METHOD FOR PRODUCING POTASSIUM CHLORIDE FROM SYLVINITE ORE Russian patent published in 2015 - IPC C01D3/08 

FIELD: chemistry.

SUBSTANCE: producing potassium chloride is ensured by dissolving sylvinite ore in a mother solution and recovering halite refuse ore. Salt-based waste is recovered in thickening agents and hydrocyclones from solvent discharge. The solvent discharge is clarified from clay-salt waste. That is followed by crystallising potassium chloride in vacuum from the clarified solution, condensing a suspension of crystallise and filtering it. Spent liquor is heated and supplied back for dissolving. The condensed salt-based waste is mixed after the thickening agents with the heated spent liquor to L:S=2-4. The prepared suspension is divided on hydrocyclones in a near-mesh grain of 0.1-0.2 mm. The hydrocyclone discharge is directed to dissolve sylvinite ore. Hydrocyclone "sands" with L:S=0.6-1.5 are partially added to the condensed suspension of potassium chloride before filtering in an amount required to correct the KCl content in a dry product to meet the specifications. The residual "sands" are directed to the filter together with halite waste.

EFFECT: invention enables producing the end product with a lower KCl limit complying with the specifications.

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