Abstract: Embodiments of an apparatus and method for ferrite formation and the removal of heavy metal ions by ferrite co-precipitation from an aqueous solution at ambient temperature have been developed. Magnetically susceptible ferrite crystals can be continuously formed from aqueous solution and the heavy metal ion solution can be continuously treated by the ferrite co-precipitation process. The heavy metal ions are incorporated into the lattice points of the spinel ferrite structures. The precipitates of ferrite materials can then be magnetically separated. The main apparatus includes a ferrous sulfate mixing tank with a feeder assembly; a reaction tank or, alternatively, neutralization and oxidation tanks; settling and polishing tanks; and a magnetic separator. The reaction tank or oxidation tank includes an air distributor; a pH controller; and promoter feeding and ferrite product recirculating systems.