SU1255577A1 - Method of regenerating solutions of pyrite cinder decomposition - Google Patents

Description

The invention relates to hydrometallurgy, in particular to the sulphate decomposition of various types of mineral raw materials and can be used for complex processing of solutions containing sulphates of ferrous and non-ferrous metals,

The purpose of the invention is to reduce the consumption of sulfuric acid.

The essence of the method of regeneration of the decomposition of a pyrite cinder with sulfuric acid is that they are subjected to heat treatment at 190-250 ° C under autoclave conditions. When this occurs, hydrolysis of iron (III) sulfate occurs with the formation of a poorly soluble basic iron sulfate with a molar ratio of 2, by the reaction FeJSO + 2Fe (OH), SO,.

As a result of this reaction, one third of H ,, SO ' spent on the formation of ferrous sulfate (III) during the decomposition of pyrite calcine is regenerated. The sulfates of non-ferrous metals, under these conditions, are not hydrolyzed and practically remain completely in solution. After separation of the solid phase, the mother liquor is returned to the decomposition stage of pyrite cinder. Upon subsequent decomposition of the calcine, an increase in the concentration of non-ferrous metals occurs and they can be concentrated within the solubility by repeated use of mother liquors at the decomposition stage of pyrite calcine,

Example, Solution containing, g / dm: Fe2 (804) 3 260; 40; SEZO 0.95; ZnSO. 2.63, heated to 200 ° C in an autoclave and incubated for 1 h. During the hydrolysis process, a poorly soluble ferrous hydroxulphate Fe (OH) S04j is formed, containing 0.0026% Cu and 0.0021% Zn. After separation of the solid phase to the uterine

a solution containing, FejCSO) 69.4; 86; CuSO 0.9 ZnS04 2.62, add 146 g / dm (based on the monohydrate) and return to the decomposition of the calcine. After decomposition of the calcine, a solution is formed containing, g / dm: Fe2 (SO,) 327.4; H, SO 39.8; CuSO 1.89; ZnS04 5.25. The solution is heated to 200 ° C. and held for 1 hour.

The degree of hydrolysis is 73.0%. After separation of the solid phase, the mother liquor containing Fe, (SOO, 88.4; 98.4; CuSO1.88; ZnSOq 5.20, is recycled. The solid phase undergoes roasting to produce iron oxide (III); The separated sulfur oxides are sent to sulfuric acid, which is recycled to the cyclic process.

The dependences of the degree of hydrolysis of the decomposition solutions of pyrite calcine and the amount of regenerated acid on the treatment temperature for solutions of different concentrations are presented in the table.

As can be seen from the table, a decrease in the treatment temperature of the solutions below 190 ° C leads to a sharp decrease in the degree of hydrolysis of iron sulfate (III), which determines the amount of regenerated acid. An increase in temperature above 250 ° C has virtually no effect on the degree of hydrolysis and leads to an unproductive increase in energy consumption. The optimum temperature range is 200 -,

After separation of the solid phase, the sulfates of non-ferrous metals remain almost completely in solution, with the solid phase less than 1% of copper and 0.3% of zinc from the initial content in the candle ends, and the consumption of sulfuric acid is reduced by 16 - 27%,

127

The known method 58 85-92

The proposed method

Editor I. Derbak

Compiled by L. Temirova

Tehred M. Khodanych Proof-reader S. Cherni

Order 4778/26 Circulation 450 Subscription

VNIIPK USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, st. Project, 4

1345

Claims (1)

METHOD FOR REGENERATING THE DECOMPOSITIONS OF A PYRITE LIQUID DECOMPOSITION WITH SULFURIC ACID, including their heat treatment, characterized in that, in order to reduce the consumption of sulfuric acid and make it possible to concentrate non-ferrous metals in working solutions, the solutions are heat treated at 190-250 ° C in autoclave conditions. <1255