Abstract:Address to ammonia nitrogen pollution of ion-type rare earth in-situ leaching process, the influence of non-ammonium leaching agents such as magnesium salt and aluminum salt on leaching process of rare earth was investigated. Taking Ganzhou rare earth ore as the research object, magnesium sulfate and ammonium sulfate were selected for comparative test through column leaching. Meanwhile, the influence of aluminum salt combined with ammonium salt and magnesium salt on leaching was investigated. The composition of leaching solution was detected, and the difference of leaching effect of different leaching agents was analyzed. The results show that the leaching efficiency of ammonium sulfate is similar to magnesium sulfate with the same mass fraction, ammonium sulfate and magnesium sulfate can reach 91.37% and 89.22% respectively. The leaching rate of rare earth after adding aluminum salt is only about 76%, so the addition of aluminum salt could not promote the improvement of rare earth leaching efficiency. The ammonium ion of ore sample can be reduced to 76 mg/L after column leaching and washing, and the magnesium ion can be reduced to 27 mg/L. The magnesium ion is easier to be washed and removed. Magnesium sulfate as leaching agent can fundamentally solve the problem of ammonia nitrogen pollution.