| 摘要 |
Procedure for the manufacture of carbonates of precipitated calcium. It allows a calcium carbonate of high purity and ultrafine and uniform grain to be obtained from raw materials which contain calcium oxide or hydroxide. It is characterized in that it comprises: a) aqueous leaching of the raw materials and separation of undissolved impurities, by decantation, filtration or centrifugation; b) carbonation in one or two stages of the solution so obtained, with a gas which contains carbon dioxide, in the presence of an additive suitable for controlling the particle size of the resultant precipitate. It comprises the use of residual products originating from processes for the manufacture of acetylene from calcium carbide as raw materials which contain calcium oxide or hydroxide. The precipitated calcium carbonate obtained shows a final particle size less than 10 microns, and preferably between 0 and 2 microns.
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