLATION UNIT FOR RUBIDIUM 7 -- AROON CON- -VACUUM Dia.) I INDUCTION HEAT- IN8 COIL . w SEALED . . .s ... . . 5. The reaction is quite rapid after. re=- 800% and the uquid ': . . * . nbidilim metal flows out of the dovnco- intotbe, ~ecei~r..mi ' . ,. 1 ' accunnrlatian of metal is observed for about 20 minutes at 'itemperature of - ,600~-800~~,~t , ie necessary in.ek dsses to use a gas .flame on the ' - - outside of tee glass toloverthe~iscosityof themetaliq+thedo~comer~ .+ ...... tube until it flows. freely,' . . . 6. The yield-of rubidiwn metal is estimated by the volume occupied in a 'calibrated Ppex receiver. It is then sealed-off under vacawp.at the neck followed by seallng the side apn capillary;. . The'ampulee ahouldbe kept on ... . . a cool, dry shelf awey from all personnel and solvent. 1t can be trans- ported by murr6unding with. 'anger. Cel (a filter aid Ad.insul&ion material) : ._: I. .. a,..,,...... , inside a metalcan which $6. , solhered'. &oundLthe top Cdge ;if a long trip is . . to be pade,...... 7. The. . Quartz jacket is..then vented to the atmosphere with argon, imd . . ..,the top .and . bottom joints opened to the atmosphere'- use a hood and .&equate . safety protection at tlje point. A torch must be used to heat the joints ...... before,they cap be loosened. .2 It is good yractice to maintain the flow of c',. inert gae inaide the jacket while dcohol or water is added to react with the rubidium metal. BE PREPARED FOR A FLASH FIRE AIJD A PO$SIBIE EXPL0610IB DURIIJG THIS OPERATION! A sample of the aqbeoue Uquor is taken for analysis and th& mlrmre'recqrded to calculatethe amount of metal not drained into' . . the receiver, . , 8. The, stainless steel reactor pot (see S~~O~~~~~~~~~OF:~~'F~.SQ~~~&O;~) is handled in exactly the samedlmhlon ns the' qu-z jacket, After any . . , . - rubidium bas been .reacted it.... is.. . neceisary to loosen the calcium fluoride slud&, cont'aining 35per.....ck.&_caliip . . and 18 pr oent rubidilrm, by the ...... : use of concentrated bydrochlqric. . .acid for.only a few minut& since it co-eive. The stahlees. . steel put i@. rimed. thobough3.y with water then -.' . dried, The sIudgefrom the stainlees &,eel pot la for fil%ratian and ...... the filtrate acemeed for rkorking of rubidium unchaqed by the reaction.' -. ., : A summary of the data'for a tnieal run is given in Table&&. . . Charge g TQtal. . ,rubidium cbmged 44,O ...... , . . . . :. . : . , . I... . . s . . . gP1 React or Product ~tal. . 30' . . ask&, was h(meta1 equivalent ) kg2 . Pyrex seal fube ~leta%: P,O .... .S,S, pat unconverted metal 4,4 ' TOTAL rubidium aeeoubb.t;'ed for , . .' 39.6 e;m Yield of metal = - 68 per cent of theory ig .- . . . . l; . woStainless Steel E@dut2~&Unit . . The we of a stainless steel reduetion-distfUaticm mt B~CBPP&desirable when the production, of 200 grams-batches of mtd wm unde@,aken, It would . . reduce the rawer 0% batches to Be run and, a% the sag t*, .reduce sx- ces~iveearposure to the @ass system from the standpoint of safety, One deeigpl canaidered was a reactor from which the rubidium vapor would be I wi%h&awn at the tog and condensed in a separate vessel, This design was , discarded, however, in order to retain the same design as the quartz system &ich uses a &or downcomer through the'mPt, A sketch of %,hedl-metal ... . . , Fig. 1.6 OSNIPLR.~W~ -9643 SECRET LlNE I/4" P LU G L'/4"VACUUM LlNE fi 1/4" VALVE No.413 HOKE I DIAPHRAGM MONEL VALVE 25mm PYREX RECEIVER "":; ( ' , ECTIONED STAINLESS STEEL REDUCTION-DISTILL ATION UN aaa lb%famwema0 ----- A mJ8~change froa $he Beeis of %he quartz system ww theuee hl valve8 sed Swage-IDk f'i.ttir~@in the gse tmd Upaid lines through- l out the errtem,, The nee of mxlel wm appro-ucd, despite its Ugh content of c~p-per, beeawe no= of the valves would be exposed $0 a te?qera$we above 200%. The 316 sfaiPless steel tubing was welded to the bnel r&a by the we of Inconel filler rod d the suggestion of Po Patriarca of'* X-10 1CgetaPurgy Bi%i~io~~~In gemr&lo %him delslgn served ads s test malt1 %or a co-cia ducti ion unit upon which the cost eatimwte is baaed in a later, : section of the reporb, It was designed with the ah~aakagethat a etades~ekeel receiver holding about 150 gram of' rubnd3m metal could be tr8zmpRted.BdeQ from the Y-3.2 to X-10 &es, Either .,amcuum or faerb. . 1. ..- .( gaa atnosshere could be mai&ained c@eP the Wal by the &rsngeq?nt' to - blank off' $he lines W&hgll.xgao 1% waa pBmne& to qe a &q--box for suP>d9vlsfon directly from the S.S. re6eiw%?.into Pyrex recelmr~for the - v,wum distills- tfon required for p%rr%iiea%fon, beeam necslae~, A ki.0-ce Pyrex receiver was at;$aehed to $he bottom mt1& of the sta3xLLesa steel receiver for coUectf m of' n~%a.I-mdex vacut138, * It etaimle~eateel rseeiwir and8 EB a read*, the bot%om o~&%etUne wm frozen Wlth &dl., I% wm %eamed later thm the sagor dmomr had -0 beeom ~hggedwlth calcium fluoride which is~latedthe receiver, About 7'5 gre~nve of metd wae 'mKLkedB' OL& int~fouar separate Fyrex, vsum sealed a~tpLb8 , . ehould have been instdled an the inlet sidb of 'the &.s. receiver aa a ' ' might glass. The~ovaraeale are available at the glass blopl~eh6ps; . . . . it is a graded glaaado-metal seal which is. quite sensitive, however,' to :: . . thermal ehock, The all-metal syateni'wm'tested~for leaks under a pressure of '30 pig and then under high raruum (0.d micron8 ~g)at both room temperature and 800'~. A Cbromel-Alumel thermabuple was inserted into the thermovell to estimcrte the tempratwe when the induction heating field was not applied, In general, the systemwas superior to expected performance under high vacuum conditions, The reactor section was insulded with asbestos tap to ... help retain mnwt of the heat' at a temperature of 680°-8000c. ', !Phe unit was operated in a parallel mame4 to the procedure described' for the quartz system. .' [email protected] wes in the we of a 300, cc-polg.ethylene . . bottle as the charging vessei. This 'allowed the charge to be prepared in ,.. a dry-box and the zlaetic tubing adaptor plugged with a rubber stopper until <: ' ready for use. The plaatic tubing vaa slippd over the 112- inch.^ .S, charge tube and the battle inverted to drop the charge of 200 gm RbP and 48 gm CB into ''the reactor:^ . It should be mntimed that the rubidik mtal from thie stainless steel system (~eduction-~un5) was the highest' quality product obtained , ~UI-11~'Lhc puJect aad vwp3rf qk~ta.~thet.&k4%'98~.&&6:;&g,:!~ c~,er$$a~.:,. . I: 5 ,. :!. supplier. When the downcomer line was found. to be plhgged, however, it waa decided to return to the quartz-gas system, The stainless steel syatem was then taken to the vacuum dry-box in X-10 and sectioned perpendicular'to the axis for.observation. The charge tube and the vacuum line at the top of the stainless steel reactor had a crust of ' CQ2 over the openings but the sludge was easily removed without any ignition of rubidium metal, An aasa;l showed that tlaia material contained 38 pr cent calc.ium ad&.per cent rubidilmr - aa the fluorides weighigg . . I. 100 grsrms, Upon eectioning the reactor axially,. a plug abuut 318 inch long waa found inside the damcolaer ,at the baec of the reactor (see Pig, r&6) It harr been impossible to drill through this section which was assayed as pure calcium fluoride. The racuwn line at 'the top was then'cut and some ru~1d.I~residue flashed upon exposure to the atmosphere,, The mnel valve at this point waa sectioned and folxnd to be clean, The apparent low yield for thie run was brought up to normal of about . 70-75 per cent when the stainless steel receiver was cut perpendicular to the exis and found to contain about 50-60 grams of riabidiums Thls 'materid. wae melted and.poured into Pgrut containers for vacuum seaUng, The residual , . metal wetting the walls of the receiver was reacted slowly with ethyl alcohol Mera helium. atmosphere. Upon ,opering the bottom outlet valve to , . , .. ' the akmsphere, Qn explosion occurred in the form of. a flash fire from the holdup estimated at about 0,l gram. The .receiver was then sectioned parallel to the axis for examinatim, This experiment proved the utility of an all- l~etalsystem but pointed olrt that a more detailed developent of the process muat be done to avoid the plugging of lines by calcium fluoride, inm Metal & Vacuum Distillat- Before. the metal can be used for corrosion tests, it is necessary to purify it by a high-vacuum distillation, This leaves the non-volatiles, eapeciaJ.ly oxides and fluoridea, as a reeidue, In the analysis -of metal sl'kiples the crude contains about 2-4 per cent oxygen,, after vacuum dfsrtillation by Dro J. Cathcart of the X-10 Metallurgy ,Division, the oxygen em Be r&due6d to about 0,l per cent, I It is canranlent to design a 20-40 cc Pyrex receiver dth a side arm' . . of.8 rn tubing, .,.lo cm in length,'. hapiog 'a "br~alr-sealflat the, center; The .I . . "break-seal" should be custom-rpsde bhcauee. . a co&rcial unit is too small in crosssectional area &is quite difficult to iupture with a short iron rod. The vacuum sealed m@le is connected to a high-4prtcuum distillation I apparatus through the side arm containing the break-seal joint. Provision should be 'made to dietill therubldiu vapor .over into a 20-40 :A' P&X I ., recei&r which is cooled by the anbicmt air. The source of heat can bi a'. 8- gaa flame moved manually to contro~'vaporizationat a temperature of about 100~-200~~under a pressure of lom5 rrm Hgo Condensation along the . Tapor rioer occurs easily and r&uir&rr a fullw-up wlth the gas flame to . ..,.,>i' ...:...... I..,.... , . , : . : ' J. ' keip the vapor mrl& over into the air-c0oled receiver. In some cases it I is desirable to repeat the distill&lob to inoreme the purity. i he find 1 . . - product' is vacuum sealed, in the uaual fashion. This procedure is 'not to be attempted by anyone inexperienced in hsndling alkali metals became it - I is hazardoue, Complete protect1on"of personnel is ibierative end more , elaborate safety features Ught be incorporated in the design of the dietiflati.on unit. $pr6 Anapstical Procedures for Alkali Vita& Oxygen...... in mall ..- Metals . A new procedure ha8 been developed by the Analytica Division of the - It is essentially a Wurt;z reaction of the alkali metal using . AIlP program, an excess of organic halide which leawe the oxides unreacted for a later - tltratim after dilution with water. The procedure waa developed by Dr. 3. C, White, et al, end is described in Analflicd. Chemistry Vol, 26, pg. 210, 1954, Other procedures are ale0 discussed in comparison to the new method of using a 40-60 per cent solution of n-butyl bromide in hexane as . ~t WM 8ecerl~sl.yto carry out 'bwtween 40-80 ansap per da~of .the au.IU &a,U in reein cohmm eluater to Wzethe efficiency of eepara- tion and to locate the rich cutr .cwtacining rubldiuan,. . We are met grateful to X. Po.Howe and Wee Jeanne M. Rogers ,of the Anawical. Division. for the c~o~,reliable and inmediate eerrlce which waca given throughout the experil~errtalphaae of this report. We were pleaaed to be of eervlce in ruppuirag high purity fractionm of rubidium and.ceeiu~~~for we am reference Deacriptim of Procedure: ...... The afkali metab, ., X+,d,. RbO and Cfa were determined for reein column . . solutions (feed solutiorv and elvte iractjolu) and in product materials, by of the flq~photometer (Beckman E.lode1 DU Spectropfaotometer with Beclean ~1- Photometer ~ttafhmcit, lo. 920.0),. The red-sensitive. . ph oto tube, Beckman No, 156, wae, used in the determination of K, Rbj and Cs; for ma, the blue semitire photomultiplier tube, RCA 1228, together with photo- mltipUer al&achment Roo 4300 wss wed. The eanplear which consiPrted for the wt -part, of carbonate eolutiags, were reacted with,BCl to convert the carb~natesalt'8 to chloridei, The reru'ltarrt solutions were diluted as required to bring the metal within a . . suitable c&errtration range for fmphotometry, Portions of the pre- pwd-aoluti o& were then aspirated into an ,oxi-h$drogen flame, light ipom the fl- waa cawed to pms through a xumochro&tor, and a narrow band of the emimkicm spctrum inclgdini( a' prominent line of spectrk of the meta3 - ~. wan broUght to be& on a phototube. The ph&ocurnnt thus produced, after electronic qllfication, vaa measured potentibaet+ically, the reading ' being on the per cent transmission (ST) scale of the spectrophotometer. . The magnitude of the%readingis proportional to the amount of the alkali metal in the solution aspirated into the flame. . . . The T (percent transmission) of a series of standards of varying * concentrations were measured in the same manner as was the unknown. A calibration curve, $ T versus concentration was constructed. The observed $ T for an unknown was then referred to this graph, and from it, the con- centration of the metal in the test solution was determined. This vak, multiplied by the dilution factor gave the concentration, usually in micrograms - (mg) per ml, of the metal in the sample. Solids, if other than chloride or nitrates, were converted to' chlorides ,: . and a solution of a specifii amount of solid was prepared. The 'concentration of the desired component in this solution was determined in the same manner . . as that described above for liquid samples. From this test result, the per . ' . cent of ppm of the desired component in the solid was calculated. Readings of $ T for the various alkali metals were made at the following wavelengths: Wavelength mu Sodium, Na 5% Potassium, K 767 Rubidium, Rb 795 Cesium, Cs 852 The detailed procedure, including operational instructions for each of the four metals, Na, K, Rb, and Cs, is -outlined in J. M. Roger's Progress . Report No, 13 (~ppendixc). J 1,6,3 Iron, Chromium and Nickel Imvurities These/.- - were determined by standard quantitative methods of wet ' /- a. chemistry, or if necessary, semi-quantitative determinations were made by X-ray, -49- 106,4 Puged Sdta . - - - The purity of these materials was checked by Dr. McVey of the Ceramics Divfsion using petrographic techniques, The aniount of HF-c'omplex .of rubidium fluoride was checked this manner. Mixtures of alkafi metal halides can also be identified accurately. 1.7 Manufacturing Cost Estimate for Rubidium Metal 1.7,1 Introduction . . According to Jo W. Mellor (6), R, Bunsen and Go Kirchhoff discovered rubidium in 1863 by identification of a dark red spectrum line not associated. with the other alkali metals, Preparation of the metal was not . . . 'I ' accomplished &ti1 H, Erdmann, et a1 (7).... used calcium metal for reduction at 400-500°C in an exhausted glass system. The... hydroxide or carbonate .... can be reduced by an excess of magnesium. A review of the ore deposits inside the continental United States is reported by R, C. Wells (8). Both light (~useorite). . and dark (Liotite) micas contain nonessential oxides as a source of rubidium, From qoeks and Rock Mineralsw by Pirsson-Knopf (John Wiley 1926 2nd. edition) the light mica in which lithium replaces a large fraction of potassium is lepidolite, a basic ore for rubidium, Other suitable ores are Biotite, which has the, . formula (H,K)~ / (Mg,~e)~,(81,~~)~ (~i0~)~. and ~in~waldi6 which is rich in iron and has lithium substituting for potassium, Wells (8) .listed these assays: on-~ssential Oxide BiotLte (a) Zfnnwaldite (b) ~i20 0065 1.92 Na20 0045 oo74 rrZ0 8.50 9058 . Rb20 1.46 1.04 Cs20 loU Qo10 . . (a) Custer City, Co DO + (b) Amelia City, Va, It was planned to study some possible methods of isolating rubidia and other alkali metals directly from the 'ores. The did not permit a process .. to be speculated upon in time for this report. his phase if the project .' should be studied fully, however, to prepare an ultimate-manufacturing cost of rubidium metal. Methods other than ion exchange should be investigated for a survey of the economics. 1.7.2 Rouah Manufac twine: Cost The fixed-bed ion exchange process and the small scale batch reduction unit are not applicable for large-scale - commercial manufacture of low-priced rubidium metal. At the present time the market price of rubidium fluoride is about 50 cents per gram so that a purchase price of $1.00 per gram, or $500. per pound, is retlsonable for lots less than five kilos of pure,metal, - The ultimate cost for the process operated during tlie course of this project, with the- assumptions that a crude rubidium salt could be -produced , , for five cents per gram and with a 95 per 'cent recovery of ammonium carbonate, is about ten cent$ per gram of rubidium metal or $50 per pound. These values are reliable for a production rate of about 40 kilos per day, end above., Eventually, continuous (4) ion-exchake and a possible continuous reduction could be developed. he demand will have to be at least 100 kilos per day to justify the, development work involved and to place rubidium on the market as a suipble heat transfer fluid. It should be mentioned that, in addition to the Dutch-Norwegian \ Pilot Plant at Ijmuiden, Holland (1). The Japanese are also engaged in extracting potassium from sea water (9). The invaluable dipicrylamine salts of rubidium and cesium all co-precipitated out of the potassium. The Japanes have separated the three invaluable alka+i metals by selective solvent extraction, amyl alcohol and xylene. -51 b ...... ', ' ... It is doubtful if the ocean is'a competitor with igneous.... rocks, hpwever,_... , . . . . I. as a basic raw material for.rubidium, New England granites show an , . 2...... average K/R~ratio of about 90 with the rubidium content ranging from ; .! . ". . . .t .. 0b02 0,09 per cent, . . '-. - 8 . .:: .. ". 108 REFERENCES ...... " .. (1) Chemical week, Page 44, March' 13, 1454 (2) W, E, Cohn and H, W, Kohn AECD -1810 ". (3) "Brooksbank and Leddicotte, J, Phys,, Chemo pgo 57, 819 (19531 (4) Ion-Exchange, Chemical Eng. progress Symposfwm Series, Vof, 50. ,. No, ,U+, pg, .87 (1954) I, R, Higgins and Jo To Roberts . ,. '\ ... (5) Persyqs Chem, E, Handbook pg. 237, McGraw ,Hill, 1950, Values . . .' are for 25O C in'.kflocalories .per gram mol, (6) ~ol'11, Reference wA Comprehensive Treatise on Inorganic and Theoretical Ehcmistryw0 J, W, Mellor (7) Jo Ao C, So 21, 259 (1899) Ho Erdmam I, E, C, Anal, Ed, 6, 4.42, 1,934, Ro Co Wellso I (8) (9) Chemical Abstracts Vol 46, 852 i (19531, , .. . . 2.0 PBPSICAL PROPERTIES OF RUBIDIUM 2.1 Introduction It was found-by a literature search and reference to the handbooks (I), (2), (3), (4) that data are not available for the physical properties of rubidium metal in the vicinity of the boiling point, Dr, Ho Fo Poppendick furnished the anticipated relation of the basic properties with temperature for the entire family of alkali metals. In addition, he offered to measure density and specific heat over a temperature range of 50° - 500°C, The most difficult value to locate was a reliable estimate of the critical temperature for r?ibidium metal. The values in the literature are from 1800° K to 2700° K in comparison to an estimate of 3000°K by Brewer (5), 2.2 'Summary of Data , 64 Atomic Number 8 37 Mole Wt, monomer (~b) 85.48 Mol, Wt. Dimer (Rb ) 170,96 Natural Isotopic ~&ndance: Fib:: 72.2 ' Rb , 27.8 Melting Point: 49 OC 102OF (b) Boiling Point: 688!.C 1270PF (b) . 679% 12520F (c) Latent Hea-t of Fusion: 6.1 col/gm latent Heat of ~a~oiization: 18.5 k~ c01 or 383 & mole Density of Liquid : 1.52 - 0.00054 (7'490~)&uo Specific Heat of Liquid: 0,086 ~tu/@b)(OF) Critical Temperature: about 30001,OK Critical Pressure: about 250 atm Sublimation : occurs from solid state (I 2.3 Density I It was arranged to have Mr. Stanly Cohen determine the density of liquid rubidium. The method consisted of operating a Westphal Balance a inside an atmospheric dry box. Two different plummets were used to improve the accuracy. The liquid metal was held in an electrically heated nickel cylinder which had a .:;thermcrvefl &'ill.ed dare into thc heaw wall; . . 3...... : I :> . . It was difficult to obtain an oqgsn-free atmosphere irmide the dry - box althnrgh it waa prrged wlth helium which had been paased thru-'a . . combiner' for oqrgen, The rubid;ium metal discolored. .inmediately upon :... . removal from the standard tapr Ppucontainc.~~. . The liquid metal. waa then purZf1e.d to remass oxide particUates by filtration through a fltrted'glasa Aznnel having a one-inch disarter filter disc of pore eize, A dieierenti.a hell* piewe bi about 10 ... pel waa required to force ft through the filter, The rubidium was heated to about 75-100~~before it ww poured into the &heated glaee iiltrr tion eyeten. The filtrate was a clean silmry liquid which rapidly dia- . . colored from the trace of oxygen in the anibient gae,, The filtered mtal waa charged to the 'nickel cyltBder by wing a rubber bulb at the end of a piece of .glms tubing. A lay-r of oxide . vsl remmd from the top.of . the ertal.after It... has been cbarged...... Data were obtafned o&r the range of 50~-400~~as sham by ago-@&, . . , It wm neeeesmy to discorntinue.thi~exptriw& becawe the vapor preeemro of mbidi~unbecones appciable abore .400% and it was be- lost by ~aprizations8d the' interior eurface of the dqbm bec- ''fogded* . . with rubidium hydraide. Powever, a ruffieient range w& eoered to -catablish the slope cb the straight Une relation b&ween denelt~and I Experimental Relati on 'ko? Qege it= ar a Flerctiob of Temrature . fIta = 1.52 - 0.00054 (T-39'~) his equation 1s slightly different from the predicted c- based ,...... upon the same sobume ehwe &wing fmioar a8 oeeurrs for sodlma, pturiosl and Na& -54- Predicted Relation /ab = 1.475 - 0.00025 (T - 39) A graph is shown in Fig, 2.2 for the density of all the alkali . : metals over a wide range of.temperatbre. 2.4 Specific Heat * &, W, Do Powers detehined the average specific heat of the liquid / between 60° C and 550° C using sealed capsules, The date3gave a linear curve' whhh showed =0.086m(op) d'summary of the . . . 7% published data (2) is: . btal -Cp -T OC -MeWo Molar Heat ~i 1.0 200 6,9 6,9o+ I 2,5 Viscosity The family of curves for the viscosity of the alkali metals given , I in Fig, 2,3 is: Laud un &La from the Liqliid Metals Handbo,ok,7 . ,. It -is of interest to note that a recent measurement of the viscosity of rubidium metal (6) was made with metal containing 0.5 per cent sodium and potassium. The difficulty of obtaining pure rubidium:was discussed in this paper. . DENSITY OF ALKALI METALS , ' Fig. 2.2 100 . 200 300 400 500 600 TEMPERATURE ,OC. .. . . DENSITY. :-OF ALKALI *METALS Earapolation of data for. 300-800%. eve. equation: /Y= 0.0666 es . . v~scoeit~cw+poise .... ' //= . . The conatante were dstemdned ,& 'follows:,' 5 = 573% /(i 0.275 og . -. .. ..:.-. . . I.. 2.5 Tpeml...... Conduct$fitp (see zdgri~.$:&~@d+l~~,~~~~~,~,~~;&.&.~~~. . , ...... 2 ' - .. 'j...... i... . , .. , . . gt,' cal. , , . 1sec.j(cm) ("c) a,7 V'Preiaeure...... of Rubidium A plot of vapor peesure iR.atmospheree against the rec1m.ce.l of the absolute teplperatyre is given in Fig.'% for each member of the .I;: ' . . . . !.'. . TEMPERATURE (OC 1 VISCOSITY OF ALKALI METALS TEMPERATURE OC THERMAL CONDUCTIVITY OF ALKALI METALS VAPOR PRESSURE OF ALKALI METALS )r alkali metals family, These data are taken from page 30 of; ~~No$oSo I 2,7. P ORNL DATA . . A cheek on the values for rubidium was made by Dso Ro Eo Moore of . - the kterials Chemistry Division, The procedure followed -was designed . by Rodebush and Dixon (7). About 8-10 grams of *mbidium metal was charged to the quartz vapor pressure apparatus in the X-10 vacuum dry box, The data are given in Table 2.1. The extrapolated boiling point, 6t3)?, and the heat of vaporation, 18,5 kg, eai/mde agree closely with values found in KelleyDscompilation (2), 679OC and 18,8, The analytical expression for the' vapor pressure is: Observed Pressure Caleula ted Pre ssum hHa) c- 2,7,2 About 25 grams of rubidium was shbed to httelle Memorial Institute , \ for vapor pressure measurements, A suxnmary of the data is given(Tab, .2;2) for , eomparf son-,:with ..tb:~OFUG '.da,%a. and to?elidab- the ~aleulatio~sthat the amount . of dimer is neglig3bleo The Battelle transposatiogl method would have indicated a higher molecular weight if the dher were signi%fcen$, EAT= . VAPOR PRESSURE DATA ,. , ...... , . . V.P. rnp He; Temp O C . * ..... 219 573.5 57.3 48108 . . . . . 250 5 429 e 3 7.76 371,7 lcg p (mm) = . . 60942 -T R OK' Boiling Point = 6870 C A% = 17.85 -K cal gm mole w 3. 2,8 Dimer content of Vapor , . , ... It was planned to conduct some experimental measurements of the : 4- .% '. .wr-!.ensity of rubidium vapor in the 'range of 100° to 800° C to determine the molecular weight of the vapor however, time did not permit the measure- ments. These data are needed to calculate the amount of rubidium dimer in the vapor. This inforxktion is required for accurate calculations of thermodynamic data. It was assumed, however, on the basis of literature - search (8) (4) that the amount of iubidium dimer was less than five per cent and could be neglected in the preparation of the T-S and H-S diagrams. This ,is not the case with sodium which has as much as 20 per cent dimer in t6e vapor ( NU-SR-62), In order to validate the assumption that rubidium 'is, .essentially, a monatomic vapor, Dr, Leo F. Brewer of the Department of Chemistry and Chemical Engineering ..at..the. University of California, Berkely Campus, was contacted. . -. ... We wish to!rhan* one ;f his students, John Engleke, who furnished' sample . i' calculations for us to follow in proving that the rubidium.dimer is a . ." .- .I I ( . ,.! -;IY": t. ', , . . t. . . i.. i' : : ...... ,. -..- ...... ,.,, ..,..-. -.- . . a negligible component of 'the Tagor, 'Faheas ca%cUtfanas imhded an ara- '.. ,. * ...... t ..';. .. polated beyond the reported (9) ternprature ob 2000%' to the estimated ; ...... :. - critical temprature of about 3000%~ . . . . . The vapor pressure of both the monomer and diner can.be calculated , segarately from available thermbQnamic~data~.At the low pressures under etudy for the Jet engine cyc&e,the ntBkdib vapr can be treated ae . . ideal gas. .Xt can then be assumed that the equf PiBrium ,cwtant for either Y . .. vapor specieb,' in equilibrdum with rubS,dlum liquid, is equeJ. to the partial ...... pressure of the respecti$e vapor molecule: . , Equation : Rb (2) Rb (B) .....-, . . K partial pressure Rb ...... :...... : ' ...... : ...... (g) * . . Since ,the standard free energy and equllibriwn const& are given by the . . I I. . . Z equation: ...... ,. . . ' 1. ,. , . ....'A* ='. .- m.: K..: ...... the partial pressure of Rb may be caleubted.: . . (B) e -AFT Rnpp~b. . (01 . . *. ' .log& , where .- atkdezd free enerwj Kg cal/(%) (mole), 4 rT = . . , T = .absolute . tempemture,' Kelvin...... ...... K a equilibrium: constant . , . . +I.j pp = partial pressure, am. The free energy functian, which mt 'be found at the ,tempratwe under consideration for each molecular spec1es, is calculated by the equatf ons a,, = fie. energy at temperature T, cal/(%) (kale) g = heat content at I, Kg cal/(mole). ' ' . . . + entropy at Tj kg..cal/(%)(mole) T temperature of sgetem, % ", Subecript 298 is atandard stake of 25?~ ...... %e atandard entropies at room tempgatwe for .both species are gkn '. , :.., . . . . on pp 78 and ~2 of pellei:?; ~ul-l&in,NO. 4.~~. (IQ,L he hetit, content snd '.... .,, . , . -. ' , . entropy differences are from Kelley 'e Bulletin No. 47.6 (9) page 194. . . ,. . . Since the specific heat of' a liquid does. not change appreciably with' . , \ ... temperature, the data for Rb (1)& p. 194 of Bulletin Nc. 476 can be . . . . 1 employed as follows t. . . C r molar P specific heat of liquid, T080 For the monomr vapor it is eatisfactory to use the data for Argon from ... .' . . ,>.- .... ,- page 19 for .. , ...... - H~C& epb (8~- s2i8j ', ' Bor a temperature of 1000% the vapor pressure of the mono~r. . is calculated to be 1.62 a$moapheres: ' .: :. . . . % H298 3487 p. 19 Table - . . :. ..%- S298 = 610' . p. 19 Table Aasuming A%98 20,505 cd , ae the standard latent heat of mole vaporization, allows the function AFT t,o be calculated: : 7 ...... T 7 F' 1 - . . for 100008: ~b y) ...... < ...... , For the dimer partid gressure at ~OOO~K,the calculation are:' ', ...... - ...... - . , 2.Rb (A') - Rb2 (g) . . Then for the equation representing dimer in equilibriumwith the liquid: Free enerm Function - 24.26' . . so that pp Rb2(g) = 0,086 atm . . This procedure is repeated at other values of temperature and then . . . . inte~p0latiOIIof thk free energy function, OF* AH^^ , CQ be 'P ...... ,., ~ -67- linearly with temperature since it ie a slowly varying function. - A somewhat dif'f';rent mthcbd muat be wed to estimate the W2(g) fugacity, paz$ial pressure in this case, at 3000%. Since W3:p;kda$@--&?&I ;atit @OO%*- w, aaaumptim is made that the difference in heat capacity between the product, Rb and reactant, :2~*C&#&~jjbis canstrmt between 2000% and 300009 2 (g) and that it is &Ten from the data & p. 14.9, , . . &om the free energy f.unction the. heat;. content and entropy change, at ...... 2000% can.be obtained., . '.. . . . ' ...... = A s2000 - 6.65,~2.303 log 3000 2000 = 13.92 - 2.70 = 11.22 entropy units The follotring is a summary of the calculations mades ...... , . . .-. '...... These values are for saturated vapor '~othat the dimes conten% will dsekease from a shift in equilibrium constant as the superheat regfoa is enlered at constant pressure, By use of the corrected moPeculas weight of the rubidium vapor, the change in specific volume can be.ealeulated and found to be negligible for preliminary studies based on all the other assmptfons made. . . -- - . 2.9 . Surface Tension of Rubidium The following equation is an approximation which compares the surface tension of wanomalouswliquids. Liquid metal, as well as water is where s O-/ = surface tension (dynes /em) PC = critical pressure (atmosphere) Tc = critical temperature ("c) A specified condition for equation (3.1) above is that: (3.2) where: T = temperature at which the surface tension is given:: The surface tension of Rb was calculated by comparing it with Na in equations (3,l) and (3.2) above. The critf cal temperature (Tc) of Rb I was obtained by averaging two values reported in the librature*(L+) (i.e., 1886OC and 1650° C, average = 17670~)~The surface tension of Na -is 200 dpes/cc at 250° C (ll), Using the above values in equation (3.2), the temperature at which the Rb surface tension is given is calculated to be 2Q0° C, Substituting these values in equation (3.1)~ the Rb surface tension is calculated as 102 dynes/cm. I To calculate the surface tension of Rb at 70o0C, a temperature of interest for reactor application, the following equation (12) was used% . where: 6 surface tenelon (dgncs/cm) p = density (g/cc) at a corresponding temperature T (OC) M = molecular. weight Tc = critics temperature (OC) ' From equation. the following relation obtained: , -Frbrn eqnatim (3.5) the aurface tension of Rb at 700'~ . is... calculated...... The following table Usta results obtainea above. Surf ace Tension . . (mes/cc - . .. '.200 ~.(7 ,a 340 i (7) .. 2000 (7) .. , . ~b . -'1767 (6) 66 13L7 (9). .. _. 700 ' . 102 .....: ..; 220- I . .... -. (9) his report see page (see original drdt) (7) see preceeding page (NAB) ...... (6) reference, forvalues used in averaging ., . A second &hod of calculating surface tenaim was used in order to ' conform the resalts obtained by the ~peceediwequation. (3il) th (3.5) This nthod idrol~sthe use of a $arochorw (10) which is &fine$ by the .... equation: * This value should be revised to conform with more recent calculation found on page of this report. At the -tilmc of this' cacl. these were available however, the error in the surfacc tenelon would not exqeed ., .. lee B.I == naoleculaS weight. . . . p = surface ten'sion; (dynes/cm) D = liquid density, (g/cc) d = -vapor density (g/cc) The nParochorn is given in the reference (13) 'for several common elements - and cqpounds. A plot of (P) ss atomic weight shows that the P for elements . ... of the same.kfmili is a straight line foratomic veightsabove 35. Also, these straight lines are roughly .parallel. These obsermtions. were used I I to obtain a value of (P) for Rbo .. I The (P) for Na and K was found by evaluating equation (3.6). These I ' 1 'kalues were plotted and- a ,straight .line drawn thsu them ,on a linear plot. This lfne was roughly prallel 'to' those for other fdPfeso A value of I (P) for Rb was obtained by interpolating 'according to, its atomic weight I (85.48) on the line for' other members of the family, The value.-obtained for (P) was 158. ~ubsf~&tin~this value for Rb in equations (3.6) the surface tension value .was , calculated to be 34 dynes/cm. Thf s empares .' . ... favorably with 66 dynei/cm, the value.. obtained by using equations \ .. (3.1) thru (3.5). -.For. other calcdation~,the value of 66 dynes/cm is . . ,.. used for Rb surface tension. ?: , , , .. .. . '.'. . 2.10 0 . . ,, -. : i.' , .. ., . . The coeffiCient o?volume expansion is defined by the . . . . I. .... I.... equation: where 8 = coefficient bf volume expansion ' B(T)= volume in cc at a specified Item'pratme . . T.- temperature, OC . . . . , . The density of Rb varies linearly with temperature as shown by Figo 2,2 ...... " , . . Rb density vs, temperature. It can be shown that equation (4,l) ean b expressed as: where s . = slope of the density vs. temperatam ..: AT curve From Ff go .2,2, the coeffi&ient of volume expansion for .Bb is determined For reference in detepming the heat transfer properties of Rb the following table lists some of the physical properties of Rb at its boiling point (688%) under a pressure of one ahosphere, Water and mere@ also listed for comparison and assistance in the following calculation, ~nalyticalcorrelation of boiling rubidium to boiling water and boiling mercury is found as follows: a, Method of Approach Some date are. known for boiling water. Since almost nothing is known about Rubidium, data for this metal were estimated by correlating . . the water and mercury data to rubidium through dimensionless::porameterso I . i o . b. Results The results of a dimensionless parameter correlation between boiling water, mercury and rubidium are listed below and compar,e the heat flux (Btu/h.. ft2) and/or the heat transfer coefficient (Btu/hr0ft2- OF) at a pressure of one atmosphere, The terms "mildn and nviolentn boiling are defined in the reference (15) and are based, in general, on the magnitude of the-temperature differential between the wall and the fluid mean temperature. For formulae and calculations for these results, see Appendix O TABLE HUT ELUX COMPARISONS FOR BOILING RUBIDIUM, BOILING IdATER, AND BOILING Ng AS IT IS BLATEZI TO BOILING WTER TAmN AS 1,O Mild boiling (1) Violent boiling (1) Peak Heat flux (for same A T ) (for same AT ) lwithout film boiling) Hg The. results'tabulated above indicate that more heat can be trans- ferred in a boiling Rubidium system than in a, comparable boiling water system. It ' should be" strongly emphasized, however,. that these results were obtained from empirical formulae that have nut .been:exprimentally tested for use with llpuid iqet'als. . Therefore, the9 sbuPd be med'qualitat- .. '. ' . ively .adwith eeiution to indicate trend8 only.' - The ability to wet a surf'ace de ' an.important factor' In 'film boiling, It was observed that liquid .Rb wets -'a.&,as surf&e. very.well, ' and .' wch better than water'. 2,12 References (1) Chemical Rubber Handbook (2) Liquid Metals Handbook (3) No No E. S0,LO Lo Quill (4) ~melihsHandbook (5) Private Communication from Leo, Fo &ewer (6) Eo ' No Andrade and E. Ro D obbs, Rdco Royal Society A-W, 12-30, (1952) \ (7) Physical Review, &, 851 (1925) (8) Nillimn and Kurch, Physical Review, &, 527 (1939) (9) K. KO Kellep, Uo So Bureau of Mines Bulletin, 476 (1949) (10) KO K. Kelley, U, So Bureau of Mines Bulletin, 477 (1950) (11) North American Mation, Inc. ; We-62 nThermodynamic Df agrams for Sodiurnw, (12) Bekerman, @ Surface Ghemi~t~~,Academic Press, 1947 (13) Weissberger, nPhysical Methods of Organic chemistry, Part lw, Second Edition, Interscience- Publishers LTD, London, 1949 (14) Jo Ho Perry, "Chemical Engineers Handbookn, 3rd lition. (15) M, Jakob fl Heat Transfern, Vol 1, Waley and Sons (1949) , , 3,1 Introduction The power cycle analysis of the feasibility of using boiling x%bidi~rm as a heat transfer medium could not be accomplished without reference to thermodynamic data on rubidium, liquid and vapor. To facilitate the cycle A analysis, temperature-entropy (T-S) and enthallpy-temperature (H-0) diagrams were constructed utili~%ggthe data available in the literature, For a first approxfmatioaj it wa~assumed that all of the rubidium liquid dissociated completely into-a monatomic vapor. Using this.major assumption the idealized temperature-entropy (T-S) (~i~.3, 4) and enthalpy-entropy (H-s) diagrams (Figure 3,6) were constructed. The following additional assumptions were ma'de in constructing the diagrams8 1. The latent heat of yaporizatioBd h9is constant; 2. The superheated rubidib vapor is a perfect monatdc . . g'as and its specific heat is equal to 5/2 R. is the - ideal gas constant), 3, In the lfquid-vapor region, the specific volume of the liquid is negligible as compared to the specific volume of the vapor, I The fsllowfng fundamental thermodynamic values for rubfdfum were used in the.'preparatfon sf the temperature-entropy and enthalpy-entropy . . diagrams s , lo Vapor pressure versus reciprocal of absolute tgmperatu9.e data, (Figure 3,l) (Ref ,l.) able 3,l) and the derived vapor -. versus ' temperature curve, (F'igure 3,2) Speef fie heat of rubidium liquid, C = '7,80 eal/gm mol .I 2, PI. 380056 BTU /#9 (Ref, 2), 3, Latent heat of vaporization, ho= 18,120 ~al/~mmol = = 5/2 R = ,0581 BTU/#, .OFo 4, Specific heat of arbfdim vapor, C~ 5. Melting hint = 39,04: = ,312.2 OK = 102OF = 5620R0 6. ~olecular.weight of rubidium = 85.48 7, Estimations sf the critical temperature vary from 1800°K (27800~) when estimated by the method of Watson to over 3000°K (~ef,5). The . - latter value is considered to be closer to the actual critical temperature, 8, The critical pressure is estimated to be over 250 atmospheres, (Ref, 5) The rcefsrance temperature used in the construction of the temperature entropy and enthalpy-entropy diagrams was the melting point of rubidium, Using the fundamental thermodynamic values given above, the data required to construct the temperature-entropy diagram were calculated and the char% plotted (See Fig, 3,3 and 3.4) a able 3,2), The equations used and the method of calculating the necessary point^ to establish the constant-pressure I line on the dfagmm for two atmospheres is as follows: 3,2,1 Entropy of the saturated If quid, S 1 m. = specific heat of the liquid = 7,80 cal/gm msl, OC=,W12 BTU/#OF c~l Tb = boiling temperature of Rb at 2 atmospheres = 747% = 1020°K = 1380°F = 18,!+0°R - reference temperature = 39900C = 312,2OK = 102OF = 562OR I To oP 18,122 eal/gm mol i 380.56 4 = latent heat vaporization . . Bm~h % = temperature of vaporization 747'~ = 102g = 1380%'. = 1840°~ ...... as, = 380.56/1840 - 0.207 BTU/#,% 3 . Entropy of saturated vapor,, SV 4~.Entropy of -superheated vapor, A SsB , . yq, = specific heat of vapor; .0581 BTU/#, 9 C~v . . T = temperature of vaporization = 1840% ... Tsv "- temperature of superheated vapor = 2100%. =2560°~(selected temperature). ' A s = .058l ln :2560/1840':= ?o191 OF. - mu/# The verriation'of temperature with'entropy at"constant predsure inthe ., . superheated vapor region waa found to be very nearly Unear when -gl&ed on . '.' the scale used-in Figure. 3:'62I and a31 such 'curves were drawn as strafght line& The data heeded for the com%ruetion of lines of cmtant epecific volm In t& vapor region were obtdned by using the Ideal Gas ~~uatlcm, The epeeific volwne .of the saturated vapor at a selected preasure was calcula- ted and then, maintaining thie calculated specific volume as a -corntan+,, the peesure corresponding to an arbitrarily selected .temperature waa . . calcu%aked. By reference to a crossplot of preesure versus entropy for oari-ous eomtant t emperaturea (Figure 2@33 @@~~~mp~~OQ~~&-%~tie the orfginaLlJ calculated specific volume at the selected temperehre was . d-d, Ply repsting tbie procadPlr 'for smral. .elected tenrpsrgturee,. with the spciiic volume conatant, data neceseary to construct the constant spcific volume ,line in the vapor regian were obtained: (~a3I.e3.3) ztT = WP - v = specific sol-, ft3~ R 2 IdeaIGae Oonstant - .729 atmospheres ft3/# mol % . . T r temperature, 41 . < . . , w = # atomic weight = 85.48 #/go1 gt = pressure, atmos . Example When the peesure equals 0.5 atlnoepheres the saturated vapor temperature equals ~0%- = 1590°R0 . ' V = .ocBgB r lgg0 / .5 = 27.i2 fd/lb .. Using Pt = .008528 ~/fand holding 7 constant at 27.X ft3~while eelecti~lg temperatures corresponding press,ures are found. By referping to.Figure , ;?:0:!% the fvdues of' entropy for these preesures me taken from the constant temperature lines: 0 Tsmperatuze, R Pres~ure,atmos , mtropy, ~tu/#% A plot of these temperatures versue corresponding ar~ni:&-of... ~etX.0~~~ determines the location of the line of ccm~~tantspecific volume of 27.12 ft3/# The lines of constat quality in the liquid-vapor region were aetermined graphiealiy by taking the direct propkion of the length of a given constant . - temperature line, Thus all points of 50% vapor fall on the Illidpoints L,. . r ,.: ? *, .. L' . r / , , ..... I , 1 . .'__. of the constant tempeleature lines between % and qo . :, ...... -, . . ., .. I Since the region of interest lies in the quality range50f from 50.h ...... ,. . . . I , I , 100 per cent it may be assumed that the specific volume of the liquid in the ...... ,. . .. . liqdd-vapor region is ve'& small as compared to the specific vilume of the ! * vapor. In this case the specific volume of the liquid-vapor mixture is equal ...... to the specific volume' of the vapor and can-'be represented 'by the following equations . . . . - ... = specific 'vohme of vapor fn the liquid-vapor region vv . . ...r. ... f = fraction of vapor in,the liquid-oap.or,mixture,...... or qualfty in percent...... V , , , ..... 1 = specifio volume of saturated Rb vapor. - ...... By dividing a qeleoted value of Tv by the value of 7 corresponding to a . , ..... -. . . given T and Pt combination the. value. of, f for the,, .. known.... Vv yalue can be . . 4. . '...... , ...... calculated. a able 3.4 and 3.5). This establishes ,the point.' on the tempera- ) ture-entropy diagram where cohstant T, f and \ lines intersect. ,' FOP a temperature. . of 1060° F (15200~)and a corresponding Pt of 0.31 . . (~i~.'3i2) calculate the value of . . . . Selecting 7 tb equal 2'7.12 fixes the value of the constant Tv line to be I drawn. f = Tv /T = 27.12/41,81 = 0.649 = 6469% . , -. These values of T = 1520°R f = .649 and Tv =27.12 fixes a point on the constant line. I, - 3.3 ?T~YDiagram The data required.for the'const3.uction of the.enthalpy-en%ropy dQgm 'for rubidium (Fig. 3.5 and 3.6) were also calculated using the avail&& thermodpmio values of Cp, Lt,,, Cyrr and choooing the base temperature for zero enthalpy to be lo/c?mf; the:'?@lan8:pdtbki.:hf hubiddi~'6~~&&9~~fl$i'31Jb~::~~bbidq~&i~~u@i:$nd the 1' dlsgram usl~ylas an example a conatant peesure of two atmospheric Is aa 3,3e1. Enthalpy of saturated liquid, Hl T,. T~ = boiling temperature,.O B = 138.0% El = .0912 X ( U80 - 102) = U.6.55 ~tu/# . . 30302. Enthalpy of vaporization . 4has been assumed to be constant aid is eq&l.to 389.56 Btu/#. Tb Tb = temperature of vaporii~tion; 1380 OF T~v= temperature of superheated *par = 2100 9' (selected) r Cpr = epecific he& of vapor. = .0581 B~u/$ 9 . H~~ e0581 (21.00 - u80)- = 41.83. - ...... B~u/#- 36r. Exthalpy of saturated vapor,'% J039, Total enthalpy, H -. . . ~ke*rOh ido&ee+ly( to do&.'e~alBP. be . .- ...... ,. . -. obtai&d. . from the' ....tempiaturc-etntropy diagram since. . tjm prepare, two ...... I. ., . .% . . .. < - ~.. ... atmospheres, and the .tempsr~turea . are Imam - ... . . The line@of constant quality msy be tranposed directly from the tempera- tw-entropr diagram wig. ZN.by reading the intersection of constant , . quality,' preaeure, txul entropy . Idnets.. ,:',.-.. , he lack of P-v=-T,. . . ~ai L the literature 'make? it .inpossible to plat, .. -...... coqlete diagrams foy T-S aad H-S .ela.ti& from %he melting point; ' of the.&$,i$&&i. .. , . .T,Y- . . .. :, _ v ..." to the critical tePpsratare.for the oaporaa B~OM B924.3;Xll .811d3@ii.;?,... . . ,. . ,. , ... ,. 1 ' Box%unately, the 'kegion of ,-%ereat. ie Pqreinwed from th6 cri-b5csb region so thst; ee&$ed eectiom were &a* for reference as -. eham . by ~igad;&l .:and '. , ... &.=.:.: . . b L. _/. I . - . . - . . - ' .', . . T9 C@ T, % , s1 B~uC$ %Blu/%-.' Bl,~~h.Em' ...... -- . . ... -. ' .. . ; 102 562 o .qi o . 380~56 , ...,.. . 122 582. . 0003 ' -, '.637 1,825. 382b39. 212 672 ,016 92 10~04 : 390~60 . . . ', ' . . " . 392 852 . b038 . 5 26,46-- 407.02 " '. .. 592 1032, :,.O56 , .,, ,425 42.89 ,423.45 : 752 12921,. ' . ,007.3 , . 387. 59.31 439b87 . . ' , ..083' . . ..6956 . , 7'5 074 456,30 932 . 3392 ., .. 1U2 ,1592...... 0094: ... 1.. , . ,356: . 92.16 472,72 . . 1.292 1'752 .104 a 321 . LO8959 489.15 1380 . ' n840. ,.'no8 ', *3$5 . la6,&. '497.U '.- . nh54 1914 .112 1236 37 t 503 093 1472 1932' ', ,U3 e,310 ls5d 01.. '50505% ' . ... a652 2912 ,,.l21 ,ao& , ., 141.4ai 522.00 a32 . 2292 .129 . ' .: . . . -295' . 15~~86. 538,42 , 2000 ' , ',ego . 43.19 553075 . 2460 ,.135',. , , ' ... ,' . . . 2732 ' ..' .. .' . . 8 239099 620.55. 3192. :: .&9 ,. .. ,. . : ...... I' ...... ,. , ...... :;...... / ...... ,' ...... I.. . . Eln!RoPY AED EziTmum QF mmmm TBE SlPERma m1OB Tb = temperature of vaporization,. . . .-. T,, = temperature of svrheated vapor 20009 (eeleeted) H = Hv + A Hev = total enthalpy S = tutal entropy 1. Quill, LoL,, (L. ~rew.er)ChemLstrx and 1Ja;allurav of Hisccllaneow l@terlalst !I!-ce, BI.X,E.8. V@1. Ttr-l@, hbGrenr-Hill, 19503 p,30 3. ~e~ey,Z. go, ~cmtribrrtiolto tha ~ata ~hccarticdWW~, X? gtgla+empraimfei Beat-C&&~ :Sea$ C,b.pa;City, aa8 W~opyData for hmganis Caqp6uds,, XhS, Bareciu of meBUetlla, 476, 1949 I I. TEMPERATUR E " F. ~ .-97-, UNCLASSIFIED OF 1 ENTROPY SAT LIQ. AT 102~~'I ,V uwlTrr** , I r*w * : I IS REFERENCE POINT 0%-c~y 19s~-s+- I! 0.2 5 0.30 0.35 0.40 0.45 Fig. 3.6 ...... 4,O COMPATIBILITY OF INCONEL AND RUBIDIUM AT ELEVATED TEMPEBBTURES .. -. 4.1 1 . . .Rubidium metal discolors immediately upon exposure to,an her$ atmosphere containing trace amounts of oxygen and/or water, There is considerabie heat generated by these re&ctions which cah become explosive in nature if not arrested by an exhaustion of the oxygen contai,ning material. It was*found by experience that the solid metal does not always ignite' spontaneousl~upon exposure to the atmosphere. A mixture of yellow and black oxides is produced on the surface as a protective crust for the metal underneath ' if water vapor is absent. Four of the oxkdes listed in the literature are: , monoxide Rb20 yellow 9 dioxide Rb202 yellow trioxide Rb203 black tetroxide . Rb204. yellow In all of this work it was considered safe ;to keep the rubidium metal in a Pyrex glass container which had been sealed under vacuum. Care was taken, however, to maintain the temperature below 25OC to ravoid.fusion and to store the sample in an isolated space in ease of fire or explosion. A face shield be worn upon exposure to any sf ze sample because of the hazard involved. The glass ampules were not annealed after sealing so that a failure would occur occasionally, Hydrogen is evolved by rubidium metal upon contact with either water or alcohol, The reactor can be violent with serious consequences if the proper precautions are not taken. Water must be excluded in the liquid state and all necessary treatments made to remove water vapdr from the system for handling the metal, The mercury-like eupfa'ce of the rubidium turns a dull gray upon' contact with water vapor.in a drybox; The Battelle Memorial Institute uses a molten alkali metal trap to remove water and, oxygen from the fresh inert gas being supplied to a dryWox, Ethyl alcohol is considered a conm&eg2% method of reacting the metal prior to disposal, his is Best done, however, &der a mixture of hexane and aloiohol. . with an inert-.gas blanket of errgon to exclude oxggen. This procedure, As employed while recovering small samples of mbidium metal for Pework, . All. the necessary safety precautions are employed because of the fire hazard,. with. remote operation. preferred. It is recommended that the liquid metal be handled inside a suitable drybox, This includes a vacuum system capable of lom5mm Hg for ?pumping downn and an inert gas purifier of activiated charcoal at the temperature of liquid nit~ogen. Two or three flushes are required to purge the oxygen and water to a. tolerable value for handling the molten metal, A Plexiglas dome is convenient . . . , fpr observing all operations. Shown in Figure 4i1 is the vacuum-dry-box qade * e aveflable at X-10, Bldg. 2000 by the courtesy of.the Metallurgy Division, . . Experience. . with an atmospheric dry box equipped with an oxygen removal unit , (catalytic ) for the inett purge gas was not sat$sfactory. he Pyrex ampules are opened inside the drybox by scratching the,glass tubing and breaking off the end ~gpositeto the oharge of metal, The meb1.f~ then melted on a small hot plate with the Purex container standing inside a metal beaker having the bottom covered with a layer of shot for' balancing, It is necessary to preheat the Pyrex funnel with an insulated electrical heating tape to,avoid solidification upon pouring from the ampule to the new container, C '. A temperature of about 75-100°C is preferred to permit easy flow of the . . \- liquid metal, No success' was experienced in an attempt to cast the rubidium metal into -11 diameter rode as is' done with ~Qdium, The solid was friable and did . - not retain its~cylind~icalshape. ' Amounts &re best judged by comparison to a known volume in a similar 'veseel, Samg1es of the liquid metal can be collected"1n vacuum-isealed tubes which .... are enlarged at one end to hold about 0,s cco Preheating of the capillary suction tube Is needed to allow rapld flow of the metal into tba enckted ., chamber after breaking off the pointed tip under the surface of the mtal. .T . The liquid mtal can be filtered through a sintered glasa funnel by arranging to apply about 5-10 pslg pressure differential acroea tbe filter medium while maintaining r temperature of 75-100 Oe. ~s'is used t o =move dirt and insoluble oxides of the crud. rrhl if a Gumdistillation unnot be per- . . formed, The tubular metal capsules used for corrosion testswbxe closed inside the & . dry box by attaching a rub&r hose with a clamp. 1% u8s: then evacuated outside the dry boa ad crimped in a ~radicpress to: cldse +ng: about 20,000 psig. :The excess tubing +asremoved dth s hack aev prior to mesling by Heliarc welding along the cut edge. Rubidium metal must be exci~d~hnear the zone of crimping to permit a satiisfactory weld8 . ' Residues fram capsule corrosion tests and/or ampules wgse removed from the dry box with tho mtsl in the solid 8kbo The residual metal bias.(r&i&id.%&ih' alcohol under an argon blanket as described previously, In same case8 it fa necessary to.dilute the alcohol with water to remove the hydroxide and/or oxide protective layer. Extreme care is required to avoid accumulation of motel and ,i . alcohol in a .wpocketnwhich will eventually be exposed to ai~bKeep other solvents away, especially acetonea +-- * -- - -- .--- -- ~ ---- *- --L - ' I I In general, ezkeme care mast be taken by those haadling alkali netale. &drooarbons such as loinera1 oil and ker~sene~araatandard agents uasd to probct 1, . ! @m metal by preventing contaet witb air, but this practice leaves much to be # desired where pity of the metal Is impo~tant,Shipaent over long. distances I . esn be-made in pealed containers which kave an inert pai?king around the ampule containihq the alkali natal.- &. 2. The Corrosion of Ineonel by,Rubidium Befare rubidium can be seriously con&dekd- as an engineering naterial, 1- its corrosiveness to-possible container materials, at proposed operating tempera- 1- - mi, sncl under conditions as nearly simuleting proposed operating conditiiona mst be obtajned. - ,. .L , The acceptad procedure for eorrlbting an alloy proposed for use as a *. 4 container material for a liquid metal is to firat conduct ,static capsale tests' in which the liquid is sealed wikhin 'a rrmall -container of the alloy and held . 0 at ths desired tenperk ture f& an extended period cf tima If the alloy , .. -', -wsdi;Y pprpres this ~~mealggtest it is nmt eq0-d to tbe iiqaEW~: in a system which incorj.omtes contact with flowing liquid metal at eleva-ted temperature, with a temperature gradient present in the system. . The wholehearted cooperation of the Metallurgy Division, ORNL, made it posiible to complete two Inconel-llubidium static capsule dsts and one dynamio- closed-loop test during the time alloted fon * this projeof . The c3ntire fabrication and aperation of the oapsule and boiling loop tests were conducted by $. E . Hoffman and associates. The rabidium metal wapr . I mmm'distilled bp John V. dathdarf. Metaqographic emmiations of the . . sect1omd capsales -and loop were conducted by Be J. ~~'68and assochtes. X-ray asa3.ysis of a rubidium-sodium alloy and tbs precipitate found in the boiling loop was conducted bg;I%. Xo Steele, ,To C, Uhib and a stsocia~e,BBiP Analytical 9hdstry Diaision, eon- 1% 4,2*2 l5U D-e Fa Ineonsl-Rubidium Ga~saleTest Thti first mpde %eat consieted of an Ineonel tube LOu Icing, baaing a 1w dnsfde diameter with hellare welded end plugs, and a bUre welded thermocouple well 09 1/4" tubing exkendint upmrd from the base of .the came to above thg bath level, The eapsule was hydrogen annealed at 195OQF for 20 Isirmtes, 'Phe volume of rubidium during the test is estimited to be 1,s cc* The exact volmpcs is unborn ,because a portion of the rubidium distilled oat of the oapde. earq-in-,sN --.,.. the test tbr- a capi~rytube .tt.ohed to a bourc~on-ta~ .,:_>: 'G.lw' ' =;-I;> , -&$:.&,; pressure gage ~onnacstedto thq tqp: of the capsule-. The rubidium was plarcred <. in th. capwle and the oapsulq se&d by heliarc veldin$ in a dryboa *ah I had. been ptvrged by alternately evacuating and flu;shing via pmified halitan, "Phs assembled eapsple wale evacuated to approximately 100 microns pressure and sealed by crimping and heliarc welding the elaeuated tube, The eapletzle was placed in a Globar eleetsic fwmace and heated to a -t;arapgrature of 1560 degrees Fo Thie temperahre was rmsrinkined for 101 home. "Phe eontrol tmperature of 1540 degrees F, was laeasured by a ther- ~iocoupleplaced in a the~"~~wo~~l~well in the center of the base of the cap- mile whieh extend into the capsule to above ths level of the Wbidium ba*, The capillary tube extending from the top of the capspule oatside the furnace to a pressure gage became plugged dwing the first five hours of' heating before eqaflfb~inmfamace kapexature was attaw - -- After raming the capsule *om the furnace the oapillar~r t* a. cr- and at UBBfO the capsule. Ihe capsule was placed drinerk atBlosphere in a drybaa, and the upper Whrmovsd with a tube cutter. Tbe opened eap- I the ml$ing point of rubidium, and inverfsd. Ho rubidiam liquid eould be pcmrd f'ro. tbs o.psule, n& collld any liquid, or solid, be seen by 'looking throagh tbplastic -boa: cover into the caparrl.. Ih. eapsale us raotd f ram the drybar a& after a few aeeonda exposure to the air it was noticred that a liqed was now present in the eapaule. The capsule was mdiatsly returned f o the drybaoc and approriaustely 1,5 cc of a golden colared metallic liquid, veq oleaa in appearance, was dlj pmed from the capsule, app~oodaate freed- Wt of the 1.paui.d was determined to be adthe awrltfrlng point 230I!', Rnese temperatures were determined by i8msrsing tibe glass btt10 ccmtaigfng the rubidium alloy in an acetone and dry ice bat&. ' !b ml3 zucmnt af golden liquid that clung to the wqlle of the test apde was ~(~p5dXyattauked upon exposum to air aad a whits hygroacopia film, probably Rm, farplsd. The gold calmed liquid was allalysed to eonlain: sodium is far in excess of the pereentsge found in any of the other; rubidium s analyzed it is postnlated that the mple beca& enriched in sodimp, as wall aia aotasaitm and caleim by the distillation of Pabidftillr mat of the ' ] capsule into tba bourdon-tube and &pi-r~ while the capsule was being 1 heatmi to the bet temmrattare, I ~thoaghth. rribidimm had hen alight17 cwtaminated by rsrg short ex- po- to air prior to insktion in the test cap- during handling, af'tep I reduetion of the BbB, it was silver in color with a ml%in#point of appro- ximately 95 degrees FO Evidently inersasina; the aoneentration of eodimao or ~xygen,An rnbidiua . lllarkedly l'awers the melting point of the alloy 19 %he gcmpoaition range consf- . having about the gasre Bb-WB ealapoaition and melting podnt as the liquid a&lyged, However9 &e fact that %he liquid war nub molten '~mtilit hsd been eqosed to the air indimtee that the additiori of olrggen to mbidium in con- centrations of between 0 to 2k lowers the melting point, This lowering of the point is accompanied a gradual color change fra silver to gold. This lawering of the melting poiqt to below room taplperatwe, awompanied bg the color change, has been noted on several occasions uhen &mallquantities of Bb mated in %he ba$tola ~f' opea fl&shu ~1-waxpoaed to air, A matallographic examination of the surfaoe of thg Ineonel capsule which was exposed to the rubidium ~llqreveals that comosiop the rohadsma of void fontstion and, org intergranular penetration is not exeesaive, In the vapor zone general void eorrosioa is evident to the depth of only .0005 inoh dth no sign oi grain bowdry corrosion (~i&e 4.1). In the regian of the bth-yapor interface mbmrface void termtion was obremd to a depth sf ,001 inch. (Figure a)o daurfaae corrosicn puutration in th. zone be lo^ tbe ~qtlidlevel ur lass thn ,0005 inch. (~igarre@J~c A --.-. A eqile of tho RubidiuwSodium UqtJd ms mhitbd for X-ray Annuair - I The aml;rri8 trrr ~coaduetodby Be U, Staolm, ' The mple -8 aaroruUy frosea bg r djdt of Be parrod WoPgh ee- of tha moaaund do9rsation limr are U~fflin PybL Line Inliaareit~ Figure 1.1 moasl 'Ekpsed to Rubidium Vapor for UI1 kurs at GbOoF. PIagnificationr lOOOX -108- NI PLATE Follhing an ~x~osukof 101 hours at $409. Magnification: lOOOX Specimen was Nickel Plotted Following %est. Figure 4,3 Inconel Exposed to Liquid Rubidium for 101 Hours at l540oF. Nag;niPicationt lOOOX Etchartt Olyceria Regia Y-12929 UNCLASSIFIED Pigure 4.4 Intergranular Corrosion of Inconel by Rubidium Vapor, Section of A Weld Following Bposure for 101 Hours at S~O*.Magnificationt 100CtX ' Rb bow centered cubic a 5.mA0, BbQH orthorhourbic a = 4,15 be b - 4.30 Ae c - 12,2.80 Bb20 ' face centered aubic a = 6,742 .RB02 Tstragond .= 6,OO e - 7,03 RbB3 Te tragonal a = -4,497 8 - ),'E07# It fr beliewd tbrt Wsmapla coabinr Rbs, RW2, and porriw ~.r BPI3 ald RbOH,. A number of diffraction 1%nemareunexplailud indirtiq at Tha attick in the region of the liquid-arpor'interfaqe, although damp&, .. im not- general au the a tbck ia th. liquid mpor region. Submarfaem '' ' :Oi' " ' b . . and +&d& A a Are nore widely i&tted; ~kdenceof inte&mmlair mid pbnetratioa n. ...5 .. . . I <' fW in tBs weld amling the tip of the thsll9ocougle well, This tip was in - , .'\ ...... th. vapor .on, Gprodrtely .25 inch above th. bath level. 'Ih. only .ririble: . . I corrosion in t~.weld ut.1 wa. int~rgrqnularvoid. td a epth of .001 inch. (Five w9 P ~lthoughno sha.g. in wight .uke.intr wen rda to determine the a- 1. 1-t of genaral mrf&ea ca~rrorion, th;, absence ef appraciable percent.$ei of Bag Cr, th. that I ' and Hi in residual alloy indicates little general surface cor- The. &face to volume ratio. mas. large enough to allow sattaration of the I' , alloy with Peg Ei and Cr in a sh6rt tiEq if solution corrosioniiaa pereat mad the vapor vould not transport Fe, Cr, or Hi so that corrosion could con- .- tin* by rrss transfer, a rne~oeaf 4* pa%sjCdrr diammfibP ImnriZ %Magb, a *035 Paehr a ma- - fa¶..$-m=- I. -I- far 100 lunu, not isU'p1- tir *st-w iqg npr hd 1sJwd kto th. pt.. qll&er to eq-r pm~mru. The bdr did not oo- Ss the-. we& - It is not belie-d that any of a air within the outer contabas qaMred the intericw of the fncmel capsule einee *he break in the wall was very mall adat tho te~ttemp8rature the air should react f,lllllsdlatdlJr with the escaping C'.'L I( v@l;g<:~. Bbo - . .ITS 5 ' .,,:c ' L<, ,- a*. 4'-,I A prficrl arwl7sis of the Rb wtrl r moved from the eapde at the coaelu$ion 9'. f , 1.: Cr 3au Bhrn 10 parts psr liillion. IP imamtion OI corrorion of the 1nck1 epciun tht us imuer8.d k th. ~b L.~L~lring t~. -at cmbe iound0 me waifit of the specimen at ' the ceaclumirnr ei IAa experiunt waa the mme a8 that rseorded before immer~%on in tihe Bbo A 'bt.llopr~eexamination of the lupple did not disclose any A rtjloprpbie emmlmti~naf 'the wall of tha Inconel capmale in tho 1,: 1,: * ngfon that ur erpend to Bb liquid (~igure&j6)df8closed general mrfaer raighaning I+ ad intergranular roU8 to a depth of .0025 inches. A band. of' the precipikter I1 '. I awrr mU.1 to tho mrfase at a depth of fram .Ol5 to 0003 incheso A I - porriblo oxpla~ytio~Of thO difference In corrosion of the tub wall and tbt of tho apmcimnt 3.8 that the tubo wall was stressed durilag an andetermined par- ' taoa of ae100 hours by the 110 psi intergel presme, The corrosion of the ' Ineoml by Rb at 1650 may be inoreased if the &conel is Pnaer etseqs, 1' Further evldene to mpport this contention y be seen in ~ig&&%.iWb&kdaha Figure L.5 Inconel Exposed to Liquid Rubidium at 3.6509 for 100 Hours. Specimen was Nickel Plated Following Test, Magnif icationr 100(PC Figure 4.6 frrconel Capsule Wall mpo~to ~iquid ~ubidiua at 16SOaF for 100 Hours. The Capsule waa3 Stressed by an Internal Pressure of 310 psi. Magnification: lOOOX -U6- Figure h.7 Region of Fracture in Incons1 Tube Following Exposure to Rubidium Vapor for 100 Hours at 1650~.Magnification: SOX %hart t Glymria Reg- .. - the psesam oa the Iaeonel fish wall, Thfs area wlais'exposed to I&$ vapm, The metal adjacent ,to the Fracture which was subjected to the highest a'tresaee has been generally af,hcke$ along the grain boundries, It may be generally eon- eluded that the static corrosion of Inconel bp. Rb at 16500~is pot exeqssire if the Ineonel is not simultaneously subjected to high stresstea, . ; ruhidfum in a closed system incorporating a temperatare g~adientme detemilabd By maas of a dpmic loop apparatus ra~~bw21ata-r ia appearance to the ... eoaventiorrrl' "th0lplal harp*, The lmded loop, 5s &am in Figare 4,.$ prior to attaching the thel.Padcouples and resistmcs knacss, The loop was constructed entirely of' Inaanel, The boiler and mpm \ sepsrerf~~eeation ad the, superheated vapor line were of 0,500 iaeh atside diameter tubing dth O,&9 ineh well thicknesss The remainder of iihe loop ma Qf tubing bavfng a 0,250 inch oatside dhaeter and 0,035 ineh uallthiaknees, The tapred sections at the gads of the .500 inch tlibing were f&d bp , awaggisg. The appetr end of the boiler section was left opon to prodhe r .?be loop was placed i9'a drybox and l-ded with 8 to 9 ee; of memna , . , distilled rubidium in a hellam atrosphere. 'Ihia qliantitp ci. mb$diam fi~&d-I$ie loop to the level indicated iri Fig. 4,8, A short sectson Qf mbber lab'iag uasl attacihed to the open tube and sealed with a hose clamp, loop was now rmmd fra .the drybox and the short erectfan of mbber tubing wasl conzpeczted to a 8aeama I gyrr-, ,the hose clamp*remkd, ad the locsp-.. evacakrd, L .-.Uia the va6'tsgll sysbm stell c~ggectedthe dmrging tinbe vas pressed.flafi and crimpedo The vacuum line asrsgiofed and the end of #e t* maled heliare welding, Chro~bel- alumel themoeouples were next spot welded to the matside of" tihe loopo 1Phe location of the therrocouplea and the overall dfnessione of the aeaemblg are shovn in the line drawing, Figme 4,%, A 12 inch claa shell re6istame n;lFnace was installed on the boiler and vapor separator section of the lo~pin the location indf cated on Figure -. This furnace was in~ulatedad the reminder of the loop left We, mom ' current was applied to the furaces the boiler leg rapidly heatad b tlru de- sired tabst tempe~atureb~'% &a %errnocouple located on the supethaated vapor line remained coldo Whrte Lsrt ma rppMed with a torch to %&e ~mdensaeamd aftarceohr mction to famth@% rubidium was molten tho Wpemture .% th6 mporheatud vapor U'xa ~~MMWrose to over 930 OF and tb@ tmpsrrfa99m fa the top of the boilor -d %soar U90 to 12000F0 The ruMcZium cooled ae . . npfd~tin t&e condensor npioo th.t the loop again plugged and circulation . . cW.edo It now appeared that U. &at output of the single fmaewas *not suf- fio%ent to lupplt the hat at,WOtgd be tr~nsferredby the cir&htiag boillng subfdi~srat .& deeired tort baperaturs of 1500°F unless the heat. lsea f n the gyebm msmdUced by in8uhUw0 or addfag another furwaee, At the end sf $he w~~ dy an whfPch the asroakpa -6 brought to temperature the loop was left w3th #a. boiw mbidf urn cbra&tfey at a mimum temperature of 1200@F0 Wdthin an hour the rubidium-%g da(, cMenaer and aftercooler solidiffsd, the beiler t'enperatur* incrba~edand bhe boiler asction operated as a capsule teat . . with a hot zgne tomporature of 15SOF for 15. hours, The next morning a 8 inch clamshell redstaace heater was phed over the center of the supesheatedwpor line and the loop ma insulated by wrapping with .asbestos tape fsom the rubidium exit and of the 8 fwch furnace to the center of the condenses.and aftercooler section. The hale of the loop us now heated to thaw the solidified rubidium, a After a very alight agorugt of heating circulation was initiated and the eqdf- , brium loop surface bmperatures indicated on Figure %@;@@p3.,m@dJ:~~.&@Cb?I~d~ 6-mcx P* Two of the equilibrium temperature vdues indicated are not strict* rccmte since the temperature measurement 4 Inches down frm the top of the boiler. seetion varied sinousoidally with a cycle time 9 Hlinutee and a tobl temprature gradient over the cycle at this loeation of 80°F (from U"bO'to . - 15500~). The surface temperature at a point 3 inches from the base of the boiler leg varied cyclicaly fron 1030 to 10'75OF with the same cycle time. Ib t.apr\c ture cycllag was detectad in the euperheated vapor Une but the tampro~amrsured 3 inches belov the upper end of the condenser log followed the same eph a maximum recorded tmnprature apread of B80F0 This cycling of t~rnpomture-8 not a rmdt of the cyclic control of eleetrfcal power input into ths mm but ws probably brought by the boiling conditions prevailing withim tha loop, .e i After 312 hour. of cireulation under the conditions indicated on Figun 469 tho, loop me cooled, ploe@d in a drybox under a helium atmosphere where it was opened wLth a ,tube eittar, drained of rubidium, arnd sectioned, ~ A stampie of the xwbfdbu~removed fsa the apparatus was submitted to do e, White sf the ANP Analytical Chemistry Dfv%sionfor chemical analgsio, a%a . mnple was alalyaesed for iron, siek.1, and chrdun in an attempt to deterins vhether any ~f the mala conatitue~ltsof Inconsl were being selectively dfmolv~d,~ and for audium as a eheck on th 8~~3ysfs of the vacuum df stilled rubidium tht was .loaded into tibe loop, The following chemical analysis was reported8 iron 100 psrts por mfhlim nickel = lesa than 25 prts per million chromiua laas than 25 parts per dllia sodium - 30Q parta per millfa Since the vacuum distilled rubidium should be fpee of iron it appears that, the iron in the Inconel was selectively df ssolved by the rubfdiu~po This df e- $. aoPutiola attack would be expected t6 occur either in the boiler by the liquid being heatad, ok in the condensor .by the newly .condensed 1iddmbfdfum, In the firmer eesae the %ragawmld not be carried over by the vapor, but would pracipitate fro. the bo%liyifpad and tend to settle to the baa@be of the loop, In the lattar ale $$ vaild be possible for kss 'Cnnsfer 'W (oee.r by precipitation of the if- frs m.lut%emim the rulbidfm as the PJ3qad cooled brr rev$lrag down the c~ndegldaram! tit$br$~~ler,There i~strong e.giaeme tglOt thf sl aodutAm and precilpfta%larn sk $ran bt a very slow rate did occur, A very anal&am@uat of flnelg davidod black P)-@B" was 'removed fromthe baee leg of . . . . %he &oop whim the loop was rinW with alcoholafter the mbidium had been dl&iaud, ThPb powdar; which rsrs ,%nsoZuble'in both aecohol ,and water, uas mamitted to R, & St.ol. for X-ray anhQwi~and although the aitual diffraction iinea could, aot be %dent$fied, excei@v& satterfng of" 'the X-ray beam occurred when . . a coppar target was used, %hfr %e a general indication of 'the presence of. lron or C~&MQS %TRthe spechen, :The'jSo@p was ~eatisnedand pepresrentative f~pecimensof the tubing were momtod, palisbed, and examined mac~tallographica1l.y~The aurface of tha, Inconel lnnp %a Us reqisul @f the Ifyd.d-vapar level Pa Elhe boiler seotisa? is shown fn The comosfon penatretion in this region dfd not exceed ,001 inch and ksin&ergranu,lar, - In the area shown a surface grain has beenspasated from the tub Mll opparsnt1;g as a result of the intergranular corrosfomo No saidenee of corrosion penetration, or measureable amolxlnt of surface srosf oa MAS f ouad in the vertical boiler seetion, ~%Z@f@&031 depicts a represen- 9 tatiae section of tho loop wall 6 inches above the liqnid level, The large yzy.- a. --in eise can be attributed to grain growth 'during the'extended heating at a tsapora ture of appr,oximrtely 150O0FO Very little iadlcaticm of .corrosion of the Inconel could be.detected along 1 the superheated vapor lr%mof the loop ~r in the welds at each end of thia leg, a The maxh surface attrek 3.n ehir leg was .0005 inches and no noticeable eroricm bad occurred, . . . . In tha' condenrer and mfter boolet mction of tho 'loop alight rurfaea ir- regularity to a depth of ,00025' inchar kr noted, Figure &f;fDf-spi:pbhsko- mpb ef the Inconel-rubidiw inWrf.cs at a point spproximrtely 3 .inchor below . - tho bead 8as .the loop saprrrti~the .superheated vapor line adcwenwr and mfter cooler section. lhis m'~lom.'wasexposed t o condensing rubidium, liquid and rapor, which. had been distilled, The slight corrosion may be attributable to - ?. sro*ioi of the Inconel by the rubidium,' or it my be due to preferential leaching'~-. . -. of a 'constituemt of the Inconol followed by recrystallization and grain.botlndary attmek which allowed the ~ll-in. to becorn. beprated from the surface of tho tub, , : Re corrosia attack. 8- k dokctud in the loop in any mgioa below the lfqdd wBfdirn leklo Zb that were expoaed to only liquid-.rubldhm . . bee of fho tapered region $a th. boiler and hpor separator mctiogo It my be tentatin4 eooc1ul.d that the corrosion of c con el by circuk- tang, boiling; wbldia care .be diemissed ao 1nglignificant for operating Ufethei of th. &ir 1UrsIy.to b. ee~bredin aircraft nuclear reactors. It should be pw~ibleto su~c.s8fully =ireula& boiling rub2diwn in an Ineonel systexn at tempratrma and pressures so high a? to be luted by the strength proportiem . . of' the;In=onelo 40.5 Wrtz&&-- QIus&i . - . .- ~~iroxfmatel~,5 cc of Rb was vacuum distilled into a quartz tube having an outside daameter. of 9 mm and an inside diameter of 7' m, Thequartz . . tube containing the Rb was sealed under vacuum, The loaded cgpgule was 13 cm . ' .. . , . long with 1.25 cm of this length filled with Rbo The capsule was then' .>. . sealed in air in an ~nconeltube having an inside diameter of ,5 inches and held 421 a funace at 1650 OF for one .hour, ...... 1. ?._. _ .I., .) ' Upon opening the outer biotedti~e1nconel capsule it was discovered that . . the Rb had reacted completely with the quartz and the quartz had shattered, . . ,,..., its shape but was broken into many fragments, The quarts capsule had.; ... No reaction was noted when the broken capsule was exposed C air. The Rb - I' . . I +he had reacted so dompletcly with quartz tkL no visible reaction ockumed , , .. ."I...... _. when the inner ,apsule surface was washed with alcohol or water, ., . Five distinct color 'ba.ds were observed in an examination of a cross-section ! ; of the quartz capsule, Progressing from the inner wall outward layers of light .I ' browm, light grey, dark grey, golden brown glasses, and unattached transparent quartz were present, All of the layers' were glassy in appearance..and a petro- graphic examSraation by To No McVay, consultant to Ceramic laboratory, Metallurgy Division, ORNL, indicated that the material was of isotropic to the silicate glasses, X-ray analysis divulged that the material was non- crystalline , either amorphous or vitreous, A plane of weakness existed between the clear quartz and the golden brown layer and separation along this plane was in evidence, An attempt to polish a specimen for metallographic analysis failed be- cause .the Rb-silicate glass apparently reacted chemically with the water used in polishing, When left over ni'ght the reaction proeeeded and the accompanying SECRET Y-12930 BOILING RUBIDIUM- - INCONEL LOOP Fig. 4.8. Loaded Rubidium-lnconel Loop Prior to Attaching the Thermocouples and Resistance Furnaces. Fig. 4.8a DIMENSIONS OF RUBIDIUM-INCONEL LOO1 AND LOCATIONS OR THERMOCOUImS BOILI'NG RUBIDIUM - INCONEL LOOP SECRET Y- 13038 OPERATING TIME - 3 12. .HR. MAXIMUM CORROSION PENETRATION - .00 1 IN. . . NOTE : EQUILIBRIUM LOOP SURFACE TEMPERATURES ARE GIVEN Fig. 4.9. Sectioned Boiling Rubidium-lnconel Loop Following Completion of 31 2 Hours of Operation Showing' Operating Conditions and Heater Locati,ons. NI- PLATE 1 Figure 4.10 Rnbidiwu-Inconel Interface in tb Region of The Liquid-Vapor Level in Tim 3oiler Section of The Boiling Rubidium-Inconel Imp. Magnification% 1OOOX E%eMaAqua hgia Figure h.11 Rubidium Vapor-Inconel Interface Representative of _ the Surface Six Inches Above the Liquid Level in the Vertical Boiler Section Magnification: 1000. Etchartt Aqua Regfa Y-3.3039 UNCLASS IFIQ] N1 PLATE I r xgure.4.12 Rubidium-Inc onel Interface The 'Region Exposed to Condensing Rubidium. Magnification: lOOQIE Etchant: Aqua RogOa : ;iY;;,- !a+=,=. -kL J.1*; E a- NI PLATE I Figure 4.U Rubidium Liquid-Inconel Interface At A Weld Located at The Base of The Tapered Region in The Boiler and Vapor Separator Section. Hagnificationt 5CUX Etchantt Aqua Regis axpnsion fractured the @astic mod; when. the remainder of the capsule, that had been stored in a jar in air, was obser~ed.afkra period of 3 weeks it. .was . . . ', discovered that the colored glass had expa,nded and separated from the clear .... . quarta and was now dark brown in color. and so longer glassy but with a dull sur fa ci3 , / . . ...... 1. Ugdd Mmtals' Handbook, NAVEXOS pi 1D) (B-), J-1952 : ... . 2, Cryrt.1 Structures, Wyckoff, Vol I, 1951 DETEBENATION OF SODIUM EJY THE FLbME SPECl'IBlPHOTOMETErR ... Stock solution . . ... - 1000 ppm of Na. ' Prepare by dissolving 2.5.b g . of :;NaCl in:water'' And ...... diluting to 1000 'k with water.'...... ... Prepam, as follows ' . .' ' ,'. ' :Na, pe,' ...... r . ' .. . . . ' ' 100 ml. 5tobk solution diluted to, 1060 qil '. 10.0 ' . ' ..2ml 100 ppm Na solution diluted 't.0.100..ml. .... : 2 b ml~l00ppm Na s.olution diluted. to. 100 .ml,. .. : b , 6 ml 1.00 ppm Na soiution ;diluted to 100.,ml. . . 6. .."...... ,"'. ' 8 ' ml 100 ppm N& solution dilutbd to,100: niL i . ' : . ' . 8...... 10 ml 100 .ppm ~a solution' diluted...... to '100 ml " . : .lo : . :. ' ... : ...... :. ( ...... , . .( . ,...... -.. . ., ...:...... Equipment . .2 ...... '...... ,...... Beckman .~odel . DU ~~ectro~h&tom6ter.,...... trithI;.~e,;,lanai . NO:. . ,9200... f lam6 photb;:. , ...j ...... : . . . . ". ' .. . . meter attachment, ...... i ...... Procedure . . .. . , ...... , . . I, Preparatson of Flame Photometer- . . ; ...... - ...... , ...... " (Check for closure of oxygen anfuel gages -of .fli& photometer, before. . s ...... I.. and after using photometer), . ' ...... 1, Set oxygen tank gage, at 5.pounds. pressure o ,'. . . , . 2, Set hydrogen tank gage so that it is just. off the zero mark? , i. ~ I 3, Light 'a match and quickly light the burner; '('~ee~water in the . . cup under, the burner at all times when the burner is on) ' ... h, Make final adjustment of pressure of ,oxygen at 20 pounds pre'ssure ~ I and hydrogen at 6. pounds press- o The ,flame photometer oxygen' ~ and hydrogen gages indicate these IIo preparation of Standard C-me lo. Set the resister on Noo 2 positiono 2. Turn photomultiplier box in'. "onn and switch on Noo 3 ...... , , . . . . . position (350 volts), . . .. '...... :. . . P~U to in , ; .. . . 3 :out phitotube lamp. hob. set. .photoiiatiplier tuba ...... proper, position, 4. Turn sensitivity s*tch to :'b,,.l.iensit'ivity 'setting. ,, ...... 5. Set the wavelength ?tale at 58%y.~...... : :.. .- . . I...... ' ...... : ...... 6; ..Set the sfit width.~~b.&t'.~~~$~.~~:~:.:.,':....'.; ...... :" '..'.. :: .;..:.. ...: ..,'.: ...... :. .. , ...... 7. Zero null pbint needle 'bi'ad~ustin~.the dark current hob...... , 3: . , 8. Pour approximately 4 ml of... the standaid.... :d~,olition containing 1.0:ppm . ' . . . . ., ...... ,...... ,. . . of Na into a : 5 ml :cup aid place-'under th=':hu$nii by means if thd , ...... ' , ...... , . ... ' elevator lever. , ~urn~hototube. . 'switch. to ilo@l posit&pn. "...... :...... , . . , ...... 9. While the N= is burnirig'i set %::Tscale' .it-35 and zh'the ' null'. ,: - ..':. .I' . .' . . .I . . . -. . . , point 'needle by adjusting the' sens,itidycontrol .knob (upper ...... -Left hand corner) ...... , . 10. T.urn off the phototube .switcho :...... '...... . ., 11. Pour 4 ml of the standard:'solutio~. . containing 2 ppm of Na into , .,. ... a 5 ml cup and place. under . .$he':burnerby'meak of the elevator . . ..I lever, 12, Zero the null point needle by adjusting the dark .current knob, Uo Turn on the phototube switch and =era the null point needle by . . ... adjusting 'the % T hob, ...... 8. 14. Turn off the phototube switch ;and reoord the % To , . . 15. Repeat steps ll thru.a for. t'hestandard solutions containing ., . . b9 6, and 8 hprn of 'Nab ' . .'; . . 0. 16. Prepare a standard calibration..curve by plotting Sg T. as the . . ordinate versus ppm of Na as the abscissa' an linear graph paper. .III. Preparation of the. Se- . . . . A* Ammonium Carbonate Solutions 1. nl Transfer a 5 ml aliquot of the carbonate solution to a 10 A . . . . volumetric f1as.k...... 2. Neutralize the solution. with =oncentrated HC~,(~dd dropvise 4 ...... a. with gentle sh.,&ng. of the flask after each drop of HC~., The ...... _...... sample isneutralized when the df. HC1 no." . .: . .', '...... '3,. . . gas evolution, . . : ..., .: ...... 3 . Dilute to.:volume with water?. . ': . ...' . . ' ...... J ... ' : ' Take an aliquot of this solutioi and '&lute to a volume whiih' ., . . 4...... will contain 2 to ioygof ~a per:m$...... : . ... , . Be Solid Samples ...... ,, . .. . .% . ... ,' . ' '. ' 1 Weigh out a sample which .will; 'contain..... at,l;.as't ;. . -100pg .of Na , . , " ., ( . , ./ '. . :...... : ...... 2 0 ~issblvein '~$3:and. add -the. solution .i$.:ju&,acidi...... 101,until . . ., . . . . ,...... 2 ., . . . i: , ...... 3 . Dilute the solution to a suitable 'v6lume in a v~lme&-ic flasko:...... 4. Take an aliquot of this solution and dilu&i to a volume which . . ' , will contain 2 to 10 )lg of. ~a'per ml...... , . . IVo Determination of Sodium in .the S'ample ...... 1. Repeat steps 1 thru 4 .under, nPreparetion....of. Flame". ... 2. Repeat steps 1 thru 10 under.,. ~~r$&katioiof the Standard curve ... . . 3. Pour approrimately. h mlof !, the' g ample solution into a 5 ml cu$ and' pZace under the burner by means of the e'le,vator 1eve.r. ... 4. Zero the null pdint needle by adjusting the dark current hob. . . . . 5. Turn on the phototube switch. and zero the null point needle by adjusting the $ T knob. . . 6. Turn bff the phototube switch and record the $ To- 7. From the standard calibration curve, detewne the pg of Na per ml I corresponding to the observed $ T. 'RecoPd this value. . . Let R=pgNa perml as determinedin step 7 . . \ ' D,- dilution factor . . W ='weight of the sample, g . - . . then PL x D =pg Na per ml in'seie(for solutions)- ...... also, R x D pg Na per g in sample (forsolids) : . . ' d ...... , I w . . . . Stock Solution . . > .. , . 1000 pprn -of Ko Prepare by dissolving '19912 g of ... KC^ QI water and , diluting to a000 ml... with water, Standard solutions ...... - .- ...... ,...... Prepare as follows: . . . . . , ... . . -...... : .: .. , ...... 100.ml stock solution dilutkd tb 1000 ml : ' .,':. . LOO , 2 ml 'LOO pprn K soiutZon diluted to.100 'ml' . 4 ml 100 pprn K' solution diluted to 100,ml . 2 " 6 .ml'iOO pprn K solution.diluted to..lOO ml . . 6 8 ml 100 pprn K solution diluted foclOO ml 8 10 ml 10'0 pprn K solutf on diluted.to 100 ml 10 Equipment - Beckman Model ~~.Spectrophotometerwith ~a&nkri Noo 9200 flame photo- I - meter attachment, ' . . Procedure . . I Preparation of Flame Photometer . . . . I I (Check for closure of oxygen and fuel gages of flame photometer before . 'I . . I + I .and after ,using photometer) I .. 1, Set' oxygen.tank gage at 5 pounds pressure, I 2. 'Set hydrogen tank .gage so tha-6 it 3s.just off the zero markd - . 3. Light a match and quickly light the6burnero (Keep water in the cup under the burner at all times &en the burner is on,). . . . . - 4.. Make final adjustment. . . . of pressure bf oxygen .at . 20 pounds pressure . . . . and hydrogen at 6 pounds pressure, he .flame photometer oxygen ...... , . . and hydrogen gaps indicate these,pressws...... I PreparPtionStandardCurv-= ' , . , ...... 1, Set the resister .on NO, 3.positione ' . . 2, Check to determine that .the photomultiplier box.is .in i!offll ...... :...... position, ...... 3. Push in phototube lamp knob:to &St red-sensitive phototube in .: ,.. '. .., . . proper position...... >...... , ...... 4. Turn sensitivity switch 'to 0.1 s&nsitivitysetting...... 5 Set the wavelength scale at ' 767 yo ...... 2-: 6. Set ,the slit 'width knob at 0.070 mm., ... 7. Zero null point needle by adjusting the dark current knob. .. , 8. Pour approximately 4 ml of .the' standard soluti6n cdntaining 10 ppm ,, of K into a 5 ml cup and place unhir the burner by mbak of the . . elevator lever, Turn phototube switbh to.itanw.'position, ... . . 9. While the K standard isburning; set % T scale at.75 and gero the .... I null needle by adjusting the', . sensitivity cdntrol hob , .' (upper left hand corner). loo Turn off the phototube switch. 11, Pour, 4 ml of the standard solution containing 2 ppm of K into a - -. 5 ml cup and place unde:r the burner by means of the elevator lever. . . I. 12, Zero the null point needle by adjusting the dark current knob, a . . U, Turq on' the phototube switch and zero the null point needle by It 1 adjuiting the ,% T knob. I 14. Tprn off. the phototube switch and record 'the % T. 15. Bepeat steps 11 thru Ik for the standard solution9 containing I . , ks 6, and 8 ppm of.Ko .:, , . 16. Prepare a standard calibration curve. .by plotting % T as the ./. ... ordinate versus ppm of K as the abscissa on linear graph paper,. .. preparation of the Suapls B. A. Ammonium .~arbo'mt'~Wlutions ...... 1, Transfer a S'ml aliquot of the carbonate solution to a l0'rrrl volumetric fh-sko 2. Neutralize the solution with, concentrated HClo .(ddd dropvise , -.. with gentle shaking of .the flask~aftera'each:dropof HClo The, sample is neutraiz6d when the additibn of HC1 produces no gas evolut iono 3* Dilute to volume with watero 4. Take an aliquot of this solution and dilute to a volume which will contain 2 to 10 g of K per ml. Y .- Be. Solid Samples I 1 Weigh out a sample which will contain at least 100~of Ko 2. Dissolve in H20 and add HC1 until the solution is just acid. ' ' I . . I 3. Dilute the solution to a suitable .volume in a volumetric flask, I I Take an aliquot of this solution and dilute to a volume which ', I be . . . . . will contain 2 to 10 pg of K per ml. ' - . ... IV. Determination of Potassiuminthe Sample . L I lo Repeat steps 1 thru 4 under, "Preparation of Fl.me,n ',2, &p,eat steps 1 thru 10 under, npreparation of the Standard Curve." 3, Pour approximately 4 ml of the sample solution into. ,a 5 ml cup and i ,Q place under the' burner by means. of the elevator lever, I - Lo Zero the null point needle by adjusting the dark current knob, 5. .Turn.on the phototube switch and zero the null .point needle by . . adjusting the % T knob. - _I ... 6. Turn off the phototube switch and mcord &he $ To 7, From the standard calibration curve, determine the P g of K per ml ' , corresponding to tho observed $ To Becord this va'lue, let B =pg K perml as deterhined in Step 7 . 'D =,dilution -factor : .. I W z weight of the sample, g then R i D=)lg per ml in sample (for solutibns) .' , also, -R x D = pg K per g. in sample (for solids) W @TETEWATIONOF HJBIDIUM BY THE FLAME SPECWPHOTOMETER ock Solution ' 1000 ppk of Bb. prnpam by dissolving 1.b5 g of BbCl in water and diluting to 1000 mlo with water, Standard Solutions Prepam as follows t 100 ml stock solution diluted to 1000 ml 100 5 ml 100 ppm Rb solution diluted to 100 ml 5 10 ml 100 ppm W solution diluted to 100 ml 10 15 ml 100 ppm Rb solution diluted to -100 ml 15 * . . 25 ml 100 ppm Bb solution, .diluted to 100 ml 25 . . Equipment Beckman Model DU Spectrophotometer with Eeckman No. 9200 flame photometer 8. attachment, Procedure I, . Preparation of Flame Photometer. . . (Check for clw- of o-n and fuel gages of flame phot6nst.r . . before and after using 'photometer) I 1, Set .oxygen tank gage at 5 pounds pressure.. .. 2. Set hydrogen tank gage so that it is just off the 'zero mark. 3,, Light a match and quickly light the burner. (Keep water in the cup under the burner at all times when the burner is. on,), . . ~I. 4. Make final adjustment. of pressure of oqgen at 20 pounds . . and hydrogen at 6 pounds pressure. The flame photometer'oxygen, . . ! and hydrogen gages indicate these pressures, 11. Preparation of Standard Curve 1, Set the resister swit'ch on No. 3 position, 2. Check to determine that the photomultiplier box is in nbffn position...... 3, Push in phototube lamp knob to set red-sensitive phototube in. , , proper position, 4, .Turn sensitivity switch to Ool sensitivity settingo ' . ,. 5i set the wavelength scale at 795 9. , ., . 6*. ..set the el%t..width 'hob at 0,.12 mm. . . ,'I* .Zem null .point qegdb 'brp 4dgpglthg .W~)~:.dark: current knobo . . ;... :, .. !';,. .. ,..$ .... .:::::. : ... :,: " ., .-& .:.+:... - 8, Po& Ippx-oxiuiate~1) ~uluf iha: standard solut'iee cofiurinjng 25ppmofBbintoa!5mlcupa~dplaceunderthe. . burner-by. ' means of .the elevator lever, Turn phototube switch to "ont8 position, . . . . ., . . . 9, While. the 'Rb standard is burning, set % T scale at 75 and serb' the ...... null point needle by adjusting the sensitivity control knob (upper left hand corner). 10, Turn off the phototube switch, llo Pour 4 ml of the standard solution containing 5 ppm of Rb into . . o 5 ml cup and place under the burner by means of the elevator .'. :. - ., lever, ... , 12. Zero the .null point needle by adjusting the dark c,urrent knob., ..'... U, - Turn on the phototube switch and zero the -null point needle. by adjusting .the $ T knob, . . 3.4. Turn off the phototube switch and record the To 15. Repeat steps 11 thru 14 for the standard 'solutions containing 10 ...... : ...... '. , ...... and 15 ppm if Rb, 16. Prepare a standard calibration curve .by plotting 8 T as the ordinate versus ppm of Rb. as the abscissa on.'linear graph-papero ...... ' . . I11 , Preparation of the Sample . . . . .'' A. Ammonium Carbonate Solutions 1. Transfer a 5 ml aliquot of the carbonate solution' to a ." . . 10 ml volumetric flask, - ' 2, Neutralize the solution with concentrated HClo , (.~dddropwise with gentle shaking of the flask after each drop of HC1, The sample is neutralized when the addition of HC1.produces no gas evolution, 3. ,Dilute to volu& with water, bo Take an aliquot of this solution and dilute to a volume which will contain 5 to 25 yg of Bb per ml. - B, 'Solid Samples- .. 1. Weigh out a sample which will contain at least 250~of Rb, 2. Dissolve in H20. and add HC1 until solution is just acid. ._.e. -. . . 1 .' 3, .Dilute' the solution to a suitable volume ins '.vol~e'trie~flask. . . ,* b.O Take an aliquot of this solution and dilute to a volume which - .... will contain 5 to 25 pg of W per m~...... IV', Determination of Bubidium'b'tlie'Sample l.*:&peat steps 1 thru 4. under, "Preparation : of Flame .gl 2, Bepeat steps 1 thni 10 undeP, "Preparation of the Standard Curve." I , 3. .POUP approximately 4.ml of the sample solution into' a 5 pll cup and . . . place under the burner by means of the elevator lever. , 4. Zero 'the null point needle by adjusting the ':dark :c&rcint hob. . . 5, Turn omthe phototube switch, and zero the null point needle by . ' .. . . adjusting the $ T.knobe. .. , 6. Turn off the phototube. . switch and rircord- the .% Po . 4. . . , . ... 7; From the standard calibration curve, determine the pg of Bb per , ml corresponding to the observed % To &cord this va&. . . ., .. 8, ~alculations . . Iat ~=pg~b per ml as.determined in step 7. ' ':, D = dilution factor W c&ight of the sample, g then R x D s 'Rb .per ml in .sample (for, solutions'.) P .', also, R x D ,pg 'Bb. per g in sample (for solids) W I ~~~NATIO~,-QF CESW BY THE FJiAME SPECTIROPHQTOPIETFZ BOO0 ppm of Cs, Prepare by dissolving 10267 g of CsCl water and diluting to 1000 nil with water, . . - - .... .- I ,p!. I ...... t...... ~tandalklSolutiogs Prepare as follows s Cs, .ppm . . ,100 ml stock solution diluted to 1000 nd 100 ml 5 ml 100 ppm Cs solution diluted to 100 5 .* PO ml 100 ppm Cs solution diluted to I00 ml 10' . . 15 ml 100 ppm Cs solutfon diluted to. 100 ml 15 ' . , 25 ml 100 ppm 'CS solution diluted to 100' ml .25 Equipment Beckman Model ~~~~ectro~hotometerwith B6ckman.No. 9200..... flbe '~., . . photometer attachmento Procedure . . 1, Preparation of Flame Photometer . . . ' (Check forclosure of oxygen and fuel gage? of flame , before and after wing photometer) . . , 1. Set oxygeli tank gage at 5 pounds pressure, . . . . 2. Set hydrogen tank gage so that it is just off. the zero mark, . 1 '" 3. Light a match and quicklylight the burner. (Keep water. in the cup under the burner: at all times when the burner is on.) be Make firial adjustment of pressure of oxygen at 20 pounds pressure arid hydrogen at 6 pounds pressure. The Plane photometer oqpn . '. and hydrogen gages indicate these pressures, 11. Preparation of .Standard Curve lo..- set the resister switch on Noo 3 position, 2, .Check . to determine that the photomultipiier box is .in ttofftt. . . i Push in phototube lamp knob to set red-sensitive phototube in 3 . -, proper posttion, 4. Turn sensitivity switch to 0.1 sensitivity setting, . Set the wavelength scale .at' 052 6. Set the slit width' knob at OOl3mn...... ... 7' Zero null point needle by adjusting the ,dark c-nt knob; ' 8. , Pour approxiniately 4 ml of the standard solutibn containing. 25 ppn . . of. Cs into a 5 ml cup and; place. under 'the burner by means . of the elevator lever. TUGphototube. switch to "on" , .positidno . . 9. , While the Cs standard is burning, s& .% T scale. at 75 ,and zero . : . . ., . . the , null. point needle ,by adjusting the sensitidty control hob (upper left h'and corner ) , , , 10. Turn off the phototube switcho ' ' ... 11, Pour 4 ml of the standard solution containing 5,'ppm .of ..Cs into a 5 ml cup and place under the burner by means of the elevator lever, I \ 12, Zero the null point needle ,by adjusting the. dark burreit knob, ' ...... \. 13, Turn on the phototube switch and zero the null point needle by I. adjusting the $ T knob. . . 140 Turn off the phototube switch and record the 5. To ...... 15. hieat steps 11 thru 14 for the standard solutions containing . . 10 and 15 ppm of Cs, 16. Prepare a standard calibration curve by plotting $ T as the oldinate versus ppi of Cs as the. abscissa on linear graphpaper. X1I0 Preparation .of the Sample A* honium Carbonate ?io-iutions lo Transfer a 5 ml aliquot of. the carbonate solution to 'a 10 ml volumetric flaskb . . . . I 2, Neutralize the solution with concentrated HCL, (~dddropwise \ with gentle shaking of the' flask after each bop of HCl, The * sample is neutralized when addition of HC1 produces no gas evolution, ) . . 443- ! 3. Dilute to volume 4. Take an aliquot of this solution and dilute to a volume which will contain 5 to 25 P g'of Cs per d. B. Solid Samples 1. Weigh out a sample which will contain at least 250pg of Cs. 2. Dissolve in H20 and add HC1 until solution is just acid, 3. Dilute the solution to a suitable volume in a volumetric flask. 4. Take an aliquot of this solution and dilute to a volume wfiich will contain 5 to 25pg of Cs per ml. ire Determination of Cesium in the Sample 1. Repeat steps 1 thru k under, Itpreparation of Flameett 2. Repeat steps 1 thru 10 under, Vreparation of the Standard Curve." 3. Pour approximately 4 ml of the sample solution hto a 5 ml cup and place under the burner by means of the elevator lever. 4. Zero the null point needle by adjusting the dark current knob. Se'Turn on the phototube switch and zero the null point needle by adjusting the $ T knob. 6. Turn off the phototube switch and record the % T. 7. From, the standard calibration curve, determine thep of Cs per ml corresponding to the observed $ To Record this value, 8. Calcaation: Let R ----pgCs per ml as determined in step 7 I D .: dilution factor W = weight of the sample 9 then R x D = pg Cs per ml in sample (for solutions) d also, R x D - pg Cs per g in for solids) --W Series TA I. Copy No. .... 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