Investigation on Rapid Coal Drying Based on Instant Controlled Pressure Drop Method

Coal slurry is a byproduct generated during coal washing, characterized by high moisture content, which limits its widespread application. This study investigated the effectiveness of deep drying coal slurry using the instant controlled pressure drop (DIC) technique combined with conventional thermal drying methods, while also exploring its drying characteristics. Experimental results indicate that, at 200°C, reducing the sample quantity significantly enhances the dehydration rate, while increasing pressure further accelerates the drying process. A modified Page model was applied to fit experimental data from the drying process, and the results demonstrated an excellent model fit, enabling accurate prediction of moisture changes in coal slurry under varying conditions. The study further revealed that increasing temperature and pressure effectively enhance the moisture diffusion coefficient, thereby improving drying efficiency. In summary, integrating DIC technology with coal slurry drying not only enhances drying efficiency but also offers high safety, providing a new technical pathway for efficient coal slurry utilization. This research delivers theoretical foundations and technical support for coal slurry drying, demonstrating significant industrial application potential.