GB317553A - Method of and machine for sorting and separating mica - Google Patents

Abstract

317,553. Frederick, L. T. May 25, 1928. Pneumatic separating.-Mica flakes are separated according to their thickness by dropping the mixed flakes down a tower 10 and applying suction at an opening 14 so as to remove those of the required thinness and flexibility. The thicker flakes drop into one compartment 28 of a bin 13 and may be subjected to further disintegrating and separating operations and the selected flakes, before collection in the compartment 29, may be subjected to a further grading by suction apparatus. In the apparatus described, the mica blocks, after being soaked in a mixture of soapstone and water and dried, are fed to a reticulated drum 11 which disintegrates the blocks, the flakes falling through the meshes into the tower. The suction device at the foot of the tower comprises two oppositely rotating perforated drums 15 in the interior of which is produced a partial and regulated vacuum The flakes adhering to the drums are carried out of the tower and are stripped by the action of tangential air blasts from elongated nozzles 24 in combination with stationary segmental cut-offs 9. Alternatively a conveyer device as described in Specification 272,429, [Class 70, Indiarubber &c.], may be used. The flakes carried out of the tower are dropped on to a perforated endless carrier 31 under the forward end of which is placed a suction box 34 which acts in combination with the centrifugal action of the carrier 31 to make a further selection of the flakes which fall into the compartments 28, 29 of the bin. An elevator 30 returns the thick flakes to the drum 11 for retreatment. Adjusting devices are provided for the suction, speed of the moving parts, and relative sizes of the compartments 28, 29, so as to regulate the degree of separation.