脱硅高岭土制备莫来石材料的研究

STUDY ON PREPARATION OF MULLITE FROM DESILICATED KAOLIN

莫来石是一种高级耐火材料 ,具有非常广泛的用途。现研究用脱硅高岭土为原料生产莫来石材料 ,以解决目前莫来石生产中存在的产品质量与生产成本不能兼顾的问题。高岭土经脱硅处理后 ,主要成分为没有活性的Al2 O3和部分没有被脱去的SiO2 ,其铝硅氧化物摩尔比已超过莫来石。在脱硅高岭土中加入部分未煅烧的生高岭土粉 ,用来调节莫来石的成分 ,并作为莫来石成型的粘结剂 ,然后经成型、煅烧 ,制成莫来石制品。结果表明 :这种方法生产莫来石 ,不用加入工业氧化铝 ,有望降低生产成本及提高莫来石的纯度。

Mullite is an advanced refractory material widely used in many industrial areas. Preparation of mullite from desilicated kaolin was discussed in order to solve the problem of failing to give attention to both product quality and producing cost. After desilication the main ingredients of desilicated kaolin were inactive Al2O3 and a little SiO2. The molar ratio of Al2O3/SiO2 increases from 0.85 to 4.62, which was higher than that of mullite. According to the theoretical composition of mullite, some uncalcined kaolin can be added to adjust the ingredient of mullite and to act as a binder. After moulding and calcining, mullite was prepared. The experiment results show that the method for preparing mullite from desilicated kaolin without adding the expensive industrial alumina is the most effective way in production with lower cost and good quality of mullite.