Development of Magnetic Separation System for Powder Separation

The interfusion of impurities such as metallic wear debris has been a problem in the manufacturing process of foods, medicines, and industrial products. Gravity separation system and membrane separation system have been widely used for powder separation, however, sufficient separation rate was never achieved. Magnetic separation is a promising method to separate magnetic particles efficiently. Magnetic separation system under wet process is used conventionally, but it has some demerits such as necessity of drying treatment after separation and difficulty of running the system in the cold region. Thus, magnetic separation under dry process is prospective as an alternative method. In this paper, we developed High Gradient Magnetic Separation (HGMS) system under dry process. The present major problem of dry HGMS system is the blockage of magnetic filter caused by particle coagulation or deposition. To solve this problem, we developed the apparatus in which arrangement of magnetic filter is variable. Using this apparatus, we optimized the filter arrangement and achieved high separation efficiency of impurities from the mixed powder (0.1 wt% content of impurities) without blocking of filters.