Abstract: Highly active cobalt-molybdenum-alumina desulfurization catalysts containing 18-30 weight-percent of MoO.sub.3 are prepared by first comulling boehmite alumina with aqueous ammonium molybdate solution, drying the resulting mixture, then comulling with a soluble cobalt salt and water, thereafter forming the resulting mixture into extrudates, and finally calcining the extrudates under controlled temperature conditions correlated with the molybdenum content of the catalyst so as to preserve adequate surface area and prevent the formation of large crystallites of cobalt molybdate. This method of preparation permits effective utilization of molybdenum in amounts up to about 30 weight-percent MoO.sub.3, a result not obtainable by conventional impregnation techniques.

Abstract: An extrusion die having a plurality of orifices arranged therein so that the number of orifices per unit area in the plane of the external die face is larger near the periphery of the die face than near the center thereof provides for the extrusion of material through all the die orifices at a relatively uniform linear velocity.