Investigation of the effect of pelletizing parameters on physical and mechanical properties of pellets prepared from Kahnouj ilmenite concentrate

Ilmenite can be upgraded through pre-reduction of pellets of ilmenite with the aim of reduction of iron oxides to metallic iron, and subsequent smelting of the pellets to obtain a high-titania slag. In this research, the effect of parameters such as rotation speed and rotation angle in a disk-pelletizer as well as the amounts of moisture and binder in the pellets on the pelletization process was studied. The optimum conditions to obtain pellets with required physical and mechanical properties were determined. 1-5% bentonite and a mixture of bentonite-Fundo cement were used as binder. Drop number and crushing strength standard tests were conducted on green and dry pellets. A slope of 40°, rotation speed of 30 rpm and pelletizing time of 60min yielded the highest pelletizing efficiency for the disk-pelletizer. The optimum amount of moisture was determined to be 9wt%. It was found out that an increase in the percentage of bentonite showed increasing-decreasing effect on strength and drop number, the optimum amount of bentonite addition being 3-4wt%. The use of mixtures of Fundo-bentonite in the pellets had an increasing effect on strength, but at higher temperatures the strength of pellets containing mixtures of Fundo-bentonite showed a decrease in comparison with that of the pellets containing only bentonite.