High Gradient Magnetic Separation System Research Articles

Removal and Recovery of Phosphorus from Wastewater using High-gradient Magnetic Separation Applying a Magnetic Adsorbent

This work examines the removal and recovery of phosphorus from treated wastewater using high-gradient magnetic separation (HGMS) applying a micron-sized ferromagnetic zirconium ferrite adsorbent. The characteristics of adsorption and desorption for zirconium ferrite were investigated. An experiment on magnetic separation with zirconium ferrite was performed. Excellent magnetic separation properties were obtained at a fluid velocity of 1 m/s and magnetic field of 2 T. Various parameters of a HGMS system for actual sewage plants were evaluated. These results show that this system could be applied to sewage plants.

Improvement of a High-Gradient Magnetic Separation System for Trapping Immunoglobulin in Serum

Recently, affinity magnetic beads have been widely used in immunomagnetic cell sorting (IMCS) technology. Today, we can easily sort and analyse DNA and antibodies (immunoglobulin) using various types of affinity magnetic beads available in the market. The diameters of the affinity magnetic beads used in immunomagnetic cell sorting are above approximately 1 ¿m because of the low magnetic fields induced by permanent magnets. At present, nanosized affinity magnetic beads are strongly desired to achieve high resolutions. We have been studying and attempting to develop a high-gradient magnetic separation (HGMS) system that employs a superconducting magnet to induce a considerably higher magnetic field than that induced by a permanent magnet. The objective is to trap smaller nanosized affinity magnetic beads using a filter made of fine stainless steel wool. In a previous study, we constructed a prototype of a desktop-type HGMS system using a cryocooler-cooled LTS magnet; we conducted preliminary experiments on trapping nanosized magnetic particles and investigated the magnetic field distribution and magnetic force around a magnetic wire in the filter by means of a numerical simulation. In this study, we succeeded in producing prototype nanobeads covered with the biosurfactant of a high-affinity ligand system for immunoglobulin G and M. Furthermore, we attempted to improve the recovery of nanobeads by adding a resonance circuit to the HGMS system. In practice, the trapped nanobeads attract one another and agglomerate due to their remaining magnetization when the magnetic field is decreased to 0 T. Therefore, the nanobeads and wire are demagnetized in the AC magnetic field by the resonance circuit, making good use of the superconducting magnet of the HGMS system.

Development of High Gradient Magnetic Separation System for a Highly Viscous Fluid

It is necessary to remove the metallic wear debris originating from pipe of manufacturing line in industrial plant processing highly viscous fluid such as foods or industrial products. In this study, we developed a high gradient magnetic separation (HGMS) system which consists of superconducting magnet and magnetic filters to remove the metallic wear debris. The particle trajectory simulation and the magnetic separation experiment were conducted with polyvinyl alcohol (PVA) as a model material of which viscosity coefficient was 1 Pa · s. As a result, maximum separation efficiency over 80% was achieved by optimization of experimental conditions such as mesh number, flow velocity and the number of filters.

Purification of the Coolant for Hot Roller by Superconducting Magnetic Separation

It is important to recycle industrial wastewater in the aspect of energy saving and minimizing the environment damage. Steel manufacture factories make an effort to purify and recycle wastewater from the manufacturing processes. A steel manufactory in Korea, POSCO (POhang iron and Steel COmpany) has also concerned about the treatment of wastewater for long time. The coolant of hot roller at steel making factory includes suspended solid (SS) like steel fines, iron oxide and emulsified oil. A laboratory-scale conduction cooled high temperature superconducting (HTS) magnet was used for high gradient magnetic separation (HGMS) systems. It consists of eight double-pancake sub-coils, two HTS current leads, a GM cryo-cooler and a cryostat without a radiation shield vessel. Sub coils were wound with 1 G HTS tapes of Sumitomo Electric Industries by wet-winding method. A Cryo-cooled high temperature superconducting magnet system with 70 mm room temperature bore and 250 mm of height was prepared. This magnet was used for batch type HGMS system. Superconducting HGMS system that had a purpose to purify the wastewater was assembled. Various magnetic seeding reactions were investigated to increase the reactivity of coagulation.

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.

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.

Development of high gradient magnetic separation system for removing the metallic wear debris to be present in highly viscous fluid

In the industrial plants processing highly viscous fluid such as foods or industrial materials, there is an issue of contamination by metallic wear debris originating from pipe of manufacturing line. It is necessary to remove the metallic wear debris in highly viscous fluid, since these debris causes quality loss. In this study, we developed a high gradient magnetic separation system by using superconducting magnet to remove the metallic wear debris. The particle trajectory simulation and the magnetic separation experiment were conducted with polyvinyl alcohol as a model material. As a result, ca. 100% and 92.2% of the separation efficiency was achieved respectively for the highly viscous fluid of 1Pas and 6Pas in viscosity, with 14 and 30mesh magnetic filters.

Development of high gradient magnetic separation system under dry condition

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 has been used widely for powder separation, however magnetic separation system is much efficient to separate magnetic particles.Magnetic separation system under wet process is used conventionally, however, it has some demerit such as necessity of drying treatment after separation and difficulty of running the system in the cold region and so on. Thus, magnetic separation under dry process is prospective as alternative method. In this paper, we developed high gradient magnetic separation system (HGMS) under dry process.In dry HGMS system, powder coagulation caused by particle interaction is considerable. Powder coagulation causes a blockage of magnetic filters and results in decrease of separation performance of dry HGMS system. In order to investigate the effect of powder coagulation on separation performance, we conducted experiments with two kinds of powdered materials whose cohesive properties are different.

Removal and recovery of phosphorus in wastewater by superconducting high gradient magnetic separation with ferromagnetic adsorbent

Prevention of eutrophication for semi-enclosed bays and ponds is serious and important challenge. In spite of the advanced wastewater treatment, typically 1mg/L phosphorus is discharged into public water bodies from wastewater treatment plants. The total amount of the discharged water is so large that the further improvement of the removal efficiency of phosphorus in the discharged water is demanded. On the other hand, recently phosphorus has become increasingly recognized as the important strategic material due to the global food problem. Therefore, the recovery and recycling of phosphorus is also important issue.In this work, removal and recovery of phosphorus from treated wastewater by High Gradient Magnetic Separation (HGMS) with ferromagnetic zirconium ferrite adsorbent were studied. Phosphorus in the treated wastewater could be removed from 1.12mg/L to 0.03mg/L by the HGMS system with 500mg/L zirconium ferrite adsorbent for 5min in adsorption time. The magnetic separation speed achieved 1m/s at 1T which was necessary for practical use. We also confirmed that phosphorus could be desorbed from zirconium ferrite adsorbent by alkali treatment in a short time.

Design and Test of Filter of High Gradient Magnetic Separation System for Trapping Immunoglobulin in Serum

Recently, affinity magnetic beads have been widely used in immunomagnetic cell sorting (IMCS) technology. Today, we can easily sort and analyze DNA and antibodies (immunoglobulin) using various types of affinity magnetic beads available in the market. The diameters of these affinity magnetic beads used in immunomagnetic cell sorting are limited to above approximately 1 mum because of the low magnetic fields induced by permanent magnets. Now, nano-sized affinity magnetic beads are strongly desired to achieve high resolutions. We have been studying and attempting to develop a high-gradient magnetic separation (HGMS) system that employs a superconducting magnet to induce a considerably higher magnetic field than that induced by a permanent magnet in order to trap smaller nano-sized affinity magnetic beads by a filter made of fine stainless steel wool. In this study, we constructed a prototype of a desktop-type HGMS system using a cryocooler-cooled LTS magnet and conducted preliminary experiments on trapping the nano-sized magnetic particles. Furthermore, we investigated the magnetic field distribution and magnetic force around a magnetic wire in the filter by means of a numerical simulation.

Development of Magnetic Separation of Water-Soluble Materials Using Superconducting Magnet

In traditional usage of magnetic separation, it had been applied only to the separation of ferromagnetic materials such as iron related compounds from kaoline minerals. If paramagnetic or diamagnetic materials are to be efficiently and rapidly separated at the level of practical use, applicable fields of magnetic separation is widely enlarged. To accomplish this goal, developments of appropriate magnetic seeding process and design of the separation system consisting of superconducting magnets should be required. Recently, we succeeded in developing a high gradient magnetic separation system for purification of wastewater from paper factory. Here we extended the previous study and consider efficient recovery of the soluble molecules and ions using a magnetic absorbents and bulk superconducting magnet in order to enlarge the application field. In the present paper, the threshold of the required magnetic field gradient and magnetic force were discussed for designing the bulk superconducting magnet. It has also reported that the originally prepared magnetic absorbents can effectively recover the organic dyes and phosphate ions, and that separation process using superconducting magnet shows the feasibility for the practical application.

Research and Development of Superconducting High Gradient Magnetic Separation for Purification of Wastewater From Paper Factory

High gradient magnetic separation (HGMS) for purification of wastewater from paper factory has been developed and withstand for 1 year operation. The system developed is a high gradient magnetic separation (HGMS) system with superconducting magnet which purifies wastewater continuously from a paper mill. The magnetic field generated by the superconducting magnet for HGMS is 2 T at the center of the bore, operating current 100 A, 680 mm long and 400 mm bore NbTi solenoid. The developed system which treats wastewater of 2000 t/day has been confirmed to show the expected performance. The purpose of the developed system is to separate COD constituents from the wastewater efficiently and economically in a small space. The required performances are follows, i) the set-up area is less than 6 m times 6 m, ii) COD of the treated water is less than 100 ppm and water can be recycled, and iii) a system can treat wastewater more than 2000 t/day. The design and the performance of the system are reported.

Removal System of Arsenic From Geothermal Water by High Gradient Magnetic Separation-HGMS Reciprocal Filter

We have developed a high gradient magnetic separation (HGMS) system to remove arsenic from geothermal water and to supply hot water for public use by using a superconducting magnet. We attained the reduction of arsenic concentration to 0.015 mg/L that is less than the standard for discharge of 0.1 mg/L and slightly larger than the environmental standard of 0.01 mg/L in Japan. The system consists of a pretreatment process that adds extra magnetization to arsenic by chemical reaction, and a reciprocal HGMS filter using a superconducting magnet that extracts magnetized arsenic from the geothermal water. We present the experimental results of the removal system.

A 3 T magnetic field generator using melt-processed bulk superconductors as trapped field magnets and its applications

An intense magnetic field generator yielding 3.15 T in the open space between the magnetic poles has been constructed by using a pair of melt-processed bulk superconductors as trapped field magnets. The field was measured in a 2 mm gap between the magnetic poles set face-to-face after the pulsed-field magnetization “IMRA” method. This field generator is composed of Sm-based 123 compounds, vacuum pumps, pulsed-field coils and GM refrigerators with compressors. The system can be used in various applications. We investigated, for instance, the application to a high gradient magnetic separation system. It was found that the alpha hematite fine particles mixed in the flowing water was completely removed by this technique which was operated in the field of 1.7 T in the gap of 20 mm.

CAPTURE AND RETRIEVAL OF PLUTONIUM OXIDE PARTICLES AT ULTRA-LOW CONCENTRATIONS USING HIGH-GRADIENT MAGNETIC SEPARATION

A high-gradient magnetic separation system has been developed for capture and retrieval of ultra-low plutonium oxide concentrations. The application of advanced matrix materials and improved methodology has demonstrated the effective collection and recovery of submicron paramagnetic actinide particles with particle concentrations as low as 10−23 M. Incorporation of multiple passes during recovery of magnetically captured particles improves the system mass balance. Activity balances for plutonium were verified with stringent sampling protocols. Collection and recovery values demonstrate that 99% of the submicron plutonium oxide particles can be accounted for when recycle loops are incorporated into capture and recovery circuits, magnetically captured particles are released by sonication, carrier fluids are organically based, and longer matrix lengths are utilized.

High-gradient magnetic affinity separation of trypsin from porcine pancreatin.

We introduce a robust and scale-flexible approach to macromolecule purification employing tailor-made magnetic adsorbents and high-gradient magnetic separation technology adapted from the mineral processing industries. Detailed procedures for the synthesis of large quantities of low-cost defined submicron-sized magnetic supports are presented. These support materials exhibit unique features, which facilitate their large-scale processing using high magnetic field gradients, namely sufficiently high magnetization, a relatively narrow particle size distribution and ideal superparamagnetism. Following systematic optimization with respect to activation chemistry, spacer length and ligand density, conditions for preparation of effective high capacity (Q(max) = 120 mg g(-1)) strongly interacting (Kd < 0.3 microm) trypsin-binding adsorbents based on immobilized benzamidine were established. In small-scale studies approximately 95% of the endogenous trypsin present in a crude porcine pancreatin feedstock was recovered with a purification factor of approximately 4.1 at the expense of only a 4% loss in alpha-amylase activity. Efficient recovery of trypsin from the same feedstock was demonstrated at a vastly increased scale using a high-gradient magnetic separation system to capture loaded benzamidine-linked adsorbents following batch adsorption. With the aid of a simple recycle loop over 80% of the initially adsorbed trypsin was recovered in-line with an overall purification factor of approximately 3.5.

High gradient magnetic separation for weakly magnetized fine particles [for geothermal water treatment

We measured the removal efficiency of hematite (Fe/sub 2/O/sub 3/) and iron (III) hydroxide (Fe(OH)/sub 3/) fine particles suspended in water in a high gradient magnetic separation (HGMS) system. Fe/sub 2/O/sub 3/ and Fe(OH)/sub 3/ have relatively small magnetic relative susceptibilities (MKS) near 10/sup -3/ and average particle diameters near 1 /spl mu/m. We demonstrated that HGMS is able to effectively separate weakly magnetized particles.

Purification of Endocrine Disrupter‐Polluted Water Using High Temperature Superconducting HGMS

We have developed a superconducting High Gradient Magnetic Separation (HGMS) system to remove endocrine disrupters from water. The system was able to purify 70 L of endocrine disrupter‐polluted water within about 10 min without generating any secondary waste. The system consists of pretreatment processes to form magnetized compounds with endocrine disrupters, and an HGMS device to extract them from water by using a strong magnetic force. We produced novel adsorbent made of micron‐sized ferric oxide particles that are not only magnetic but also hydrophobic. Because some endocrine disrupters are hydrophobic as well, the ferric oxide particles adsorb endocrine disrupters eluted in water according to hydrophobic interaction. We succeeded in decreasing bisphenol A concentrations in the fortified water from 69 to 16 ng/L and nonylphenol from 7.0 to 0.9 mg/L. Furthermore, we have successfully demonstrated that we could regenerate the ferric oxide particles, so that they can be re‐used for adsorption of endocrine disrupters in water.

High gradient magnetic separation of a biologically produced FeS adsorbent using sulphate reducing bacteria

A High Gradient Magnetic Separation (HGMS) technique has been used to selectively recover biologically produced iron sulphide (FeS) particles with adsorbed heavy metal ions, from a soil remediation effluent stream. The HGMS system has been optimised and its performance investigated as a function of the magnetic field, flow rate and concentration of biological particles, with time. Results have shown that an efficiency of over 95% can be obtained, proving that HGMS is a valuable method for the concentration of heavy metal contaminated soils, especially when the adsorbed heavy metals are toxic and difficult to handle by other means.

Magnetic enrichment of antibody-secreting cells

Amino acid polymer antigens have been covalently coupled to sheep erythrocytes (SRBC) and these have been used in the high gradient magnetic separation (HGMS) technique to enrich murine lymph node cells which had specific receptors for antigen. The method was rapid and provided excellent cell recovery including the fraction retained on the HGMS column. The system could be operated to enrich preformed rosettes, or as an affinity column when preloaded with antigen-coupled SRBC. A 10-fold enrichment of plaque-forming cells was observed in either mode. The HGMS system employed a conventional electromagnet and the fractionation procedure required about 30 min for a sample of up to 10 8 cells.