Reuse of coal gangue to prepare adsorbent with multiscale pore structure for emulsified water removal

[Display omitted] •Coal gangue was prepared into porous skeleton with open pores by foaming method.•LDH were decorated on the pore wall surface to form multistage pore structure.•The composite showed high efficiency removal for emulsified water.•Low cost and readily available raw materials give it great scale application potential. A novel composite adsorbent with interconnected multiscale pore structure was prepared by loading layered double hydroxide(LDH) on the inner pore wall of CBPM (coal gangue “ball–window” porous monolith) as the skeleton. Numerical simulation of the fluid flow characteristics in the 3D interconnected structure was investigated. The structure exhibits large specific surface area and abundant binding sites due to the significantly enhanced transport channels and sufficient LDH dispersion. As a multifunctional adsorbent, it has filtration function. The LDH@CBPM (composite of LDH and CBPM) shows excellent removal efficiency and recyclability for trace emulsified water from contaminated oil, especially can be directly used as a flow filter unit. The advantages of low cost and facile operation make it potentially used in a broader application field.