Author:

Keywords:

nickel nanoparticles, mineral carbonation, steelmaking slags, catalytic additive, carbonic acid

Abstract:

Carbon dioxide mitigation through mineral carbonation is still economically inefficient, despite the mounting knowledge pool on the subject. This inefficiency is due to high energy demand, slow reaction kinetics and low conversion degrees (and implicitly limited CO2 sequestration). Additive usage remains an interesting choice to accelerate CO2 absorption, especially if mild process conditions can be maintained. Most research conducted to date has sought additives to increase mineral dissolution and carbonate precipitation. This work presents a different approach regarding the use of pure nickel nanoparticles (NiNP) as a mineral carbonation additive. The mechanism of NiNP, of catalytic nature, is based on increasing the quantities of dissolved CO2 and dissociated carbonic acid in the process water, thus increasing the concentration of bicarbonate ions available to react with solubilised alkaline earth metals. This effect has the potential to reduce the time needed to reach a certain level of conversion through mineral carbonation. This study presents results and discussions regarding the effect of NiNP on the CO2 mineralization by four alkaline materials (pure CaO and MgO, and AOD and CC steelmaking slags), on the product mineralogy, on the particle size distribution, and on the morphology of resulting materials.