A numerical model is developed to simulate the coupled effect of thermal and reactive solute transport in a fracture. The analysis is based on the fluid circulation model in a single fracture with an injection well and a production well. The model includes thermal convection and dispersion along the fracture and transient heat exchange between the fracture and the reservoir matrix. The simulation of solute transport is incorporated by considering advection and dispersion of solutes along the fracture and one-dimensional diffusive limited solute transport in the reservoir matrix. The model is extended to simulate linear reaction kinetics of silica transport leading to a coupling between thermal and reactive solute transport processes. The model is used to examine the effect of rock-water interactions on the amount of silica mass transfer and fracture aperture variation. The maximum value of variation in fracture aperture occurs near the inlet. The peak is mitigated and is shifted away from the injection well with time.