Dry, electrostatic separation is a potentially efficient method of removing pyrites from coal. However, progress in the past was hampered by a lack of a quantitative analysis of the process. To help us design better separation equipment, we have developed a hydrodynamic model of separation of pyrites from coal in a batch electrofluidized bed. The simulations were done on a Cray-2 computer. The input variables include the surface charge of the particles and the solids stress, which were measured.
Realistic shapes and sizes of bubbles were computed with and without an applied electric field for a two-dimensional bed with a central jet. The bubble sizes and the rising velocities were smaller with an applied field, consistent with observations. Computed electrophoretic mobilities in the fluidized bed will be useful for a better design of continuous beds.