Preparation and characterization of low-density mullite-based ceramic proppant by a dynamic sintering method

Low-density mullite-based ceramic proppants were prepared from bauxite (49.74 wt% Al2O3), soft-clay and manganese dioxide by a dynamic sintering method. The apparent density and breakage ratio of specimens were systematically investigated as a function of sintering temperature. The morphology structure and phase composition of specimens were investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results show that the proppants were composed of acicular mullite and glass phases. The proppants prepared from calcined bauxite showed a better performance than the proppants prepared from natural bauxite. With increasing sintering temperature properly, the proppants showed an enhanced crystallinity and a denser microstructure, and the proppants sintered at 1355 °C had the best performance with 2.792 g/cm3 of apparent density and only 3.22% of breakage ratio under 52 MPa.