Study of Crushing and Physical Separation Properties of Nickel-Hydrogen Battery

Abstract

The crushing and physical separation technologies as the pre-treatment of hydrometallurgical process were carried out for recovering valuable metals such as Ni, Co and rare earth from nickel-hydrogen battery. Two types of nickel-hydrogen batteries which use a paste type electrode and sintered type electrode were roasted in the temperature range of 273–873 K and crushed by a single-axis cutter mill, a hammer crusher and a two-axis shear force crusher. Then the crushed products were classified with screens to give size distributions of the valuable metals. Magnetic separation was carried out for the crushed products of nickel-hydrogen battery using a paste type electrode. The optimum crushing conditions are different from the type of electrode. For the sintered type electrode, the crusher having an impact force is effective. For the paste type nickel foaming electrode, the crusher having a cutting and shear force is suitable. Classification after roasting in the proper conditions such as temperature and atmosphere followed by a magnetic separation is possible to separate Fe and NiO. The nickel content more than 80 wt% is possible.