Sintering behavior and mechanical properties of sintered ceramics based on spodumene tailings

In this study, ceramics was prepared by slip casting (no pressure was used during shaping step) and atmospheric pressure sintering with low-melting point glass (LPG) powder as the binding material to facilitate the transformation of spodumene flotation tailings (SFTs) into ceramics at lower temperatures. The influence of sintering temperature and mass ratio of LPG on the mechanical properties (flexural strength and compressive strength) of ceramic materials was studied by orthogonal test. The results showed that when the mass ratio of LPG powder was higher than or equal to 20 wt% and the sintering temperature was higher than or equal to 550 °C, mutual adhesion between the sample particles was realised and consequently the ceramic materials could be prepared with good mechanical properties (the maximum flexural strength=19.55 MPa, the maximum compressive strength=42.25 MPa, average porosity=24.52%, average apparent density=1.66 g/cm3, and average water absorption=14.79%). The sintered ceramics were characterized by XRF, XRD, optical microscopy analysis, SEM, TGA-DSC and FT-IR. The formation of liquid phase at high temperature may lead to the mutual bonding between particles, which might be the main reason for the improvement of mechanical properties of ceramic materials. Overall, SFTs were successfully sintered at low temperature to prepare ceramic materials with good mechanical properties, which are crucial for energy conservation and environmental preservation.