烧结-碱溶法从高铝粉煤灰中浸出镓的研究

摘要

With high⁃aluminum coal fly ash as raw material, a gallium⁃containing solution was prepared with a process consisting of fly ash activated by calcination, alkali dissolution, filtration and washing. The effects on gallium leaching by factors, including types of sintering additives, kinds of alkaline solution, concentration of alkaline solution, liquid⁃solid ratio, leaching temperature and leaching time, were investigated. Results showed that with sodium carbonate as sintering additive and sodium hydroxide as leaching solvent, alkaline solution at the concentration of 200 g/L, liquid⁃solid ratio at 40∶1, leaching temperature at 60 ℃ and leaching time of 6 h, the content of gallium in the leaching solution reached 41.438 g/t.%以高铝粉煤灰为原料，通过对粉煤灰进行烧结活化、碱溶、滤洗等工艺，制得含镓溶液。探讨了烧结助剂种类、碱液种类、碱液浓度、液固比、浸出温度、浸出时间等因素对镓浸出效果的影响。结果表明：以碳酸钠作为烧结助剂，氢氧化钠作为浸出液溶剂，在碱液浓度200 g／L、液固比40∶1、浸出温度60℃、浸出时间6 h时，浸出液中镓含量达到41．438 g／t。