| 摘要 |
PURPOSE:To produce easily aragonite type calcium carbonate having superior dispersibility by introducing gaseous CO2 into aq. slurry of Ca(OH)2 having a specified concn., temp., and content of soluble phosphate. CONSTITUTION:0.1-20wt.% [basing on the amt. of Ca(OH)2] soluble phosphate (e.g. H3PO4, Na2HPO4) expressed in terms of tervalent PO4<3-> is added to aq. slurry of Ca(OH)2 having 5-40wt.% concn. at 5-45 deg.C. A carbonation reaction is caused by introducing gaseous CO2 into the slurry to obtain thus aragonite type calcium carbonate. The obtd. aragonite type calcium carbonate is used pref. as a filler or coating material, etc. for paper, providing filled paper having high brightness, opacity, size value of paper and pigmented paper, etc.
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