Study on Leaching of Rare Earth from Weathered Crust Elution Deposited Rare Earth Ore with Complex Ammonium Agents

Abstract

Rare earth(RE) was leached from weathered crust elution-deposited rare earth ore with composite ammonium salts as leaching agent.The effects of ratio of composite ammonium salts and concentration of leaching agent,ratio of liquid to solid(L/S),flow rate and pH value on leaching rate of RE were investigated.The results show that the best mass ratio of leaching agent of NH4Cl,NH4NO3,(NH4)2SO4 is 4∶5∶6.The bigger L/S and lower flow velocity is,the higher leaching rate is.The best leaching effect is achieved when concentration of leaching agent is 10 g/L and pH value is 3.5.