High Gradient Superconducting Magnetic Separation for Iron Removal From the Glass Polishing Waste

Cerium oxide used for glass polishing agent is processed as wastewater mixed with the polishing sludge of the glass. The recycling of cerium oxide may have a large influence on reduction of environmental burden and resources recycling. In the treatment process of wastewater, the complex of cerium oxide and iron flocculant is formed by co-precipitation to clear the fluid. In order to recycle the cerium oxide, it is necessary to eliminate the cohesion and then remove the iron content. In this study, the aggregated particles were dispersed by pH adjustment, and the iron content was separated by the developed high gradient magnetic separation system (HGMS) with superconducting magnet. The optimum condition was examined by calculation and experiment. In addition, we succeeded to remove the silica particle by magneto-Archimedes levitation. It was confirmed that ferrous particles and silica particles can be removed from wastewater by using superconducting bulk magnet, which makes it possible to reuse ceria particle as the polishing agent.