Selective Fragmentation of Oolitic Iron Ores by Microwave Pretreatment

ABSTRACTThere are plentiful of oolitic iron ore resources on the earth, which cannot be currently exploited because of great difficulties for beneficiating the ore. In this work, the selective fragmentation of a Chinese oolitic iron ore (which fragments ore particles along the interfaces of iron and gangue minerals) through microwave was studied in order to liberate the iron minerals at a coarse particle size and thus to effectively concentrate the iron minerals from the ore. The experimental results have shown that a large amount of fractures on the oolitic iron ore were formed along iron and gangue mineral interfaces after being treated by microwave radiation at an appropriate frequency and potential. Following a microwave treatment, the oolitic iron ore was ground by using a ball vertimill. It was indicated that the pretreatment increased the liberation of the iron and gangue minerals at the same particle size, about 10-20% and 10-30% respectively.