Low-Intensity Magnetic Separation: Principal Stages of a Separator Development – What is the Next Step?

Abstract

An analysis of the technological limitations of magnetite quartzite beneficiation illustrated the imperfections of the traditional classification by size. As an alternative to size classification, separation by the degree of magnetite grain liberation can be employed. Comparative analysis of the mineral phase properties of the magnetic separation feed and its magnetic product has confirmed that wet drum magnetic separators currently used for wet treatment of magnetite ores have a low selectivity of separation. The removal of inter-grown particles into a separate product to enable more efficient and selective disintegration is expected to offer significant energy saving. A new-generation selective separator has been developed and a pilot model built; test results are promising. Grain selection by different degrees of mineral liberation is possible when the wet method is utilized. Magnetic selection allows for substantial benefits to be made through process optimization, including: (1) energy savings in the grinding process; (2) reduction of losses arising from over-ground magnetite in the operational tailings; (3) increased grain size; (4) avoidance of over-grinding; and (5) filtration and pelletization improvements.