YS/T 1149.8-2016Methods for chemical analysis of zinc concentrate roasting--Part 8: Determination of acid-soluble silicon dioxide content--Molybdenum blue spectrophotometry (English PDF)

Foreword

YS/T 1149 "Zinc concentrate calcite chemical analysis method" is divided into the following eight parts.

- Part 1. Determination of zinc content - Na2EDTA titration;

- Part 2. Determination of acid and zinc content - Na2EDTA titration;

- Part 3. Determination of sulfur content - Combustion neutralization titration;

- Part 4. Determination of soluble sulfur - Barium sulfate gravimetric method;

- Part 5. Determination of iron content - Na2EDTA titration;

- Part 6. Determination of acid soluble iron - Flame atomic absorption spectrometry and Na2EDTA titration;

- Part 7. Determination of silica content - Molybdenum blue spectrophotometric method;

Part 8. Determination of acid - soluble silica - Molybdenum blue spectrophotometric method.

This section is part 8 of YS/T 1149.

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

This part of the National Nonferrous Metals Standardization Technical Committee (SAC/TC243) proposed and centralized.

The main drafting unit. Zhuzhou Smelting Group Co., Ltd., Henan Yuguang Zinc Industry Co., Ltd., Beijing Mining and Metallurgy Research Institute.

This part participates in the drafting unit. Beijing Nonferrous Metals Research Institute, China Nonferrous Guilin Mineral Geology Research Institute Co., Ltd., Shenzhen Jinling South Nonferrous Metals Co., Ltd., Yunnan Chihong Zinc and Germanium Co., Ltd.

This part of the main drafters. Yang Ping, Chen Xiongfei, Li Shengchen, Chen Yunhong, Niu Junmin, Hu Zhenzhen, Xiao Juan, Yang Jianbing, Bai Ru, Yang Ruiqiong, Xu Shumin, Zhou Lingbo, Ye Shiyuan, Guo Jun, Yang Jianyou.

Chemical Analysis of Zinc Concentrate Part 8. determination of the amount of acid - soluble silica Molybdenum blue spectrophotometric method

1 Scope

This part of YS/T 1149 specifies the method for the determination of the amount of acid-soluble silica in the concentrate of zinc concentrate.

This part is applicable to the determination of the amount of acid soluble silica in the concentrate of zinc concentrate. The measurement range is 0.20% ~ 4.00%.

2 Method summary

The samples were sulphated at 85 °C ~ 90 °C for 20min by sulfuric acid (9 191). In sulfuric acid medium, silicon and molybdate were used to form molybdenum heteropoly acid.

The ascorbic acid reduces the molybdenum heteropoly acid to molybdenum blue. The absorbance was measured at a wavelength of 650 nm at a spectrophotometer.

3 Reagent

Unless otherwise stated, the reagents used in this section are analytical reagents and distilled or deionized water in accordance with national or industry standards.

Or a fairly pure water.

3.1 sulfuric acid (rho1.19g/mL).

3.2 ammonia (rho0.90g/mL).

3.3 Sulfuric acid (1 1).

3.4 Sulfuric acid (19).

3.5 Sulfuric acid (9 191).

3.6 Ammonia (1 1).

3.7 Ammonium molybdate (50 g/L).

3.8 ascorbic acid (20g/L), with the current distribution.

3.9 p-nitrophenol solution (1 g/L).

3.10 reduction solution. ascorbic acid (3.8) and sulfuric acid (3.3) according to 1/2 ratio of mixing, with the current distribution.

3.11 silica standard storage solution. accurately weighed 0.5000g grade pure silica (pre-950 °C for 30min, placed in the dry Cooler to room temperature) in a platinum crucible containing 5 g of a mixed flux (two parts of anhydrous sodium carbonate and one part of potassium carbonate), mixed and then covered Cover 2g mixed flux, placed in 900 °C ~ 950 °C high temperature furnace melting 1h, slightly cold, the crucible outside the water washed and placed in 300mL polytetrafluoro Ethylene beaker, add 150mL hot water to leach, wash the crucible, cool, into the 500mL volumetric flask, diluted with water to the scale, mix. Storage in plastic bottles. 1 mL of this solution contains 1 mg of silica.

3.12 Silica standard solution. Remove 10.00mL of silica standard storage solution (3.11) in a 100mL plastic vial with water Dilute to the mark and mix well. This solution contains 1 mL of 100 µg of silica.

4 Instruments

4.1 constant temperature water bath.