摘要 |
Disclosed is the recycling of aluminum dross. Aluminum dross is crushed into particles which are size-classified on the basis of 1 mm. The aluminum dross particles equal to or smaller than 1 mm in size are leached with an aqueous sodium hydroxide solution to give a leachate which contains sodium aluminate as a result of the reaction the aluminum metal of the aluminum dross particles with sodium hydroxide. The aluminum dross particles greater than 1 mm in size are remelted to recover aluminum metal. In the leachate, a small quantity of aluminum hydroxide is seeded, followed by hydrolyzing the sodium aluminate to obtain aluminum hydroxide. Meanwhile, the leachate is filtered to obtain a residue. This residue is subjected to washing, drying and roasting. The mixing of the roasted residue with aggregate and alumina cement gives alumina castable refractories. It is economically very advantageous in that aluminum dross is reused as a raw material for aluminum hydroxide and for alumina castable refractories, instead of being discarded. Also, hydrogen gas can be obtained as a by-product in the process of recycling.
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