Carbonation reaction properties and reaction mechanisms of red mud under different carbon dioxide pressures

Abstract

The carbonation utilization of solid waste such as red mud is an important strategy to deal with greenhouse gas emission control. To explore the carbonation reaction properties of red mud particles under different CO2 curing pressures, experiments were designed. The results show that in the range of 0–14 bar, as the CO2 curing pressure increases, the carbonate content in the carbonation product gradually increases and becomes stable. When the CO2 pressure increases to 18 bar, the amount of carbonate minerals will further increase. The pore change characteristics of red mud particles before and after carbonation are not significant, and no obvious carbon accumulation is observed on the surface of the particles. The carbonation of red mud particles is a liquid phase reaction, and the carbonation products are mainly deposited in the solution. The CaCO3 produced by carbonation is mainly calcite and aragonite types. The relevant results can provide reference for the carbonation utilization of red mud.