PROCESS FOR THE PRODUCTION OF PRECIPITATED CALCIUM CARBONATE, PRECIPITATED CALCIUM CARBONATE AND USES THEREOF

摘要

The present invention relates to a process for the production of precipitated calcium carbonate, comprising the following steps: a) providing a reaction vessel containing an aqueous phase at an initial temperature; b) injecting a carbon dioxide generating compound into the aqueous phase until the pH of the aqueous phase is in the range of around 5 to around 7; and c) subsequently adding a calcium hydroxide slurry at an initial temperature to the reaction vessel while continuing the injection of the carbon dioxide generating compound, in order to obtain an aqueous slurry of the precipitated calcium carbonate. The addition rate of the calcium hydroxide slurry to the reaction vessel in step c) is such that an average electrical conductivity of the reaction contents in the reaction vessel during the reaction is in a range of 100 to 6,000 μS/cm.

主权项

1. Prismatic, sealenohedral or colloidal precipitated calcium carbonate obtained by the process comprising the following steps:
(a) providing a reaction vessel containing an aqueous water phase at an initial temperature; (b) injecting a carbon dioxide generating compound into the aqueous water phase until the pH of the aqueous phase is in the range of pH 5 to pH 7; and (c) subsequently adding a calcium hydroxide slurry at an initial temperature to the reaction vessel while continuing the injection of the carbon dioxide generating compound, in order to obtain an aqueous slurry of precipitated calcium carbonate, wherein, in step (c) the addition rate of the calcium hydroxide slurry to the reaction vessel is such that an average electrical conductivity of the reaction contents in the reaction vessel during the reaction is in a range of 100 to 6000 μS/cm, and wherein (i) prismatic precipitated calcium carbonate is obtained when the average electrical conductivity of the reaction contents in the reaction vessel during the reaction is in a range of 100 to 1200 μS/cm, (ii) scalenohedral precipitated calcium carbonate is obtained when the average electrical conductivity of the reaction contents in the reaction vessel during the reaction is in a range of 1200 to 6000 μS/cm, and (iii) colloidal precipitated calcium carbonate is obtained when the average electrical conductivity of the reaction contents in the reaction vessel during the reaction is in a range of 1200 to 6000 μS/cm and the aqueous water phase contains at least one additive to facilitate production of colloidal precipitated calcium carbonate.