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。
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 leac- hing and residual rates of rare earth and thorium were investigated. The results showed that the optimum conditions of micro- wave assisted decomposition of rare earth concentrate were as follows ： roasting temperature 225 ~C, 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.
出处
《稀土》
EI
CAS
CSCD
北大核心
2013年第6期45-50,共6页
Chinese Rare Earths
基金
内蒙古自然科学基金项目(2012MS0714)
内蒙古自治区高等学校科学研究项目(NJZY13149)
内蒙古科技大学创新基金(2011NCL064)
白云鄂博矿多金属资源综合利用国家重点实验室资助项目(BO-13-001)
关键词
微波
稀土精矿
低温焙烧
硫酸
microwave
rare earth concentrate
low temperature roasting
sulfuric acid
