Effect of sodium dodecyl sulfate on the CO2 sequestration and rheological properties of alkali-activated coal gasification slag backfill pastes
Using alkali-activated coal gasification slag backfill pastes(ACP)to sequester CO2 can achieve coal gasification slag utilization and CO2 sequestration goals,while the rheological properties of ACP are negatively affected by CO2 sequestration.This paper applying sodium dodecyl sulfate(SDS)as an air entraining agent to optimize the rheological and CO2 sequestration properties of ACP.The results show that numerous bubbles occur inside ACP after the addition of SDS,the bubbles have effect of"vis-cosity reduction and ball lubrication"and can act as nucleation site for calcite,resulting in improving of the CO2 sequestration and rheological properties of ACP.Additionally,at 2％SDS dosage,the yield stress,plastic viscosity,and hysteresis loop area decrease to the lowest value,and the CO2 sequestration amount of ACP reaches its maximum.However,with excessive SDS,it is found that the specific surface area and pore volume of ACP decrease,resulting in the decrease of CO2 sequestration.Additionally,ac-cording to a carbon footprint analysis,adding SDS can decrease carbon emission throughout the ACP lifecycle,and help accomplish carbon reduction goals.
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