1、Designation: B562 95 (Reapproved 2012)Standard Specification forRefined Gold1This standard is issued under the fixed designation B562; 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 parenthes
2、es indicates the year of last reapproval. Asuperscript epsilon () 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 99.95Gold having a minim
3、um fineness of999.5.1.1.3 Grade 99.99Gold having a minimum fineness of999.9.1.1.4 Grade 99.995Gold 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 stand
4、ard. 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 this sta
5、ndard to become familiarwith all hazards including those identified in the appropriateMaterial Safety Data Sheet (MSDS) for this product/materialas provided by the manufacturer, to establish appropriatesafety and health practices, and determine the applicability ofregulatory limitations prior to use
6、.2. Referenced Documents2.1 ASTM Standards:2E29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE1446 Test Method for Chemical Analysis of Refined Goldby Direct Current Plasma Emission Spectrometry3. Materials and Manufacture3.1 The metal may be produced
7、 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 to
8、 the chemical compo-sition prescribed in Table 1.NOTE 2For purposes of determining conformance with thisspecification, an observed value obtained from analysis shall be roundedto the nearest unit in the last right-hand place of figures used in expressingthe limiting value, in accordance with the rou
9、nding method of PracticeE29.5. Sampling5.1 On agreement between the manufacturer and thepurchaser, 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 constitutea lo
10、t 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 order to
11、 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 analternativ
12、e 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 dividedinto thr
13、ee 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.1This specification is under the jurisdiction of ASTM Committee B02 onNonferrous Metals and Alloys and is the direct
14、 responsibility of SubcommitteeB02.05 on Precious Metals and Electrical Contact Materials.Current edition approved Nov. 1, 2012. Published November 2012. Originallyapproved in 1972. Last previous edition approved in 2005 as B562 95 (2005).DOI: 10.1520/B0562-95R12.2For referenced ASTM standards, visi
15、t the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-295
16、9. United States16. Method of Analysis6.1 Chemical composition of the materials set forth in thisspecification shall be determined, in case of disagreement, inaccordance with Test Method E1446. The selection of testmethods for the determination of elements not covered by thattest method shall be a m
17、atter of agreement between 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 considere
18、d shall be made to the 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, an
19、d shall then agree eitherto 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 condemne
20、d for defects in theproducts 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 p
21、ackage, one for the manufacturer, 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 agr
22、eeable umpire, who shall 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 ofr
23、ejection being established, 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
24、or otherwise legibly 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
25、99.995Gold, min 99.5 . . .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 .
26、. 0.003 0.001Arsenic, 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
27、in this table.B562 95 (2012)2APPENDIX(Nonmandatory Information)X1. TEST METHOD FOR CHEMICAL ANALYSIS 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 sam
28、ple along with required 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 assa
29、yed and the sample is 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 Ap
30、paratusX1.4.1 Muffle 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
31、.2 Nitric acid, 32 Baume, 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, 25 mgX1.5.6 Proof gold wire, 99.999 %X1.6 ProcedureX1.6.1 Sample PreparationWire brush chill pin samplesto remove glass particles from surface, then cu
32、t and roll. Afterrolling, 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 sampl
33、e. Weigh fine gold at0.4975 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 furnac
34、e (no air flow) at approximately1225C 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 2C
35、1A P 1B P 1CBBBBBwhere: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 app
36、ear silvery butnot solidified. 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 bea
37、ds by squeezing bead with 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 passing
38、twice through hand roller, 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.
39、X1.6.12 Coil fillets into “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.B562 95 (2012)3X1.6.
40、15 Remove the basket, rinse with hot deionized 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 ba
41、sket (still containing coronets) on thehot plate and dry.X1.6.18 Place the basket in an annealing furnace at 1550F(843.3C) for 7 min.X1.6.19 Cool gold coronets and weigh.X1.7 CalculationX1.7.1 Gold Concentration:Gold concentration in parts per thousand 5A 3 B 31000Cwhere:A = Final gold weight, g,B =
42、 Average of two proof 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
43、are expressly advised 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 no
44、t revised, either reapproved 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
45、you may attend. If you 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,Unit
46、ed 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).B562 95 (2012)4
