Mechanism analysis of microwave-carbonation solidification for carbide slag-based low-carbon materials

This study proposes an innovative strategy for compacting carbide slag-based low-carbon bricks (CS-LCB) through a combination of microwave and carbonation curing, aiming to improve the properties through microwave pretreatment combined with carbonation curing and to realize the preparation of low-carbon materials. The effects of microwave pretreatment on the main properties of CS-LCB-containing limestone and fly ash were systematically investigated. After carbonation curing, the pressed CS-LCB exhibited strong strength and effective CO₂ capture capacity. The nucleation effect of limestone helps accelerate the carbonation rate of CS-LCB. In contrast, the interaction between fly ash and carbide slag effectively improves the microstructure. Microwave pretreatment further accelerates the pozzolanic reaction and early carbonation rate of fly ash and carbide slag, improving the early strength of CS-LCB. Additionally, after 14 days of carbonation, CS-LCB retained more than 70.8 % of its initial strength below 500 °C but nearly completely lost its strength at 900 °C.