某泥岩型铀矿石预处理技术研究

Study on Pretreatment Technology of A mudstone Type Uranium Ore

我国北方某泥岩型铀矿石泥化严重,矿石中的碳酸盐矿物和石膏含量高,采用常规搅拌直接浸出回收铀时,试剂消耗量大、铀浸出率低、生产成本高。为解决此问题,在浸出之前先对矿石进行了搅拌打散—筛分分级—粗粒堆浸—细粒浮选分组预处理,即将矿石分成+0.15 mm和-0.15mm两个粒级,80%以上的石膏赋存于+0.15 mm粗粒级中,这部分矿石可以不磨矿,采用堆浸法能够回收其中的铀,铀浸出率87.50%;90%以上的碳酸盐矿物赋存于-0.15 mm细粒级中,该粒级以氧化石蜡皂作为碳酸盐矿物浮选的捕收剂,水玻璃作为分散剂和活化剂,采用1次粗选2次精选开路浮选工艺流程处理,可获得-0.15 mm粒级高碳酸盐含铀产品和低碳酸盐含铀产品,高碳酸盐含铀产品作业产率28.72%,CO2含量33.85%,作业回收率84.68%。

A mudstone type uranium ore in North China is heavily argillized with high content of car⁃bonate and gypsum minerals in the ore.When conventional stirring is used for direct leaching of uranium,there is a high reagent consumption,low uranium leaching rate and high production cost.In order to solve this problem,the ores have been pretreated by agitation,separation,screening,coarse heap leaching and fine flotation before leaching.First,the ores are divided into two partial sizes of+0.15 mm and-0.15 mm.More than 80%of gypsum is stored in+0.15 mm coarse-grained ores,which can be recovered by heap leaching without grinding,and the leaching rate of uranium is 87.50%.More than 90%of carbonate miner⁃als are stored in-0.15 mm fine-grained ores.The oxidized paraffin soap was used as the collector of car⁃bonate mineral flotation,and water glass was used as dispersant and activator.The open circuit flotation process with one roughing and two cleaning processes was used to obtain the-0.15 mm high carbonate ura⁃nium bearing products and low carbonate uranium bearing products.The operation yield of high carbonate uranium bearing ore was 28.72%,the CO2 grade was 33.85%,and the operation recovery was 84.68%.