Patent ID: 6113668
Filing Date: 2000-09-05
Classification: B22F,C22C

Abstract:
A process for manufacturing a starting powder material useful for compacting and making fine grained hardmetal bodies, beginning from a metal oxide powder or from a reducible hard metal compound, said process comprising the steps of:reducing the oxide or the metal compound into metal;carburizing of the metal;performing a mechanical-chemical powder particle dressing and/or mixing process;said process further comprising the step of utilizing a cyclone device and a cyclone process in at least one of the reducing and carburizing steps;wherein the device is a temperature controlled reaction chamber, arranged at least in sections in approximately rotational symmetry around a longitudinal axis with admission and outlet openings for powdered stock to undergo reduction and/or to be carburized and for reacting gas with the stock and for carrier gas, the powdered stock, carrier gas and reacting gas being continuously introduced into the reaction chamber,and wherein the continuously introduced powdered stock, while maintaining the solid state, passes through the reaction chamber with high powder velocities on paths orbiting the longitudinal axis with velocity components tangential to chamber walls of the device at least in sections, the powdered stock being guided through the reaction chamber based upon the direction and velocity of the powdered stock upon entry, as well as by flow parameters of carrier and/or reaction gas at the entry,and wherein the powdered stock exits the device at least with a portion of 90% by volume having undergone chemical reaction of reduction and/or carburization in 0.1-60 seconds after admission.