-._. -..—..-—-- National Academy v’” of Sciences Iational Research Council NUCLEAR SCIENCE SERIES The Radiochemistry of Niobium and Tantalum -—– J-.’ COMMITTEE ON NUCLEAR SCIENCE L. F. CURTISS, Chabman ROBLEY D. EVANS, Vice Chairman National Bureau of Stawiarda Massachusetts Instituteof Technology J. A. DeJUREN, Secre&wy WeMnghouae Electric Corporation C. J. BORKOWSKI J. W. IRVINE, JR. Oak Ridge National Laboratory Massachusetts Instituteof Technology ROBERT G. COCHRAN E. D. KLEMA Texas Agricultural and Mechanical Northwestern”University College W. WAYWE MEINKE SAMUEL EPSTEIN University of Michigan California Instituteof Technology J. ,J. NICKSON U. FANO Memorial Hospital, New York National Bureati of Standarde ROBERT L. PLATZMAN Laboratoire de Chimie Physique HERBERT GOLDSTEIN Nuclear Development Corpratlon of D. M. VAN PATTER -rica Bmtol Research Foundation LIAISON MEMBERS PAUL C. AEBERSOLD CHARLES K. REED Atomic Ene~ Commission U. S. Air Force J. HOWARD McNHLLEN WfLLLAM E. WRIGHT National Science Foundation Office of Naval Researoh SUBCOMMITTEE ON RADIOCHEMISTRY W. WAYNE MEINKE, Chairnuzu HAROLD KIRBY Univer.ai@ of Michigan Mound Lahratmy GREGORY R. CHOPPIN GEORGE LEDDICOTTE Florida State University Oak Ridge National Laboratory GEORGE A. COWAN JULIAN NTELSEN Los Alamos Scientific Laboratory Hanfoni Laboratories ARTHUR W. FAIRHALL ELLIS P. STEINBERG University of Washington Argome National Laboratory JEROME HUDIS PETER C. STEVENSON Brookhaven National Laboratory Universi@ of California (Livermore) EARL HYDE LEO YAFFE Universi@ of California (Berkeley) McGill Universi~ CONSULTANTS NATRAN BALLOU” JAMES DeVOE Naval Radiologic@ Defe,pseLaboratory Univer.9i@ of Michigan WILLIAM MARLOW National Bureau of Standarda CHEMISTRY The Radiochemistry of Niobium and Tantalum ELLIS P. STEINBERG Argonne National Labo?’atovy 97OO South Cass Avenue Argonne, IiWnois t“ August1961 z s PRO‘=‘k, Subcommittee on Radiochemistry National Academy of Sciences—National Research Council Prfntedin U6A. Price s0.75.AvailablefromtheOfficeofTechnical services,DepwtmentofCommerce,Washington25,D.C. FOREWORD The Subcommittee on Radlochemlstry Is one of a number of subcommittees working under the Committee on Nuclear Science wlthln the National Academy of Sciences - National Research council . Its members represent government, industrial, and university laboratories In the areas of nuclear chemistry end analytical chemistry, The Subcotittee has concerned Itself with those areas of nuclear science which tivolve the chemist, such as the collec- tion emd distribution of radiochemlcal procedures, the estab- lishment of specifications for radlochemically pure reagents, availability of cyclotron time for service irradiations, the place of radlochemistry in the undergraduate college program, etc. This series of monographs has grown out of the need for up-to-date compilations of radiochemleal information and pro- cedures. The Subcommittee has endeavored to present a series which will be of maximum use to the working scientist and which contains the latest available information. Each mono- graph collects In one volume the pertinent Information required for radlochemlcal work with an lnd~vidual element or a grotip of closely related elements. An expert In the radlochemlstry of the particular element has written the monograph, followlng a standard format developed by the Subcommittee. The Atoplc Energy Commlsslon has sponsored the prlntlng of the series. The Subcommittee Is confident these publications will be useful not only to the radlochemlst but also to the research worker In other fields such as physics, biochemistry or medicine who wishes to use radlochemlcal techniques to solve a speclflc problem. W. Wayne Mehke, Chairman Subconmdttee on Radlochemlstry iii INTRODUCTION CONTENTS I. GENERAL KEVIEWS OF THE INORGANIC AND ANALYTICAL CHEMISTRY OF NIOBIC?4 AND TANTALUM. 1 II. GENERAL REV7XWS OF THE RADIOCHEMISTRY OF NIOBIUM AND TANTALUM .Z . 2 III . TABLE OF ISOTOPES OF NIOBIUM AND TANTALUM . 2 IV. REVIEW OF THOSE FEATURES OF NIOBIUM AND TANTALUM cHEMIsTRy OF.CHDF INTEREST To RADIoCHSTS . 4 1. NETALLIC STA!FE . 4 2. SOLUBLE SALTS . 4 ‘3. INSOLTJB.LESALTS . 4 4. BEHAtiOR OF~ACER QUANTIT12?S. 7 5. COMPLEX IONS . 8“ 6. SOLVENT EXTRACTION BEHAVIOR . 8 7. ION EXCHANGE . 15 v, SAMPLE DISSOLUTION AND INTERCHANGE WITH CARR~ . 19 VI. COUNTING TECHNIQUES . .. 00.. 19 VII . COLLECTED PROCEDURES . ● . 21 The Radiochemistry of Niobium and Tantalum ELLIS P. STEINBERG Avgonne National Laboratory* 9700 South (%zss Avenue Argonne, li!t?inois I. GENERAL REV~WS OF THB INORGANIC AND ANALYTICAL CHEMISTRY OF NIOBIUM ‘AND TANTALUM nThe ~ lYtiCal Chemi Btw Of Tantalum and Niobium, - W. R. Sahoeller (Chapnan and Hall, Ltd., London, 1937) . ‘Analysis of Minerals and Ores of the Rarer Elements, u W. R. Schoeller and A. R. Powell (3rd ed. ~rlffln, London, 1955). Chap. 15 In “Chapters In the Chemistry of the Less Famlllar Elements,” B. S. Hopkins (Stlpes Publ. Co., 1940). ‘Tantalum and Niobium,” Q. L. Miller (Academic press, 1959). “Analytical Chemlatry of Nloblum and Tantalum,n R. H. Atldnson, J. Stelgman, and C. F. Hlskey, Anal. Chem. 2A, 477 (1952). m“che~~al Elements and their mmpoumls)m H. V. Sl@W~CJC (Oxford Unlverslty Press, 1950), Pp. 804-853. “Annotated Blbllography of the Analytical Chemistry of Nb and Ts,* Jan. lgs5-June 1953, F. Cuttitta, 13eol. SUI’VeYBulletin 1029-A. (USWO, 1957). *Operatedbythe Urdversityof Chicago under ContractW-3 l-109-eng-38. 1 ‘Eeaearoh on the”CcmpoundEJ of Nioblwn and Tantalum, ” J. C. de Narlgnac, Amn. ohlm. (Phys.) g, 5 and ~, 249 (1866). II. GENERAL REV~S OF ~ RADIOCHEXIWIRY OF NIOBIUM AND TANTALUU D. N. Hume prepared a pre Mmlnary review of the radlochem - 10try y~:Bomp.....,or the,,.. masm.....“f!lm~n,. produot. elqenta ,lR 1945, but It was not publl~hed. Some material from that review has been. .. incorponted In the pre8ent. mu-vey. me followlnz revlewe con- tain infomatlon on radlochemlcal methods” for a nmiber of ele- mentO: .. H. L, Mneton and J. Mlskel, 9Radlochemlcal Sepamtlon Technlcluem,m Axinual Review of”Nualeati Science q, 269 “(1955). W. i. Heinke, ‘NUcleotics* “-l. Chem. ~j 104R (1%0) . III . TABIE OF.IS07R2- OF NIC@IllM @ TANTAIJJM IBotope Hair-LLfe Type of Decay Method of Frepa&lon O.eh B+ Nb(p, p4n); Zr(p,xn); Bi81 (612,4n) mm 1.9h p+” &3m ,. 240 IT HOW decay 14.6oh in?” .. P+ z#(d,2n); HoW(d. a); . Plo(y,pn) ~glm 64d”” IT Z#(d,n); Hog4(d,an) N# long Ec Z#O(d,n) #2m 13h Ec ~93(pJpn) Nb9’ lo.ld EC, no 13- Y(&, n);Zr(pn, );~(yJn)j Nb(n,2n); Nb(d,T);Mo(n, p); Ho~4(d;=) “ *93m My IT Z#3decay; Nb93(n,nl) ~94m “IT 99+$ Nb(n,y),; Nb(tl,p) 6.6m p--o.ls 2 TABLE OF ISOTOPES OF NIOBIUM AND TANTALUM (cent’d ) 180tOpe Half-life TY!Pe of Decay Method of Prep~tiOn ~94 1.8X104Y sp act p-,no EC Nb(n,7) 97 ~95m goh IT Nuclear flsdon; Mo (d,a); Zr95 decay ~95 jbd @- nuclear flsslon; ?fo(d,a) Zr95 decay ~r96(p,nl ~% 2j.35h P- ~098(y,pl; ,zr97 ~97m 60S IT decay ~97 72.lJn P- Mo(n,p); Mo(Y,P); nu- clear flaalon ~98 ~098(n,p); ~oloo(d a); 51 .5m P- J nuclear flaslon ~oloo N%gg 2.4m P- (Y,P);nuclear fis- sion 176 8.Oh EC Lu(a,3n); Ta sPallatlon; 73m #76 decay ~177 5jh EC Lu(a,2n); Iu(a,3n); Hf(P, 177 n); Ta spallatlon; W decay Ta178 2.lh EC - 97!%, P+-3% Lu(a,n) ;Hf(P,n);Ta(p,P3n) Ta 178 178 9.35m EC 9ti, P+==% Hf(p,n); W decay ~179 +OOd EC Lu(a,n) ;Hf(P,n);!M(p,P2n) Talaom ~181 8.15h (n,2n);Ta181(y,n) 182m Ta 16.5m Ta(n,’y) 182 Ta 115.ld Ta(n,y) ;Ta(d,p);W(d,a); W(n, p) Ta183 5.od P- W(n,p);W(Y,P); M(nJpn) ~184 #84 8.7d P- (n,p) ~185 W186 5om !3- (YJP) Ta186 10.5m r3- W(n,p) 3 IV. REVIEW OF THOSE FEATURES OF NIOBIUM AND TANTALUM CHEMISTHY OF CHIEF INTEREST TO RADIOCHEMISTS 1. The Metallic State Nloblum and tantalum are very almllar In their chemical and physical propertle6. The metals are dlfflcult to obtain. Niobium maY be prepared by reducing the pentoxlde with aluml- num thermlte and heating In vacuo to drive off excess alumlnum. Tantalum Is best prepared by reducing B fluorotantalate (e.g., ~TaF7) wlthan alkali metal and purlfled by heating In vacuo In an electric arc to volatilize Impurltlea. Both are hard, grey metals with high meltlng points; niobium melting at 1950”C and tantalum at 2800”C. They absorb hydrogen and react wltk halo- gens, carb,on, oxygen and nitrogen at high temperatures although nloblum ccmblnes only slowly with oxygen. Both tantalum and niobium are very resistant to chemical attack, only HF among the acids having any action on them. Aqueous alkalies do not attack the metals, and fused alkalies do so only slowly. 2. Soluble Salta P&ntavalent Nb and Ta form no simple cations In aqueous solution and exist only In the form of complex Ions. Nlobio ancl tantallc acddsare very weak and are readily hydrolyzed. The ortho’nlobates (e.g., Na#b04) and hexanlobates (e.g., ~Nb6019) are soluble In water. The alkaline hexatanlatea are the only readily soluble tantalate6 known. The only important valence of Nb and Ta Is +5. Polaro- graphic reduction to the +3 and +4 atatea In oxalate and tar- trate” solutlona has been demonstrated by ElSon. ‘1) The reduced libsolutions exhlblt a half-time for oxldatlon in alr of 10-15 minutes , while the corresponding Ta solutions exhibit ti.meeof the order of hours. 3. Insoluble Salts The most characteristic compound of both niobium and tan- 4 talum Is the very Insoluble pentoxide which Is dissolved neither by acids nor bases In the absence of complex forming Ions. The hydrated oxides are precipitated when acid Is added to a solu- tion of a nlobate or tantalate.