High Gradient Magnetic Separation & Improvement of Brightness of Clays

High Gradient Magnetic Separation (HGMS) is the latest approach to the processing of fine particles ( 5 micro meter) that are weakly paramagnetic. It has shown a great promise in the beneficiation of several minerals and ores. It found its first commercial application in clay industries for the removal of the colouring bodies from clay in order to improve its brightness. These kaolin clays find application in paper, pharmaceutical, ceramic, rubber, plastic and paint industries. HGMS is also useful in water treatment, beneficiation of coal, iron ore, rock phosphate, gold tailings and other secondary sources such as wastes. The HGMS unit combines a magnet and matrix design which provides uniform high magnetic flux densities in a large volume and a very high magnetic field gradient. This unique combination permits processing of very fine and weakly paramagnetic particulates. However there has been no detailed investigations on kaolin clays of Indian origin using HGMS. We have initiated research in HGMS in India and detailed investigations of some of the Indian kaolin clays using a SALA 10-15-20 laboratory model HGMS unit have been carried out.