YS/T 239.3-2010Methods for chemical analysis of antimony trisulfide. Part 3: Determination of free sulfur content. Burning and sodium hydroxide titration method (English PDF)

Foreword

YS/T 239 "Methods for chemical analysis of antimony trisulfide" There are seven sections.

--- Part 1. Determination of antimony content cerium sulfate titration;

--- Part 2. Determination of the amount of sulfur compounds and combustion titration method;

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

--- Part 4. aqua regia insolubles - Gravimetric method;

--- Part 5. Determination of arsenic content of arsenic molybdenum blue spectrophotometric method;

--- Part 6. Determination of iron content of phenanthroline spectrophotometry;

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

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

This is Part 3.

The partial replacement of YS/T 239.3-1994 "antimony trisulfide chemical analysis of combustion iodometric method for the determination of free sulfur." versus YS/T 239.3-1994 compared to this part of the following changes.

--- Text format has been modified;

--- Complements the precision and quality assurance and control provisions.

This standard by the national non-ferrous metals Standardization Technical Committee (SAC/TC243) centralized.

1 Scope

This section YS/T 239 specifies the method for the determination of free sulfur content of antimony trisulfide.

This section applies to the determination of free sulfur content of antimony trisulfide. Measurement range. free sulfur mass fraction of 0.0050% to 0.20%.

2 Method summary

With carbon tetrachloride and leaching of free sulfur compound isolated by filtration substrate, evaporating the solvent and drying, high temperature combustion in a stream of oxygen, sulfur conversion Sulfur dioxide, hydrogen peroxide absorbed and converted into sulfuric acid, methyl red - methylene blue solution as indicator, titrated with standard sodium hydroxide solution Titrated.

3 Reagents

Unless otherwise indicated, the reagents used in this section refer to water and recognized analytical reagent and tertiary water.

3.1 potassium hydroxide.

3.2 anhydrous calcium chloride.

3.3 CTC.

3.4 Absorption of hydrogen peroxide solution (298).

3.5 phenolphthalein indicator (10g/L ethanol).

3.6 methyl red - methylene blue mixed indicator. 20 unit volume of methyl red ethanol solution (0.3g/L) and 3 per unit volume of methylene blue solution (1g/L) and mixed.