Preparation and characterization of low-density ceramic proppant containing coal gangue additive

Abstract

Low-density ceramic proppants were prepared from calcined flint clay and solid waste coal gangue by pelleting, drying, screening and sintering, namely solid state sintering method. The density and breakage ratio of the proppants were systematically investigated as a function of sintering temperature. The morphology and phase composition of the proppants were examined by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results show that the ceramic proppants are composed of acicular mullite and granular cristobalite. Bulk density and apparent density of the proppants rise and thereafter down with increasing the sintering temperature. The proppants sintered at 1400 °C have the best performance with 1.28 g/cm3 of bulk density, 2.84 g/cm3 of apparent density and 7.89% of breakage ratio under 52 MPa closed pressure. The prepared ceramic proppants meet China industrial standard requirements SY/T5108-2014.