3820.  ----- [VESTERDAL, H. G]. (Standard Oil Development Co.). Process of Reducing Iron Group Metal Oxides. United States Patent 2,479,435, Aug. 16, 1949; appl. filed May 14, 1946. Serial No. 669,530; 6 claims (Cl. 252-472). Chem.. Abs., vol. 43, 1949, p. 9419.

Finely divided O compounds of ferro-magnetic metals, particularly Fe group metal oxides and carbonates, are subjected in the form of a suspension in a reducing gas, to reducing temperatures for a time sufficient to cause partial reduction but insufficient to cause partial reduction but insufficient to decrease the activity of the reduced catalyst. Particles of the desired degree of reduction are separated by means of a magnetic field, and the particles insufficiently reduced are recycled to the reduction zone. 2 foreign patents and 5 United States patents cited.