Investigation of Electrophysical and Rheological Characteristics of Water–Coal Suspensions

This paper presents a comprehensive study on the influence of coal particle concentration (0–50%) on the electrophysical and thermal-engineering properties of coal–water suspensions (CWS). It was experimentally established that the electrical conductivity (σ) exhibits a sharp increase in the range of 0–10%, followed by saturation at concentrations exceeding 15%. The critical percolation concentration (pc) was found to be 12%, which is in good agreement with Stauffer’s percolation theory. Combustion efficiency (ղcomb) reaches its maximum at 10–12%, subsequently declining due to rheological constraints. An optimization model is proposed that accounts for conductivity, combustion efficiency, and hydraulic losses. Based on the findings, a working concentration range of 8–12% is recommended for industrial applications.