Study on phase evolution and mechanical properties of reconstructed granite

Abstract

In this paper, reconstructed granite with enhanced mechanical properties is prepared by re-melting and re-sintering granite wastes based on the formation process of natural granite. The sintering process, phase composition, and mechanical properties are deeply investigated. The optimal synthesizing process is sintering granite wastes at 1090 °C for 2 h with a preloading pressure of 25 MPa. Reconstruction results in excellent mechanical properties with a Vickers hardness of 5.30 GPa, a bending strength of 64.84 MPa, and an elastic modulus of 68.77 GPa, which are superior to those of natural granite (Vickers hardness of 3.64 GPa, bending strength of 23.40 MPa, and elastic modulus of 58.77 GPa). The sintering process plays a decisive role in improving the mechanical properties, which not only regulate the phase composition and refine the grain size but also effectively decrease the formation of cracks. This work not only clarified the mechanism between the phase evolution and mechanical properties of reconstructed granite but also proposed a viable way to dispose granite wastes for natural resource recycling.