Research on moisture detection of coal slime filter cake based on a flow-moisture model

Aiming at the problems in the coal slime filter pressing process, such as excessively long pressing time, the difficulty of achieving real-time moisture detection throughout the process with existing filter presses, high energy consumption, and long filtration cycles, this study investigates the variation pattern of moisture removal from filter cake with pressing time. Using an automatic constant-stress testing machine, the evolution characteristics of dewatering for coal slime filter cakes under different particle sizes, slurry viscosities, and pressures were analyzed. A mathematical derivation model based on filtrate flow rate and filter cake moisture was established, and a moisture detection device for coal slime filter cake was designed to achieve real-time moisture monitoring throughout the filter pressing process. Experimental results show that under the same pressure, filter cake moisture decreases as coal slime particle size increases. Higher slurry viscosity makes dewatering during filter pressing more difficult. Increasing the filter pressing pressure can effectively reduce filter cake moisture. When the feeding pressure increased from 5 MPa to 10 MPa, the filter cake moisture decreased from 24.7% to 13.7%. Compared with traditional coal slime moisture detection methods, the developed moisture detection device achieves an accuracy of up to 97%. The research results provide theoretical and practical technical support for reducing energy consumption in the coal slime filter pressing process, improving solid-liquid separation efficiency, and advancing intelligent coal slime filter pressing.