Removal of fine gangue minerals from Chador-malu iron concentrate using hydroseparator

Phosphorus and silica are the main impurities of the Chador-malu iron ore which need to be reduced to the required values of 0.1 and 2%, respectively. The impurities in the final iron concentrate are mainly due to the presence of fine particles (less than 25 μm) of silica and apatite in the concentrates of magnetic separators and flotation circuits. In this study, the removal of very fine gangue minerals from iron concentrate of the Chador-malu processing plant was investigated using a laboratory hydroseparator. The laboratory-scale hydroseparator experiments were conducted under various operational conditions. The results showed that the silica and phosphorus contents of the flotation feed samples (less than 45 μm) decreased from 4.13% and 0.58% to 2.90 and 0.45%, respectively, while the iron grade increased from 59.5% to 63.5% by setting the effective parameters of the separator. The follow up flotation tests on the hydroseparator product resulted in an iron concentrate with silica and phosphorus contents of less than 2% and 0.04%, respectively. Moreover, its phosphorus content was reduced from 0.66% to 0.1% by desliming the final magnetic concentrate with hydroseparator. In this case, around 76% of phosphorus was removed.