In order to overcome the problem that exist in the technology of the lower extraction rate of aluminium oxide from fly ash, the acid dissdution method with KF·2H2O as firing cosolvent is used for extraction of aluminium oxide from fly ash ,the extracting rate of alumium oxide is more than 95%.The effects of the amount of cosolvent, calcination temperature, solid-liquid ratio, digestion temperature and time ect. on the dissolution rate of alumium oxide in fly ash were investigated. The sintered samples and acid leaching residue were characterized by the XRD. The results show that solubilization of potassium fluoride has obvious activated effects for the alumium oxide in pulverized coal ash;in addition, the main phase is nepheline after activation, and finally, fluorine enters into the acid leaching residue;the extracting rate of alumium oxide in fly ash can reach up 97% under the optimal conditions of activation ratio of 20∶19, activation temperature of 900 ℃,activation time of 1 h, 6 mol/L HCl, solid-liquid ratio of 1∶4, and dissolution time in 30 min at 60 ℃.
Zhang Xiaodong,Zhao Feiyan,Guo Zhaohua等. Study on extraction of aluminium oxide from fly ash by solubilization of potassium fluoride[J]. CCI, 2017, 40(1): 30-33.