粉煤灰提取氧化铝工艺能耗分析

Energy Consumption Analysis for Alumina Extraction from Coal Fly Ash

介绍了粉煤灰预脱硅-碱石灰烧结法、盐酸浸取法和硫酸焙烧法提取氧化铝的工艺方法,计算和分析了以上三种工艺的理论能耗。结果表明,三种工艺中预脱硅—碱石灰烧结法能耗最高,为1 707kgce(每吨Al_2O_3,下同),其中烧结工序就占总能耗的53.67%;盐酸浸取法与硫酸焙烧法能耗较低,分别为1 396kgce和1 476kgce,比预脱硅—碱石灰烧结法分别降低了18.3%和13.5%。盐酸浸取法中42.57%的能耗集中在AlCl_3·6H_2O晶体热解工序,而Al_2(SO_4)_3·18H_2O晶体脱水能耗占硫酸焙烧法总能耗的51.38%。

Techniques to extract alumina from fly ash with predesilication and soda-lime sintering process, hydrochloric acid leaching process, and sulfuric acid roasting process were introduced. The theoretical energy consumption of each process was calculated. The results indicate that energy consumption of predesilication-soda-lime sintering process is 1 707 kgce （for one ton Al2O3） and 53.67% f the whole energy consumption concentrates in sintering process. Hydrochloric acid leaching process and sulfuric acid roasting process consume less energy, with energy consumption of 1 396 kgce and 1 476 kgce respectively, which drops by 18.3% and 13.5% respectively compared to predesilieation-soda-lime sintering process. In hydrochloric acid leaching process, pyrolysis energy consumption of aluminum chloride accounts for 42.57% of the total energy consumption, while dehydration process of aluminum sulfate takes up 51.38% of the whole energy consumption in sulfuric acid roasting process.