Dealkalinization Effect of Carbon Dioxide in Flue Gas on Bayer Red Mud

Red mudRed mud is a bulk solid waste generated by the aluminaAlumina industry, which is difficult to use on a large scale due to its strong alkalinity. Meanwhile, carbon dioxideCarbon dioxide in flue gas is one of the main factors contributing to global warmingGlobal warming. Therefore, this paper employs flue gas carbon dioxideCarbon dioxide to neutralize the alkaline substances in red mudRed mud. The results showed that with the introduction of carbon dioxideCarbon dioxide into the red mudRed mud at 35 °C, a liquid-to-solid ratio of 10, and an aeration capacity of 20 L/h for 30 min, the dealkalinizationDealkalinization rate of red mudRed mud reached 33.12%. The reduction in alkalinity was due to the acid–alkali neutralization reaction of carbon dioxideCarbon dioxide with alkali compound in red mudRed mud. The carbon dioxideCarbon dioxide in the flue gas has a dealkalinizationDealkalinization effect on red mudRed mud, which can realize the dual purpose of red mudRed mud dealkalinizationDealkalinization and carbon dioxideCarbon dioxide neutralization.