Production manner null of aragonite crystal form

摘要

PURPOSE:To efficiently produce calcium carbonate of aragonite crystal form industrially, by slaking CaO with H2 to form water slurry of Ca(OH)2 and carbonating the slurry under a specific condition. CONSTITUTION:Lime stone is calcined to form CaO, which is slaked with H2O having the molar ratio to CaO of =15 in case of =70 deg.C water temperature and with water in any amount in case of 70 deg.C water temperature to give water slurry of Ca(OH)2. Then the water slurry is adjusted to 5-40wt.% concentration and 5-65 deg.C temperature and carbonated with a CO2 gas in an amount of 4l/min/kg Ca(OH)2 (calculated as 100% CO2 gas) to give the aimed calcium carbonate. The aragonite excellently exhibits its characteristics in the field especially of paper manufacturing and plastics. In paper manufacturing field, since aragonite has more excellent dispersibility than calcite, aragonite exhibits excellent opacifying power when used as a loading material or pigment of coating color.