Improved manufacture of homogeneous, ductile pieces of chemically pure metals of the tungsten group, having a high melting point, such as tungsten, molybdenum, and uranium, and also of titanium, amp; chromium

摘要

253,161. Gewerkschaft Wallram Abteilung Metallwerke, Voigtlõnder, H., and Kaufels, O. Feb. 7, 1925. Dry processes of f extracting tungsten and other refractory metals; thermo-aluminic and like metal-extracting processes. - Tungsten, molybdenum, uranium, titanium, chromium, and like metals having a high melting-point are obtained in ductile form from their oxides by exothermic reduction, the violence of which is lessened and controlled by (a) first reducing the oxide with a gaseous or other reagent and then completing the reduction by means of a metal such as aluminium, or (b) reducing the oxide by means of aluminium or the like in the presence of contact materials such as metals or metal oxides, or (c) causing the oxide and reducing-agent to act on each other in very finely-divided form, e.g. atomized or vaporized, or carried in heated gas currents, preferably in counter-current. External heat may be applied if necessary. The molten product may be stratified by magnetic or centrifugal means before solidifying, several metals being thus obtained in separate layers. Specification 23499/09 is referred to.