METHOD TO PROCESS NEPHELINE ORES TO PRODUCE ALUMINA AND SODA PRODUCTS Russian patent published in 2012 - IPC C22B21/00 C01F7/38 C22B1/14 C22B3/04 

FIELD: mining.

SUBSTANCE: method includes preparation of a nepheline-lime-soda charge, its sintering in a tubular rotary furnace by heat released when burning fossil coal. After sintering, leaching, desiliconisation and carbonisation of an aluminate solution is carried out to produce alumina and soda products. The fossil coal to burn is a brown coal, the solid residue of which contains calcium oxide CaO of at least 30 wt %, and silicon oxide SiO₂ of not more than 40 wt %. Brown coal from the Kansko-Achinskiy field is burnt.

EFFECT: reduced consumption of lime in charge preparation and lower content of silicon oxide in an aluminate solution, using a less scarce fossil coal as fuel.

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