Improved Method of Dressing or Grading China Clay.

摘要

18,294. Batt, H. J., and Bowden, W. Aug. 15. Pottery.-In a method of dressing or grading China-clay, the clay after excavation is broken up and exposed to a constant current of air heated to about 250‹ F., and is agitated to facilitate drying. It is then screened in order to separate out anything above a quarter-inch mesh, and is allowed to fall in a thin wide stream which is subjected to a current of air heated to about 150‹ F. The clay is thus blown over graded screens, preferably rotary tubular screens having sections of different grades of fineness, through which the heavier particles fall into bins. The air blast carries the lighter particles against a series of stationary baffles or screens of increasing fineness of grade, or the particles may be allowed to fall by gravity as the air current becomes spent. The different grades of sand, grit, mica, and clay are thus separately collected. Finally the clay is passed through a grading-reel or centrifugal screen provided with a fine silk or wire mesh.