A STUDY OF THE IRON GRADE VARIATION OF PELLETS DURING ROASTING

The research of the iron grade variation of pellets during roasting were conducted, which includes the effect of FeO oxidation and the addition of bentonite on the iron grade of pellets The results show that there is pertinency between the pellet grade and the proportioning ratio of bentonite and the FeO content of concentrate The iron grade of pellets was decreased by 0 04% and 0 5%～0 6% with the 1% increase of FeO content in iron concentrate and the proportioning 1% of bentonite into the mixture respectively The iron grade of pellets was decreased by 2 0%～2 5% by the proportioning 2 5% of bentonite due to the weight increase resulting from the FeO oxidation and bentonite's impoverishment The calculated grade of pellets agrees well with the assaying results, which depends on the assaying accuracy of TFe, FeO and ignition loss, especially the ignition loss should include the weight increase of FeO