Pyrite removal from iron ore concentrate by column flotation

Pyrite is the most common and widely distributed sulfide mineral in the Earth’s crust and is usually associated with iron oxide minerals. It is generally considered a gangue mineral creating serious problems during the process of steel production. In the presence of magnetite or hematite¡ the fine particles of pyrite respond inevitabley to magnetic separation due to the bulk effect of the magnetic matrix. Therefore¡ these particles are not adequately rejected by magnetic separation. Reverse flotation is an effective method for sulfur reduction in iron ore processing. Recently¡ due to their lower capital and operational costs and their capability in concentrate production with higher grade and recovery¡ in comparison with mechanical cells¡ column flotation is widely used in iron ore industry. The aim of this research is to reduce the sulfur content of magnetic separators concentrate from 0.5% to lower than 0.1% using column flotation. For this¡ by carrying out 26 experiments¡ the effect of operational factors such as gas superficial velocity¡ froth height¡ collector and frother dosages¡ solid percent and pH were investigated. The findings of this study reveal that the column flotation is an effective method for the iron ore desulfurization so that in an optimal condition¡ a product with sulfur grade of 0.08% and iron recovery of 99% can be obtained. The comparison of results showed that¡ in an optimal condition¡ the performance of column flotation was higher than mechanical flotation.