An Improved Method of Utilizing Aluminium Skimmings, Screenings, Slags and analogous Materials.

摘要

Aluminium skimmings, dross, slag, &c., after first separating the larger metallic particles, are mixed with a reducing agent such as tar, asphalt, petroleum, resin oil or like hydrocarbon material and heated with exclusion of nitrogen to a nitride-forming temperature (1200 DEG C.) after which a nitrogenous gas such as air is admitted when nitrogen is absorbed to some extent and the temperature rises. On cooling, the smaller metallic particles will be found to have fused together so that they can be removed. After removing these metallic particles and magnetic iron oxide if desired the material is treated with boiling water preferably in presence of lime or other alkaline agent to liberate ammonia from the nitride, and the aluminous material may be then treated for recovering aluminium sulphate and copper compounds. ALSO: Aluminium skimmings, dross, slag, &c., after first separating the larger metallic particles, are mixed with a reducing agent such as tar, asphalt, petroleum, resin oil, or like hydrocarbon material and heated with exclusion of nitrogen to a nitride-forming temperature (1200 DEG C.), after which a nitrogeneous gas such as air is admitted when nitrogen is absorbed to some extent and the temperature rises. On cooling, the smaller metallic particles will be found to have fused together so that they can be removed. After removing these metallic particles and magnetic iron oxide if desired, the material is treated with boiling water, preferably in presence of lime or other alkaline agent to liberate ammonia from the nitride, and the aluminous material may be then treated for recovering aluminium sulphate and copper compounds.