AS 3515.1-1996

1 - AS 3515.1-1996 GOLD AND GOLD BEARING ALLOYS - DETERMINATION OF GOLD CONTENT (LESS THAN 30%)-GRAVIMETRIC METHOD
4 - PREFACE
5 - CONTENTS
6 - SECTION 1 SCOPE AND GENERAL
6 - 1.1 SCOPE
6 - 1.2 REFERENCED DOCUMENTS
6 - 1.3 DEFINITIONS
6 - 1.3.1 Cornet
6 - 1.3.2 Cupellation
6 - 1.3.3 Gold cornet
6 - 1.3.4 Laboratory sample
7 - 1.3.5 Parting
7 - 1.3.6 Prill
7 - 1.3.7 Proof
7 - 1.3.8 Surcharge
7 - 1.3.9 Test portion
7 - 1.3.10 Test sample
7 - 1.4 REAGENTS
7 - 1.4.1 General requirements
7 - 1.4.2 Nitric acid (1+2)
7 - 1.4.3 Nitric acid (1+1)
7 - 1.4.4 Nitric acid (1+7)
7 - 1.4.5 Silver
7 - 1.4.6 Proof gold
7 - 1.4.7 Copper metal
7 - 1.4.8 Lead foil
7 - 1.4.9 Ammonium hydrogen difluoride
7 - 1.5 APPARATUS
7 - 1.5.1 Magnesite cupels
7 - 1.5.2 Anvil and hammer
7 - 1.5.3 Analytical balance
7 - 1.5.4 Analytical balance
8 - 1.5.5 Cupellation furnace
8 - 1.5.6 Muffle
8 - 1.5.7 Rollers
8 - 1.5.8 Parting trays (baskets)
8 - 1.5.9 Prill cleaning brush
8 - 1.6 PRECISION
8 - 1.7 ACCEPTANCE OF RESULTS
8 - 1.7.1 Certified reference materials
8 - 1.7.2 Test results
9 - 1.8 TEST REPORT
10 - SECTION 2 SAMPLE PREPARATION AND ASSESSMENT
10 - 2.1 SAMPLE PREPARATION
10 - 2.2 DETERMINATION OF THE TOTAL PRECIOUS METALS, APPROXIMATE GOLD, SILVER AND TOTAL BASE METALS CONTENT
10 - 2.2.1 Test portion preparation
10 - 2.2.2 Cupellation
10 - 2.2.3 Parting
11 - 2.2.4 Calculations
12 - SECTION 3 TOTAL PRECIOUS METALS CONTENT LESS THAN 40%
12 - 3.1 SCOPE
12 - 3.2 PRINCIPLE
12 - 3.3 NUMBER OF DETERMINATIONS
12 - 3.4 PROOF TESTS
12 - 3.5 PREPARATION OF TEST PORTION
13 - 3.6 CUPELLATION
13 - 3.7 PARTING
14 - 3.8 CALCULATIONS
14 - 3.8.1 Change in mass of proof
14 - 3.8.2 Adjusted mass of the gold cornet
15 - 3.8.3 Gold content
16 - SECTION 4 TOTAL PRECIOUS METALS CONTENT GREATER THAN 40%
16 - 4.1 SCOPE
16 - 4.2 PRINCIPLE
16 - 4.3 NUMBER OF DETERMINATIONS
16 - 4.4 PROOF TESTS
16 - 4.5 PREPARATION OF THE TEST PORTION
17 - 4.6 CUPELLATION
17 - 4.7 PARTING
17 - 4.8 CALCULATIONS
17 - 4.8.1 Change in mass of proof
17 - 4.8.2 Adjusted mass of the gold cornet
18 - 4.8.3 Gold content
19 - APPENDIX A - METHODS OF SAMPLING DORE BULLION
19 - A1 SCOPE
19 - A2 CRITERIA FOR SELECTION OF A METHOD
19 - A3 VACUUM TUBE SAMPLING
19 - A3.1 Principle
19 - A3.2 Procedure
19 - A4 DIP SAMPLING
19 - A4.1 Principle
19 - A4.2 Sampling apparatus
20 - A4.3 Procedure
21 - A5 SAMPLING BY CLIPPING
21 - A6 SAMPLING BY SAWING
21 - A7 SAMPLING BY DRILLING

Sets out a gravimetric procedure (fire assay) for the the determination of gold content in gold and gold alloys with a concentration of less than 30 percent. Two methods are specified: the first where the total precious metals content is greater than 40 percent and the second is used when the total precious metals content is less than 40 percent.

This Standard sets out sample preparation and gravimetric procedures for the determination of gold content in the range 0.2% to 30% in gold and gold bearing alloys with, <2% nickel, <0.05% rhodium, <0.05% tungsten and <0.5% tin. Platinum and palladium should be absent.There are two methods of gold determination described: the first method is used when the total precious metal content is less than 40% and the second method is used when the total precious metal content is greater than 40%. A preliminary assay may first be performed to determine the gold, silver and base metal present.

First published as AS 3515.1-1996.