Nepheline-based water-permeable bricks from coal gangue and aluminum hydroxide

Nepheline-based water-permeable bricks are prepared with coal gangue and aluminum hydroxide by raw material pretreating, mixing, isostatic molding, roasting, and self-curing. These bricks exhibit balance between their mechanical and water-permeable properties. In this study, two main factors, the raw material ratio and the molding pressure, are studied. The mineral phase, porous structure, and mechanical properties of the samples are characterized by X-ray diffraction, scanning electron microscopy and mercury injection, respectively. The compressive strength and water permeability of the bricks meet Chinese industry standard JC/T945-2005 for water-permeable bricks. The compressive strengths of the samples are between 30.6 and 34.3 MPa. The permeability coefficients range from 1.37 cm s−1 to 1.55 cm s−1. © 2016 American Institute of Chemical Engineers Environ Prog, 2016