Improved Process for the Recovery of Metals from Tinning, Galvanizing and like Waste.

摘要

Waste oils and fats from tinning, galvanizing, and like processes are treated for the recovery of the metals in the form of salts, oxides, and metallic tin, by the addition of mineral acid of such strength that no emulsions are formed, the mixture being agitated by compressed air and the salt solution which separates being drawn off. ALSO: Waste containing oils and fats from tinning, galvanizing, and like processes is treated for the recovery of the metals by the addition of mineral acid of such strength that no emulsions are formed, the mixture being agitated by steam or compressed air, and the salt solution which separates being drawn off. When sulphuric acid is used, the solution is evaporated and calcined, or the metal may be precipitated as hydroxide. When hydrochloric acid is used, tin may be precipitated from the solution by metallic iron or zinc, and the zinc present may be precipitated by milk of lime.