( 中南大学 冶金科学与工程学院， 长沙 410083)
摘 要: 针对我国铝土矿资源特点和我国烧结法生产氧化铝的现状，论述了强化烧结法生产氧化铝新工艺。 采用铝硅比为9.62的矿石，按照钙比为1.3~2.0， 碱比为1进行配料， 在1250℃以上进行熟料烧成。 实验结果显示： 烧成的熟料溶出条件宽松，二次反应程度弱； 溶出浆液在170℃左右直接进行加压脱硅，脱硅后溶液的硅量指数大于200， 再加入适量的石灰进行深度脱硅，即使溶液中氧化铝浓度超过200g/L时，精液的硅量指数也大于600， 且得到的水化石榴石中二氧化硅饱和系数大于0.28； 通过加入晶种和采用新的碳酸化分解工艺制度，产品中的SiO2 含量降至0.025%， Na2O含量小于0.37%； 加入表面活性剂， 不仅能将碳分母液蒸发至Na2OT浓度大于300g/L， 而且还可有效减缓表面上结疤的形成速度。部分结果已应用于工业实践中, 单台窑产能提高了19.7%， 工艺能耗降低了24.71%。
关键字: 强化烧结法； 氧化铝生产； 工艺； 应用
for alumina production
（ College of Metallurgical Science and Engineering,
Central South University, Changsha 410083, China）
Abstract: Based on the Chinese bauxite character and the status of the traditional sintering process, the intensified sintering process was studied. In the charge, the mass ratio of alumina to silica is 9.62, calcium ratio 1.3-2.0, alkali ratio 1.0, and then the charge is sintered above 1250℃. It is convenient for sinter to be leached, and the secondary reaction appears little. The slurry after sinter leaching is transferred into autoclave for desilicification at about 170℃, and the siliceous modulus of solution reaches more than 200. Then some lime is added for deep-desilication at normal pressure, the siliceous modulus of solution increases more than 600 even if the Al2O3 content is more than 200g/L.The SiO2 coefficient in hydrate garnet from deep-desilication is more than 0.28. Under conditions of the addition of seed and application of novel technology of carbonization, the contents of Na2O and SiO2 in product are less than 0.37% and 0.025%, respectively. When surfactant is added into spent liquor in the evaporation, the concentration of Na2OT can reach more than 300g/L, and the scale on the heating surface can be abated obviously. With the application of intensified sintering process the output of every rotary kiln increases by 19.7%, in the same time the energy consumption of alumina production decreases by 24.71%.
Key words: intensified sintering process; alumina production; technology; application
