DOCSLIB.ORG

Formation of Silver Sulfide in the Photographic Image During Fixation

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Formation of Silver Sulfide in the Photographic Image During Fixation JOURNAL OF RESEARCH of the National Bureau of Standards-C. Engineering and Instrumentation Vol. 4C, No.1, January- March 1960 Formation of Silver Sulfide In the Photographic Image During Fixation Chester I. Pope (October 23, 1959) . A photo.graphic s!h:er im~g e is made ,Permanent (fix ed) aft~r development by bathing It 111 a solutIOn contall1lng thIOsulfate whICh forms a soluble tlllosuifate complex with the residual silver halide. Some of the sil ver in the image is sulfided by the thiosulfate during ~ xat io~. The p~rpo se of this study was to determine the amount of sulfiding of the silver III the Image dunng fi xatIOn of film and paper. The amount of the silver reacting depends on the type of t he light-sensitive layer. Also, during bleaching, the residual thiosulfate in the film or paper reacts with silver in a potassium dichromate-sulfuric acid bleach bath to form silver sulfide. For one paper, it was shown that the amount of silver sulfide which was formed in the bleach bath increased with the increase of the concentration of the residual thiosuifate in the paper. A procedure was developed for the reduction of silver sulfide in an emulsion layer to silver so t hat the silver sulfide may be determined in terms of the optical density of the silv l' deposit. The use of hypo eliminators was investigated and a test pro­ cedure was found for testing the effectiveness of hypo eliminators. A smaH amount of potassium iodide added to the fi xing bath was found effec t iv e in preventing most of the sulfiding of the silver image during fi xation. 1. Introduction silver sulfide formed in the bleach bath for one paper. A third source of silver sulfide may be traced to the A photographic silver image is made permanent residual silver thiosulfate complex and thiosulfate (fixed) after development by bathillg it in a solution which have not been removed in the washing process containing thiosulfate which forms a soluble thio­ but have reacted during storage to form silver sulfate complex with the residual silver halide. sulfide. This silver sulfide is present before and Some of the silver in the image is sulfided by the after the silver has been bleached. The silver thio­ thiosulfate during fixation . The permanence of the sulfate complex eventually decomposes Lo forl11 silver image in processed film and paper is I'elated Lo silver sulfide. The residual thiosulfate, because of the degree of sulfiding of the silver in the image which its labile sulfur, reacts with the silver in Lhe image takes place during fixation and the amount of silver to form silver sulfide, especially at high relative thiosulfate complex and thiosulfate which remain humidities. The effect of excessive sulfiding of the after the washing process. The purpose of this silver image first appears in the areas of low sil ver study was to determine the amount of sulfiding of density, the highlights, causing the image Lone to the silver in the image during fixation of film and become brownish. Eventually silver sulfide, itself, paper. A brown stain or "ghost" image remains may bleach, particularly at high relative humidities when the silver in an image is removed by most and in the presence of excess salts which have not bleaching solutions [1, 5, 6, 7, 8, 9, 11).1 This stain been removed during the washing process [4]. has been identified as silver sulfide [1, 2, 3]. Levenson and Sharpe [11] made an intensive study The silver sulfide residue which remains when a of the role of thiosulfate in the formation of silver silver image is bleached may have three sources. sulfide stains in a bromide emulsion during the The first is the reaction of the silver in the image bleaching process. They found that the stain was with the thiosulfate during fixation. The amount produced after the silver image had been in contact of this sulfiding of the silver depends on the type of with thiosulfate either in the developer or after fixing the sensitized emulsion. This silver sulfide is in a sodium thiosulfate fixing bath. They exposed present before and after the silver has been bleached. their samples to a step wedge and plotted the silver The second source of silver sulfide is the residual density and the stain density against relative values silver thiosulfate complex and thiosulfate which of the logarithm of exposure to show the amount of have not been removed in the washing process and stain produced by the corresponding silver densities have not yet reacted with the silver in the image to for a bromide fine-grain emulsion. They concluded form silver sulfide but do react in the bleach bath. that a certain amount of thiosulfate was strongly This reaction was used to study the effect of different absorbed on the silver of the image as thiosulfate residual thiosulfate concentrations on the amount of or as a thiosulfate complex and that it reacted with silver ions in the bleach to form silver sulfide. This 1 Figurcs in brackets indicate the literature references at the end of this paper. subject is discussed further in section 6. 65 530231- 60- 5 2 . Processing Procedures The permanganate bleach converted the silver sulfide to silver chloride. The potassium bromide Samples of the photograpbic film and paper were in the clearing bath prevented the loss of silver in cut to 1% in. by 10 in. and exposed to a step wedge. the gelatin layer because silver chloride is more Not more than eight samples were proccssed or soluble than silver bromide. There was a partial treated at one time. About 2 liters of fres h solu tio n solution of the sil ver chloride when sodium chloride were used in each processing operation cmploying was used in the clearing bath. Unfortunately, the nominal 8- by 10-in. enameled trays. The samples gelatin layer was quite soft afLer treatment in the were continuously agitated by hand during process­ clearing bath and the high alkalinity of most de­ ing and washed in running tap water. The process­ velopers caused the gelatin to break loose from the ing solutions arelisteu in the appendix, section 8. The support. The amidol developer was found to be temperature of the processing solutions were at room satisfactory for papers and most films. However, temperature (22° to 28° C). films with a normally soft gelatin layer should be washed 5 min after treatment in the cloaring bath, 2.1 . Developing and Fixing the Silver Image Lreated 5 min in a 2-percent solution of formaldehyde, Tho samples wer e devoloped 3 min, treated 1 and washed 10 min before drying. min in the short stop bath, and fixed 10 min in two T he r eduction of silver sulfid e in the gelatin baths (5 min in cach bath). Next t he samples were layer to silver appeared to be quantitative. When rinsed 1 min in tap water , treated 10 min in the this reduced silver was sulfided the original silver hydrogen peroxide eliminator No.1, bathed 2 min sulfide densities were again obtained. The silver in a I-percent solution of sodium sulfite, washed was sulfided in an atmosphere of hydrogen sulfid e. 30 min, and hung to dry at room temperature. Two The sample of film or paper was eoaked in water for fixing baths wer e used to facilitate tbe removal of 5 min and, after r emovin g the surface water with a the silver t hiosulfate complex. T ests showed that blotter, it was suspended for 1 hI' in a ?f-ga llon the amount of silver sulfide formed in the silv er bottle above a solu tion oontaining 50 g of sodium sul­ imago during fixation reached a maximum in about fide (N azS· 9H20 ), 35 g of citric acid (H3C6H50 7· I-IZO), 3 min in the acid-hardening fixing bath. and 500 ml of water. After this treatment t he sample was washed for 30 min in r Ullnin g tap water. 2.2. Bleaching the Silver Image The samples wer e treated 5 min in tho dichromate 3. Removal of the Thiosulfate During the bleach bath, washed 30 min in tap wator at 25 °± Washing Process 2° C, treated 5 min in tho clearing bath, treated ;) min in the thiosulfate eliminator No.3, and washod The thiosulfaLe must be removed from processed 30 min in tap water. The operation was performed films and papers when investigating the reaction of in daylight but not in direct sunlight. Tho bleach thiosulfato with the silver of the image during removed tho silver , leaving the silver sulfide which fixation. Solutions which remove the thiosulfate formed during fixation. Additional silver sulfide from the gelatin layer and paper base are generally was formod when the silver thiosulfato complex or known as "hypo eliminators." Crabtroe et al. [1 3] residual thiosulfate was present. The potassium showed that hydrogen peroxid e in an ammoniacal dichromate-sulfuric acid bleach oxidized the sil ver solution eliminates thios ulfate from photographic in the image in 1 to 2 min. The bleach did not materials. The hydrogen peroxide oxidizes the dissolve the silver-sulfide residue when the bleaching thiosulfate to sulfate. This hypo eliminator was time was ex tended to 15 min. The clearing bath, used in the experimental ,vork reported in this which was used to remove the residual diohromate, paper and is listed as formula No. 1 in the appendix , was t he on e employed by Levenson and Sharpe section 8.1. It is the same hypo eliminator used in [11] and proved to be quite satisfactory for both an American Standards Association photographic films and papers.
Load more

Recommended publications
  • Ag2s Solubility in Sulfide Solutions up to 250°C in Order to Estimate Possible Silver Sulfide Complexes in Ore Solutions, the S
    Geochemical Journal, Vol. 21, pp. 291 to 305, 1987 Ag2S solubility in sulfide solutions up to 250°C ASAHIKO SUGAKI', STEVEN D. SCOTT', KENICHIRO HAYASHI', and ARASHI KITAKAZE1 Institute of Mineralogy, Petrology and Economic Geology, Faculty of Science, Tohoku University, Sendai 980, Japan' and Department of Geology, University of Toronto, Toronto M5S 1A1, Canada' (Received December 2, 1987: Accepted February 22, 1988) In order to estimatepossible silver sulfide complexes in ore solutions, the solubilityof Ag2Swas measuredbetween 25° and 250°Cin NaOH-H2S-H20solutions of 0.0 to 4.1m NaHSconcentration. Solu bilitychanges as a functionof temperature,total reducedsulfur concentration ES (mHS + mHS-)and pH. A maximumsolubility of 2140ppmAg was obtained at 250°Cin 4.1m NaHSconcentration under PH 2Sof 29.1 atm. From these solubility data, reactions to form silver sulfide complexes are estimated as follows: Ag2S + H2S = Ag2S(H2S), Ag2S + H2S + HS = Ag2S(H2S) (HS)-, Ag2S + H2S + 2HS = Ag2S (H2S) (HS)22 and Ag2S + 2HS = Ag2S (HS)22-. The equilibrium constants for these reactions are given in Table 2. Assuming that such silver sulfide complexes as above are in an ore solution , Ag2S (argentite or acanthite) is precipitated in response to changes of temperature, pH and total sulfur concentration (ES). Decrease of pH and ES is more effective than that of temperature. Silver sulfide complexes are more important than silver chloride complexes in ore solution of high ES, neutral to slightly alkaline pH and geologically reasonable chloride concentrations. INTRODUCTION to the experimental study by Seward (1973), Thermochemical data for aqueous metal bisulfide complexes are significant for the trans species at elevated temperatures and pressures port of gold in ore solutions under epithermal are indispensable for understanding transport of conditions, even if chloride complexes have the metals in hydrothermal solution.
    [Show full text]
  • An Investigation of the Crystal Growth of Heavy Sulfides in Supercritical
    AN ABSTRACT OF THE THESIS OF LEROY CRAWFORD LEWIS for the Ph. D. (Name) (Degree) in CHEMISTRY presented on (Major) (Date) Title: AN INVESTIGATION OF THE CRYSTAL GROWTH OF HEAVY SULFIDES IN SUPERCRITICAL HYDROGEN SULFIDE Abstract approved Redacted for privacy Dr. WilliarriIJ. Fredericks Solubility studies on the heavy metal sulfides in liquid hydrogen sulfide at room temperature were carried out using the isopiestic method. The results were compared with earlier work and with a theoretical result based on Raoult's Law. A relative order for the solubilities of sulfur and the sulfides of tin, lead, mercury, iron, zinc, antimony, arsenic, silver, and cadmium was determined and found to agree with the theoretical result. Hydrogen sulfide is a strong enough oxidizing agent to oxidize stannous sulfide to stannic sulfide in neutral or basic solution (with triethylamine added). In basic solution antimony trisulfide is oxi- dized to antimony pentasulfide. In basic solution cadmium sulfide apparently forms a bisulfide complex in which three moles of bisul- fide ion are bonded to one mole of cadmium sulfide. Measurements were made extending the range over which the volumetric properties of hydrogen sulfide have been investigated to 220 °C and 2000 atm. A virial expression in density was used to represent the data. Good agreement, over the entire range investi- gated, between the virial expressions, earlier work, and the theorem of corresponding states was found. Electrical measurements were made on supercritical hydro- gen sulfide over the density range of 10 -24 moles per liter and at temperatures from the critical temperature to 220 °C. Dielectric constant measurements were represented by a dielectric virial ex- pression.
    [Show full text]
  • Revised Version the Crystal Structure of Uytenbogaardtite, Ag3aus2, And
    Title The crystal structure of uytenbogaardtite, Ag3AuS2, and its relationships with gold and silver sulfides-selenides Authors Bindi, L; Stanley, Christopher; Seryotkin, YV; Bakakin, VR; Pal'yanova, GA; Kokh, KA Date Submitted 2017-03-30 1 1 1237R – revised version 2 The crystal structure of uytenbogaardtite, Ag3AuS2, and its relationships 3 with gold and silver sulfides-selenides 4 1, 2 3,4 5 5 LUCA BINDI *, CHRISTOPHER J. STANLEY , YURII V. SERYOTKIN , VLADIMIR V. BAKAKIN , 3,4 3,4 6 GALINA A. PAL’YANOVA , KONSTANTIN A. KOKH 7 8 1Dipartimento di Scienze della Terra, Università di Firenze, Via G. La Pira 4, I-50121Firenze, Italy 9 2Natural History Museum, Cromwell Road, London SW7 5BD, United Kingdom 3 10 Sobolev Institute of Geology and Mineralogy of the Siberian Branch of the Russian Academy of Sciences, pr. 11 Akademika Koptyuga, 3, Novosibirsk 630090, Russia 4 12 Novosibirsk State University, Pirogova str., 2, Novosibirsk 630090, Russia 5 13 Institute of Inorganic Chemistry, Siberian Branch of the RAS, prosp. Lavrentieva 3, 630090 Novosibirsk, Russia 14 15 * e-mail address: [email protected] 16 17 Abstract 18 The crystal structure of the mineral uytenbogaardtite, a rare silver-gold sulfide, was solved 19 using intensity data collected on a crystal from the type locality, the Comstock lode, Storey 20 County, Nevada (U.S.A.). The study revealed that the structure is trigonal, space group R 3 c, 3 21 with cell parameters: a = 13.6952(5), c = 17.0912(8) Å, and V = 2776.1(2) Å . The refinement 22 of an anisotropic model led to an R index of 0.0140 for 1099 independent reflections.
    [Show full text]
  • [email protected] 1-800-424-9300 (North America) Website: +1-703-527-3887 (International)
    Date of Issue: 27 July 2021 SAFETY DATA SHEET 1. SUBSTANCE AND SOURCE IDENTIFICATION Product Identifier RM Number: 8554 RM Name: IAEA-S-1 (Sulfur Isotopes in Silver Sulfide) Other Means of Identification: Not applicable. Recommended Use of This Material and Restrictions of Use This Reference Material (RM) is an international measurement standard that defines the Vienna Cañon-Diablo Troilite (VCDT) scale for relative differences in sulfur (S) isotope-number ratios, R(34S/32S). A unit of RM 8554 consists of one bottle containing approximately 0.5 g of silver sulfide (Ag2S). Company Information National Institute of Standards and Technology Standard Reference Materials Program 100 Bureau Drive, Stop 2300 Gaithersburg, Maryland 20899-2300 Telephone: 301-975-2200 Emergency Telephone ChemTrec: E-mail: [email protected] 1-800-424-9300 (North America) Website: https://www.nist.gov/srm +1-703-527-3887 (International) 2. HAZARDS IDENTIFICATION Classification Physical Hazard: Not classified. Health Hazard: Not classified. Label Elements Symbol: No symbol/No pictogram. Signal Word: No signal word. Hazard Statement(s): Not applicable. Precautionary Statement(s): Not applicable. Hazards Not Otherwise Classified: None. Ingredients(s) with Unknown Acute Toxicity: None. 3. COMPOSITION AND INFORMATION ON HAZARDOUS INGREDIENTS Substance: Silver sulfide Other Designations: Disilver sulfide. Components are listed in compliance with OSHA’s 29 CFR 1910.1200. For actual values, see the NIST Report of Investigation. Hazardous Component(s) CAS Number EC Number Nominal Mass Concentration (EINECS) (%) Silver sulfide 21548-73-2 244-438-2 100 RM 8554 Page 1 of 6 4. FIRST AID MEASURES Description of First Aid Measures Inhalation: If adverse effects occur, remove to well-ventilated (uncontaminated) area.
    [Show full text]
  • Safety Data Sheet Page 1/4 Acc
    Safety Data Sheet Page 1/4 acc. to OSHA HCS Printing date 04/13/2017 Revision date 04/12/2017 Version 2 1 Identification Product identifier Product name: Silver sulfide Stock number: 11416 CAS Number: 21548-73-2 EC number: 244-438-2 Details of the supplier of the safety data sheet Manufacturer/Supplier: Alfa Aesar Thermo Fisher Scientific Chemicals, Inc. 30 Bond Street Ward Hill, MA 01835-8099 Tel: 800-343-0660 Fax: 800-322-4757 Email: [email protected] www.alfa.com Information Department: Health, Safety and Environmental Department Emergency telephone number: During normal business hours (Monday-Friday, 8am-7pm EST), call (800) 343-0660. After normal business hours, call Carechem 24 at (866) 928-0789. 2 Hazard(s) identification Classification of the substance or mixture in accordance with 29 CFR 1910 (OSHA HCS) The substance is not classified as hazardous according to 29 CFR 1910 (OSHA GHS). Hazards not otherwise classified No information known. Label elements GHS label elements Not applicable Hazard pictograms Not applicable Signal word Not applicable Hazard statements Not applicable WHMIS classification Not controlled Classification system HMIS ratings (scale 0-4) (Hazardous Materials Identification System) HEALTH 1 Health (acute effects) = 1 FIRE 0 Flammability = 0 REACTIVITY 1 Physical Hazard = 1 Other hazards Results of PBT and vPvB assessment PBT: Not applicable. vPvB: Not applicable. 3 Composition/information on ingredients Chemical characterization: Substances CAS# Description: 21548-73-2 Silver sulfide Concentration: ≤100% Identification number(s): EC number: 244-438-2 4 First-aid measures Description of first aid measures After inhalation Supply fresh air. If required, provide artificial respiration.
    [Show full text]
  • Silver Substitution Into Common Metal Sulphides from Cobalt, Ontario Silver Substitution Into Common Metal Sulphides from Cobalt, Ontario
    LICENCE TO McMASTER UNIVERSITY This [Thesis, Project Report, etc.] by ~arah MMalcolmsoR for [Full Name(s)] Undergraduate course number _----.:!4w.:.K..l.!.06lol..-______ at McMaster University under the supervision/direction of Dr. J. R. Kramer In the interest of furthering teaching and research, I/we hereby grant to McMaster University: 1. The ownership of 7 copy(ies) of this work; 2. A non-exclusive licence to make copies of this work, (or any part thereof) the copyright of which is vested in me/us, for the full term of the copyright, or for so long as may be legally permitted. Such copies shall only be made in response to a written request from the· Library or any University or similar institution. I/we further acknowledge that this work (or a surrogate copy thereof) may be consulted without restriction by any interested person. (This Licence to be bound with the work) Silver Substitution into Common Metal Sulphides from Cobalt, Ontario Silver Substitution into Common Metal Sulphides from Cobalt, Ontario by Sarah Malcolmson A Thesis Submitted to the Department of Geology in Partial Fulfilment of the Requirements for the Degree Bachelor of Science McMaster University April, 1995 ii BACHELOR OF SCIENCE, (1995) McMaster University (Geology Honours Specialist) Hamilton, Ontario TITLE: Silver Substitution into Common Metal Sulphides from Cobalt, Ontario AUTHOR: Sarah Malcolmson SUPERVISOR: Dr. J. R. Kramer iii Abstract The occurrence of silver in galena, chalcopyrite, sphalerite, and pyrite as well as tailings from Cart Lake, Cobalt Ontario were investigated to compare with the undetectable ( <1 o-11 g/g) Ag found in runoff water from the Cobalt area.
    [Show full text]
  • THE MONATOMIC IONS! 1. What Is the Formula for Silver? Ag 2. What Is
    Name: ______________________________ THE MONATOMIC IONS! 1. What is the formula for silver? Ag+ 22. What is the formula for cobalt (II)? Co2+ 2. What is the formula for cadmium? Cd2+ 23. What is the formula for chromium (II)? Cr2+ 3. What is the formula for manganese (II)? Mn2+ 24. What is the formula for copper (II)? Cu2+ 4. What is the formula for nickel (II)? Ni2+ 25. What is the formula for tin (IV)? Sn4+ 5. What is the formula for chromous? Cr2+ 26. What is the formula for lead (IV)? Pb4+ 6. What is the formula for zinc? Zn2+ 27. What is the formula for iron (III)? Fe3+ 2+ 2+ 7. What is the formula for cobaltous? Co 28. What is the formula for mercury (I)? Hg2 8. What is the formula for cuprous? Cu+ 29. What is the formula for lead (II)? Pb2+ 9. What is the formula for ferrous? Fe2+ 30. What is the formula for mercury (II)? Hg2+ 2+ 2+ 10. What is the formula for mercurous? Hg2 31. What is the formula for iron (II)? Fe 11. What is the formula for stannous? Sn2+ 32. What is the formula for copper (I)? Cu+ 12. What is the formula for plumbous? Pb2+ 33. What is the formula for tin (II)? Sn2+ 13. What is the formula for chromic? Cr3+ 34. What is the formula for fluoride? F- 14. What is the formula for cobaltic? Co3+ 35. What is the formula for chloride? Cl- 15. What is the formula for cupric? Cu2+ 36. What is the formula for hydride? H- 16.
    [Show full text]
  • Li Na K Be Mg Ca B Al Ni Au Ag
    LAST NAME____________________ FIRST NAME____________________________ DATE ___________ 6.1 NAMING IONIC COMPOUNDS = Use the notes to write the correct names of the IONIC COMPOUNDS created by the Cations and Anions. SIMPLE EXAMPLES Anions Cations ↓ F Cl Br I Li Lithium Fluoride Lithium Chloride Lithium Bromide Lithium Iodide Na Sodium Fluoride Sodium Chloride Sodium Bromide Sodium Iodide K Potassium Fluoride Potassium Chloride Potassium Bromide Potassium Iodide Be Beryllium Fluoride Beryllium Chloride Beryllium Bromide Beryllium Iodide Mg Magnesium Fluoride Magnesium Chloride Magnesium Bromide Magnesium Iodide Ca Calcium Fluoride Calcium Chloride Calcium Bromide Calcium Iodide B Boron Fluoride Boron Chloride Boron Bromide Boron Iodide Al Aluminum Fluoride Aluminum Chloride Aluminum Bromide Aluminum Iodide Ni Nickel Fluoride Nickel Chloride Nickel Bromide Nickel Iodide Au Gold Fluoride Gold Chloride Gold Bromide Gold Iodide Ag Silver Fluoride Silver Chloride Silver Bromide Silver Iodide And some more Anions Cations ↓ O S N Li Lithium Oxide Lithium Sulfide Lithium Nitride Na Sodium Oxide Sodium Sulfide Sodium Nitride K Potassium Oxide Potassium Sulfide Potassium Nitride Be Beryllium Oxide Beryllium Sulfide Beryllium Nitride Mg Magnesium Oxide Magnesium Sulfide Magnesium Nitride Ca Calcium Oxide Calcium Sulfide Calcium Nitride B Boron Oxide Boron Sulfide Boron Nitride Al Aluminum Oxide Aluminum Sulfide Aluminum Nitride Ni Nickel Oxide Nickel Sulfide Nickel Nitride Au Gold Oxide Gold Sulfide Gold Nitride Ag Silver Oxide Silver Sulfide Silver
    [Show full text]
  • 15.6 Solubility Equilibria and Solubility Product
    _________________________________________________ Chapter 15 Applications of Aqueous Equilibria 325 Solution a. clear b. yellow c. green-blue d. yellow Problems 39-43 at the end of thIs study chapter cover material from this section. 15.6 Solubility Equilibria and Solubility Product When you finish this section you will’be able to: • interconvert between solubility and K, and • solve problems relating to the common ion effect. As with many of the previous sections, Solubility equilibria use principles that you have used before. This section deals with solubility, the amount of a salt that can be dissolved in water. Your textbook points out that the solubiity of a salt is variable, The solubility product (“Km”) is constant (at a given temperature). The solubility equilibrium expression is set up as any other. For example, the equilibrium expression for the dissolution of Ag2S in water is 2S(s) 2Ag’(aq) + Ag S(aq) K = 1.6 x 1O ber that the pure solid, AgS, is noncluded i: the equffibrium- expresalon. Example 15.6 A Solubility Equilibrium Expressions Write products2(s)and equilibrium expressions for the following dissotution reactions: a. 3(s)Ba(OH) b. PbCO c. Ag2CrO4(s) d. Ca3(P04>2(s) Solution a. Ba(OH)2(s) Ba(aq) + 2OW(aq) = 2 [Ba21 [0H1 2(aq) + b. PbCO3(s) Pb C032(aq) = ] [Pb2j [CO32 2Ag(aq) + 4’(aq) c. Ag2CrO4(s) CrO = 2 [Ag9 [Cr0421 3Ca2(aq) + 43(aq) d. Ca3(P04)2(s) 2P0 = [Ca9 [PO4]2 326 Chapter 15 Applications of Aqueous Equilibria , from Solubility Data Example 15.6 B K1 x , for Ag2S.
    [Show full text]
  • Iron, Steel and Swords Script - Page 1 Cerrusite Veins and a Cut Crystal (The "Light of the Desert")
    Early Metal Technology 2. Silver and Lead Silver Native silver is rather rare. Not as rare as native copper (if one excludes the "anomaly" of the "old copper complex" in North America), but still rarer than native gold. Native silver has been used but, just like gold, relatively late. The oldest occurrence of silver comes from a "hoard" found in the famous cave in Alepotrypa / Greece, dated to the mid 5th to early 4th millennium BC. It is thus roughly contemporary to the first gold in Varna. However, the Greeks neglected to supply any pictures of that hoard (in the Net). Native silver Source. Photographed in the Metropolitan Museum NYC. It appears that there aren't many artifacts around that were made from native silver. Hardly surprising considering how scarce it is. You can also get silver from "gold parting" but that was done rather late (roughly after 1500 BC) and does not produce elemental silver but a compound, same thing as an ore. So nothing helps: If you want silver, you must smelt some ore Silver sulfides are the most easily found ores, and those are typically mixed up with the lead sulfide galena (PbS) or with lead carbonate called cerrusite (PbCO3). The neolithic Anatolian towns knew galena because the people who lived there (in Çatal Höyük, to be exact) about 9000 years ago had made beads out of galena. They wouldn't have noticed the silver sulfide in there because even silver-rich galena rarely contains more than 0.5 % of the stuff. Nevertheless, most of the silver produced in antiquity was from the little bit of silver sulfide or other silver compounds contained in the lead ores galena or cerrusite.
    [Show full text]
  • Microscopic Study of Montana Silver Ores. Edwin Johnson
    Montana Tech Library Digital Commons @ Montana Tech Bachelors Theses and Reports, 1928 - 1970 Student Scholarship 5-1935 Microscopic Study of Montana Silver Ores. Edwin Johnson Follow this and additional works at: http://digitalcommons.mtech.edu/bach_theses Part of the Ceramic Materials Commons, Environmental Engineering Commons, Geology Commons, Geophysics and Seismology Commons, Metallurgy Commons, Other Engineering Commons, and the Other Materials Science and Engineering Commons Recommended Citation Johnson, Edwin, "Microscopic Study of Montana Silver Ores." (1935). Bachelors Theses and Reports, 1928 - 1970. 49. http://digitalcommons.mtech.edu/bach_theses/49 This Bachelors Thesis is brought to you for free and open access by the Student Scholarship at Digital Commons @ Montana Tech. It has been accepted for inclusion in Bachelors Theses and Reports, 1928 - 1970 by an authorized administrator of Digital Commons @ Montana Tech. For more information, please contact [email protected]. E. G. by A Tfle is ~:;fbt Ltted. to the :"1e'"'I,"rtr'lent of Cec Lo.: ill. Pc..J7tial .b'u1fi1111ent of the J.1ecuj_rer'~)"1t~ f or- .1 ne De.'ree of Bo,che1or ci ~ciei1ce in Ge,~loeic~~l .L!Jn'ineerlIlC;; , dChuOL l.Lay 19:)5 ONTA/i\ SCHPOLQf MINES lIR y. MICROSCOFIC STUDY OF MONTANA SILVER ORES by EDWIN JOHNSON A Thesis Submitted to the Department of Geology in Partial Fulfillment of the Requirements for the Degree of Bachelor of Science in Geological Engineering //:2-82 MONTANA SCHOOL OF MINES BUTTE, MONTANA May 1935 MONTANA SCHOO~Of MINts LlBRAll, CONTENTS Page INTRO~UCTION • • • • · . • • • • 1 LABORATORY FROCEDURE • • • • • • . · . Grinding and Polishing · . ..... Methods Used for the Identification of the 3 Silver Minerals • • • • • • • • • · .
    [Show full text]
  • United States Patent (19) 11, 3,943,001 Miles (45) Mar
    United States Patent (19) 11, 3,943,001 Miles (45) Mar. 9, 1976 (54) SILVER SULFIDE CATHODE FOR LIQUID 58 Field of Search .............. 136/86 A, 6 LN, 86 R AMMONIA BATTERES AND FUEL CELLS CONTAINING SULFUR AND HS IN THE 56) References Cited ELECTROLYTE UNITED STATES PATENTS 75) Inventor: Melvin H. Miles, Murfreesboro, 2,937,219 5/1960 Minnicket al................... 36/6 LN Tenn. 2,996,562 8/1961 Meyers...... ... 136/6 LN 3, 21,028 2/964 Story....................................... 136/6 (73) Assignee: The United States of America as 3.248,265 4/1966. Herbert.................... ... 136/6 LN represented by the Secretary of the 3,408,229 10/1968 Posey et al....................... 13676 LN Navy, Washington, D.C. G . Primary Examiner-G. L. Kaplan 22 Filed: July 5, 1973 Assistant Examiner-H. A. Feeley (21) Appl. No.: 376,784 Attorney, Agent, or Firm-Richard S. Sciascia; Joseph Related U.S. Application Data M. St. Amand (63) Continuation-in-part of Ser. No. 63,638, July 19, 57 ABSTRACT 1971, abandoned. A rechargeable silver sulfide cathode for batteries and 52) U.S. Cl.............................. 1366 LN 13686 R fuel cells using liquid ammonia electrolytes. (51) int. Cl.'......................................... H01M 10/00 5 Claims, 3 Drawing Figures U.S. Patent March 9, 1976 3,943,001 Afg. J. 2O c RESIDUAL E CURRENT . T = -50° C O 1. 4. 3 -2O - 4 O -O-O.8-O.6 -O-4-O,2 O O.2 O,4 POTENTIAL VS Pb/Pb (NO3)2.V O > N Afg. 2. g-O. 3. d l -0.2 f s 3.
    [Show full text]