Red mud is an alkaline solid waste released from Al2O3 smelting and can be used as capture agent to absorb CO2 in fume.In this paper

red mud from Bayer process of China Aluminum Corporation was selected and used

and the effect of reaction temperature

time

and ratio of solid to liquid

agitation speed and CO2 flow rate on absorbing efficiency of red mud was investigated to obtain the best process parameters and conditions.The results show that one gram fluidic red mud containing 44.12%（mass） water can capture 0.11—0.12 g CO2 at 40℃

under the ratio of solid to liquid of 1∶10

the reaction time of 120 min

the agitation speed of 700 r·min-1 and the CO2 gas flow rate of 0.25 L·min-1.The properties of red mud before and after absorbing CO2 were characterized by XRD

SEM

BET

and FT-IR.The data from XRD show that main components of red mud are Ca2SiO4

CaCO3

Na2Si2O5

CaTiO3

Ca3Si2O5

Ca3Al2O6

and NaCO3

after the reaction with CO2

the peaks of Ca2SiO4

Na2Si2O5 and Na2CO3 in XRD pattern disappear.Furthermore

owing to the alkaline substances in red mud can react with CO2 to get carbonates；some new phases can be found in the XRD spectrum.The analysis by SEM

BET and FT-IR imply that the microstructures and shapes of red mud have occurred a change and are different before and after capturing CO2.These data results show that red mud can be used for capturing CO2 in fume and provide an effective way with low cost for reducing carbon emissions.