Methods for chemical analysis of copper concentrates - Part 2: Determination of gold and silver contents - Flame atomic absorption spectrmetric method and fire assay method
1 Scope
This method specifies the determination of gold and silver contents in copper concentrate.
This method applies to the determination of gold and silver contents in copper concentrate. Determination scope of Method 1: silver: 10.0 g/t~300.0 g/t; determination scope of Method 2: gold: 0.50 g/t~40.00 g/t; silver: 50.0 g/t~2 500.0 g/t
2 Method 1: Flame Atomic Absorption Spectrometric Method
2.1 Summary
Dissolve test material with nitric acid and perchloric acid, determine the silver absorbance with air-acetylene flame through atomic absorption spectrometer at a wavelength of 328.1nm in diluted hydrochloric acid medium, and calculate the silver contents according to standard curve.
2.2 Reagents
Unless otherwise specified, during the analysis, only identified analytical grade reagent and distilled water, or deionized water or water with equivalent purity are to be used.
2.2.1 Ammonium bifluoride.
2.2.2 Hydrochloric acid (ρ=1.19 g/mL).
2.2.3 Hydrochloric acid (1+9).
2.2.4 Nitric acid (ρ=1.42 g/mL).
2.2.5 Nitric acid (1+1).
2.2.6 Perchloric acid (ρ=1.67 g/mL).
2.2.7 Standard silver storage solution: Weigh 0.1000g fine silver (wAg ≥99.99%) and place it in a 200mL beaker. Add 20mL nitric acid (2.2.5) and then heat it until full dissolution. Cool it to room temperature and then transfer it to a 200mL brown volumetric flask. Dilute it with chloridion-free exchange water to the scale and then mix it uniformly. 1mL of such solution contains 500μg silver.
2.2.8 Standard silver solution: Put 10.00mL standard silver storage solution (2.2.7) in a 100mL volumetric flask. Dilute it with hydrochloric acid (1+9) to the scale and then mix it uniformly. 1mL of such solution contains 20μg silver.
2.3 Instrument
Foreword I
1 Scope
2 Method 1: Flame Atomic Absorption Spectrometric Method
3 Method 2: Fire Assay Method
