| 摘要 |
PURPOSE:An aqueous suspension of calcium hydroxide is charged in a reactor equipped with agitation blades and the reactions are carried out in specific 3 stages to give the titled complex of high whiteness and gloss, being suitable for use in paper coating, in high efficiency. CONSTITUTION:An aqueous suspension of calcium hydroxide, whose viscosity is less than 2,000cps in the concentration of 400g/l is adjusted in its concentration to 50-250g/l and introduced into a cylindrical reactor in which the ratio of blade diameter to the inner diameter of the tank is 2/3-1/4. As the blades are allowed to rotate at 200-2,000rpm at 5-25 deg.C, carbon dioxide is introduced into the suspension. The introduction rate of carbon dioxide is kept at 8-20l/min per 1kg of the calcium hydroxide until the degree of carbonization reaches 3-7%, at 0.5-3l/min until 10-20%, finally at less than 20l/min at 30-60%, in 3 stages. Thus, the titled complex given by the formula (x is 0.7-2.3, y is 0.3-6) is given thereby.
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