粉煤灰是电厂煤粉高温燃烧后的固体废弃物,也是用于提取氧化铝和制备陶瓷、微晶玻璃、耐火材料等高附加值产品的潜在资源。粉煤灰中的杂质铁对制备上述制品的工艺选择和制品质量、性能均有重大影响。本文对内蒙古准格尔电厂高铝粉煤灰(CFB灰)进行了脱碳除铁的实验研究。实验表明,粉煤灰经900℃煅烧2 h,基本上可除去碳;除铁的优化工艺条件为:盐酸浓度20%,液固比5∶1,温度为80℃,搅拌时间为60 min,除铁率达80%以上。
Fly ash is a kind of solid waste generated in high temperature combustion of coal at coal-fired power plants.Fly ash is also potential resource for extracting alumina,and for producing ceramics,glass-ceramics,temperature refractory matters and other high value-added products.The iron impurity in fly ash is one of the main factors to cause poor property and performance of the final products.This paper conducted experimental studies on decarburization and iron removal of high-aluminum fly ash of Jungar power plant in the Inner Mongolia.The results showed that carbon can be removed completely from fly ash after 2 h calcination at 900℃;the optimum iron removal condition,which gives more than 80% of iron removal rate,is 20% hydrochloric acid-leaching,liquid-solid ratio 5∶1,and stirring for 60 min at 80℃.