CARNALLITE PREPARATION PROCESS Russian patent published in 2007 - IPC C01F5/30 C01D3/04 

FIELD: industrial inorganic synthesis.

SUBSTANCE: invention relates to preparation of synthetic carnallite from magnesium chloride solutions using gallium chloride feedstock having as components potassium chloride or mixture thereof with magnesium production electrolyte. Process comprises mixing preheated concentrated magnesium chloride solutions with potassium chloride feed slurry, which has been prepared by interaction of a part preheated mother liquor with potassium chloride feed, subsequent cooling of mixture using vacuum crystallization, isolation of crystallizate, and recycle of the mother solution to starting reactants' mixing stage. Part of mother solution is treated at 90-100°C to isolate calcium sulfate with the aid of a metal sulfate taken in amount required to lower content of calcium chloride in solution to 0.9-1.5%, while maintaining calcium chloride concentration in the mixture of concentrated magnesium chloride solutions within a range of 3 to 6% by means of withdrawing a part of mother liquor for treatment with a metal sulfate. Mixing of solutions with starting reactant is conducted at 90-100°C. As a metal sulfate, aqueous solutions of magnesium sulfate, sodium sulfate, and potassium sulfate are used. As potassium chloride feedstock, potassium chloride or mixture with magnesium production electrolyte. When preparing slurry, preheated mother solution is supplied before or after removal of calcium chloride therefrom, or their mixture.

EFFECT: enabled processing of magnesium chloride solutions having elevated calcium chloride content without withdrawal of return solutions to remove excess calcium chloride and to reduce loss of useful components.

4 cl, 3 ex