碱法造块焙烧提取粉煤灰中氧化铝的研究

In order to effectively solve the problems caused by a large amount of fly ash, such as the research of environmental pollution and the realization of the maximum utilization value of fly ash, the sintering method is introduced to improve the extraction rate of fly ash. In this paper, the improvement of alumina extraction rate after adding agglomeration method was compared, and the best experimental conditions of extracting alumina by alkali roasting were explored under the agglomeration method. Through X-ray diffraction analysis and SEM scanning electron microscope analysis of sintering clinker and leaching slag, it is found that mullite phase and quartz phase in fly ash raw material are fully transformed into nepheline phase with higher activation degree during sintering process. Aluminum element exists in filtrate after acid leaching, and SiO2 content in leaching slag reaches 90%. The kinetic study shows that the capillary channels in fly ash particles and blocks act as the skeleton of coke in blast furnace, and the agglomeration treatment creates a mesoscopic porous structure for reaction, which not only reduces the distance between solid and liquid phases, but also effectively improves the mass transfer conditions of gas and liquid phases, so as to enhance the extraction of aluminum.