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