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ORIGINAL RESEARCH article

Front. Mater.
Sec. Structural Materials
Volume 11 - 2024 | doi: 10.3389/fmats.2024.1461198
This article is part of the Research Topic Resource Utilization of Solid Waste in Road Engineering View all 13 articles

Study on the Strength Characteristics and Micro Mechanism of Modified Solidified Red Mud

Provisionally accepted
Ziyi Ding Ziyi Ding Yu Cheng Yu Cheng Lu Jin Lu Jin *Wentong Wang Wentong Wang Shiying Yan Shiying Yan
  • Shandong University of Science and Technology, Qingdao, China

The final, formatted version of the article will be published soon.

    The residue generated during the production process of alumina, known as red mud, is a type of solid waste. The engineering properties of red mud can be significantly enhanced through the modification and solidification using inorganic materials. This study primarily utilized red mud as the raw material, supplemented with fly ash, lime, and clay, to conduct a solidification experiment of red mud. Orthogonal tests with three factors of two ash ratio (ratio of lime to fly ash), two ash content (total lime and fly ash), and red mud types were designed to study the changes of different ratios and maintenance conditions, etc., on the engineering properties of red mud. In addition, the micro-mechanisms of modified red mud were investigated by means of XRF, XRD, SEM and EDX. The results show that for optimum moisture content, red mud types are the most important influencing factor and for maximum dry density, two ash content is the most important influencing factor. For strength characteristics, the optimum two ash ratio was 1.5:1, the optimum two ash content was 50%, and the optimum red mud types were 70% CRM (red mud made of Chalco Shandong Co., Ltd) mixed with 30% clay. The addition of lime, fly ash, and clay improves the temperature shrinkage coefficient of the red mud. Through the analysis of microscopic composition and structure, it can be seen that goethite (α-FeO(OH)) and magnetite (γ-Fe2O3) in the red mud reacted with the modified materials to generate crystalline aluminosilicate and amorphous hydrated silicate gel, and these products together with the original calcium carbonate (CaCO3), tricalcium aluminate (Ca3Al2O6) and garnet (Ca3TiFeSi3O12) in the red mud which have certain strengths enhance the structural strength of the modified red mud. The optimum ratio obtained from the combined test results was lime: fly ash: CRM = 30:20:50.

    Keywords: red mud, modification treatment, orthogonal test, engineering characteristics, micro mechanism Elgarahy, A. M., Eloffy, M. G., Priya, A. K., 814 Yogeshwaran, V., Yang, Z., Elwakeel, K. Z., Maldonado, E

    Received: 08 Jul 2024; Accepted: 26 Jul 2024.

    Copyright: © 2024 Ding, Cheng, Jin, Wang and Yan. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Lu Jin, Shandong University of Science and Technology, Qingdao, China

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