关键词: 稀土, 磷矿, 杂质, 混酸

Abstract: The leaching law of rare earth and impurities in the process of decomposition of phosphate ore containing rare earth by mixtures of sulfuric and phosphoric acids was studied. The results showed that leaching rates of rare earth oxides in Zhijin phosphate ore and Fanshan phosphate ore are 62.73% and 52.84%, respectively, under the conditions of concentration of phosphoric acid of 8.6 mol/L, 3 h leaching time, excessive coefficient of sulfuric acid of 1.00, temperature at 80℃, liquid?solid ratio at 6:1 L/g. Within a certain range, the leaching rates of rare earth in two phosphate ores increase with the increasing of time and liquid?solid ratio. The leaching rate both increase at first and then decrease with the increasing of temperature and excessive coefficient of sulfuric acid. The leaching rates of the main components (Y2O3, La2O3, CeO2 and Nd2O3) in light rare earth decrease with the increasing of atomic number. Although ores are different, the law of rare earth leached out to the phosphoric solution is the same.

Key words: rare earth, phosphate ore, impurities, mixed acid