Abstract: When lithium was produced in the process of aluminothermic reduction LiAlO₂ clinker in vacuum condition where the clinker was prepared by calcined mixture of lithium carbonate， alumina and calcium oxide at normal atmosphere， the reduction residue containing CaO·Al₂O₃ and 12CaO·7Al₂O₃ was obtained. In order to recycle the reduction residue， the residue was firstly leached with a mixture solution of sodium hydroxide and sodium carbonate， and then aluminum hydroxide was produced by decomposing the leaching solution with carbon dioxide. The effects of leaching temperature， leaching time， particle size， sodium carbonate concentration， sodium hydroxide concentration and lithium reduction rate on leaching rate of alumina were investigated. The results showed that the leaching rate of alumina is 80.73% under the conditions of the particle size distribution d₉₀ of 74μm，the leaching temperature of 95℃， the leaching time of 120min， the Na₂CO₃ concentration of 240g/L and NaOH concentration of 8.9g/L， when the residue is from the reduction lithium process with a reduction rate of 97%. The average particle size and the whiteness of aluminum hydroxide obtained by carbonation precipitation are 6.50μm and 96.9， respectively.

Key words: aluminothermic reduction, reduction residue, leaching, carbonation decomposition, aluminum hydroxide