稀土抛光粉废料再生利用试验研究

Experimental Study on Reutilization of Waste Rare Earth Polishing Powder

采用市售无机酸低温分解稀土抛光粉废料制备超精密稀土抛光粉,考察了无机酸种类与用量、反应温度、反应时间、浸出次数对稀土浸出效果的影响,检测了所制备稀土抛光粉粒度和化学成分,并分析了制备过程的反应机理。结果显示,在盐酸浓度37%、酸料质量比值3.5、反应温度98～103℃、一次浸出8h、二次浸出7h的条件下,稀土抛光粉废料经盐酸二次浸出后稀土浸出率高达99.23%;本工艺可制备出CeO_2含量67.64%、La_2O_3含量24.39%、F含量6.00%的超精密稀土抛光粉,该抛光粉平均粒度0.39μm,粒度分布均匀。

Ultraprecise rare earth polishing powder was prepared by low temperature decomposition of waste rare earth polishing powder with commercially available inorganic acid. The effects were investigated of type and dosage of inorganic acids, reaction temperature and time, and leaching times on rare earth leac- hing. The particle size and chemical composition of the prepared rare earth polishing powder were deter- mined, and the reaction mechanism during the preparation process was analyzed. The results indicate that the rare earth leaching rate is up to 99.23 % after two-stage leaching of waste rare earth polishing powder with hydrochloric acid under the following conditions, hydrochloric acid concentration of 37% ,acid/mate- rial mass ratio of 3.5 ,reaction temperature 98-103 ℃,primary leaching for 8 h,and secondary leaching for 7 h. Ultraprecise rare earth polishing powder containing 67.64% CeO2,24.39% La2 03 and 6.00% F can be prepared,and its particle size distribution is uniform with average particle size of 0.39 μm.