US3642511A - Method of treating wollastonite with acid
A novel method of producing from wollastonite finely divided pigments and fillers of unusually high opacifying power, high brightness, low bulk density and low abrasiveness for use in paper, paint and other products by reacting the wollastonite in the form of a slurry with sulfuric acid, preferably at an elevated temperature, to form calcium sulfate pigment particles and to solubilize at least ...