METHOD OF PRODUCING COARSE CHEMICALLY PRECIPITATED CALCIUM CARBONATE WITH PLATE SHAPE OF PARTICLES Russian patent published in 2005 - IPC

FIELD: industrial inorganic synthesis.

SUBSTANCE: soda ash production waste, namely 2.58% calcium chloride solution, is carbonized at continuous stirring with soda ash solution containing 18.7% Na₂CO₃, or 10.58% carbonate ion. During the synthesis conducted at 60-70^оС, continuous streams of reactants are maintained so that sodium carbonate consumption were not higher than 103.5 kg/m³·^{h to keep constant excess of carbonate ions at level of 2.35. Precipitate is filtered, reslurried, washed at stirring, refiltered, and dried. Content of CaCO₃ in product is at least 99%. Plate-shaped particles of product have average size 10-12.5 μm and maximum size 25 x 5 μm.}

EFFECT: increased purity of product.

1 tbl, 6 ex