Preparation and microstructural characterization of a novel 3D printable building material composed of copper tailings and iron tailings

This paper proposes an environmentally friendly 3D printable building material composed of copper tailings and iron tailings that matches well with an extrusion-based printing process. The experimental results show that copper tailings and iron tailings have the best compounding effect on mechanical properties at a mass ratio of 1:4. The microstructure and gelation activities of 3D printable building material were characterized by XRD, FTIR and SEM techniques. The research results show that the hydration products of 3D printable building material composed of copper tailings and iron tailings are mainly ettringite and C-S-H gel, which contribute for the development of strength. It is found that the ettringite, C-S-H gels, and cemented crystals are closely connected to form a three-dimensional structure, which makes the matrix more compact, and importantly enhances the mechanical properties of 3D printable building material. Furthermore, the leaching toxicity and radioactivity of 3D printable building material were tested, and the results show that the 3D printable building material composed of copper tailings and iron tailings is environmentally friendly. (C) 2020 Elsevier Ltd. All rights reserved.