METHOD OF PRODUCING LITHIUM HYDROXIDE OUT OF SPODUMENE CONCENTRATE Russian patent published in 2009 - IPC C22B26/12 C22B3/08 

FIELD: metallurgy.

SUBSTANCE: invention refers to method of producing lithium hydroxide out of spodumene concentrate. The method includes activation and successive sulphatisation of the concentrate, water leaching of sulphatised concentrate with transition of lithium sulphate into a solution. Further neutralisation of leaching pulp is carried out. After separation of neutralised pulp out of produced solution of lithium sulphate lithium hydroxodialuminate is settled at ambient temperature by treatment with concentrated solution of sodium aluminate at weight ratio Al:Li 11.5÷12.5 in produced pulp. Further causticization of lithium hydroxodialuminate is led with lime milk at consumption CaO 4.0÷4.5 g per 1 g in lithium hydroxodialuminate with following separation of lithium hydroxide solution from calcium aluminate final slag. Crystallisation is performed by evaporation out of solution of lithium hydroxide with successive separation of pulp of lithium hydroxide crystals into solid and liquid phases.

EFFECT: reduction of lithium losses and also reduced power consumption of process.

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