Pore Characteristics and Slurryability of Coal Blends

Abstract

The pore characteristics and slurryability of two coal blends between Shigang anthracite coal and Huangling bituminous coal (SG/HL), and Guizhou anthracite coal and Xiaotun lean coal (GZ/XT), respectively, were investigated. The fractal dimensions of coal were calculated in the two regions of P/P 0 < 0.45 and P/P 0 > 0.45 and defined as D 1 and D 2, respectively. Upon an increase in the blending ratio of parent coal with smaller BET surface area (S BET) and total pore volume (TPV), the S BET and TPV of coal blends monotonously decreased. D 1 was mainly related to the S meso/macro(10–220 nm)/S total and mineral phase within coal while D 2 was closely affected by the V meso(2–10 nm)/V total. D 1 of SG/HL coal blends had no apparent linear correlation with the pore structure parameters whereas D 1 of GZ/XT coal blends changed linearly with the pore structure parameters. Both D 2 of SG/HL coal blends and that of GZ/XT coal blends changed linearly with the pore structure parameters. The slurry quality of coal water slurry (CWS) prepared from coal blends is comprehensively affected by the physicochemical properties and blending ratio of parent coals. Therefore, the maximum solid loading (MSL) and water separation ratio (WSR) of CWS prepared from coal blends do not always change linearly with the blending ratio of parent coal.