The choice of high gradient magnetic separation processes for removal of Fe2O3 carriers from quartz raw material

This review article surveys the subject of choice of high gradient magnetic separation processes for removal of Fe2O3 carriers from quartz raw material by electromagnetic separator with magnetic field intensity of 1.4 T. The review is based on current experience of authors during research phase, as well as project development phase and initial operation of facilities in several locations. Quartz mineral raw material in those locations appeared as sandstone or as loose material. In addition to that, quartz raw material from those locations contained various impurities, i.e. Fe2O3 carriers. The choice of this process for Fe2O3 removal depended on mineralogical composition, shape and the content of minerals, and Fe2O3 removal rate after this process was from 29 to 65%. Magnetic separation is magnetic induction of 1.4 T. It is applied on commercial assortments which were previously subjected to washing and classification processes. It is always the assortment which has to have the lowest Fe2O3 content. The choice of, "dry" or, "wet" magnetic separation (with water flush) also depends on the fact whether this desired assortment is intended for market as dry or wet, as well as on the composition of magnetic impurities. In most cases, the process applied is the wet one.