Designing HGMS matrix arrays for selective filtration

High Gradient Magnetic Separators typically use a random array of wire matrix elements such as stainless steel wool or expanded metal for the magnetic capture of fine particles. Difficult mineral separation tasks may require systematic and controlled matrix construction to allow more selective separation of one material over another. Of interest here is the dependence of the magnetic capture force on the spacing and shielding of wire matrix elements and how such design parameters lead to a more selective matrix array. A laboratory technique developed in our group provides good confirmation of computer modeling studies. We use arrays of nickel or iron wires, spaced from 6 to 30 times the wire radius. Magnetite filled epoxy is added to the volume around the wire matrix. The wires are magnetized to saturation and the dispersed magnetite moves away from the negative gradients above and below the magnetized wires. The computer studies correlate to the magnetite patterns observed.