关键词: 废弃荧光粉, 微波辅助, 浸出, 稀土

Abstract: A waste phosphors contains 49.63% rare earth oxide,which has high value for recovery and utilization.In order to achieve the rapid and efficient leaching of rare earth elements in this waste phosphors,microwave assisted leaching of rare earth elements Y and Eu from the waste phosphor with hydrochloric acid was studied.The calculation of leaching thermodynamics shows that the red phosphors can react with acid in the temperature range of 273~373 K,while the green and blue phosphors do not react with acid,and the rare earth elements Y and Eu in the red powder can be preferentially leached by acid leaching method.The leaching experimental results show that under the conditions of microwave power of 600 W,microwave radiation time of 60 min,microwave temperature of 60 ℃,hydrochloric acid concentration of 4 mol/L,hydrogen peroxide addition amount of 0.2 mL/g and liquidsolid ratio of 7.5 mL/g,the leaching rate of the elements Y and Eu can reach 98.84% and 88.72%,which almost realizes the complete leaching of the rare earth elements in the red phosphors.Compared with the conventional heating method,the microwave radiation assisted leaching can significantly shorten the reaction time without reducing the leaching rate.It provides a technical basis for the rapid and efficient leaching of rare earth elements in waste phosphors.

Key words: waste phosphors, microwave assisted, leaching, rare earth