Hydrogen Plasma Arc Melting

Abstract

The thermal plasma generator, generally known as the plasma torch, is already in practical use in various fields of the metals industry, such as welding, cutting and metal spraying. In addition, a number of studies have been made for the utilization of thermal plasmas in smelting and melting since the early stages of its development. This is indicated by numerous related publications and by the introduction of several processes into practice [1-6]. The temperature of a thermal plasma generated by a plasma torch ranges from 5000 to 20 000K at pressures around 0.1 MPa. Plasmas can be considered to be the result of converting electric energy into a gas-flow that contains high-density thermal energy. Since various gases, such as H₂, O₂ and N₂, as well as inert gases like Ar, are used as the plasma-generating gas, the thermal plasma is useful not only as an excellent heat source but also as an efficient source of reagents, by means of dissociated an d activated species that are formed at high temperature [2, 3].