Dissolution of Uranium and Rare Earth Elements from a Low-Grade Phosphate Ore Using Different Acids

Herein, it was aimed at determining the best leaching agent for extracting uranium (U) and rare earth elements (REEs) from a low-grade phosphate ore. Before leaching tests, the beneficiation of U and REEs contents in the raw ore were investigated by using the Falcon concentrator. The U content in the preconcentrated ore increased to 1629.66 ppm from 392 ppm with a recovery of 92% and the amount of REEs was found to be 747.20 ppm. These values suggested that the preconcentrated ore can be used as REEs source due to its content. It was then dissolved in different acid mediums at a temperature of 40 °C for 2 hours to evaluate the effect of HClO4, CH3COOH, H3PO4, HCl, and HNO3 on the extraction of U and REEs. Among all leaching agents, the use of H3PO4 as the leaching agent suggested more promising results compared to others at the fixed experimental conditions. The influences of leaching temperature and acid concentration were also studied and the optimal experimental conditions to dissolve all of U and REEs from the ore are as follows: H3PO4 concentration of 4 M, temperature of 50 °C, time of 4 hours.