Refining of molten copper - where mixt. of oxygen and fuel is blown at high velocity onto surface of molten bath

摘要

Molten metals are refined after oxidn. or redn., by bringing solid-, liq.-, or gaseous-reducing agents in contact with the bath. The reducing agent is a reactive mixt. of pressurised oxygen and fuel, blown at high velocity and in a non-reacted state into the molten bath. The O2-fueld mixt. pref. has a stoichiometric ratio lambda of 1. The O2 can be present as gaseous oxygen, gas enriched with O2, or in a chemical cpd. added to the mixt. The fuel is pref. a higher hydrocarbon, e.g. propane, butane, light petrol; or H2; gas enriched with H2; coal dust; a fuel gas, esp. natural gas. The mixt. pref. has pressure 10-50, esp. 20-25 kp cm2, and velocity above 100 m/second, pref. supersonic velocity; and is used esp. in the continuous refining of copper. Compared with conventional refining methods, more complete removal of impurities (e.g. Pb, As, Sb, Bi, etc) and redn. in refining costs are ensured.