| 摘要 |
High brightness, whiteness and opacity calcium carbonate pigments (44 and 58) may be produced by magnetic separation (34 and 50). A composition of matter comprising high brightness calcium carbonate pigments (44 and 58) produced by using magnetic separation (34 and 50) on a properly dispersed, minimum viscosity slurry to optimize contaminant liberation and removal, with the impurities being liberated by and during grinding (32 and 46) prior to magnetic separation (34 and 50) while maintaining said slurry temperatures at or above 50 degrees C. The magnetic separation (34 and 50) of a dispersed, minimum viscosity slurry separates coarse to ultra-fine particles in slurries ranging from 5 % to 65 % solids by, at least in part, removing and selectively separating dolomitic components from the calcium carbonate mineral systems. |
