F. Mishima

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.

Research and Development of Superconducting Magnetic Separation System for Powdered Products

The superconducting magnetic separation system which separates ferromagnetic particles from powder mixture has been developed. It is required to remove the impurities from the powdered products without using chemical or heating processing. The impurities are usually powdered stainless steel from the piping which are deformed strongly and shows ferromagnetism. Magnetic separation using permanent magnets have been used for the separation. The conventional magnetic separation system has not shown the expected performance especially for the small sized impurities. To solve the problem, superconducting magnetic separation system was developed. We used the magnet with magnetic field up to 2 T. The boa size was 100 mm in diameter. Inside of the magnetic boa the magnetic filters are located to produce the high magnetic gradient. The performance of the separator was reported together with the design guideline.

Research and Development of Magnetic Purification System for Used Wash Water of Drum

A high gradient magnetic separation system for purifying used wash water of drum was developed. The waste water is a mixture of various types of contaminant. The wastewater is made into floe containing ferromagnetic particles in the magnetic seeding tank. The magnetic seeded waste water is pumped into the high speed magnetic sedimentation device equipped with multiple permanent magnets. The small floe which can not be captured in the device is separated by a high gradient magnetic separation device using HTS (high temperature superconducting) bulk magnet. In the developed separation device, the ferromagnetic filters are installed in the flow channel to generate high magnetic field gradient. The combination of these devices can reduce the load to the magnetic separation system and enables long-time operation. It was found that the COD value can be currently reduced from ca. 200-500 to less than 100 ppm. It was shown that this system satisfies the requirements to be used as a magnetic separation system for the used wash water of drum.

High-Speed Magnetic Filtration System Using HTS Bulk Magnet for Used Wash Water of Drum

Fundamental study of a high speed filtration system using HTS magnet for purifying the used wash water of drum has been made. This system consists of a magnetic seeding device and a magnetic filtration device. Since the wastewater is a mixture of various used wash water, the wastewater treatment is difficult to realize practically. For that reason, the wastewater is processed as industrial waste products. In the purification system the waste component in the wastewater is made into the floc containing magnetite in the magnetic seeding device. The wastewater is made to flow close to HTS bulk magnet and the floc is filtered by magnetic force. It was found that the system shows the extensibility and is low cost because of the simple construction.

Fundamental Study on Magnetic Separation of Aquatic Organisms Using a Superconducting Magnet

Recently, destruction and disturbance of marine ecosystem have been caused by adventive aquatic organisms. To solve the problems, water treatment technique is necessary to remove aquatic organisms efficiently. In this study, magnetic separation system for continuous removal of the aquatic organisms using superconducting magnet which generates strong magnetic field was developed. The jar tests to remove aquatic organisms using permanent magnet showed that nearly 100% of separation efficiency was achieved by aggregation of aquatic organisms using ferromagnetic particles and flocculants. Cost and waste reduction by lowering agent dosages was examined for practical application of magnetic separation system, and continuous processing equipment was designed by simulation and experiment using superconducting magnet.