Effect of Alkali Activator on Preparation, and Mechanical and Thermal Properties of Iron Mine Tailing-Based Lightweight Materials

Lightweight materials applied in construction field were prepared using waste iron mine tailings (WIMT) as raw materials, the commercial silicate cement (CSC) as cementing agent, NaOH as the alkali activator, and triethanolamine lauryl sulfate (TLS) as foaming agent via foam-gelcasting method. The effects of water/cement (W/C) mass ratio (0.6-1.0), addition of NaOH (0-0.15wt%) and foaming agent (0-0.3vol%) on the porosity, bulk density, and mechanical properties of the iron mine tailing-based lightweight materials were studied. The results showed that the mechanical properties of iron mine tailing-based lightweight materials were improved by adding NaOH, the as-prepared materials had a 7-day compressive strength of 5.18 MPa, porosity of 51.40%, bulk density of 1.73 g/cm 3 and thermal conductivity of 0.193 W・(m -1 K -1 ) when the W/C ratio was 0.8, the mass ratio of WIMT/CSC/NaOH 1.85:1:0.15, and foaming agent content 0.3vol%.