Response characteristics of the resistivity and water content during the imbibition process in remolded coal without gas

The water content distribution in a coal body is closely related to the gas distribution. It is difficult to directly determine the water content distribution in the process water imbibition. To retrieve the water content by the resistivity value and establish a relationship between the resistivity and water content, the response characteristics of the resistivity and water content of remolded coal formed under different loads are studied by a self-designed resistivity experimental system. The results show that the resistivity of the remolded coal decreases over time during the imbibition process, including a rapidly decreasing stage and a slowly decreasing stage. The resistivity of the remolded coal is related to the water in the macropore in the rapidly decreasing stage. In the slowly decreasing stage, the resistivity is related to the contact between coal particles. The pressing load, imbibition range, and imbibition speed are negatively correlated with porosity. The resistivity of the steady state is also negatively correlated with the water content and pressing load. The relationship between the resistivity of the steady state and the water content fit a power function. This study reveals the law of resistivity and the water content during the imbibition process and provides an effective methodology to bridge the gap for measuring water content distribution during the imbibition process.