Electrochemical recycling of recycled concrete powder: Selective recovery of calcium and silica to enable sustainable construction materials

Zheng Fang; Guangqi Xiong; Zongxuan Shao; Shuai Zhou; Guangfeng Ou; Lei Liu; Michio Suzuki; Chong Wang; Yuya Sakai

Resources, Environment and Sustainability (Dec 2024)

Electrochemical recycling of recycled concrete powder: Selective recovery of calcium and silica to enable sustainable construction materials

Zheng Fang,
Guangqi Xiong,
Zongxuan Shao,
Shuai Zhou,
Guangfeng Ou,
Lei Liu,
Michio Suzuki,
Chong Wang,
Yuya Sakai

Affiliations

Zheng Fang: College of Materials Science and Engineering, Chongqing University, Chongqing 400045, China; Institute of Industrial Science, The University of Tokyo, Komaba 4-6-1, Meguro-ku, Tokyo 153-8505, Japan
Guangqi Xiong: Department of Civil and Environmental Engineering & Research Centre for Resources Engineering towards Carbon Neutrality, The Hong Kong Polytechnic University, 999077, Hong Kong, China
Zongxuan Shao: Institute of Industrial Science, The University of Tokyo, Komaba 4-6-1, Meguro-ku, Tokyo 153-8505, Japan
Shuai Zhou: College of Materials Science and Engineering, Chongqing University, Chongqing 400045, China
Guangfeng Ou: Institute of Industrial Science, The University of Tokyo, Komaba 4-6-1, Meguro-ku, Tokyo 153-8505, Japan
Lei Liu: Engineering Research Center of Nano-Geomaterials of Ministry of Education, China University of Geosciences, Wuhan 430074, China; Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China; Laboratory of Advanced Mineral Materials, China University of Geosciences, Wuhan 430074, China; Institute of Industrial Science, The University of Tokyo, Komaba 4-6-1, Meguro-ku, Tokyo 153-8505, Japan; Corresponding author at: Engineering Research Center of Nano-Geomaterials of Ministry of Education, China University of Geosciences, Wuhan 430074, China.
Michio Suzuki: Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo, Tokyo 113-8657, Japan
Chong Wang: College of Materials Science and Engineering, Chongqing University, Chongqing 400045, China
Yuya Sakai: Institute of Industrial Science, The University of Tokyo, Komaba 4-6-1, Meguro-ku, Tokyo 153-8505, Japan

Journal volume & issue: Vol. 18
p. 100182

Abstract

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Rapid urbanization produces billions of tons of concrete waste annually, with recycled concrete powder (RCP) posing significant challenges due to its high porosity and limited reusability. To overcome RCP’s inherent limitations and maximize resource utilization, we developed a novel “Recycled Concrete Powder Electrolyzer” for selective recovery of key components. This electrochemical method efficiently extracted Ca2＋ ions from RCP, achieving a 96% calcium extraction efficiency comparable to acid leaching. The process produced high-purity portlandite (94% purity; 65.58% yield) with crystal sizes below 30μm, ideal for cement manufacturing, while also recovering fine sand powder and silica-containing products. A Ca(NO3)2 electrolyte enhanced Ca2＋ migration and prevented membrane fouling, resulting in lower energy consumption compared to the NaNO3 system. By converting RCP into a carbon-free cement precursor and recovering valuable components, this approach demonstrates the feasibility of transforming problematic waste into sustainable construction materials. It offers a circular economy solution for concrete waste recycling, reducing landfill burden while providing a low-emission alternative for cement production.

Published in Resources, Environment and Sustainability

ISSN: 2666-9161 (Online)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Geography. Anthropology. Recreation: Environmental sciences; Technology: Environmental technology. Sanitary engineering: Environmental effects of industries and plants
Website: https://www.journals.elsevier.com/resources-environment-and-sustainability/

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