Development of Ceramic Materials from Mining Waste for the Production of Sustainable Construction Materials

Abstract

The construction industry faces a challenge in adopting sustainable practices that minimize environmental impact. The search for eco-friendly alternatives has led to the development of materials incorporating recycled waste, optimizing natural resource use. For that reason, ceramic materials with recycled mining waste are gaining attention for their ability to improve the physical and mechanical properties of products while managing mining waste. This approach aligns with circular economy principles by promoting material reduction, reuse, and recycling, which in turn reduces CO2 emissions and enhances manufacturing sustainability. Innovations in the ceramic industry can play a key role in transitioning to a more environmentally responsible model. In this research the main goal is understand the properties and environmental benefits through efficient waste management in new construction materials. For that, this study develops new ceramic materials using recycled mining sludge from Panasqueira mine (Portugal) exploring their potential for sustainable production. Specifically, this research evaluated the impact of adding different proportions of mining sludge (10%, 25%, and 50% by weight) on ceramic brick manufacturing and the samples were fired at controlled temperatures of 800, 950, and 1100 °C, allowing the evaluation of the thermal influence on the final properties of the samples. The methodology employed involved multiple stages, and the following methods were employed: the chemical and mineralogical properties of the materials used were analyzed using X-ray fluorescence (XRF) and X-ray diffraction (XRD) techniques to identify their composition. TGA was performed to assess the thermal properties of the materials. Elastic properties and compactness were evaluated by measuring ultrasonic pulse velocities. The mineralogy, texture, and microstructure of the samples were examined using SEM, providing detailed information about the structural and compositional characteristics. The chromatic properties get to study the aesthetic effects of waste incorporation and their use in new and ancient buildings. The results highlighted that the addition of mining sludge did not significantly alter the overall mineralogy. However, XRD and SEM analyses confirmed that sludge acted as a flux, promoting the formation of mineral phases at lower temperatures and increasing the vitreous phase, improving ceramic structure. The addition of sludge, combined with higher firing temperatures, enhanced the mechanical properties, as evidenced by increased ultrasonic pulse velocities, indicating greater internal cohesion and strength. Color changes were influenced by waste proportions and firing conditions, with higher temperatures (1100°C) producing the most significant variations compared to control samples. The main conclusions confirm that using mining sludge in ceramic manufacturing offered environmental and economic benefits, including reduced clay extraction and water consumption (by 22% to 50%). This led to a more sustainable process, aligning with the industry's goal to lower the carbon footprint. The addition of mining sludge in ceramic brick production improves production sustainability, reducing the use of raw materials, saving energy, and recycling industrial waste. These findings demonstrate the potential of this new ceramic material as an eco-friendly solution for the construction industry. This research is part of the project PCI2024-153488 funded by MICIU/AEI/ 10.13039/501100011033 and ERDF/EU. © 2025, Polish Mineral Engineering Society. All rights reserved.