Mechanism of the effect of modified TiO2 on the strength of gold tailings-based no-fire bricks samples

Brick-making from gold tailings is one of the common utilization methods, however, this method usually requires pressurized sintering. This study investigates the effect of modified TiO 2 on the strength of gold tailings-based no-fire bricks under ambient temperature and pressure conditions. Gold tailings, river sand, and gravel were used as raw materials, with cement-epoxy resin serving as the composite binder and modified TiO 2 acting as the reinforcing agent. The surface of TiO 2 was modified by silane coupling agent KH-560 and polyethyleneimine (PEI), and the effect of modified TiO 2 on the performance and characterization of gold tailings-based no-fire bricks was investigated. The results show that 25% KH-560 silane coupling agent and 75% polyethyleneimine (PEI) modify TiO 2 best. The optimal compressive strength of 79.6 MPa was achieved in gold tailings-based no-fire bricks with 2% modified TiO 2 addition. Microscopic morphology and chemical analysis confirmed that the modified TiO 2 significantly enhanced the structural integrity of gold tailings-based no-fire bricks.