METHOD FOR PRODUCING GERMANIUM CONCENTRATE FROM COALS Russian patent published in 2007 - IPC C22B41/00 

FIELD: chemical and metallurgical industry branches, possibly producing germanium concentrate from coals.

SUBSTANCE: method comprises steps of subjecting coal in the form of coal layers to heat treatment in shaft type apparatus by supplying air to lower part of said apparatus and heating upper layer of coal till its burning temperature. After creating stable burning zone heating of upper zone is interrupted and temperature in burning layer is kept no less than 1000°C and temperature in calcined layer is kept no less than 700°C. Motion rate of burning zone is sustained due to controlling air flow rate at specific feed of air 250 -300 nm³/m² h. When burning zone achieves lower part of apparatus air feed is interrupted.

EFFECT: increased degree of germanium extraction from coals without pyro-metallurgical concentration of germanium concentrate.

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