The effect of water quality and sediment properties during the purification process of low concentration Co2+ liquid waste by neutralized ferrite method was investigated. The removal efficiency of Co2+ increased with the increasing of Co2+ concentration in influent from 0.01 mg/L to 10 mg/L. Boric acid with the concentration of 0—1 000 mg/L promoted the removal of Co2+. The neutralized ferrite method produced the smaller amount of wet sediment with water content of 89.06%. The dried sediment showed strong magnetic, while the wet one was relatively weak. Decreasing the concentration of boric acid, increasing pH or temperature were able to improve slightly magnetism of wet sediment. The use of Fe3O4 as seed crystal could improve the magnetism of wet sediment significantly, which was beneficial to magnetic separation.