Steel-making slag for mineral sequestration of carbon dioxide by accelerated carbonation

Diffusion of calcium ions and kinetics of carbonation reactions are hardly affected by pressure changes that determine overall CO2 sequestration capacity.

“Because the diffusion of calcium ions and kinetics of carbonation reactions are hardly affected by pressure changes that determine the overall CO 2 sequestration capacity [46,115].”

High pressure accelerates CO2 sequestration rate at early stage of aqueous carbonation but hardly affects final CO2 sequestration capacity of slag.

“High pressure was found to accelerate the CO 2 sequestration rate at the early stage of aqueous carbonation but hardly affect the final CO 2 sequestration capacity of slag, which is consistent with the effect of pressure on the CO 2 uptake of fly ash (as introduced earlier).”

Slight decrease in CO2 sequestration capacity after 50 or 60°C can be attributed to rapid growth of calcite layers on surface of slag particles.

“The slight decrease in the CO 2 sequestration capacity after 50 or 60 • C in [46,133] can be attributed to the rapid growth of the calcite layers on the surface of slag particles, as discussed in Sections 3.1 and 3.2.”

Continuous increase in temperature from 50 to 80°C seemed to slightly decrease capacity of CO2 sequestration of slag.

“However, the continuous increase in the temperature from 50 to 80 • C seemed to slightly decrease the capacity of CO 2 sequestration [46].”

With temperatures rising from 20 to 50°C, both rate and capacity of CO2 uptake of slag were increased.

“In [46], it was reported that with temperatures rising from 20 to 50 • C, both the rate and capacity of CO 2 uptake of slag were increased.”

To achieve maximum potential of CO2 sequestration of slag, temperature control in carbonation treatment is crucial.

“To achieve the maximum potential of CO 2 sequestration of slag, temperature control in carbonation treatment is crucial [46,114,133], as highlighted in Sections 3.1 and 3.2.”