Abstract:

The report presents the results of roasting and leaching of Bac Nam Xe rare earth ore and the separation of uranium, thorium, iron from acid leaching solution by neutralization method and solvent extraction method. The results show that the decomposition conditions are at the temperature of 4500C, the ratio of ore/concentrated sulfuric acid is 1/1, the roasting time of 2 hours and the water leaching with solid/liquid ratio is 1/5; Slurry and washing with a solid/liquid ratio of 1/4 will get result of more than 60% of Th and more than 45% of U are in solid residue, while the efficiency of rare earth extraction is more 95%. By the method of neutralization with the MgO agent at pH 4 to 4.5, the separation efficiency of Th, U, Fe impurities from the aqueous solution are respectly 85,37 and 98%, respectively. By solvent extraction technique with the use of primary amine (N1923) and tertiary amine (TOA), the separation efficiency of Th, U impurities is 95.8 and 95.3%, respectively.