Preparation of high-strength ceramsite from coal gangue, fly ash, and steel slag

Coal gangue (CG) and fly ash (FA) are generated in large quantities worldwide. In this study, high-strength and lightweight aggregate ceramsites were prepared from CG, FA, and steel slag (SS) without any additional chemical additives through high-temperature sintering. The study aimed at determine the sintering mechanism and optimal production process by evaluating the performance of ceramsites produced under various conditions. The results indicated that the ratio of CG, FA, and SS significantly influenced the ceramsites' properties. When the ratio of CG, FA, and SS was 3 : 1 : 1 and the sintering temperature was 1200 °C, the ceramsites demonstrated optimal performance. These ceramsites had a bulk density of 947 kg m⁻³, an apparent density of 1859 kg m⁻³, a high compressive strength of 21.17 MPa, and a 1 hour water absorption of 1.35%. The high-strength and lightweight aggregate ceramsites produced from CG, FA, and SS hold promise as construction materials, particularly due to the benefits of waste recycling. This study highlights the potential of utilizing these ceramsites as sustainable alternatives in various construction applications.