ASTM_E_1805_-_13.pdf

Designation:E180513Standard Test Method forDetermination of Gold in Copper Concentrates by FireAssay Gravimetry1This standard is issued under the fixed designation E1805;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 parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method is for the determination of gold incopper concentrates in the content range from 0.2 g/g to 17g/g.NOTE1The lower scope limit is set in accordance with PracticeE1601.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.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 standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.For specificwarning statements,see 11.3.1,11.5.4,and 11.6.5.2.Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE50 Practices for Apparatus,Reagents,and Safety Consid-erations for Chemical Analysis of Metals,Ores,andRelated MaterialsE135 Terminology Relating to Analytical Chemistry forMetals,Ores,and Related MaterialsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE882 Guide for Accountability and Quality Control in theChemical Analysis LaboratoryE1601 Practice for Conducting an Interlaboratory Study toEvaluate the Performance of an Analytical Method3.Terminology3.1 For definitions of terms used in this test method,refer toTerminology E135.4.Summary of Test Method4.1 A test sample of copper concentrate is fluxed and fusedin a clay crucible.The precious metals are reduced,collected ina lead button,and then cupelled to remove the lead.Theremaining dor bead is parted with nitric acid to remove thesilver and other impurities from the gold.The gold is thenannealed,cleaned,and weighed on a microbalance.5.Significance and Use5.1 In the metallurgical process used in the miningindustries,gold is often carried along with copper during theflotation concentration process.Metallurgical accounting,pro-cess control,and concentrate evaluation procedures for thistype of material depend on an accurate,precise measurementof the gold in the copper concentrate.This test method isintended to be a reference method for metallurgical laborato-ries and a referee method to settle disputes in commercialtransactions.It is also a definitive method intended to testmaterials for compliance with compliance with compositionalspecifications and to provide data for certification of referencematerials.It is essential that each performance of the methodbe validated by applying it to appropriate reference materials atthe same time and in the same manner as it is applied to theunknowns.5.2 It is assumed that all who use this test method will betrained analysts capable of performing skillfully and safely.Itis expected that the work will be performed in a properlyequipped laboratory under appropriate quality control practicessuch as those described in Guide E882.6.Interferences6.1 Elements normally found in copper concentrates withinthe limits of 1.1 do not interfere.High concentrations ofarsenic,antimony,tellurium,bismuth,nickel,and platinumgroup metals(and,in some instances,copper),however,mayinterfere with the fusion and cupellation steps.1This test method is under the jurisdiction of ASTM Committee E01 onAnalytical Chemistry for Metals,Ores,and Related Materials and is the directresponsibility of Subcommittee E01.02 on Ores,Concentrates,and Related Metal-lurgical Materials.Current edition approved April 1,2013.Published June 2013.Originallyapproved in 1996.Last previous edition approved in 2007 as E1805-07.DOI:10.1520/E1805-13.2For referenced ASTM standards,visit 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 19428-2959.United States1 7.Apparatus7.1 Analytical Balance,capable of weighing to 0.1 g.7.2 Assay Mold,100-mL capacity.7.3 Cube or Cone Mixer,1000-g capacity.7.4 Cupel,magnesite or bone ash,40-g lead capacity.7.5 Drying Oven,forced air circulation with temperaturecontrol,104 C.7.6Fire Assay Bead Brush.7.7 Fire Assay Bead Pliers.7.8 Fire Assay Clay Crucible,20-g to 30-g sample capacity.7.9 Fire Assay Muffle Furnace,gas-fired or electric,equipped with air circulation systems and with draft controls,capable of temperatures to 1100 C 6 10 C,and withventilation controls for acid and lead fumes.7.10 Fire