AS 2678.5-2002

1 - AS 2678.5-2002 ZINC SULFIDE CONCENTRATES-CHEMICAL ANALYSIS - DETERMINATION OF SILVER AND GOLD CONTENTS-FIRE ASSAY A
4 - PREFACE
5 - CONTENTS
7 - 1 Scope
7 - 2 Normative references
7 - 3 Principle
7 - 3.1 Scorification
8 - 3.2 Cupellation
8 - 4 Reagents
8 - 4.1 Sodium carbonate
8 - 4.2 Litharge
8 - 4.3 Silica
8 - 4.4 Potassium nitrate or sodium nitrate
8 - 4.5 Flour
8 - 4.6 Nitric acid
8 - 4.7 Nitric acid wash solution
8 - 4.8 Nitric acid
8 - 4.9 Hydrochloric acid
8 - 4.10 Borax
8 - 4.11 Silver metal
8 - 4.12 Gold metal
8 - 4.13 Aqua regia
8 - 4.14 Ammonia solution
8 - 4.15 Standard solutions
9 - 4.16 Calibration solutions
9 - 5 Apparatus
9 - 5.1 Volumetric glassware
9 - 5.2 Conventional fire assay equipment
10 - 5.3 Balances
10 - 5.4 Atomic absorption spectrometer (AAS)
10 - 5.5 Filtration equipment
10 - 5.6 Burette
10 - 6 Sample
10 - 6.1 Test sample
10 - 6.2 Test portion
10 - 7 Procedure
10 - 7.1 Number of determinations
11 - 7.2 Trial fusion
11 - 7.3 Blank tests
11 - 7.4 Charge preparation
11 - 7.5 Primary fusion
12 - 7.6 Selection of recovery procedure
12 - 7.7 Scorification
13 - 7.8 Cupellation
13 - 7.9 Treatment of the lead buttons or silver/gold beads
14 - 7.10 Determination of silver in the test solution by flame atomic absorption spectrometry
14 - 7.11 Determination of gold in the test solution by flame atomic absorption spectrometry
15 - 8 Expression of results
15 - 8.1 Silver content
15 - 8.2 Gold content
16 - 9 Precision
16 - 9.1 Expression of precision
16 - 9.2 Method for obtaining the final result
16 - 9.3 Precision between laboratories
17 - 9.4 Check of trueness
18 - 10 Test report
19 - Annex A Procedure for the preparation and determination of the mass of a predried test portion
19 - A.1 Scope
19 - A.2 Principle
19 - A.3 Reagents
19 - A.4 Apparatus
19 - A.5 Procedure
20 - A.6 Calculation of the test portion dry mass
21 - Annex B Trial fusion
21 - B.1 Introduction
21 - B.2 Procedure
22 - Annex C Blank determination
22 - C.1 Introduction
22 - C.2 Procedure
23 - Annex D Flowsheet of the procedure for the acceptance of analytical values for the test samples
24 - Annex E Derivation of precision equations
24 - E.1 Introduction
24 - E.2 Design of test programme
24 - E.3 Test samples
24 - E.4 Statistical evaluation
31 - Annex F Bibliography

Sets out a fire assay flame AAS method for determining the silver and gold contents of zinc sulfide concentrates. This Standard is identical with and has been reproduced from ISO 15248:1998.

This International Standard specifies a fire assay and flame atomic absorption spectrometric procedure for the determination of silver and gold contents of zinc sulfide concentrates.The method is applicable to the determination of silver and gold in zinc sulfide concentrates containing up to 60 % ( m/ m) zinc in the form of zinc blende and related materials.The method is applicable to silver contents from 10 g/t to 500 g/t and gold contents from 0,1 g/t to 12 g/t.

First published as AS 2678.5-2002.