High-gradient Magnetic Separation Modeling

One important objective of trajectory analysis is to determine the limiting trajectory and thus the critical radius of particle capture. As shown in Fig. 3.7-2, the limiting trajectory is defined as the exact path that divides the particle trajectories into those leading to capture by the collector and those passing by the collector. The distance between the limiting trajectory and the axis is then defined as the critical radius (R ), which can be used to determine the removal efficiency of magnetic filtration (Watson, 1973)  

The trajectory model is limited to a clean wire. Once particles are deposited on the surface of matrix elements or onto other particles already deposited, changes in the surface characteristics of the collector will affect subsequent capture of par- 

In general, the approaches of the trajectory analysis and the build-up models are based on the force-balance equation. Among the forces (external and interparticle) involved in the system, magnetic and hydrodynamic forces, the most significant ones, also compete with one another. The performance of magnetic separation is, therefore, examined in terms of magnetic velocity (Vjj ) and superficial velocity ( Vq) (Watson, 1973), 

Cuyper, M. D., P. Muller, et al., 2003,/. Pltys.-Condens. Mater. 15 S1425-S1436. 

Svoboda,)., Magnetic Methods for the Treatment of Minerals, Elsevier, New York, 1987. Tsouris, C., S. Yiacoumi, andT. C. Scott, 

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Eisentrager A, Vella D, Griffiths IM (2014) Particle capture efficiency in a multi-wire model for high gradient magnetic separation. Appl Phys Lett 105 033508... 

Oak, M.J., Modeling and experimental study of high gradient magnetic separation vrith application to coal beneficiation," unpublished M.S. thesis. Auburn University, AL, Dec. 8 (1977). 

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