关键词: 赤泥, 水洗, 脱碱

Abstract: Red mud,a solid waste residue of alumina refinery industrial production,is a serious pollution source because of its strong basicity.Experiments of washing strong alkaline red mud with water of different temperatures (20,55,75,95 ℃) were carried out.Results showed that the mass concentration of initial washing solution was relatively higher,average mass concentration of 6-time′s washing solutions was at 2.44~2.72 g/L,and mass concentration of the solution washed by cold water (20 ℃) was the highest.pH of each washing liquid had little change.Recovery efficiency of alkali was not changed significantly with washing water of different temperatures and the alkali recovery amount of the former 3 time′s washing accounted for more than 70% of the total.Among them,recovery amount of alkali with the cold water washing was the highest.After 6 time′s washing,the mass of recoveried sodium hydroxide was as high as 8.18 mg from every gram of red mud. 

Key words: red mud, washing；dealkalization