Abstract The realization of clean extraction of aluminum hydroxide from high-alumina coal fly ash would be beneficial to achieve better overall coal utilization, and renders environmental and economic benefits. The current study mainly aimed to develop a nonhazardous approach to conduct electrolysis for alumina extraction from sulfuric acid leachate of high-alumina coal fly ash. The XRD, SEM, LPSA, FT-IR and ICP-AES results revealed that aluminum hydroxide was a main electrolysis product, with current efficiency of 83.25% under the optimized conditions as t = 1 h, J = 600 A/m2. The median particles of aluminum hydroxide after 1-h and 6-h electrolysis were 35.3 and 40.1 μm, respectively. The electrolysis mechanism was analyzed by cyclic voltammetry, which showed that the H2O gained electrons on the cathode to form OH– and H2. The OH– reacted with Al3+ to form Al(OH)3. In addition, the effluent of electrolysis was sulfuric acid and can be reused as a leaching reagent to promote zero pollution discharge. Hence, the electrolysis process provided an environment-friendly and efficient approach for alumina extraction from high-alumina coal fly ash.

中文翻译：

---

从粉煤灰合成硫酸浸出液中回收氧化铝的清洁电解工艺

摘要 实现从高铝粉煤灰中清洁提取氢氧化铝，有利于实现更好的煤炭综合利用，具有环境效益和经济效益。目前的研究主要旨在开发一种无害的方法，从高铝粉煤灰的硫酸浸出液中电解提取氧化铝。XRD、SEM、LPSA、FT-IR 和 ICP-AES 结果表明，氢氧化铝是主要的电解产物，在 t = 1 h、J = 600 A/m2 的优化条件下，电流效率为 83.25%。电解 1 小时和 6 小时后氢氧化铝的中值颗粒分别为 35.3 和 40.1 微米。循环伏安法分析了电解机理，结果表明 H2O 在阴极上获得电子形成 OH-和 H2。OH– 与 Al3+ 反应形成 Al(OH)3。此外，电解出水为硫酸，可作为浸出剂重复使用，促进零污染排放。因此，电解工艺为从高铝粉煤灰中提取氧化铝提供了一种环保高效的方法。