Delving into the role of microwave curing on the strength and cement hydration features of cemented tailings backfill

Cemented tailings backfill (CTB) comprises tailings, binders, and water and is filled into goaves to regulate the ground pressure and ensure production safety. Thus, shortening the curing time of CTB has been a popular research topic in backfill mining as it maximizes the extraction of the neighboring stopes while lowering mining-related costs. In this study, a self-made horn microwave experimental device was developed to rapidly enhance CTB’s strength property. Subsequently, the microwave-curing effects on the upper surface temperature, strength, deformation coefficient, and hydration reaction of CTB were explored through uniaxial compressive strength, X-ray diffraction, and thermogravimetric/differential thermogravimetric experiments. Experimental marks revealed that the strength property of early-aged (up to 7 d) CTB composites could be rapidly enhanced by microwave curing, except for the 7-d-cured fills with microwave curing times of 5–7 min. Moreover, the hydration reactions of CTB after 3- and 7-d curing were substantially accelerated by microwave curing. Thus, this study offers a novel method of satisfactorily increasing early-aged CTB strength and exploring its hydration mechanisms effectively.