Magnetic capture of fine particles

ABSTRACT The magnetic collection of fine paramagnetic particles requires a high intensity high gradient magnetic field. The most effective method of separation has proven to be Wet High Intensity Magnetic Separation (WHIMS) and High Gradient Magnetic Separation (HGMS). These wet separation techniques utilize high intensity electromagnets and a flux converging matrix. The matrix amplifies the magnetic field and provides high gradient collection sites as the feed material filters through. Production unit separators can typically treat up to 50 TPH of dry feed as a slurry. Recent developments in high intensity magnetic separation has improved the magnetic collection of fine particles. Magnetic field strengths up to 50,000 gauss have been produced in pilot scale separators using superconducting technology. A 20,000 gauss Superconducting HGMS, capable of treating 500 GPM of slurry, has been commercialized. The application of computers to optimize conventional technology has led to increased magnetic field strength in WHIMS systems. A new HGMS system with a vibrating matrix has also been developed to treat fine or pulverized dry feed. New developments in matrix criteria have also improved fine particle collection. The proper selection of matrix based on geometry and size has resulted in the capture of submicron particles. Described are high intensity magnetic separator parameters and the effect on fine particle collection.