1957. ------. [KREBS, R. W.] (Standard Oil Development Co.). Slurry Handling. United States Patent 2,518,337, Aug. 8; 1950; appl. filed Apr. 26, 1946, Serial No. 665,073; 2 claims (Cl. 260-449).

Catalyst that has been used in hydrocarbon synthesis is dewaxed by solvent treatment. The usual practice is to return the catalyst to the reaction zone in a slurry with a concentration of ½-lb. catalyst per gal. solvent. According to this invention the concentration is raised to 5-10 lb. Catalyst per gal. solvent. This flowable, but not pumpable, slurry is treated with hydrocarbon gases to form a froth, which is returned to the reaction zone. The amount of solvent oil returned to the system per unit volume of catalyst is reduced 20%. 2 literature refs. and 2 foreign and 8 United States patents cited.