| 摘要 |
A method of comminuting a solid material, having a non-sheet structure, comprises grinding the solid material with a particulate grinding material in an aqueous medium containing a non mucilaginous dispersing agent. Substances described include calcium carbonates, calcium sulphate, calcium silicate, and titanium dioxide, particularly chalk whiting for use in paper making. Dispersing agents include a water-soluble acrylic polymer of from .2 to .4% by weight, or polyphosphates. Grinding materials may be 1/2 " to 100 B.S. mesh, Ottawa sand, Molocite, or synthetic resin pellets. The ratio by weight of grinding material to solid material may be from 2:1 to 5:1. High reflectance of the ground material is achieved by extended grinding times. |
