| 摘要 |
<p>In a process for refining carbon-containing metals and alloys in an induction furnace in the presence of a reducing atmosphere obtained by expelling the initial atmosphere by means of an inert gas or vapour and subsequently removing the inert gas &c. by the introduction of the reducing gas, the introduction and removal of the gas for expelling the atmosphere in the furnace is effected only when the bath has become practically motionless by cutting off the current and when a protecting slag layer has been formed due to the particles in the slag rising to the surface when the current is cut off. The charge is normally covered by a slag but if no slag is present a slag-forming substance is added before the current is cut off, the slag layer being removed before switching on the current again. Alternatively, when no slag is present, slag-forming substances in small amounts are added before cutting of the current, but this slag which forms a skin is not removed before the current is switched on again. Slag forming substances which are added comprise hydroxides or carbonates or mixtures thereof of the alkaline or alkaline earth metals. The process may be applied to the refining of iron or iron alloys such as ferrochromaluminium ferrochrommagnesium and ferrochromcalcium.</p> |
