Surface modified calcium carbonate containing minerals and its use

摘要

The present invention is related to ball-shaped spherical surface modified spherical calcium carbonate comprising minerals, the process for preparing such ball-shaped spherical surface modified spherical calcium carbonate comprising minerals, and their use.

主权项

1. A product obtained by a process for producing ball-shaped spherical surface modified calcium carbonate comprising particles, wherein the process comprises the steps of:
a) providing at least one aqueous calcium carbonate containing mineral slurry; b) providing at least one water-soluble acid; c) providing gaseous CO2 generated in situ and/or supplied externally; d) contacting the aqueous calcium carbonate containing mineral slurry of step a) with the acid of step b) and with the CO2 of step c) under stirring conditions to obtain ball-shaped spherical surface modified calcium carbonate comprising particles; and e) optionally dewatering the aqueous slurry, wherein at least one processing agent is added before, during or after the aqueous calcium carbonate containing mineral slurry of step a) is contacted with the acid of step b) and the CO2 of step c), and wherein the processing agent is selected from the group consisting of ferrous sulfate, ferric sulfate, ferrous chloride, aluminum sulfate, and their hydrated forms, and wherein the processing agent is added in an amount of up to 8 wt. % based on the dry weight of the slurry.