Patent ID: 8821628

Claim:
A process for obtaining a diluted aqueous suspension of dispersed calcium carbonate, from a concentrated dispersed calcium carbonate suspension, providing improved optical properties to coatings made from the diluted aqueous suspension of dispersed calcium carbonate, the process comprising the steps of: a) providing an aqueous suspension comprising dispersed calcium carbonate and at least one dispersing agent, wherein the aqueous suspension has a solids content of between 65 wt.-% and 85 wt.-%, based on the total weight of the aqueous suspension; b) providing at least one alkali carbonate and/or alkali hydrogen carbonate, wherein the alkali ion is selected from potassium and/or sodium; c) diluting the aqueous suspension of dispersed calcium carbonate and the at least one dispersing agent with water; and d) before and/or during and/or after step c), contacting the aqueous suspension of dispersed calcium carbonate and the at least one dispersing agent with the at least one alkali carbonate and/or alkali hydrogen carbonate, to obtain an aqueous suspension of dispersed calcium carbonate having a pH value of 7.5 to 12.