Preparation of high bulk density anhydrous sodium carbonate crystals
AssigneeGeneral Chemical Corporation
InventorsRustom P. Poncha, Ronald E. Sorg
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Abstract
Sodium carbonate having a high bulk density and pseudo-cubic crystal structure is prepared from impure trona purge liquors from the crystallizers containing high concentration of organics, silica and sulfate by a sequence of steps involving (1) treatment of the liquors with MgO; (2) separation of the treated liquor from the insoluble reaction products; (3) addition of Ca and Mg compounds to the liquor; (4) evaporating the solution to obtain sodium carbonate monohydrate crystals; (5) separating the crystals from the mother liquor; and (6) heating the crystals at temperature of about 150.degree.-200.degree. C. to convert to dense ash.
Claims7
A process for preparing pure anhydrous sodium carbonate crystal from impure purge liquor obtained from calcined trona via the monohydrate process and containing silica, organic material and sulfate impurities comprising the steps of
- (1) treating the purge liquor with magnesium oxide and by the addition of an effective amount and up to about 2 percent sodium bicarbonate;
- (2) separating the insoluble reaction product from the mother liquor;
- (3) adding soluble calcium and magnesium salts to the separated mother liquor;
- (4) evaporating the treated resulting solution from step (3) to yield sodium carbonate monohydrate crystals;
- (5) separating the formed crystals from the mother liquor;
- and
- (6) heating the crystals thus derived to a temperature of at least about 140.degree. C. to convert the crystals to a dense sodium carbonate product.
Dependencies are inferred from the claim text.