高铝粉煤灰碱溶预脱硅过程研究

Pre-desilication Process of Alumina-rich Fly Ash in Alkali Solution

为了获得内蒙古准格尔高铝粉煤灰碱溶预脱硅的优化工艺条件,采用正交实验设计对预脱硅工艺进行优化。结果表明,准格尔粉煤灰细灰脱硅的优化实验条件如下:脱硅温度为95℃,粉煤灰与苛性碱的质量比为1∶0.6,脱硅时间为1 h,碱液中苛性碱的质量分数为15%。在优化实验条件下,准格尔高铝粉煤灰的脱硅率可达48.6%,脱硅粉煤灰中氧化铝与二氧化硅的质量比由1.27增大到2.23。

In order to get the optimal process conditions for silica extraction from Junggar alumina-rich fly ash in alkali solution, the orthogonal experiment design was applied. The results show that the optimal conditions are as follows: reaction temperature is 95 ℃, caustic alkali concentration is 15%, reaction time is 1 h, fly ash-alkali ratio is 1:0.6. Under these conditions, the extraction rate of silica from high alumina fly ash achieves 48.6%, and the mass ratio of alumina and silica in the desilicated fly ash can be improved from 1.27 to 2.23 after pre-desilication.