(中南工業(yè)大學(xué)有色冶金系，長沙 410083
中州鋁廠，焦作 454174)
摘 要: 對加入石灰后的高苛性比鋁酸鈉溶液中氧化鋁的回收進(jìn)行了研究。熱力學(xué)計算結(jié)果表明，氧化鈣較氫氧化鈣更容易使鋁酸鈉溶液中的鋁酸根離子轉(zhuǎn)化為水合鋁 酸鈣，使鋁酸鈉溶液的平衡苛性比能達(dá)到很高的值；水合鋁酸鈣隨著溫度的升高，穩(wěn)定性降低，因而能在拜爾法高溫溶出過程中分解以代替石灰，并回收其中的氧化鋁。實驗結(jié)果表明，影響水合鋁酸鈣形成因素的大小順序為：溫度≈堿濃度＞CaO/Al2O3＞時間。
關(guān)鍵字: 鋁酸鈉溶液 氧化鈣 水合鋁酸鈣
（Department of Nonferrous Metallurgy, Central South University of Technology,Changsha 410083, P. R. China
1 Zhongzhou Alumina Factory, Jiaozuo 454174, P. R. China）
Abstract:The recovery of alumina in the high mole ratio (αk) 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 αk 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.
Key words: aluminate solution calcium oxide calcium aluminate hydrate
