METHOD AND APPARATUS FOR REUSING HARD METAL WASTE BY APPLICATION OF PLASMATECHNIC

摘要

The invention relates to a process for processing and re-use of hard metal wastes. The hard metals used for the production of hard metal tools largely consist of tungsten carbide and also contain cobalt. The wastes are difficult to pulverise but can only be re-used in the form of powder. According to the invention, the hard metal wastes are given a shock heat treatment in a plasma flame, during which the structure of the cobalt forming the ss-phase is altered such that the hard metal can later be easily milled and pulverised. The chemical composition of the hard metal and also the structure of the carbide phases are thereby hardly changed, and when the material reaches the sintering temperature when re-used, the perturbed cobalt phase also recrystallises and takes on its original structure again. The invention furthermore concerns an apparatus for carrying out the process. This apparatus has a reactor, a plasma generator, and also a metering apparatus and devices for conducting away the hot gas and the end product. The apparatus according to the invention is characterised in that it has a mechanical auxiliary device for regulating the residence time of the hard metal waste in the reactor.