| The leaching of rare earth (RE) in phosphate rock with nitric acid was studied. The effects of temperature, nitric acid concentration, time, particle size, and liquid-to-solid ratio on RE leaching rate were studied. The optimum conditions for RE leaching were 40% HNO3, 60 ℃, liquid-to-solid ratio 2.5, agitation speed 300 r/min, -0.038 mm accounting for 82%, leaching time 90 min. Under the above conditions, the percentage of RE leaching rate and decomposition percentage of phosphate rock were both higher than 98%. |