Abstract: The effects of roasting temperature, roasting time and molar ratio of sulfuric acid to ore on the extracting rates of Al and Fe from bauxite by sulfuric acid roasting and water leaching were investigated through single-factor experiments and orthogonal experiments. The results showed that the optimum conditions were obtained as the molar ratio of sulfuric acid to ore of 3.75:1, roasting temperature of 325℃ and roasting time of 2.5 h. The extracting rate of Al was over 98% and that of Fe over 80% under the optimum conditions. The sequence of each factor affecting the extracting rates of Al and Fe is the molar ratio of sulfuric acid to ore > roasting temperature > roasting time. The process was proved to be significant with advantages of high extraction rates and low temperature.

Key words: bauxite, sulfuric acid, aluminum, iron, roasting, water leaching

摘要： 通过单因素实验和正交实验研究了铝土矿硫酸焙烧与水浸提铝铁过程中焙烧温度、焙烧时间和酸/矿摩尔比对铝和铁提取率的影响. 结果表明，在酸/矿摩尔比3.75:1、焙烧温度325℃，焙烧时间2.5 h的条件下，Al提取率达98%, Fe提取率达80%，各因素对铝铁提取率的影响顺序为：酸/矿摩尔比>焙烧温度>焙烧时间. 该工艺具有焙烧温度低、金属提取率高等特点，对铝土矿的开发利用具有重要的意义.

关键词: 铝土矿, 硫酸, 铝, 铁, 焙烧, 水浸