GB559049A - Improvements in and relating to the reduction of metals to powdered or granular form - Google Patents

Abstract

559,049. Granulating metals; magnetic separators. TELEPHONE MANUFACTURING CO., Ltd., and PADDLE, L. H. April 30, 1942, No. 5828. [Classes 72 and 82 (ii)] [Also in Group III] In a process for reducing metals to powdered or granulated form by bringing a falling stream of molten metal into intimate contact with a surrounding stream of gas, the molten metal is delivered from a crucible under the pressure of the gaseous fluid employed to effect the pulverization. The molten metal falling through the outlet 3 in the crucible 1 comes into contact with gaseous fluid ejected through an annular nozzle 5, or a ring of nozzles which may be so arranged as to give the gaseous stream a whirling motion. The falling metal stream passes through a Venturi nozzle 4 of refractory material. The powdered or granular metal is deposited in a receiver 6 which may contain a cooling liquid which may have non-oxidizmg or other protective properties. The gas employed may be an inert gas, which is circulated through the apparatus, being withdrawn from the receiver 6, preferably through a filter and purifier 10, by means of a pump 7, and introduced thereby through a pipe 11 into a jacket surrounding the crucible, a branch 12 allowing the gas to exert pressure on the surface of the molten metal in the crucible. The crucible jacket may contain a heating element 2. Air or oxygen may be employed instead of .an inert gas, in which case powder or granules of an oxide of the metal are obtained. When ferrous metal is being treated, a magnetic separator may be employed for separating metallic particles from the gas stream. One pole 13 of the magnet may be situated within the stack 16, the other pole 14 surrounding the stack. Heating elements may be arranged at intervals along the stack so that the falling powder or granules may be subjected to any desired heat treatment.