K_2O对高铝矾土烧结合成莫来石的影响

Influence of K_2O on Sintering-Synthesizing Mullite with Bauxite

分别对K2O含量为0.34%的山西阳泉高铝矾土矿和K2O含量为1.43%的河南巩义高铝矾土矿进行了烧结合成莫来石试验。试验结果表明:K2O影响高铝矾土烧结致密化,K2O含量越高,高铝矾土烧结速率越快,内部气孔越不容易排出,越难以烧结致密;在高温条件下,K2O与莫来石反应生成钾霞石和白榴石导致莫来石分解,并产生体积膨胀,使烧结莫来石显气孔率增加,致密度降低。

The test of sintering-syntheszing mullite with bauxite containing 0.34 % K20 from Shanxi Yangquan and bauxite containing 1.43 % K20 from Henan Gongyi was carried out. The result shows that K20 influences on the sintering densification of bauxite. The content of K20 in bauxite is greater, the sintering rate of bauxite is higher, the excretion of the internal pores and the sintering densification of bauxite is harder. In high temperature, K20 react with mullite to form kaliophilite and leucite, which leads to the decomposition of mullite and the expansion of the sintering body, with the rise in apparent porosity and the reduction in density.