SU1176240A1 - Method of determining iron hydroxides - Google Patents

Abstract

METHOD OF DISSEMINATION OF THE IRON OF HYDROXIA in the presence of hematite. including calcining the material being analyzed, dissolving it with a selective solvent, filtering the solution and subsequent quantitative recording of iron in the filtrate by one of the known methods, characterized in that 4-5% is used as a solvent to increase the accuracy and selectivity of the determination in the presence of Mai-netite a solution of hydroxy acid, acidified with sulfuric acid to a concentration of 0.370, 46 mol / l at 90-100 ° C for 20-30 minutes.

Description

O) 1C 4

eleven

This invention relates to analytical chemistry and can be used for iron hydroxides in oxidized iron ores and enrichment products containing magnetite.

The aim of the invention is to improve the accuracy and selectivity of the determination.

Example 1.0.25 g of a mixture of iron, hematite and magnetite hydroxyls / crushed to 0.1 mm is placed in a porcelain crucible and calcined for 2 hours.

Then, the calcined sample was transferred into a 150 cm beaker, 50 cm of 4% hydroxylamine solution acidified with sulfuric acid (0.46 mol / l) was poured, placed in a thermostat and dissolved for 30 minutes at. Stirring speed is 500 rpm.

The solution is filtered into a 400 cm beaker. The precipitate and the filtrate is washed 6 times with water. The solution is added to wet salts., Then 15 cm concentrated nitric acid is poured to decompose hydroxylamine and evaporated to dryness. The dry residue is twice treated with hydrochloric acid to remove nitric acid and the iron is determined by the bichromate method.

The initial mixture contains 58.2% hematite; 0.3% magnetite; 8.8% hydroxide.

62402

Determined by the proposed method, 8.8% of hydroxides (error 0.0), in a known manner, 9.0% of hydroxides (error 0.2%).

5 Example 2.O, 25 g of Krivoy Rog oxidized ore is calcined. To the calcined sample, 50 cm of a 5% aqueous solution of hydroxylamine acidified with sulfuric acid (to a concentration of 0.37 mol / l) are added and dissolved at 20 minutes.

The iron hydroxide content in the ore, determined by calculation based on chemical and thermal analyzes, is 5.4%; hematite 13.8%, magnetite 10.0%. 4.9% guide of oxides was determined (0.5% error); in a known manner of 8.5% (error 3.1%).

Example 3. To O, 25 g of calcined magnetite, 50 cm of a 4-5% hydroxylamine solution acidified with sulfuric acid (to a concentration of 0.42 mol / l) are added and dissolved at 95 ° C for 25 minutes.

Next are analyzing, as in example 1.

The sample contains 0.9% hematite, 70.8% magnetite, 0.0% hydroxide.

4.0% of hydroxides was determined (about 1% by 4.0%), by a known method of 29.4% (an error of 29.4%).

Claims (1)

METHOD FOR DETERMINING THE HYDROXIDE IRON in the presence of hematite, including calcining the analyzed material, dissolving it with a selective solvent, filtering the solution and subsequent quantitative registration of iron in the filtrate using one of the known methods, characterized in that, in order to increase the accuracy and selectivity of determination in the presence of magnetite, as the solvent, a 4-5% solution of hydroxylamine acidified with sulfuric acid to a concentration of 0.370.46 mol / L at 90-100 ° C for 20-30 minutes is used. § ω m Ci er Ί176240