Study on the flow and bonding-reinforcement characteristics of composite foam slurry material used to block mine leakage

To study the fluidity and bonding-reinforcement characteristics of composite foam slurry material (CFSM) on broken coal mass, the hydration mechanism, the rheological law, and the process of bonding-reinforcement were analyzed systematically. The results revealed that the Herschel-Bulkely model could describe the rheological properties of CFSM accurately by fitting the shear stress-shear rate curve (fitting coefficient>0.99), indicating that CFSM was a pseudoplastic fluid with yield stress. Based on the rheological model of CFSM, the diffusion equation of the material in the fissure channel was theoretically deduced, and it was obtained that the material rheological index, viscosity and crack width were the key factors affecting the diffusion performance. Moreover, the surface morphology and functional groups of the CFSM-coal contact interface showed that the active groups on the CFSM and coal molecules exhibited chemical bonding and physical coating at the interface. An interface bonding model of CFSM-coal composed of a weak effect layer, an enrichment layer, a contact layer and an etching penetration layer was established. •The hydration reaction mechanism of composite foam slurry material was exhibited.•The rheological characteristic of composite foam slurry material was investigated.•The diffusion law and equation of composite foam slurry material was obtained.•The bonding-reinforcement mechanism of this material was revealed.