GB/T 3884.20-2018Methods for chemical analysis of copper concentrates—Part 20:Determination of mercury content—Solid sampling and direct mercury analysis method (English PDF)

Foreword

GB/T 3884 "Chemical Analysis Method for Copper Concentrate" is divided into 21 parts.

--- Part 1. Determination of copper content iodometric method;

--- Part 2. Determination of gold and silver content by flame atomic absorption spectrometry and fire assay method;

---Part 3. Determination of sulfur content by gravimetric method and combustion-titration method;

--- Part 4. Determination of magnesium oxide content by flame atomic absorption spectrometry;

---Part 5. Determination of the amount of fluorine ion selective electrode method;

---Part 6. Determination of lead, zinc, cadmium and nickel - Atomic

---Part 7. Determination of lead content by Na2EDTA titration;

---Part 8. Determination of zinc content by Na2EDTA titration;

---Part 9. Determination of arsenic and bismuth - Hydride generation - atomic fluorescence spectrometry, potassium bromate titration and diethyl dithio Silver formate acid spectrophotometry;

---Part 10. Determination of enthalpy - hydride generation - atomic fluorescence spectrometry;

--- Part 11. Determination of mercury content by cold atomic absorption spectrometry;

--- Part 12. Determination of fluorine and chlorine content by ion chromatography;

--- Part 13. Determination of copper content electrolysis;

--- Part 14. Determination of gold and silver content by fire test method and atomic absorption spectroscopy;

---Part 15. Determination of iron content - Potassium dichromate titration;

---Part 16. Determination of the amount of silica - Potassium fluorosilicate titration and gravimetric method;

---Part 17. Determination of the amount of aluminium oxide - chrome azurol S micellar solubilizing photometric method and precipitation separation - fluoride salt replacement - Na2EDTA titration;

---Part 18. Determination of arsenic, antimony, bismuth, lead, zinc, nickel, cadmium, cobalt, magnesium oxide, calcium oxide Shot spectroscopy

---Part 19. Determination of enthalpy - inductively coupled plasma mass spectrometry;

--- Part 20. Determination of mercury content - Direct method of solid injection;

--- Part 21. Determination of copper, sulfur, lead, zinc, iron, aluminium, calcium, magnesium and manganese.

This part is the 20th part of GB/T 3884.

This part is drafted in accordance with the rules given in GB/T 1.1-2009.

1 Scope

This part of GB/T 3884 specifies the method for determining the amount of mercury in copper concentrates.

This section applies to the determination of mercury in copper concentrates, the measurement range (mass fraction). 0.050µg/g ~ 21.0µg/g.

2 Normative references

The following documents are indispensable for the application of this document. For dated references, only dated versions apply to this document. For undated references, the latest edition (including all amendments) applies to this document.

GB/T 6682 Analytical laboratory water specifications and test methods

3 Method summary

In an oxygen atmosphere, after the sample is dried and pyrolyzed in a decomposition furnace, mercury is atomized and mercury vapor is carried into the single wavelength by the oxygen stream.

The optical absorption cell measures the absorbance (peak height or peak area) of mercury at a wavelength of 253.7 nm, and the amount of mercury is calculated by a standard curve method.

4 Reagents

Unless otherwise stated, only reagents identified as superior grade are used in the analysis, and the water used is the first grade water in accordance with GB/T 6682. Or water of considerable purity.

4.1 Nitric acid (rho = 1.42 g/mL).

4.2 Nitric acid (1 19).

4.3 Potassium dichromate solution (10 g/L). 1 g of potassium dichromate was weighed and dissolved in 100 mL of water.

4.4 Mercury standard storage solution. Weigh 1.354g of mercury dichloride dried in advance with phosphorus pentoxide for 24h, dissolved in a small amount of water, added 50 mL of nitric acid (4.1), 10 mL of potassium dichromate solution (4.3), make up to 1000 mL with water, and mix. This solution contains 1000 µg of mercury per ml. Or use certified standard substances directly.

4.5 Mercury Standard Solution A. Accurately transfer 2.00 mL of mercury standard stock solution (4.4) to a 100 mL volumetric flask and add 1 mL of dichromic acid. Potassium solution (4.3), make up to volume with nitric acid (4.2), and mix. This solution contains 20 µg of mercury per ml.

4.6 Mercury Standard Solution B. Accurately transfer 5.00 mL of mercury standard solution A (4.5) to a 100 mL volumetric flask and add 1 mL of potassium dichromate. Solution (4.3), make up to volume with nitric acid (4.2), and mix. This solution contained 1 µg of mercury per ml.

4.7 Oxygen (wO2 >= 99.99%).

5 Instruments

Direct mercury analyzer. The lower limit of mercury detection should be no more than 0.50 ng, and the upper limit should be no less than 1000 ng.