用铝灰制备氢氧化铝的试验研究

作为铝业废渣，铝灰中含有20％～50％的铝。利用铝灰生产氢氧化铝并进而生产高纯聚合氯化铝，能够有效利用资源，消除环境污染。通过试验，提出了用铝灰制备氢氧化铝的工艺流程，并以铝灰中铝的溶出率和氢氧化铝中氧化铝质量分数2个指标，对碱溶法制备氢氧化铝工艺中的影响因素进行了讨论。结果表明，延长反应时间，加大碱的投入量，可以提高铝的溶出率以及成品氢氧化铝中氧化铝的质量分数。

Preparation of Aluminum Hydroxide From Aluminum Ashes

There are 20%- 50% of aluminum in aluminum ash from aluminum industry. The preparation of aluminum hydroxide with the aluminum ash and production of high purity polyaluminium chloride are studied. Based on experiment results, the processes and influence factors for preparation of aluminum hydroxide with the aluminum ashes and sodium hydroxide solution have been discussed. The dissolving rate of aluminum from aluminum ashes and mass fraction of alumina in aluminum hydroxide as two evaluation indexes are put forwarded. The results show that prolonging reaction time and increasing dosage of aluminum hydroxide can improve reaction process and alkaline leaching rate of aluminum.