As a material with a 90% correlation to the national economy, aluminum oxide production generates highly alkaline waste residue—red mud. China has accumulated over 1.6 billion tons of red mud, occupying more than 120,000 mu of land and accounting for approximately 55% of the global total. Currently, annual red mud discharge increases by about 120 million tons, with a resource utilization rate below 10%. This poses environmental pollution and has become an urgent and pressing concern for governments at all levels and relevant enterprises. Therefore, comprehensive utilization of red mud represents a major key common technical challenge for the global aluminum industry. It has been included in the International Aluminium Institute (IAI) 2050 major research agenda, with major aluminum companies, universities, and research institutes worldwide conducting experimental and applied research. This project involves high technical difficulty and complexity. The team led by Distinguished Professor Chen Zhongping at our institute, in collaboration with Chinalco, Jingxi Tiangui Aluminum Co., Ltd., and Guilin University of Technology. After nearly a decade of collaborative industry-academia-research-application efforts, they have elucidated the phase transformation behavior of iron minerals and the reaction pathways of geopolymers in red mud. This breakthrough enables efficient recovery of high-value elements such as iron and gallium, achieving synergistic extraction of multiple metals and high-value utilization of bulk solid waste. The innovation significantly surpasses existing technological standards in both technical advancement and engineering application.

On August 23, 2025, the evaluation meeting for the project “Key Technologies for Large-Scale Value-Added Resource Utilization of Red Mud,” led by our institute, was successfully held in Nanning, Guangxi. Organized by the China Circular Economy Association, the meeting was chaired by Lü Zhengyu, Director of the Science and Technology Standards Department of the association. A panel of seven experts, including renowned professors and researchers from Beijing, Guangdong, Guangxi, and other regions, participated in the review session.

(Project Technical Evaluation Meeting Venue)

(Professor Chen Zhongping, Distinguished Visiting Professor, Presents Research Findings)

This project is led by Guangxi Jingxi Tiangui Aluminum Co., Ltd., in collaboration with an innovative consortium comprising Shenzhen University, Guilin University of Technology, Chinalco (Zhengzhou) Aluminum Co., Ltd., Guangxi Communications Investment Technology Co., Ltd., Wuhan University of Technology, Guangxi Nanbai Expressway Co., Ltd., Guangxi Baima Airport Expressway Co., Ltd., Guangdong Tongchuang Kexin Environmental Protection Co., Ltd., and Guangxi Zhuang Autonomous Region Environmental Protection Research Institute. Professor Chen Zhongping, a distinguished visiting professor at our institute, presented the research team's findings. The team conducted systematic closed-loop research encompassing theoretical analysis, experimental testing, and field implementation focused on key technologies for large-scale value-added resource utilization of red mud. This work yielded the following innovative outcomes:

1. Clarified the phase transition mechanism of hematite minerals in red mud from goethite to hematite, overcame the challenge of mismatching between strong magnetic separation of iron and alumina leaching, broke through the technical bottleneck of low iron recovery efficiency in traditional red mud processing, and developed a complete set of industrialized green iron extraction technology for red mud. This achieved an iron extraction yield of 30% and increased iron recovery rate from 19% to 40%.

2. Developed targeted enhancement resins for selective adsorption of gallium metal while synergistically recovering other valuable metals. Created technologies to eliminate organic impurities and other contaminants. Established a complete industrial-scale resin adsorption process for gallium extraction, enabling China to produce over 90% of the world's gallium metal. This supports the vigorous development of China's electronics and information industries as well as national defense and military sectors.

3.Pioneered the concept of near-zero red mud discharge. Developed key technologies including high-blend red mud geopolymer mix design, and created a series of road engineering materials centered on red mud-based cementitious materials. Established a complete industrialized technology suite for large-scale value-added utilization of red mud with fully independent intellectual property rights. Achieved major breakthroughs with red mud blending exceeding 60% and a 40% improvement in material performance, significantly expanding the scope of red mud resource utilization.

The above results have been applied on a large scale in Jingxi Tiangui Aluminum Industry, Aluminum (Zhengzhou) Aluminum Industry, Aluminum Corporation of China Guangxi Branch, Jingxi Green Source Technology and other units, as well as Guangxi Baima Airport Highway, Nanbai Highway Reconstruction and Expansion, Pingguo Aluminum Mining Highway, and mine and highway projects in Guangdong, Henan, Shandong and other places, with remarkable economic and social benefits. It has obtained 36 invention patents, published more than 30 high-level papers, 2 monographs and 3 standards.

Experts of the Evaluation Committee listened to the report of the project team, reviewed the relevant information, and after questioning, discussion and deliberation, the Evaluation Committee believes that the overall technical level of the project research results has reached the international leading level. This is a major breakthrough in the field of solid waste resource utilization, and an important progress in the field of green, low-carbon, soil and water restoration and sustainable development, which will lead the development direction of China in this field.