Abstract: The traditional separation process to treat the rich magnesia low-grade pyrolusite usually results in such problems as worse pollution and lower efficiency in separation of manganese and magnesia.In order to solve these problems and achieve development and utilization of high magnesium low-grade pyrolusite,and taking a rich magnesium low grade pyrolusite in Guangxi as raw material,mix solution of high pure MnSO₄ and MgSO₄ prepared by the process of acidizing reduction roasting +reduction of pyrolusite pulp by tail gas (SO₂)-combined leaching of reduction products-impurity removal from leaching solution was adopted to make conditioning tests for Mn2+ concentration by NH₄HCO₃.The results showed that with mole ratio of NH₄HCO₃ and MnSO₄ as 2.25,the reaction time for 60 min,the reaction temperature at 30 ℃,and stirring speed of 120 r/min,separation rate of magnesium and manganese reached 96.96%.The Mn-Mg separation process not only achieve comprehensive utilization of tail gas (SO₂) from acidizing reduction roasting,but also effectively separates from manganese and magnesia in leaching solution.

Key words: Rich magnesia low-grade pyrolusite, Acidizing reduction roasting, High pure magnesium manganese sulfate solution, Separation rate of manganese and magnesia