The removal of particles from the matrix of a high-gradient magnetic separator

The desorption of hematite particles from the matrix of a magnetic separator was studied experimentally as a function of the pH value and flowrate of the water used for flushing. It was found that the removal of particles was strongly dependent on the pH value of the flushing water, the optimum being at pH 11. A model based on Derjaguin-Landau-Verwey-Overbeek (DLVO) theory was developed, and the experimental results were analyzed in terms of this model, which offers a good explanation of the residual forces hampering the removal of particles from a matrix.