Process for making cubical sintered aluminous abrasive grains

Abstract

Abstract Process for making an aluminous abrasive grain formed from bauxite, or mixtures of bauxite and Bayer Process alumina, wherein the comminuted aluminous material is mixed with water and ferric ammonium citrate and reduced to a state of fine subdivision by milling to give a fluid slurry of high solid content, placing said slurry in an electrophoretic cell having one or more electrically conducting rotating anodes, and one or more electrically conducting stationary cathodes. The slurry is maintained at a predetermined level so that the rotating anodes are partially immersed. The anodes are connected to a source of positive direct current and the circuit completed by connection of the cathodes to the same source of direct current but to the negative terminal thereof. The solid aluminous material migrates to the anodes where it adheres as a layer which is continuously removed from the slurry by rotation of the anodes, is partially dried by impingement of warm air whereupon the layer releases from the surface of the anodes in the form of platelike pieces which are blown free of the cell by the warm airstream. The layer is controlled to a thickness equal in one dimension of the final grain compensated for subsequent shrinkage. The platelike pieces resulting are further dried, broken to approximately cubical grains, screened, optionally rounded by air mulling, screened, sintered and screened to give the final product.

Inventors

• 👤 Herbert F G Ueltz
• 👤 Alfred G Rzucidlo

Bibliographic Details