Valorization of clay-based mining wastes from Oued El Aneb marble quarry for terracotta production

Purpose. Valorization of marble quarry waste for the production of terracotta meeting industrial requirements. In this context, our work has focused on the use of clayey waste from the Oued El Aneb marble quarry for the manufacturing of terracotta bricks. The principle is based on using a mixture of different clays (yellow, red, black, and gray clays) derived from marble extraction to produce terracotta under various firing temperatures. Methodology. After sampling and mechanical preparation of the samples in the laboratory, the clayey waste was characterized using several analytical techniques, including X-ray diffraction (XRD), infrared spectroscopy (IR), atomic absorption spectroscopy (AAS), scanning electron microscopy coupled with EDS analysis (SEM-EDS), and X-ray fluorescence (XRF). For the manufacturing of terracotta bricks, tests were conducted under various firing temperatures. Findings. The use of waste materials from marble quarrying represents an innovative approach to the recovery and valorization of mining waste. The tests conducted for the production of terracotta bricks from these materials have yielded promising results. The fired clay materials obtained from these formulations exhibit high performance characteristics, particularly in terms of firing shrinkage (ranging from 0.47 to 1.44 %), water absorption (between 10.87 and 15.47 %), and flexural strength (ranging from 3.82 to 8.72 MPa). Originality. The results of the research into the use of mining waste from the marble quarry of Oued El Aneb under different firing temperatures has made it possible to substantiate the effectiveness of producing high-quality terracotta bricks that meet industrial requirements. Practical velue. The technical properties (physical and mechanical) of the terracotta materials produced from waste raw materials, particularly firing shrinkage, water absorption, and flexural strength, demonstrate the effective valorization of clay waste from marble extraction at Oued El Aneb.