高苛性比铝酸钠溶液中氧化铝的回收

来源期刊：中国有色金属学报1999年第2期

论文作者：李小斌 刘桂华 彭志宏 张传福 何伯泉 刘祥民

文章页码：403 - 406

关键词：铝酸钠溶液 氧化钙 水合铝酸钙

Key words：aluminate solution ; calcium oxide ; calcium aluminate hydrate

摘    要：对加入石灰后的高苛性比铝酸钠溶液中氧化铝的回收进行了研究。热力学计算结果表明，氧化钙较氢氧化钙更容易使铝酸钠溶液中的铝酸根离子转化为水合铝 酸钙，使铝酸钠溶液的平衡苛性比能达到很高的值；水合铝酸钙随着温度的升高，稳定性降低，因而能在拜尔法高温溶出过程中分解以代替石灰，并回收其中的氧化铝。实验结果表明，影响水合铝酸钙形成因素的大小顺序为：温度≈碱浓度＞CaO/Al₂O₃＞时间。

Abstract: The recovery of alumina in the high mole ratio (α_k) aluminate solution was studied. The thermodynamic calculation results i ndicated that the formation of calcium aluminate hydrate from aluminate solution with CaO is easier than that with Ca(OH)₂, and the value of α_k is great at low temperature ; the temperature rise leads to the reduction of stability of calcium aluminate hydrate in the aluminate solution, and it can be decomposed at high temperature , which can both substitute for Ca(OH)₂ and recover alumina in the process of Bayer. The order of affecting the formation of calcium aluminate hydrate is as follows: temperature≈concentration of caustic soda＞CaO/Al₂O₃ (mole ratio)＞time.