高铝粉煤灰的活化

Activation of High-alumina Fly Ash

以碳酸钠为活化剂,研究了粉煤灰提取氧化铝过程中物料煅烧参数及活化机理。通过X射线衍射表征了粉煤灰在碳酸钠活化前后物相的变化,分析了煅烧温度、煅烧时间以及粉煤灰与碳酸钠的配比等因素对莫来石反应完全程度的影响规律。结果表明:在碱溶前,粉煤灰主要为莫来石和玻璃相,碱溶后,粉煤灰熟料的物相主要为可溶性强的霞石。粉煤灰与碳酸钠的混合比例为1∶0.85,煅烧时间为90 min,煅烧温度为880℃,氧化铝浸出率为69.3%。

The calcination parameters and activation mechanism are studied in the processing of extracting alumina from fly ash using sodium carbonate as activating agent. The phase change before and after the activation of fly ash are characterized by the X ray diffraction, the calcination temperature, the calcination time and the mixture ratio of the ash and sodium carbonate are analysized on the influence rule of reaction degree of mullite completely. The results show that mullite and glass phase in fly ash are manifested before the alkali dissolution and soluble nepheline in fly ash clinker is proved after the alkali dissolution. The mixture ratio of the ash and sodium carbonate is 1 ： 0.85, the calcination temperature is determined at 880℃, and calcination time is determined at 90 min, leaching rate of alumina can reach to 69.3%.