GB1018631A - Process and electric-arc heated lance for the non-exothermic treatment of metal-containing material - Google Patents

Abstract

In a process involving non-exothermic interaction between a gas and a metal-containing material, the gas stream is heated by passage through an arc established from a rod electrode disposed axially in the gas flow; the arc may pass to an annular electrode at the gas outlet or to the metal-containing material. One or more additional passages for the supply of gas may be provided coaxial with that containing the electrode. Particular embodiments disclosed include the degassing of molten metals with a stream of hot inert gas, the desulphurization of molten ferrous metals with a stream of hot inert gas containing a reagent such as lime, calcium carbide or calcium cyanamide, and the carburization of molten metal with gas or a suspension of carbon. The process may also be applied to the reduction of metallic compounds either by directing a stream of heated reducing gas thereon, or by introducing the compound into either the reducing gas or into a separate arc-gas where a multi-channel lance is used. Easily ionizable substances such as argon, krypton, silicon tetrachloride, titanium tetrachloride chlorosilanes, or oxides or carbonates of alkali, alkaline earth or rare earth metals may be added to the arc-gas to stabilize the arc.