A Study of the Parametric Effects on Magnetic Coal Ceaning
A coal-cleaning technique was evaluated to determine its effectiveness to remove sulphur and ash contents of dry pulverized coals before combustion in power stations. Dry high-gradient magnetic separation (HGMS) experiments were conducted on a British coal from Coalfield Farm North using ferromagnetic stainless steel wire meshes as the separator matrix which was located in the bore of a superconducting solenoid magnet. The parametric effects of magnetic field, air velocity and separator length on the process were investigated. Increasing magnetic fields and separator lengths and decreasing air velocities each individually increases the percentage reductions of pyritic sulphur, total sulphur and ash. Reduction efficiencies up to 91, 65 and 61 per cent for pyritic sulphur, total sulphur and ash respectively were obtained. These results have at least shown that dry HGMS could possibly provide a simple and economic alternative to flue gas desulphurization to reduce sulphur dioxide emissions to the atmosphere from coal-fired power stations, with the additional benefit of an ash removal capability.