The neutralization and recycling of red mud – a review

Red mud (bauxite residue) is a highly alkaline solid waste of alumina production. The amount of red mud is huge while its alkalinity hinders the application in construction industries. Up to now, the most common treatment of red mud is disposed in man-made dams. However, the long-term storage of large-amount red mud pollutes environment and underground water, threats human life and leads to a huge waste of valuable metals resources. Recently, researchers have proposed various strategies to solve the red mud problems. In this review, the neutralization and recycling status of red mud have been systematically illustrated, their advantages and disadvantages are also discussed in detail in terms of environmental and economic benefits. Moreover, the recommendation of red mud treatment in the future is suggested, the application in road base material is highly valued because of the huge consumption.