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1、BRITISH STANDARD BS ISO 10378:2005 Copper, lead and zinc sulfide concentrates Determination of gold and silver Fire assay gravimetric and flame atomic absorption spectrometric method ICS 73.060.99 ? Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 06:42:30 GMT+00:00 2006, Uncontrolled Copy, (c
2、) BSI BS ISO 10378:2005 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 16 September 2005 BSI 16 September 2005 ISBN 0 580 46413 X National foreword This British Standard reproduces verbatim ISO 10378:2005 and implements it as the UK national
3、 standard. The UK participation in its preparation was entrusted to Technical Committee NFE/36, Copper, lead and zinc ores and concentrates, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The Britis
4、h Standards which implement international publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publ
5、ication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible internatio
6、nal/European committee any enquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the ISO title pag
7、e, pages ii to vi, pages 1 to 52, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. DateComments Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 06:42:30 GMT+00:0
8、0 2006, Uncontrolled Copy, (c) BSI Reference number ISO 10378:2005(E) INTERNATIONAL STANDARD ISO 10378 Second edition 2005-07-01 Copper, lead and zinc sulfide concentrates Determination of gold and silver Fire assay gravimetric and flame atomic absorption spectrometric method Concentrs sulfurs de cu
9、ivre, de plomb et de zinc Dosage de lor et de largent Mthode gravimtrique par essai au feu et spectromtrie dabsorption atomique dans la flamme BS ISO 10378:2005 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 06:42:30 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ii Licensed Copy: sheffieldun sh
10、effieldun, na, Mon Nov 27 06:42:30 GMT+00:00 2006, Uncontrolled Copy, (c) BSI iii Contents Page Foreword. v Introduction. vi 1 Scope . 1 2 Normative references. 1 3 Principle. 2 3.1 Fusion 2 3.2 Cupellation 2 3.3 Parting 2 3.4 Retreatment. 2 3.5 Correction for blank contamination 2 4 Reagents 2 5 Ap
11、paratus 4 6 Sample . 5 6.1 Test sample . 5 6.2 Test portion. 5 7 Procedure 5 7.1 Number of determinations. 5 7.2 Trial fusion. 5 7.3 Blank tests. 5 7.4 Charge preparation. 6 7.5 Primary fusion. 7 7.6 Cupellation 7 7.7 Retreatment of residues. 8 7.8 Determination of gold in the primary bead 8 7.9 Det
12、ermination of gold and silver in secondary beads and blanks, and of silver in prills. 9 7.10 Determination of silver in the parting solution 11 8 Expression of results . 11 8.1 Mass fraction of gold 11 8.2 Mass fraction of silver 12 9 Precision 13 9.1 Expression of precision. 13 9.2 Method for obtai
13、ning the final result (see Annex H). 14 9.3 Precision between laboratories. 15 9.4 Check of trueness. 17 9.4.1 General. 17 9.4.2 Type of certified reference material (CRM) or reference material (RM) 17 10 Test report . 18 Annex A (normative) Procedure for the preparation and determination of the mas
14、s of a predried test portion 19 Annex B (normative) Trial fusion 21 Annex C (normative) Blank determination 22 Annex D (normative) Inquartation 23 Annex E (normative) Determination of vaporization loss of silver during the cupellation process . 24 Annex F (normative) Sulfuric acid - Parting 25 BS IS
15、O 10378:2005 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 06:42:30 GMT+00:00 2006, Uncontrolled Copy, (c) BSI iv Annex G (normative) Determination of impurities in parting solutions and washings.27 Annex H (normative) Flowsheet of the procedure for the acceptance of analytical values for t
16、est samples (see 9.2) 31 Annex I (informative) Flowsheet of the method.32 Annex J (informative) Roasting method.33 Annex K (informative) Guide to the preparation of dilutions for the determination of silver in parting solutions and residues34 Annex L (informative) Derivation of precision equations.3
17、5 Bibliography .52 BS ISO 10378:2005 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 06:42:30 GMT+00:00 2006, Uncontrolled Copy, (c) BSI v Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of
18、preparing International Standards is normally carried out through ISO technical committees. Each member body interested in 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,
19、 in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main t
20、ask of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attent
21、ion 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 identifying any or all such patent rights. ISO 10378 was prepared by Technical Committee ISO/TC 183, Copper, lead, zinc and nickel ores and concentrat
22、es. This second edition cancels and replaces the first edition (ISO 10378:1994), which has been technically revised. BS ISO 10378:2005 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 06:42:30 GMT+00:00 2006, Uncontrolled Copy, (c) BSI vi Introduction This International Standard describes a me
23、thod 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 laboratories to determine the mass fraction of gold and silver in suitable samples using instrumental methods. BS ISO 10378:2005 Licens
24、ed Copy: sheffieldun sheffieldun, na, Mon Nov 27 06:42:30 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 1 Copper, lead and zinc sulfide concentrates Determination of gold and silver Fire assay gravimetric and flame atomic absorption spectrometric method WARNING This International Standard may involve h
25、azardous 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 Scope This International Standard specifies a fire assay gr
26、avimetric 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 concentrates: The method is applicable to the determination of mass fractions of gold from 0,5 g/t to 300 g/t and
27、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 concentrates The method is applicable to the determination of mass fractions of gold from 0,1 g/t to 25 g/t and of mass fractions of silver from 200 g/t to
28、3 500 g/t in lead sulfide concentrates containing mass fractions of lead from 10 % to 80 %. Zinc concentrates The 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 in zinc sulfide concentrates containing
29、mass fractions of zinc up to 60 %. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments)
30、applies. ISO 385-1:1984, Laboratory glassware Burettes Part 1: General requirements ISO 648:1977, Laboratory glassware One-mark pipettes ISO 1042:1998, Laboratory glassware One-mark volumetric flasks ISO 3696:1987, Water for analytical laboratory use Specification and test methods ISO 4787:1984, Lab
31、oratory glassware Volumetric glassware Methods for use and testing of capacity ISO 9599:1991, Copper, lead and zinc sulfide concentrates Determination of hygroscopic moisture in the analysis sample Gravimetric method BS ISO 10378:2005 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 06:42:30 G
32、MT+00:00 2006, Uncontrolled Copy, (c) BSI 2 3 Principle Fire 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 preconcentrated into
33、a precious-metal alloy. The stages that comprise the determinations are described in 3.1 to 3.5 inclusive. 3.1 Fusion The 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. 3.2 Cupellation
34、The 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. 3.3 Parting Gold is separated from the primary bead by treatment with nitric
35、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. 3.4 Retreatment All residues are retreated to maximize the recovery of gold a
36、nd 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. 3.5 Correction for blank contaminatio
37、n Contamination by gold and silver impurities in the reagents is corrected for by fusing the reagents without the test portion. 4 Reagents During 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 Lith
38、arge (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 nitrate NOTE If sodium nitrate is used, the masses specified for potassium nitrate will have to be modified: 33 8
39、5,0 g of KNOg of NaNO 101,1 = 4.5 Flour BS ISO 10378:2005 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 06:42:30 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 3 4.6 Borax, fused anhydrous sodium tetraborate (borax glass powder). 4.7 Nitric acid, concentrated (20 1,42 g/ml), chloride concentrat
40、ion (41) If this condition exists, the difference between the reported result and the certified value is statistically significant. In Equations (40) and (41), the symbols have the following meanings: c is the final result, in grams of gold or silver per tonne, of the certified reference material; A
41、c is the certified 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 reference material used, as defined in 9.4.2. 9.4.2 Type of certified reference material (CRM) or referen
42、ce material (RM) The 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 programme The quantity C (see 9.4.1), in grams of gold or silver per tonne, is given by the f
43、ollowing equation: 222 Lrc 2(/ )CSSnSA=+ (42) where S2 Ac is the variance of the certified value; n is the number of replicate determinations. 9.4.2.2 Reference material certified/characterized by one laboratory The quantity C (see 9.4.1), in grams of gold or silver per tonne, is given by the follow
44、ing equation: 22 Lr 2 2/CSSn=+ (43) It is recommended that this type of certified reference material be avoided, unless the particular CRM is known to have an unbiased certified value. BS ISO 10378:2005 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 06:42:30 GMT+00:00 2006, Uncontrolled Copy
45、, (c) BSI 18 10 Test report The test report shall include the following information: a) identification of the sample; b) reference to this International Standard, i.e. ISO 10378; c) mass fraction of gold of the sample, expressed in grams per tonne; d) mass fraction of silver of the sample, expressed
46、 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. BS ISO 10378:2005 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 06:42:30 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 19 Annex A (
47、normative) Procedure for the preparation and determination of the mass of a predried test portion A.1 Scope This 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 sulfide concentrates. The method is applicab
48、le to copper, lead and zinc sulfide concentrates not susceptible to oxidation and having hygroscopic moisture contents ranging from 0,05 % to 2 %. A.2 Principle The test portion to be used for analysis is dried in air in an oven maintained at 105 C 5 C. The dried test portion is then weighed and use
49、d for the analysis. No correction for hygroscopic moisture is required. A.3 Reagents A.3.1 Desiccant, such as self-indicating silica gel or anhydrous magnesium perchlorate. WARNING Care shall be taken when disposing of exhausted magnesium perchlorate. It shall be washed down the sink with a stream of running water. A.4 Apparatus Ordinary laboratory equipment, and the following. A.4.1 Analytical balance, sensitive to 0,1 mg. A.4.2 Weighing vessels, of g