Revolutionizing Construction: Harnessing Phosphorus Tailings for Lightweight, High-Strength Wall Materials

The beneficiation of low-grade phosphate ore leads to the production of a substantial quantity of phosphate tailings, thereby not only occupying land but also endangering the environment and potentially posing safety concerns. In this work, extrusion molding, steam-curing, and calcined phosphate tailings are employed to fabricate lightweight wall materials with superior strength. It is found that the wall material has a special structure of interwoven needle-like crystals as a way to provide high flexural strength. The main composition of 34.94% phosphate tailings, 36.75% calcined phosphate tailings, 16.64% silica fume, 6.67% anhydrous magnesium sulfate is required to achieve an optimal maintenance process for 4 h of heat preservation at 120 °C saturated vapor pressure environment. The prepared wall materials yield a flexural strength of 24.9 MPa, compressive strength of 18.9 MPa, softening coefficient of 0.81, apparent density of 1.594 g cm⁻³, and thermal conductivity of 0.269 w/(m K), which meet the requirements of the Chinese standard “Lightweight strip board for building partition walls”. Moreover, the calculation revealed that phosphate tailings have a comprehensive utilization rate of 77.23%, effectively mitigating the issues arising from their accumulation and serving as an efficient means of utilizing solid waste derived from phosphate tailings.