Reducing bentonite usage in iron ore pelletization through synergistic modification with mechanical force and DMSO: Effects and mechanisms

Bentonite is a necessary binder in producing pellets. Its excessive use reduces the iron grade of pellets and increases production costs. Minimizing bentonite dosage is essential for producing high-quality iron ore pellets. Addressing the gap in the application of organically-intercalated modified bentonite in the pelletizing field, this study introduces an innovative modification process for bentonite that employs the synergistic effect of mechanical force and dimethyl sulfoxide to enhance the intercalation of organic compounds within bentonite, thus significantly enhancing its binding performance. The colloid value and swell capacity of modified bentonite (98.5 mL/3g and 55.0 mL/g) were much higher than the original bentonite (90.5 mL/3g and 17.5 mL/g). With the decrease of bentonite dosage from 1.5wt% to 1.0wt%, the drop number of green pellets from a height of 0.5 m and the compressive strengths of roasted pellets using the modified bentonite (6.0 times and 2916 N per pellet) were significantly higher than those of the original bentonite (4.0 times and 2739 N per pellet). This study provides a comprehensive analysis of the intercalation modification mechanism of bentonite, offering crucial technical insights for the development of high-performance modified bentonite as iron ore pellet binders.