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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。
The recovery of alumina from the highly caustic sodium aluminate solution after lime addition was studied. Thermodynamic calculation results show that calcium oxide is more likely to make the aluminate ions in the sodium aluminate solution into calcium aluminate hydrate than calcium hydroxide so that the equilibrium caustic ratio of the sodium aluminate solution can reach a very high value. Calcium aluminate hydrate As the temperature increases, the stability is reduced and therefore can be decomposed instead of lime during the high-temperature dissolution of the Bayer process and the aluminum oxide recovered therein. The experimental results show that the order of magnitude of the formation factors of hydrated calcium aluminate is temperature ≈ alkali concentration> CaO / Al2O3> time.