GB/T 1819.9-2017Methods for chemical analysis of tin concentrates—Part 9: Determination of tungsten trioxide content—The thiocyanate spectrophotometric method (English PDF)

Foreword

GB/T 1819 "tin concentrate chemical analysis method" is divided into the following 21 sections.

--- Part 1. Determination of moisture thermal drying method;

--- Part 2. Determination of tin content potassium iodate titration;

--- Part 3. Determination of iron content cerium sulfate titration method;

--- Part 4. Determination of lead content by flame atomic absorption spectrometry and Na2 EDTA titration;

--- Part 5. Determination of arsenic Arsenic antimony molybdenum blue spectrophotometry and iodometric titration;

--- Part 6. Determination of the amount of antimony; malachite green spectrophotometry and flame atomic absorption spectrometry;

--- Part 7. Determination of bismuth content by flame atomic absorption spectrometry;

--- Part 8. Determination of zinc content by flame atomic absorption spectrometry;

--- Part 9. Determination of tungsten oxide content; thiocyanate spectrophotometry;

--- Part 10. Determination of sulfur content High-frequency induction furnace combustion infrared absorption method and potassium iodate titration;

--- Part 11. Determination of the amount of aluminum oxide chromium azure S spectrophotometry;

--- Part 12. Determination of the amount of silica silicon molybdenum blue spectrophotometry and sodium hydroxide titration;

--- Part 13. Determination of magnesia, calcium oxide content; Flame atomic absorption spectrometry;

--- Part 14. Determination of copper content by flame atomic absorption spectrometry;

--- Part 15. Determination of fluorine content ion selective electrode method;

--- Part 16. Determination of silver content; Flame atomic absorption spectrometry;

--- Part 17. Determination of mercury content; atomic fluorescence spectrometry;

--- Part 18. Determination of nickel content by flame atomic absorption spectrometry;

--- Part 19. Determination of cobalt content; Flame atomic absorption spectrometry;

--- Part 20. Determination of cadmium content by flame atomic absorption spectrometry;

--- Part 21. Determination of calcium, magnesium, copper, lead, zinc, arsenic, antimony, bismuth, silver content Inductively coupled plasma atomic emission spectrometry.

This section GB/T 1819 Part 9.

This section drafted in accordance with GB/T 1.1-2009 given rules.

This Part replaces GB/T 1819.9-2004 "Determination of tin oxide content of tungsten oxide - Determination of thiocyanate spectrophotometry." This section compared with GB/T 1819.9-2004, the following major changes.

--- Determination range from the original "0.020% ~ 25.00%" revised "0.050% ~ 35.00%";

--- method to increase the interference summary description of the allowable amount of elements;

--- Reducing agent from titanium trichloride - stannous chloride to titanium trichloride;

--- Modify the formulation of the standard solution of tungsten trioxide;

--- "Note 1 ~ Note 4" the contents of the merger to the corresponding terms;

--- Quantitative 6.4.2 in the calcium content;

--- 6.4.2 increase in high fluoride content of the sample processing methods;

--- Working curve from the original three curves to two, and made the appropriate adjustments to the scope;

--- Modify the content of precision;

--- Added "test report" clause.

1 Scope

This section GB/T 1819 specifies the determination of tin oxide content of tungsten oxide.

This section applies to the determination of the amount of tungsten trioxide in tin concentrate. Measurement range. 0.050% ~ 35.00%.

2 Method summary

The sample was melted with sodium peroxide and leached with water to separate the tungsten from most of the metal. In hydrochloric acid medium, with titanium trichloride tungsten also The original pentavalent and thiocyanate generated yellow complex, measured at a spectrophotometer wavelength of 400nm absorbance.

Not more than 40 mg tin, 12 mg silicon, 6 mg antimony, 3 mg lead, 2 mg iron, 1 mg bismuth, 1 mg phosphorus, 1 mg arsenic, 0.5mg manganese, 0.2mg fluorine, 0.1mg copper does not interfere with the determination.

3 Reagents and materials

Unless otherwise specified, only analytical confirmatory reagents and secondary water are used in the analysis.

3.1 Sodium peroxide.

3.2 Ammonium chloride.

3.3 Hydrazine sulfate.

3.4 Disodium ethylenediaminetetraacetate (Na2EDTA).

3.5 Anhydrous ethanol.

3.6 Hydrochloric acid (p = 1.19 g/mL).

3.7 Hydrochloric acid (3 2).

3.8 Titanium trichloride hydrochloric acid solution Pipette 2mL titanium trichloride solution (commercially available, 15%), diluted with hydrochloric acid (3.7) to 30mL, and mix. use Preparation time.

3.9 Sodium hydroxide solution (50 g/L).

3.10 Potassium thiocyanate solution (500g/L).

3.11 Aluminum trichloride solution (500g/L).

3.12 Standard solution of tungsten trioxide A. Weigh 0.2000g previously fired at 800 °C 40min and cooled to room temperature in a desiccator trioxide Tungsten (wWO3 >= 99.99%), placed in 250mL Teflon beaker, adding 50g of sodium hydroxide, 100mL water, slightly heated to dissolve Completely, cooled, moved into 1000mL volumetric flask, diluted with water to the mark, mix well. Store in plastic bottle. This solution contains 1mL 200 µg of tungsten trioxide.

3.13 Standard solution of tungsten trioxide B. Pipette 20.00mL of tungsten trioxide standard solution A (3.12) in a 100mL volumetric flask with hydrogenation Sodium solution (3.9) diluted to the mark, mix well. Store in plastic bottle. This solution 1mL contains 40µg of tungsten trioxide.

3.14 Iron crucible, 30mL.