GB/T 4324.24-2012Methods for chemical analysis of tungsten - Part 24: Determination of phosphorus content - Molybdemum blue photometry (English PDF)

1 Scope

GB/T 4324 provisions of this part of the tungsten powder, tungsten trioxide, tungsten, tungsten blue, purple tungsten, tungsten carbide, tungsten acid, ammonium paratungstate, ammonium metatungstate phosphorus

Determination of content.

This Part applies to tungsten powder, tungsten measure, tungsten trioxide, tungsten blue, purple tungsten, tungsten carbide, tungsten acid, ammonium paratungstate, metatungstate phosphorus content set. Determination of the range of 0.0002% ~ 0.018%.

2 Method summary

Tungsten powder, tungsten bar, fine (in) tungsten carbide particles with hydrogen peroxide decomposition; blue tungsten potassium hydroxide and hydrogen peroxide decomposition; tungsten trioxide, tungstic acid,

Ammonium paratungstate, ammonium metatungstate decomposition of potassium hydroxide; Violet Tungsten, coarse grain tungsten carbide is oxidized to tungsten oxide after decomposition with potassium hydroxide. In ammonia

Solution to EDTA chelated iron, manganese, copper, magnesium and other impurities to precipitate phosphorus beryllium salt as a carrier, separated from the cobalt, manganese, iron, calcium, magnesium and other impurities. in

Sulfuric acid medium, such as arsenic interference with tartaric acid masking elements to ammonium molybdate as chromogenic reagent, phosphorus with ammonium molybdate forming yellow phosphomolybdic heteropoly acid, an anti-bad

Ascorbic acid as a reducing agent for the reduction of phosphorus molybdenum yellow phosphorus molybdenum blue colored complex, the absorbance measurements.

3 Reagents

Unless otherwise indicated, this part of the reagents used are in line with national standards or industry standard analytical reagents, which are twice distilled water

Distilled water.