【摘要】 针对稀土精矿低温酸浸浸出效率低的问题,采用微波辅助浓硫酸低温焙烧稀土精矿的工艺,研究了微波预处理酸浸矿的焙烧温度、酸矿比、焙烧时间对稀土和钍浸出率及残留率的影响。结果表明:微波辅助酸浸稀土精矿的最佳条件为:焙烧温度225℃,酸矿比1.5,焙烧时间10 min。此条件下的稀土和钍的浸出率分别为97%、95%,残留率均低于5%,其技术指标不低于现行工艺。同时对比相同条件下直接酸浸焙烧工艺,稀土和钍的浸出率均达到95%以上,水浸渣均符合国家安全排放标准,但前者的焙烧时间为后者的1/8,大大缩短了稀土浸出时间,为稀土及钍资源的工业化综合回收利用提供了新途径。更多还原

【Abstract】 On the basis of low efficiency present in acidic leaching of rare earth concentrate at low temperature,the process of microwave-assisted decomposition of rare earth concentrate with sulfuric acid was adopted.The effects of roasting temperature,the ratio of acid to ore,roasting time of rare earth concentrate by microwave-assisted acid leaching on the leaching and residual rates of rare earth and thorium were investigated.The results showed that the optimum conditions of microwave assisted decomposition of rare earth concentrate were as follows:roasting temperature 225 ℃,the ratio of acid to ore 1.5 and roasting time 10min,and the leaching rates of rare earth and thorium are 97 % and 95 %,respectively and the residual rates are both lower than 5%,which are not less than that of the current process.Meanwhile,under the same conditions,compared with direct sulfuric acid leaching,leaching rates of rare earth and thorium with microwave-assisted decomposition both reached more than 95 %,water leaching residue meet national standards for safety discharge,and roasting time was 1 /8 of that with direct sulfuric acid leaching,which greatly shorten the leaching time of rare earth concentrate,such a new way was provided for industrial comprehensive recovery of rare earth and thorium resources.更多还原