Magnetic Separation System for Recovery of Glass Polishing Agent

The polishing agent, mainly composed of cerium oxide (CeO₂), is used for fine polishing of products such as liquid crystal panels. The impurities of iron oxide, silica, and alumina get mixed in the cerium oxide-based polishing waste water. In order to reuse the polishing agent, it is necessary to remove these impurities. In this study, the impurities were removed utilizing the difference of magnetic susceptibility in order to recover the polishing agent. In our previous study, we proposed a technique to recover cerium oxide in high purity. In the first stage, iron oxide was removed from the polishing waste water by high-gradient magnetic separation. In the second stage, silica and alumina were removed by magneto-Archimedes method utilizing the magnetic force in vertical direction. In this study, we proposed a magnetic separation method utilizing the magnetic force in horizontal direction, and examined the application possibility of the method for continuous processing in practical use.