1、Designation: B 562 95 (Reapproved 2005)Standard Specification forRefined Gold1This standard is issued under the fixed designation B 562; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parenth
2、eses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers refined gold in cast bar form(Note 1).1.1.1 Grade 99.5Gold having a minimum fineness of 995.1.1.2 Grade 99.95 Gold having a m
3、inimum fineness of999.5.1.1.3 Grade 99.99 Gold having a minimum fineness of999.9.1.1.4 Grade 99.995 Gold having a minimum fineness of999.95.NOTE 1Other forms of unfabricated gold of commerce are not to beexcluded under this specification.1.2 The values stated in inch-pound units are to be regardedas
4、 standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of th
5、is standard to become familiarwith all hazards including those identified in the appropriateMaterial Safety Data Sheet for this product/material as pro-vided by the manufacturer, to establish appropriate safety andhealth practices, and determine the applicability of regulatorylimitations prior to us
6、e.2. Referenced Documents2.1 ASTM Standards:2E29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE 1446 Test Method for ChemicalAnalysis of Refined Goldby Direct Current Plasma Emission Spectroscopy3. Materials and Manufacture3.1 The metal may be produce
7、d by any process that yields aproduct capable of meeting the requirements of this specifica-tion. The purchaser, upon request, shall be informed of therefining process used.3.2 The bars shall be of a quality generally acceptable to thetrade.4. Chemical Composition4.1 The refined gold shall conform t
8、o the chemical compo-sition prescribed in Table 1.NOTE 2For purposes of determining conformance with this specifi-cation, an observed value obtained from analysis shall be rounded to thenearest unit in the last right-hand place of figures used in expressing thelimiting value, in accordance with the
9、rounding method of Practice E29.5. Sampling5.1 On agreement between the manufacturer and the pur-chaser, a sample may be taken from the melt before pouring(Note 3). The sample shall be in the form of shot or pins (Note4 and Note 5).NOTE 3A single melt or bar(s) cast from a single melt shall constitu
10、tea lot for sampling.NOTE 4Pins of38 in. (9.5 mm) or other suitable diameter may be castinto graphite molds or drawn into evacuated glass tubes. In some cases itmay be necessary to draw the glass tube pins through 60-grit emery paperbefore acid leaching to remove adhering glass particles.NOTE 5In or
11、der to avoid surface contamination, the sample, irrespec-tive of its nature, is to be leached in hot 1 + 1 HCl for 5 min, washed inwater, rinsed twice in alcohol or acetone, and dried in a muffle at 110Cbefore portions are taken for analysis.5.2 On agreement between manufacturer and purchaser analte
12、rnative sampling procedure may be used.5.3 The amount of sample taken shall be sufficient to supplythree portions for analysis; the mass of each portion shall besufficient to permit the determination of its composition as setforth in Table 1.5.4 After mixing thoroughly, the sample shall be dividedin
13、to three parts, each placed in a package and sealed; one forthe manufacturer, one for the purchaser, and one for theumpire.5.5 All tools required are to be reserved exclusively for thiswork.6. Method of Analysis6.1 Chemical composition of the materials set forth in thisspecification shall be determi
14、ned, in case of disagreement, inaccordance with Test Method E 1446. The selection of test1This specification is under the jurisdiction of ASTM Committee B02 onNonferrous Metals and Alloys and is the direct responsibility of SubcommitteeB02.05 on Precious Metals and Electrical Contact Materials.Curre
15、nt edition approved May 1, 2005. Published June 2005. Originallyapproved in 1972. Last previous edition approved in 1999 as B 562 95 (1999).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volum
16、e information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.methods for the determination of elements not covered by thattest method shall be a matter of agreement be
17、tween themanufacturer and the purchaser.6.2 Chemical composition of materials required for Grade99.5 refined gold shall be determined by a test method similarto the fire assay test method listed in the appendix.7. Rejection and Rehearing7.1 Rejection:7.1.1 Claims to be considered shall be made to th
18、e manu-facturer in writing within 30 days of receipt of the material atthe purchasers plant, and the results of tests made by thepurchaser shall accompany such claims. The manufacturershall be given one week from the date of receipt of thecomplaint to investigate his records, and shall then agree ei
19、therto satisfy the claim or to submit samples to an umpire. Noclaim shall be considered unless a portion of the original goldbars can be shown to the representative of the manufacturer.7.1.2 Where the gold satisfies the requirements of thisspecification, it shall not be condemned for defects in thep
20、roducts in which it is used.7.2 Investigation of ClaimsIn a question of chemicalcomposition, a sample shall be drawn by representatives ofboth parties in accordance with Section 5. The sample shall besuitably separated into three parts, each of which shall beplaced in a sealed package, one for the m
21、anufacturer, one forthe purchaser, and one for an umpire, if necessary. Themanufacturer and the purchaser shall each make an analysis,and if the results do not establish or dismiss the claim to thesatisfaction of both parties, the third sample shall be submittedto a mutually agreeable umpire, who sh
22、all determine thequestion of fact, and whose determination shall be final.8. Settlement of Claims8.1 The expenses of the manufacturers representative andof the umpire shall be paid by the loser or divided in proportionto the concession made in case of compromise. In the case ofrejection being establ
23、ished, the damages shall be limited to thepayment of transportation charges both ways by the manufac-turer for substitution of an equivalent weight of gold conform-ing to this specification.9. Product Marking9.1 The brand by which the manufacturer can be identifiedshall be cast or otherwise legibly
24、marked upon each bar. Thebar shall be marked with the fineness together with the meltnumber, bar number, and weight to the nearest 0.001 troy oz(0.03 g).10. Keywords10.1 gold; refined goldTABLE 1 Chemical RequirementsElementAComposition,%Grade 99.5 Grade 99.95 Grade 99.99 Grade 99.995Gold, min 99.5
25、. . .Gold, min (by difference) . 99.95 99.99 99.995Silver + copper, max . 0.04 . .Silver, max . 0.035 0.009 0.001Copper, max . 0.02 0.005 0.001Palladium, max . 0.02 0.005 0.001Iron, max . 0.005 0.002 0.001Lead, max . 0.005 0.002 0.001Silicon, max . . 0.005 0.001Magnesium, max . . 0.003 0.001Arsenic,
26、 max . . 0.003 .Bismuth, max . . 0.002 0.001Tin, max . . 0.001 0.001Chromium, max . . 0.0003 0.0003Nickel, max . . 0.0003 .Manganese, max . . 0.0003 0.0003ABy agreement between manufacturer and purchaser analyses may be required and limits established for elements not specified in this table.B 562 9
27、5 (2005)2APPENDIX(Nonmandatory Information)X1. TEST METHOD FOR CHEMICALANALYSIS OF REFINED GOLD BY CUPELLATION FIRE ASSAYX1.1 ScopeX1.1.1 This test method covers the cupellation analysis ofGrade 99.5 refined gold for gold content.X1.2 Summary of Test MethodX1.2.1 The weighed sample along with requir
28、ed silver,copper, and lead is cupelled until all base metal is absorbed andonly the precious metals remain. The silver is then removed bydissolution with nitric acid. The remaining gold is dried,annealed, and weighed. Synthetic proof samples of knownamounts of gold are also assayed and the sample is
29、 correctedfor gains or losses in the proof sample.X1.3 InterferencesX1.3.1 The presence of the following elemental concentra-tions will lead to erroneous results.Element Max. %Nickel, Iron, Tin 2.0Tungsten 0.5Paladium, Platinum 0.01Iridium, Rhodium, Ruthenium, Osmium 0.01X1.4 ApparatusX1.4.1 Muffle
30、furnace, capable of maintaining 1250C andhaving adjustable air flow control.X1.4.2 Analytical balance, capable of weighing 60.002mg.X1.4.3 Rolling mill.X1.4.4 Platinum basket.X1.5 Reagents and MaterialsX1.5.1 Nitric acid, 22 Baume, 1.169 6 0.01 specificgravity by hydrometer.X1.5.2 Nitric acid, 32 Ba
31、ume, 1.285 6 0.01 specificgravity by hydrometer.X1.5.3 Lead foil.X1.5.4 Silver wire, 99.99 % (0.001 ppt Au)X1.5.5 Copper disks,25mgX1.5.6 Proof gold wire, 99.999 %X1.6 ProcedureX1.6.1 Sample PreparationWire brush chill pin samplesto remove glass particles from surface, then cut and roll. Afterrollin
32、g, inspect the sample for inclusions or other signs ofsegregation. Drillings and grain samples are as is.X1.6.2 Weigh samples in triplicate at 0.50_ g and placein 2.5-g lead cornucopias, along with 1.25 g of fine silver and1/2 disk of copper.X1.6.3 Prepare two proofs per sample. Weigh fine gold at0.
33、4975 6 0.00050 g. Add silver at 1.25 g, along with 1/2 diskof copper.X1.6.4 Close lead cornucopias and compress with pliersinto spheres to fit cupels. Place in numbered tray compart-ments.X1.6.5 Load a set of 15 (three rows of five) 1 in. magnesitecupels into the muffle furnace (no air flow) at appr
34、oximately1225C and allow to dry for 30 min. Calibrate the temperatureof the furnace by noting the temperature necessary to melt puregold.X1.6.6 Carefully place each lead wrapped sample in acupel, starting with the next to the front row, as follows:BBBBB3A P 3B P 3C2A P 2B P 2C1A P 1B P 1CBBBBBwhere:
35、B = blank cupel, andP = proof.Close the door and wait 2 to 3 min until all samples becomemolten. Open the draft and adjust after 1 min for sufficient draft(fumes visibly rising off cupels and flowing back to vent in rearof furnace).X1.6.7 After 8 to 10 min the samples will appear silvery butnot soli
36、dified. At this point remove the cupels from the furnaceone at a time and place in front of the furnace door, where thesamples will immediately solidify and blink.X1.6.8 Once cooled, remove beads from cupels with flatpliers and place in dimpled porcelain trays.X1.6.9 Clean beads by squeezing bead wi
37、th flat plier andbrushing away adhering bone ash.X1.6.10 Flatten beads with one middle blow and severalend blows. Roll beads to about 0.040 in. by passing twicethrough hand roller, and anneal at 1550F (843.3C) for 7 min.X1.6.11 Roll beads to a thickness of 0.015 in. by passingtwice through hand roll
38、er, and anneal again at 1550F(843.3C) for 7 min. Finally roll beads to 0.012 in., and annealone final time at 1550F (843.3C) for 7 min. The edges of therolled bead must be smooth and have no roughness. It isimportant that all fillets of each row are the same size andthickness.X1.6.12 Coil fillets in
39、to “coronets” or spirals using thin-nose pliers or rolling tool.X1.6.13 Place coronets in a platinum basket in a definitepattern so as not to mix each coronet.X1.6.14 Place the basket in 22 Baume nitric acid at 105C(boil gently) for 45 min, for full basket.X1.6.15 Remove the basket, rinse with hot d
40、eionized waterand place in 32 Baume nitric acid at 110C (boil gently) for 45min, for full basket.X1.6.16 Rinse the basket first in hot deionized water, then ahot 5 % ammonium hydroxide solution rinse, and three morehot deionized water rinses.X1.6.17 Place the basket (still containing coronets) on th
41、ehot plate and dry.X1.6.18 Place the basket in an annealing furnace at 1550F(843.3C) for 7 min.B 562 95 (2005)3X1.6.19 Cool gold coronets and weigh.X1.7 CalculationX1.7.1 Gold Concentration:Gold concentration in parts per thousand 5A 3 B 3 1000Cwhere:A = Final gold weight, g,B = Average of two proof
42、 factors, andProof factor 5Initial proof gold weight, gFinal proof gold weight, gC = Initial sample weight, g.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised
43、 that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either rea
44、pproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If yo
45、u feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).B 562 95 (2005)4
