水热辅助2段酸溶法从高岭土尾矿提取氧化铝的研究

Study on Alumina Extraction from Kaolin Tailings by the Hydrothermal-assisted Two Times Acid Extracting Process

以高岭土尾矿为原料提取氧化铝,研究水热辅助2段酸溶工艺提取氧化铝的条件,考察了高岭土尾矿煅烧活化和溶出条件对高岭土尾矿中氧化铝溶出率的影响。实验结果表明,煅烧活化条件为:煅烧温度650℃、煅烧时间2 h;溶出的最佳工艺条件为:第1阶段采用浓盐酸酸溶提取氧化铝,液固质量比4∶1、水热反应温度85℃、水热反应时间12 h;第2阶段采用质量分数15%的盐酸酸溶提取氧化铝,液固质量比4∶1、水热反应温度85℃、水热反应时间12h。在此条件下,高岭土尾矿中氧化铝总溶出率达到75.5%。

Kaolin tailings was used as a raw material to extract alumina. The conditions of eXtracting alumina using the hydrothermal-assisted two times acid extracting process were studied, the effects of conditions of calcining activation and extracting on the extracting rate of alumina from kaolin tailings were investigated. The experimental results showed that the conditions of calcining activation were the calcination temperature 650 ~C and calcination time 2 h; the best technological conditions of extracting were as follows： in the first stage, alumina was extracted using concentrated hydrochloric acid, the mass ratio of liquid-solid 4 ： 1, hydrothermal reaction temperature 85℃, hydrothermal reaction time 12 h; in the second stage, alumina was extracted using the mass fraction of hydrochloric acid 15%, the mass ratio of liquid-solid 4 ： 1, hydrothermal reaction temperature 85℃, hydrothermal reaction time 12 h. Under the condition, the total extracting efficiency of alumina from kaolin tailings achieved 75.5%.