Pre-treatment Process of Alkali Fusion of Fluorescent Powder for Recovery of Waste Rare Earth
TIAN Huan1, WEI Hao1, LAI Li2, ZHAO Zhuo1,2
1.School of Metallurgical Engineering, Anhui University of Technology, Ma'anshan 243032, Anhui, China;
2.School of Materials Science and Engineering, Anhui University of Technology, Ma'anshan 243032, Anhui, China
Abstract：In view of the existing problems, such as a lower recycling utilization rate of fluorescent powder and serious environmental pollution caused by improper disposal, a process consisting of alkaline roasting, washing and acid leaching was adopted for the pre-treatment of waste rare earth fluorescent powder, and effects of additives dosage in roasting, liquid to solid ratio, acid concentration, leaching temperature and leaching time on rare earth leaching effect were explored. The experimental results show that this process resulted in the recovery rates of four rare earth elements as follows: 99.47% Y2O3, 97.79% Eu2O3, 87.55% CeO2, 92.67% Tb4O7. And phase and morphology analysis of the products from alkali fusion indicated that the compact structure of green powder was effectively destroyed and it existed in the form of aluminate. The proportion of added sodium hydroxide could bring great impact on the leaching rates of four kinds of rare earth elements, while the hydrochloric acid concentration and leaching temperature brought great influence on the leaching of Tb4O7 and CeO2.
2018, Vol. 38 
