Patent ID: 6238633
Filing Date: 2001-05-29
Classification: C01F,C04B,C22B,Y02P

Abstract:
A process for preparing calcium aluminate product from a salt-containing aluminum dross containing aluminum metal, water-insoluble material and fluxing compounds, comprising:(a) crushing the salt-containing aluminum dross;(b) treating the crushed dross in a digester with water to dissolve water-soluble compounds contained therein to provide an aqueous solution containing both soluble and insoluble materials;(c) separating the insoluble material from the aqueous solution containing soluble materials by:(i) wet screening to separate a course fraction having a high metallic aluminum content from a fine fraction and aqueous solution; and(ii) classifying said fine fraction to remove aluminum metal therefrom and to recover aqueous solution containing NMP;(d) recovering a body of non-metallic product (NMP) from said aqueous solution, a major portion of the non-metallic product comprised of Al.sub.2 O.sub.3 and minor portions of said body comprised of at least one of SiO.sub.2 and MgO, the non-metallic product (NMP) having less than 1 wt. % each of aluminum metal and aluminum nitride and having an LOI at 1400.degree. C. of 5 to 35 wt. %;(e) adding a source of calcium oxide to said body of non-metallic product (NMP) to provide a blend;(f) forming said blend into discrete bodies; and(g) heating said bodies to a temperature in the range of about 1093.degree. to 1193.degree. C. to form said calcium aluminate product without said bodies forming agglomerates.