MANUFACTURE OF ALKALI METAL SALTS VIA COMBINED ION-EXCHANGE/CRYSTALLIZATION METHOD Russian patent published in 2004 - IPC

FIELD: industrial inorganic synthesis.

SUBSTANCE: invention relates to a method of manufacturing alkali metal nitrate and alkali metal phosphate from phosphate raw material and nitrate raw material in a single process comprising following stages: (i) interaction of phosphate raw material with nitrate raw material to form aqueous nitro-phosphate reaction mixture optionally followed by separation of solids; (ii) passing aqueous nitro-phosphate reaction mixture to the first ion-exchange phase, carried out in case when alkali metal ion-saturated ion-exchange resin is available to exchange cations present in reaction mixture by alkali metal ions of the resin to form stream enriched by alkali metal ions; (iii) performing first crystallization of the above reaction mixture under conditions favoring crystallization of alkali metal nitrate and separating the latter from liquor solution; (iv) passing the above liquor solution to the second phase of ion exchange carried out in case when alkali metal ion-saturated ion-exchange resin is available to exchange cations present in reaction mixture by alkali metal ions of the resin to form stream containing phosphate enriched by alkali metal ions; and (v) performing second crystallization of stream obtained in stage (iv) under conditions favoring crystallization of alkali metal phosphate and separating crystallized alkali metal phosphate from mother solution.

EFFECT: enhanced process efficiency, minimized amount of wastes, and reduced power consumption.

15 cl, 1 dwg, 6 tbl, 4 ex