Efficient HGMS for highly magnetic materials

The range of applicability of high gradient magnetic separation has been extended to recovery of ferrimagnetic material from fluids containing an equal weight of nonmagnetic particles at solids concentrations of 20 to 35%. A newly designed matrix permits unimpeded passage of nonmagnetic particles as large as 3 mm and at the same time, recovers the ferrimagnetic particles in thin sheets. In this manner entrainment of nonmagnetic materials within flocs of ferrimagnetic particles is minimal. It is demonstrated that efficient separation of magnetite having a mean particle diameter of 12 μm from fine coal having a mean particle size of 850 μm can be attained at a throughput of 30 tons of magnetite/hr/ft²(300 metric ton/hr/m²).