Simultaneous disposal and utilization of coal chemical wastewater in coal and petroleum coke slurry preparation: Slurrying performance and mechanism

Preparation of coal gasification wastewater (CGW) into coal-water slurry (CWS) or petroleum coke (PC)-water slurry (PCWS), which is then used as a feed material for gasification, enables the recycling of CGW and consequently solves its environmental pollution problems. The present study focused on slurrying behavior of CWS and PCWS prepared with CGW. The slurrying mechanism was studied based on the coal (or PC)-additive adsorption and hydrophobic property of the coal (or PC). Results showed the additive and CGW inclusions exhibited synergistic effects when they were adsorbed onto the coal (or PC). Increasing the adsorption amount of the additive facilitated the formation of a stable hydration shell outside the coal (or PC) particles, which enhanced the separation and dispersion of particles in the suspension. Therefore, CWS (or PCWS) was easily prepared into a high-concentration suspension when CGW was used instead of clean water; that is, CGW improved the slurrying performance. Therefore, preparing CWS (or PCWS) with CGW is a favorable option for simultaneously treating and utilizing CGW.