Resource-saving and environment-saving production technologies of secondary aluminum alloys

The main directions of resource-saving and environment-saving fabrication technologies of secondary aluminum alloys in modern industrial conditions are considered. The types of feedstocks and applied smelting aggregates are analyzed, and promising ways to further improve this production process are shown. It is revealed that the traditional processing method of secondary aluminum feedstock, which is widely used in practice, is thermal treatment in a medium of molten chloride salts. Salt-free technologies of processing aluminum dross, which are based on the separation of metal and oxides by the mechanical effect on them under conditions of high temperatures in the medium of the furnace atmosphere or collector metal, are proposed. Their advantages over the widespread salt technology are considered: materials applied to treat the melt are substantially less expensive than alkali metal chlorides; dump slags are environmentally pure; and the process has high productivity since it is performed in one metallurgical aggregate, which excludes the necessity of cleaning the walls and bottom part in it. The examples of implementing the salt-free processing technologies of aluminum feedstock under consideration under conditions of several Russian metallurgical enterprises are shown.