1、BSI Standards PublicationBS ISO 10378:2016Copper, lead and zinc sulfideconcentrates Determinationof gold and silver Fire assaygravimetric and flame atomicabsorption spectrometricmethodBS ISO 10378:2016 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 10378:2016.
2、 Itsupersedes BS ISO 10378:2005 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee NFE/36, Copper lead and zinc ores and concentrates.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not
3、 purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2016. Published by BSI StandardsLimited 2016ISBN 978 0 580 89275 2ICS 73.060.99Compliance with a British Standard cannot confer immunity fromlegal obliga
4、tions.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 29 February 2016.Amendments issued since publicationDate Text affectedBS ISO 10378:2016 ISO 2016Copper, lead and zinc sulfide concentrates Determination of gold and silver Fire assay gravim
5、etric and flame atomic absorption spectrometric methodConcentrs de sulfure de cuivre, de plomb et de zinc Dosage de lor et de largent Mthode gravimtrique par essai au feu et spectromtrie dabsorption atomique dans la flammeINTERNATIONAL STANDARDISO10378Third edition2016-02-15Reference numberISO 10378
6、:2016(E)BS ISO 10378:2016ISO 10378:2016(E)ii ISO 2016 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2016, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mech
7、anical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, Swi
8、tzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 10378:2016ISO 10378:2016(E)Foreword vIntroduction vi1 Scope . 12 Normative references 13 Principle 23.1 General . 23.2 Fusion 23.3 Cupellation 23.4 Parting 23.5 Retreatment . 23.6 Correction for blank contamination .
9、24 Reagents 25 Apparatus . 46 Sample . 56.1 Test sample . 56.2 Test portion 57 Procedure. 67.1 Number of determinations . 67.2 Trial fusion 67.3 Blank tests . 67.4 Charge preparation . 67.5 Primary fusion . 77.6 Cupellation 87.7 Retreatment of residues 87.8 Determination of gold in the primary bead
10、. 97.9 Determination of gold and silver in secondary beads and blanks, and of silver in prills 107.10 Determination of silver in the parting solution .118 Expression of results .128.1 Mass fraction of gold . 128.2 Mass fraction of silver 139 Precision 149.1 Expression of precision 149.2 Method for o
11、btaining the final result (see Annex H) .159.3 Precision between laboratories . 159.4 Check of trueness . 179.4.1 General. 179.4.2 Type of certified reference material (CRM) or reference material (RM) .1810 Test report 18Annex A (normative) Procedure for the preparation and determination of the mass
12、 of a predried test portion 19Annex B (normative) Trial fusion .21Annex C (normative) Blank determination 22Annex D (normative) Inquartation .23Annex E (normative) Determination of vaporization loss of silver during the cupellation process .24Annex F (normative) Sulfuric acid Parting 25Annex G (norm
13、ative) Determination of impurities in parting solutions and washings 27 ISO 2016 All rights reserved iiiContents PageBS ISO 10378:2016ISO 10378:2016(E)Annex H (normative) Flowsheet of the procedure for the acceptance of analytical values for test samples (see 9.2) .31Annex I (informative) Flowsheet
14、of the method 32Annex J (informative) Roasting method .33Annex K (informative) Guide to the preparation of dilutions for the determination of silver in parting solutions and residues 34Annex L (informative) Derivation of precision equations .35Bibliography .50iv ISO 2016 All rights reservedBS ISO 10
15、378:2016ISO 10378:2016(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in
16、 a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commiss
17、ion (IEC) on all matters of electrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents shou
18、ld be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for ide
19、ntifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).Any trade name used in this document is information given for the conven
20、ience of users and does not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword -
21、 Supplementary informationThe committee responsible for this document is ISO/TC 183, Copper, lead, zinc and nickel ores and concentrates.This third edition cancels and replaces the second edition (ISO 10378:2005), in which 6.2 has been technically revised and the warning notice in A.3.1 has been upd
22、ated. ISO 2016 All rights reserved vBS ISO 10378:2016ISO 10378:2016(E)IntroductionThis International Standard describes a method for the determination of the mass fraction of gold and silver in copper, lead, and zinc sulfide concentrates. This International Standard was prepared to enable laboratori
23、es to determine the mass fraction of gold and silver in suitable samples using instrumental methods.vi ISO 2016 All rights reservedBS ISO 10378:2016Copper, lead and zinc sulfide concentrates Determination of gold and silver Fire assay gravimetric and flame atomic absorption spectrometric methodWARNI
24、NG This International Standard may involve hazardous materials, operations, and equipment. It is the responsibility of the user of this International Standard to establish appropriate health and safety practices and determine the applicability of regulatory limitations prior to use.1 ScopeThis Inter
25、national Standard specifies a fire assay gravimetric and flame atomic absorption spectrometric method for the determination of the mass fraction of gold and silver in copper, lead, and zinc sulfide concentrates as follows. Copper concentratesThe method is applicable to the determination of mass frac
26、tions of gold from 0,5 g/t to 300 g/t and of mass fractions of silver from 25 g/t to 1 500 g/t in copper sulfide concentrates containing mass fractions of copper from 15 % to 60 %. Lead concentratesThe method is applicable to the determination of mass fractions of gold from 0,1 g/t to 25 g/t and of
27、mass fractions of silver from 200 g/t to 3 500 g/t in lead sulfide concentrates containing mass fractions of lead from 10 % to 80 %. Zinc concentratesThe method is applicable to the determination of mass fractions of gold from 0,1 g/t to 12 g/t and of mass fractions of silver from 10 g/t to 800 g/t
28、in zinc sulfide concentrates containing mass fractions of zinc up to 60 %.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated refer
29、ences, the latest edition of the referenced document (including any amendments) applies.ISO 385, Laboratory glassware BurettesISO 648, Laboratory glassware Single-volume pipettesISO 1042, Laboratory glassware One-mark volumetric flasksISO 3696, Water for analytical laboratory use Specification and t
30、est methodsISO 4787, Laboratory glassware Volumetric instruments Methods for testing of capacity and for useISO 9599, Copper, lead and zinc sulfide concentrates Determination of hygroscopic moisture in the analysis sample Gravimetric methodINTERNATIONAL STANDARD ISO 10378:2016(E) ISO 2016 All rights
31、 reserved 1BS ISO 10378:2016ISO 10378:2016(E)3 Principle3.1 GeneralFire assaying for the determination of gold and silver comprises a series of steps to separate firstly the precious metals from most of the associated metals, followed by separation of the gold from silver and other metals pre-concen
32、trated into a precious-metal alloy.The stages that comprise the determinations are described in 3.2 to 3.6 inclusive.3.2 FusionThe samples are fused in a crucible after mixing with a litharge-based flux which, under reducing conditions, collects the precious metals in a metallic lead button.3.3 Cupe
33、llationThe base metals present in the lead button are substantially separated from the precious metals by oxidizing fusion. Cupellation produces a bead largely comprising a silver-gold alloy with small quantities of other metals.3.4 PartingGold is separated from the primary bead by treatment with ni
34、tric acid. The gold prill is weighed. Gold prills having a mass less than 50 g are dissolved in aqua regia and the gold is determined by atomic absorption spectrometry (AAS). Silver is determined in the parting solution by AAS.3.5 RetreatmentAll residues are retreated to maximize the recovery of gol
35、d and silver. The addition of collectors for either gold or silver is not required, as both metals are present in sufficient amounts to be readily visible after the cupellation stage. The second bead is dissolved in acids followed by analysis of both metals by AAS.3.6 Correction for blank contaminat
36、ionContamination by gold and silver impurities in the reagents is corrected for by fusing the reagents without the test portion.4 ReagentsDuring the analysis, use only reagents of recognized analytical grade and water that complies with grade 2 of ISO 3696.4.1 Sodium carbonate, anhydrous.4.2 Litharg
37、e (PbO), assay grade having a mass fraction of gold of less than 0,01 g/t and a mass fraction of silver of less than 0,2 g/t.4.3 Silica, precipitated.4.4 Potassium nitrate or sodium nitrateNOTE If sodium nitrate is used, the masses specified for potassium nitrate will have to be modified:2 ISO 2016
38、All rights reservedBS ISO 10378:2016ISO 10378:2016(E)gofKNO gofNaNO33=85 0101 1,4.5 Flour4.6 Borax, fused anhydrous sodium tetraborate (borax glass powder).4.7 Nitric acid, concentrated (201,42 g/ml), chloride concentration AC (41)If this condition exists, the difference between the reported result
39、and the certified value is statistically significant. ISO 2016 All rights reserved 17BS ISO 10378:2016ISO 10378:2016(E)In Formulae (40) and (41), the symbols have the following meanings:cis the final result, in grams of gold or silver per tonne, of the certified reference material;Acis the certified
40、 value, in grams of gold or silver per tonne, of the certified reference material;C is a quantity, in grams of gold or silver per tonne, depending on the type of the certified refer-ence material used, as defined in 9.4.2.9.4.2 Type of certified reference material (CRM) or reference material (RM)The
41、 reference materials used for this purpose should be prepared and certified in accordance with ISO Guide 35.9.4.2.1 Reference material certified/characterized by an interlaboratory test programmeThe quantity C (see 9.4.1), in grams of gold or silver per tonne, is given by Formula (24):CSSnSA=+22L2 r
42、2c(42)whereS2Acis the variance of the certified value;n is the number of replicate determinations.9.4.2.2 Reference material certified/characterized by one laboratoryThe quantity C (see 9.4.1), in grams of gold or silver per tonne, is given by Formula (43):CSSn=+22L2 r2(43)NOTE It is recommended tha
43、t this type of certified reference material be avoided, unless the particular CRM is known to have an unbiased certified value.10 Test reportThe test report shall include the following information:a) identification of the sample;b) reference to this International Standard, i.e. ISO 10378;c) mass fra
44、ction of gold of the sample, expressed in grams per tonne;d) mass fraction of silver of the sample, expressed in grams per tonne;e) date on which the test was carried out;f) any occurrences noticed during the determination that may have had an influence on the results.18 ISO 2016 All rights reserved
45、BS ISO 10378:2016ISO 10378:2016(E)Annex A (normative) Procedure for the preparation and determination of the mass of a predried test portionA.1 GeneralThis Annex specifies a method for the preparation and determination of the mass of a predried test portion in the analysis of copper, lead, and zinc
46、sulfide concentrates. The method is applicable to copper, lead, and zinc sulfide concentrates not susceptible to oxidation and having hygroscopic moisture contents ranging from 0,05 % to 2 %.A.2 PrincipleThe test portion to be used for analysis is dried in air in an oven maintained at 105 C 5 C. The
47、 dried test portion is then weighed and used for the analysis. No correction for hygroscopic moisture is required.A.3 ReagentsA.3.1 Desiccant, such as self-indicating silica gel or anhydrous magnesium perchlorate.WARNING Care needs to be taken whenever disposing of exhausted magnesium perchlorate an
48、d all other laboratory chemicals. Environmental regulations often apply. Users should seek specialists advice to determine an appropriate, effective, health-conscious, safety-conscious, and environmentally sound means of disposal.A.4 ApparatusOrdinary laboratory equipment, and the following.A.4.1 An
49、alytical balance, sensitive to 0,1 mg.A.4.2 Weighing vessels, of glass or silica or corrosion-resistant metal, with externally-fitting airtight covers.For small test portions (of mass less than 3 g), the mass of the vessel shall be as small as possible, i.e. less than 20 g.A.4.3 Laboratory oven, capable of maintaining a temperature of 105 C 5 C.A.5 ProcedureA.5.1 Preparation of the weighing vesselDry the weighing vessel and its cover (A.4.2) by heating in the laboratory oven (A.4.3) at 10
