Development of an attrition-leaching hybrid process for direct aqueous mineral carbonation

[Display omitted] •Attrition leaching, a new hybrid process for direct aqueous mineral carbonation.•Hybrid process yields continuous mechanical exfoliation of passivation layer.•Proven synergy between mechanical exfoliation and mineral carbonation.•Hybrid process yields up to 80% carbonation in 24h.•Robustness of the hybrid process towards variations in ore type. Mineral carbonation is the single most eligible companion solution to geosequestration for mitigation of anthropic CO2 emissions on a large scale. Amongst its possible pathways, direct aqueous mineral carbonation stands out as one of the most promising ones. The originality of the present work lies in the transposition of the concomitant exfoliation/mineralisation concept, which was first proposed by the mineral carbonation research group from the Arizona State University in early 2000s, inside a dedicated attrition environment, more specifically inside a stirred bead mill. Experimental results and analyses bring definite proofs about the possibility and synergy of concomitant exfoliation and mineralisation. Given high carbonation yield for olivine and serpentinised ores (up to 35% in 5h and 80% in 24h in water, and 70% in 5h with inorganic additives) and the capacity of stirred mills to process mining size throughputs, this work leads to real perspectives for developing large scale robust solutions for direct aqueous mineral carbonation.