METHOD FOR PROCESSING METALLURGICAL SLAG Russian patent published in 2022 - IPC C22B7/04 C22B3/08 C01B33/12 

FIELD: metallurgy.

SUBSTANCE: invention relates to the field of metallurgy, namely to methods for hydrometallurgical processing of slags containing heavy non-ferrous metals, iron, silicon and sulfur. Metallurgical slag containing iron silicates and impurities of metal sulfides, including copper and nickel, is processed. Its sulfuric acid decomposition is carried out with the formation of hydrogen sulfide and the transfer of the main part of iron(II) and silicon dioxide into a leaching solution, and the main part of copper and nickel into an insoluble residue. The insoluble residue is separated from the leaching solution. Dehydration of the solution is carried out to obtain a mixture of silicon dioxide and iron(II) sulfate, as well as water washing of silicon dioxide from iron(II) sulfate and drying of silicon dioxide. The decomposition of slag is carried out with 7-12% sulfuric acid at S : L = 1 : 7-10 in the presence of copper ions taken in stoichiometric or excessive amounts with respect to the hydrogen sulfide formed, and the value of the redox potential of 250-350 mV. The resulting insoluble slag residue is subjected to water washing.

EFFECT: method makes it possible to increase the manufacturability and environmental friendliness of the method, eliminate the release of hydrogen sulfide into the atmosphere, increase the content of silicon dioxide, increase its specific surface area and reduce the content of impurities while ensuring a high degree of extraction of silicon dioxide.

6 cl, 8 ex