The physicochemical properties, thermal conversion performance, and kinetic characteristics of pressurized pulverized coal gasification slag

Pressurized pulverized coal gasification, as an efficient and clean conversion technology, has been widely applied and promoted; however, it still generates substantial amounts of fine slag. This study proposes an approach to achieve energy recovery and reuse of pressurized gasification fine slag. The structural properties of such fine slag, along with its reaction characteristics under a CO₂/A_r atmosphere, were evaluated. Comparisons with Shenmu pulverized coal revealed that the fine slag exhibits a slightly smaller average particle size. Additionally, the specific surface area of the fine slag is approximately 1.75 times that of its raw coal, endowing it with a stronger adsorption capacity for reaction gases. Thermogravimetric experimental results indicate that the reaction characteristics of pressurized gasification fine slag with a carbon content of 28.80% are comparable to those of coal char derived from raw coal. At a heating rate of 15 ℃/min, when the temperature is below 910℃, the conversion rate of high-carbon slag exceeds that of coal char. Consequently, pressurized gasification fine slag with high carbon content can serve as a feedstock for secondary gasification.