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A New Treatment of Rare Earth Ores in Molten Sodium Hydroxide

熔融氢氧化钠处理稀土矿的新方法

基本信息

批准号：
01550585
负责人：
OKUWAKI Akitsugu
金额：
$ 1.22万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1989
资助国家：
日本
起止时间：
1989 至 1990
项目状态：
已结题

项目摘要

New treatment method for rare earth ores has been studied by using molten alkali. Basing on the experimental results. the optimum conditions were found as follows : reaction temperature. 350 ^ﾟC : under atmosphere : ore size. 100 mesh< ; ore/NaOH weight ratio*0.2. reaction time. 0.5 h. After washing of the reaction products obtained under the optimum conditions to remove alkali with water. oxides of lanthanum and other rare earth metals were extracted more selectively than CeO_2 in a 0.5 M HCl leaching below 5 M. The content of CeO_2 in the HCl leaching residue reached to 60 % or higher. This shows that the residue has enough grade as cerium concentrate. The content of CeO_2 would be able to increase. but the yield of cerium concentrate will decrease because of cerium (IV) dissolution. Since the cerium concentrate is composed of fairly homogeneous micro particles of ca. 0.1 mum. It can be used for the abrasives of glass. Etc. On the other hand. Crude rare earth chloride in which lanthanum chloride was the principal constituent as obtained by concentration of the HCl leaching solution.Additionally. The kinetic study on the reaction indicated that the dissolution process of oxygen into molten alkali was the rate determining step. Therefore. A continuous reactor of rotary kiln is more suitable than a mixing tank reactor.Based on the results. We have developed a new procedure for leaching rare earth ores. This method can be applied easily for preparation of cerium concentrate and the rare earth chloride mixture at mine sites in China where mixed rare earth ores are abundant.

研究了用熔融碱处理稀土矿的新方法。根据实验结果。确定了最佳工艺条件：反应温度。350 ℃：大气下：矿石粒度。100目< ;矿石/NaOH重量比 *0.2。反应时间0.5 H.在最佳条件下得到的反应产物经洗涤后用水除去碱。在低于5 M的0.5M HCl浸出中，镧和其它稀土金属的氧化物比CeO_2更有选择性地被萃取。盐酸浸出渣中CeO_2含量可达60%以上.这表明残渣具有足够的铈精矿品位。CeO_2的含量也会增加。但由于铈（IV）的溶解，铈精矿的产率会降低。由于铈精矿由相当均匀的钙微粒组成。0.1妈妈.它可用于玻璃的磨料。等等，另一方面。通过浓缩盐酸浸出液获得以氯化镧为主要成分的粗氯化稀土。反应动力学研究表明，氧在熔融碱中的溶解过程是反应的速率控制步骤。因此。回转窑连续式反应器比混合槽式反应器更适合于生产。我们开发了一种浸出稀土矿的新方法。该方法适用于我国混合稀土矿资源丰富的矿区铈精矿和混合氯化稀土的制备。