Statistical optimisation of some parameters affecting flocculation of Egyptian iron ore

Abstract

Many tonnages of iron ores are mined annually. Upgrading of such ores is a prerequisite and a mandatory step before their further usage in subsequent purposes as for example in the blast furnace. According to the kind and nature of the ore associated impurities, its fineness and degree of liberation, the suitable processing technique will be selected. In this paper, upgrading of an Egyptian iron ore applying the selective flocculation approach was studied. Different types of starch were used as flocculants. The potato starch among the studied starches showed the best separation results. However, the results showed a fluctuation in the obtained concentrates grade and recovery. Therefore, statistical design of experiments, Box Behenken design, was used as an optimisation tool. The results of the design, applied to potato starch, showed that the iron grade up to 55% could be obtained as a preconcentrate. Regrinding of the preconcentrate to 100% less than 25 μm followed by selective flocculation at the design optimum conditions; a final concentrate with 61% Fe could be obtained.