Patent ID: 8883098

Claim:
A process for preparing precipitated calcium carbonate (PCC) useful for ink jet printing applications comprising the steps of: a) preparing a calcium hydroxide slurry by mixing quicklime (CaO) with water; b) screening the calcium hydroxide slurry obtained in step a) to obtain a screened slurry; c) adjusting the temperature of the screened slurry to obtain a temperature adjusted slurry; d) contacting the temperature adjusted slurry with a carbon dioxide-containing gas at a carbonation gas flow rate of below 30 liters per minute at standard temperature and pressure per kilogram calcium hydroxide in the presence of (i) magnesium sulphate and aluminium sulphate, (ii) magnesium sulphate and zinc sulphate, or (iii) magnesium sulphate, aluminium sulphate and zinc sulphate, to obtain agglomerates/aggregates; and e) screening the agglomerates/aggregates obtained in step d) to obtain ultrafine PCC agglomerates having a mean aggregate diameter of 1 to 5 μm, wherein the ultrafine PCC agglomerates comprise ultrafine calcium carbonate particles bound together.