摘要
碳酸钠分解法处理含氟稀土精矿,稀土(钍)的浸出提取率与生产上常用的硫酸分解法或氢氧化钠分解法相同.用此法分解本省海滨砂矿的独居砂,稀土(钍)的浸出率低于30%.本文研究了以氟化钙作为独居砂的添加剂,模拟含氟稀土精矿的碳酸钠分解法进行了独居矿的分解试验.用稀硫酸或稀盐酸为浸出用酸,稀土(钍)的浸出率分别达95%和98%以上,浸出料液符合生产上的工艺条件要求.
Sea-sand distributed along the coast of southern Fujien is found to contain monatize and also together with titania, ferro-titania, zirconia etc. Constituents of rare earths which ivolved in the fine monatize obtained by flotation are mainly phosphates of cerium group as thier spectrogram shown.Process of usual preliminary decomposition of monatize in rare earths production is now adopted either by means of an acid treatment with concentrated sulfuric acid, or a base treatment with concentrated caustic soda solution. As for the bustnasite, it had been reproted while the mineral is ignited with soda as a cracking agent, the recovery rates of rare earth oxides and thoria from the mineral are similar to that from monatize by acid or base process mentioned above. They are all over 95%.In this paper, the authors deal with the soda process for decomposing monatize from Fujien at first, but fail to obtain a fair result. The recovery rates fo rare earth oxides and thoria are less than 30%. However, by adding fluorite as a flux with soda to the powderized ore in ignition, it is predominantly to promote the efficiency for leaching out the oxides from ignited mixtures by acid extraction.Optimun conditions of the procedure mentioned above are: (I) proportion of soda and fluorite to mineral by weight is 75% and 10-12% respectively, (2) ignition temperature-650℃, ignition time-1.5 hours, (3) acid leaching time-1.5 hours, leaching temperature-70-80℃, (4) concentration of acid (H_2SO_4 or HCl)-4N. The recovery rates of these oxides by sulfuric acid extraction or by hydrochloric acid extraction are greater than 95% or 98% respectively.Stock solution prepared in such way may be applied to production for preparing rare earths salts and thorium salts.
出处
《福建师范大学学报（自然科学版）》
CAS
1980年第2期65-72,共8页
Journal of Fujian Normal University：Natural Science Edition
