| abstract |
Process for preparing a calcium carbonate with a surface under reaction in an aqueous environment, comprising the following steps: a) providing at least one ground natural calcium carbonate (GNCC); b) provide at least one water soluble acid; c) provide gaseous CO2; d) bringing said GNCC from stage a) into contact with said acid from stage b) and with said CO2 from stage c); characterized in that: (i) each of said acid (s) of step b) has a pKa greater than 2.5 and less than or equal to 7, when measured at 20 ° C, associated with ionization of its first available hydrogen, and a corresponding anion formed by the loss of this first available hydrogen capable of forming water-soluble calcium salts; (ii) after contacting said acid (s) with said GNCC, at least one water-soluble salt is additionally provided, which in the case of a salt containing hydrogen has a pKa greater than 7, when measured at 20 ° C, associated with the ionization of the first available hydrogen, and whose salt anion is capable of forming calcium salts insoluble in water. |