METHOD OF LEACHING OF VALUABLE COMPONENTS AND RARE-EARTH ELEMENTS FROM CINDER MATERIAL Russian patent published in 2015 - IPC C22B59/00 C22B7/00 C22B3/18 

FIELD: metallurgy.

SUBSTANCE: invention relates to biohydrometallurgy, in particular to biotechnology of extraction of valuable components and rare-earth elements from coal combustion products - cinder material. The method of leaching of valuable components and rare-earth elements from cinder material includes preparation of a pulp in the bioreactor with the ratio of solid vs liquid phases (S:L) = 1:5, and the ratio of cinder material vs. element sulphur is 10-20:1. Then pH level of the pulp of concentrated sulphuric acid is brought to the values 2.0-3.0, nutritious salts are added to the pulp and the pulp is inoculated by adding of 10% of the culture liquid containing cenosis of acidophile chemolithotrophic microorganisms. Then the process of biooxidation of element sulphur by microorganisms is performed with mixing the pulp, aeration by air and at the temperature 44-46°C, followed by formation of sulphuric acid, decrease of pH level and leaching of valuable components and rare-earth elements.

EFFECT: decrease of consumption of reagent (sulphuric acid) for leaching of valuable components and rare-earth elements from cinder material and decrease of consumption of electric power for maintaining of temperature of reactionary mix.

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