Dry Process of Extracting China Clay, Mica and Quartz from Decomposed Granite.

摘要

27,034. Gaved, A. E. Nov. 28. Mills and apparatus; roller mills.-In a dry process for extracting China-clay, mica, and quartz from decomposed granite, the granite, after being broken into lumps and dried, is crushed in a jawcrusher or roller mill c, Fig. 1, and discharged into an inclined rotary cylindrical trommel b, which is clothed partly with fine wire-gauze to separate the clay and mica, and partly with coarse wire-netting to separate the quartz, the tailings being returned to the mill. The mixed clay and mica are discharged by a worm f on to a sieve i, which is reciprocated by eccentrics l and clothed with silks of three different meshes. The powdered clay passes through the finest part of the sieve i to the compartment j of a bin beneath, and is delivered by a worm k to a receiver m, while the graded mica is received in compartments j1, j2 and falls into receivers m1, m2. Fig. 3 shows a modification in which a coarse cylindrical screen o is arranged within the trommel n, the mixed clay, mica, and fine quartz separated by the trommel undergoing a second screening in a finer trommel s to separate the quartz. The screen o receives the crushed material from the mill and is fitted with carrier vanes to pulverize it.