Abstract:Ionic type rare-earth ore was column leached with ammonia magnesium sulfate leaching. Equilibrium of H2O, REO, Mg2 , and SO2- 4 during leaching was investigated. The results show that water absorbing capacity of rare earth ore is about 344 mL/kg. Leaching rate of rare earth elements is 99% above with loss rate of only 0.045% during the whole process. 0.24% magnesium ions residue exists in orebody, amount of magnesium ions in leaching solution rises 4.7% with balance rate of 98.76%. SO2- 4 rises by 0.52%. Leaching rates of impurities Fe and Si drop from 0.435% and 0.703% with ammonium sulfate as leaching agent to 0.03% and 0.13% respectively with magnesium sulfate as leaching agent, while leaching rate of impurities Al remains unchanged.