Abstract:Principle of two stage organic caustic method was introduced. Alumina was recovered from two-stage organic caustic slag by leaching with sodium carbonate. Effects of sodium carbonate concentration, leaching temperature, leaching time, and ratio of liquid to solid (L/S) on alumina recovery rate were investigated. The results show that alumina recovery rate is 90% above under the optimum conditions including concentration of sodium carbonate of 90 g/L, reaction temperature of 100 ℃, reaction time of 80 min, and L/S of 10.