Title: Enhancing Reactivity of Calcined Clays for Sustainable Cement Production through Optimization of Rotary Kiln Parameters

Author(s): Abdelmoujib Bahhou, Yassine Taha, Yasmine Rhaouti, Mohamed El Amal, Rachid Hakkou, Mostafa Benzaazoua, and Arezki Tagnit-Hamou

Publication: Symposium Paper

Volume: 362

Issue:

Appears on pages(s): 738-762

Keywords: reactivity; clay; thermal treatment; rotary kiln; life cycle assessment; strength activity index

DOI: 10.14359/51742006

Date: 6/17/2024

Abstract:
The use of calcined clays as a substitute for traditional cement materials has the potential to significantly reduce the carbon emissions of the cement industry. However, for their widespread adoption and urgent need to feed the cement industry, it is essential to have a comprehensive understanding of the methods involved in processing these clays to ensure maximum reactivity. Thermal treatment of these clays induces chemical reactions that transform the combined materials into reactive pozzolan by eliminating hydroxyl groups from the clay structure, resulting in the activation of alumina and silica oxides. A commonly employed industrial method for activating these clays is through the use of a rotary kiln. With an optimal temperature profile and material retention time, rotary kilns play a crucial role in ensuring the production of high-quality calcined clays. This study aims to enhance control performance and achieve a highly reactive marl by optimizing the preparation process through three steps: (1) characterizing the raw materials, (2) optimizing the kiln parameters, and (3) conducting the life cycle assessment of the process. The reactivity of the calcined marl will be evaluated using the ASTM C1897 Standard Test Methods and the strength activity index.