PURPOSE: To grow crystals of aragonite type prismatic CaCO3 suitable for use as a coating pigment for paper making by reacting Ca(OH)2 with CO2 under specified conditions using seed crystals of aragonite type prismatic CaCO3.
CONSTITUTION: A slurry of seed crystals of aragonite type CaCO3 having ≤about 2μm major axis size and ≤about 0.2μm minor axis size is mixed with a Ca(OH)2 emulsion so as to make the molar ratio of Ca(OH)2/CaCO3 1W5, and the concn. after the mixing is adjusted to 50W250g/l. While stirring this slurry, a gas contg. ≥about 10vol% CO2 is blown into the slurry at a rate adjusting the amount of CO2 in the gas to 0.5W10Nl/min per 1kg CaCO3, and they are reacted at about 5W80°C to grow crystals of aragonite type prismatic CaCO3. The resulting CaCO3 crystals are suitable for use in a field of the paper making industry and can enhance printing luster, printing strength, etc.
KUMASAKA TETSUO
GOTOU NOBORU
| JPS5343097A | 1978-04-18 | |||
| JPS5450499A | 1979-04-20 |