Precipitated calcium carbonate (PCC) is produced by precipitating a calcium salt out of a solution under defined conditions. Normally, a filtered solution of calcium hydroxide Ca(OH)2 (from burnt lime) is used as the calcium source. This must not contain any colored impurities. Calcium carbonate is precipitated by the admixture of gaseous carbon dioxide or sodium carbonate Na2CO3.
The form of calcium carbonate obtained – in other words, its particle shape and particle size distribution – depends on the precipitation conditions, such as concentration, temperature and temperature change during precipitation, agitation energy, pH and other factors.
