| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method for manufacturing calcium carbonate efficiently utilizing an exhaust gas such as flue gas. SOLUTION: Carbon dioxide in the exhaust gas from an incinerator is absorbed in a caustic soda solution by a vapor-liquid contacting method and then a sodium carbonate solution is produced. Milk of lime is produced by hydration of quicklime using a caustic soda solution in which sodium hydroxide is contained by 6-12%. Calcium carbonate is synthesized by the reaction of the milk of lime with the sodium carbonate solution. As carbon dioxide in the exhaust gas is already converted to the sodium carbonate solution, the carbonation reaction is not influenced by the exhaust gas temperature and calcium carbonate of a desired shape can be produced. A carbonation plant can be constructed without any relation to a gas exhausting place.</p> |
