ASTM_E_1898_-_13.pdf

Designation:E189813Standard Test Method forDetermination of Silver in Copper Concentrates by FlameAtomic Absorption Spectrometry1This standard is issued under the fixed designation E1898;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 covers the determination of silver inthe range of 13 g/g to 500 g/g by acid dissolution of thesilver and measurement by atomic absorption spectrometry.Copper concentrates are internationally traded within thefollowing content ranges:ElementUnitContent RangeAluminum%0.05to2.50Antimony%0.0001to4.50Arsenic%0.01to0.50Barium%0.003to0.10Bismuth%0.001to0.16Cadmium%0.0005to0.04Calcium%0.05to4.00Carbon%0.10to0.90Chlorine%0.001to0.006Chromium%0.0001to0.10Cobalt%0.0005to0.20Copper%10.0to44.0Fluorine%0.001to0.10Goldg/g1.40to100.0Iron%12.0to30.0Lead%0.01to1.40Magnesium%0.02to2.00Manganese%0.009to0.10Mercuryg/g0.05to50.0Molybdenum%0.002to0.25Nickel%0.0001to0.08Silicon%0.40to20.0Silverg/g18.0to8000Sulfur%10.0to36.0Tin%0.004to0.012Zinc%0.005to4.301.2 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 its use.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 MaterialsE882 Guide for Accountability and Quality Control in theChemical Analysis LaboratoryE1601 Practice for Conducting an Interlaboratory Study toEvaluate the Performance of an Analytical MethodE1763 Guide for Interpretation and Use of Results fromInterlaboratory Testing of Chemical Analysis Methods3.Terminology3.1 DefinitionsFor definitions of terms used in this testmethod,refer to Terminology E135.4.Summary of Test Method4.1 The analyst has the option of either digesting the samplein HNO3and HCl or HNO3and HClO4,depending on theirpreference and equipment availability.The filtered solutionsare aspirated into an air-acetylene flame of an atomic absorp-tion spectrometer.Spectral energy at approximately 328.1 nmfrom a silver hollow cathode lamp is passed through the flameand the absorbance is measured.This absorbance is comparedwith the absorbance of a series of standard calibration solu-tions.5.Significance and Use5.1 In the primary metallurgical processes used by themineral processing industry for copper bearing ores,copperand silver associated with sulfide mineralization are concen-trated by the process of flotation for recovery of the metals.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 1997.Last previous edition approved in 2007 as E1898-07.DOI:10.1520/E1898-13.2For 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 5.2 This test method is a comparative method and isintended to be a referee method for compliance with compo-sitional specifications for metal content or to monitor pro-cesses.5.3 It is assumed that all who use this method will be trainedanalysts capable of performing skillfully and safely.It isexpected that work will be performed in a properly equippedlaboratory and that proper waste disposal procedures will befollowed.Appropriate quality control practices must be fol-lowed such as those described in Guide E882.6.Interferences6.1 Elements normally found in copper concentrates do notinterfere.Use of instrumental background correction is re-quired to compensate for non specific absorption interferencesin the flame.7.Apparatus7.1 Atomic Absorption Spectrometer,capable of resolvingthe 328.1 nm silver line,equipped with an air-acetylene premixburner and a silver hollow cathode lamp.The performance ofthe instrument must be such that the response of silverabsorbance is linear over the range of 0.5 g/mL to 4.0 g/mL.8.Reagents and Materials8.1 Silver C