Research on dry permanent magnetic separator of fine coal

Abstract

It's popularized that dry permanent magnetic separator for coal separation in order to achieve desulphurization and dust reduction to ease enviromental pollution. However, due to weak magnetic coal minerals, conventional magnetic separator is far from for effective separation of fine coal. This paper proposes a new type of permanent magnetic separator with unique magnetic system structure. Selecting NdFeB magnets and magnetization along the longitudinal symmetry axis to generate high background field, together with the magnetic media of soft cone iron to produce high gradient force. And the new permanent magnetic separator with reasonable magnetic system design is validated through mathematical modeling and analysis. At the polar distance of 0.45mm within the separation space, magnetic field strength can up to 1.3T. The new magnetic separator was used for different power plant for dry coal separation test, When the particle size is below 0.074mm, the desulfurization rate is 52.57%, 48.95%, respectively; and ash removal rate is 41.79%, 43.95%, respectively. The magnetic separator can achieve the dry coal pyrite separation; it also provides technical support for effective solution in coal-burning air pollution.