1956. ------. [KREBS, R. W.] (Standard Oil Development Co.). Method of Sintering a Catalyst. United States Patent 2,510,823, June 6, 1950; appl. filed June 30, 1947, Serial No. 758,206; 2 claims (Cl. 260-449.6). Chem. Abs., vol. 44, 1950, p. 8094.

Fe fines, which cannot be maintained in the reaction zone under fluid conditions because of their small particle size, are sintered 1,300°-2,000° F. to form agglomerates large enough for the fluidizing range 20-200 microns. The coarser particles are separated by gaseous classification and returned to the reaction zone without grinding. The sintering is done in a reducing atmosphere so that the Fe or other metal remains in an unoxidized state. 1.5 ton catalyst fines (below 20 microns) per hr. are sintered at 1,700° F. in a vessel 20 ft. in sintering section diameter and 3 ft. in quenching or collecting-zone diameter. The gas velocities are 0.2 ft. per sec. and 1 ft. per sec. in the sintering and quenching zones respectively. The fines are agitated to induce agglomeration. 3 United States patents cited.