降低拜耳法氧化铝生产中水解损失研究

Study on Reducing Hydrolysis Loss in Bayer Process Alumina Production

氧化铝生产中,赤泥分离和洗涤工序主要负责将铝酸钠溶液中的赤泥分离出来,然后用热水进行四次洗涤,在此过程中,铝酸钠溶液会发生水解,造成氧化铝损失,影响氧化铝综合回收率。生产上可采取有效措施管控赤泥洗涤过程中氧化铝水解损失,优化赤泥A/S指标。通过分析铝酸钠溶液水解损失情况和机理,采取提高沉降槽温度、减少沉降槽存量、控制合适的泥层高度、提高赤泥洗涤效率等措施,减少赤泥分离和洗涤过程中的水解损失,对降低生产成本,有重要意义。

In alumina production,the red mud separation and washing process is mainly responsible for separating the red mud from the sodium aluminate solution,and then washing it with hot water for four times.In this process,the sodium aluminate solution will be hydrolyzed,resulting in alumina loss and affecting the comprehensive recovery rate of alumina.In production,effective measures can be taken to control the alumina hydrolysis loss during red mud washing and optimize the red mud a/s index.By analyzing the situation and mechanism of hydrolysis loss of sodium aluminate solution,measures such as increasing the temperature of settling tank,reducing the stock of settling tank,controlling the appropriate height of mud layer and improving the efficiency of red mud washing are taken to reduce the hydrolysis loss in the process of red mud separation and washing,which is of great significance to reduce the production cost.