| 摘要 |
<p>1,050,316. Wet grinding; mixing-apparatus. PITTSBURGH PLATE GLASS CO. June 2, 1965 [June 3, 1964], No. 23442/64. Headings B1C and B2A. A process for reducing the size of solid particles dispersed in a liquid media comprises agitating the solid particles and liquid media with a mass of solid particles containing zirconium or hafnium, and separating the metal-containing solid particles from the liquidsolid dispersion. The zirconium-containing particles may (a) contain at least 40% zirconium (b) be stabilized or partially stabilized zirconia produced by heating zirconia having a monoclinic crystalline structure to about 2500 ‹C. in the presence of calcium oxide or magnesium oxide so that the zirconia is formed with a cubic crystalline structure and (c) have a particle size from 0.05 mm to 5 mm preferably from 0.25 mm to 3 mm and be present in an amount from 25% to 70% of the total volume of the particles and liquid media. The solid particles may be pigment particles dispersed in a liquid film-forming vehicle. The particles are reduced in size to a particle diameter of not more 0.0375 mm. The process may be carried out continuously or batchwise. Apparatus for carrying out the process may comprise a vertical mill having a hollow shell in which is rotatable a vertical shaft having impellers disposed thereon, the impellers being solid discs or discs having radial slots in the perimeter thereof. The apparatus may have a cooling jacket. Examples are described.</p> |
