The Current Problem of Red Mud and Its Solution Strategies

Red mud is an industrial by-product produced in the aluminum industry. How to deal with the red mud has always been a global challenge. This study preliminarily analyzed the generation, hazards and utilization status of red mud, proposed solution strategies for promoting the efficient utilization of red mud and the sustainable development of related industries.

Keywords:Efficient utilization; Industrial development; Red mud

Red mud is an industrial by-product produced during the process of extracting alumina from bauxite. It is named so because it contains a large amount of iron oxide and appears red. Red mud has a strong alkalinity, with a pH value usually above 10 and sometimes even reaching 12 or higher. The main components in red mud include SiO₂, Al₂O₃, CaO, Fe₂O₃, Na₂O, as well as some heavy metals and rare earth elements. The production volume of red mud is extremely large. Generally, for every one ton of alumina produced, approximately one to two tons of red mud by-products are generated. The global storage of red mud has exceeded 4 billion tons, with an annual increase of about 120 million tons.

For a long time, there has been no effective way to deal with red mud. Red mud is mainly piled up to form large storage yards, which not only occupies excessive land resources, but also poses significant environmental pollution and ecological health risks. For instance, red mud dust particles cause air pollution, alkaline leachate pollutes water and soil, as well as causes corrosive damage to living organisms and heavy metal poisoning, etc. Poorly managed red mud storage yards may experience dam failure accidents due to heavy rain, geological disasters, etc. Such accidents have occurred in history, which can cause incalculable losses to the health of the surrounding people and the ecological environment. Therefore, red mud has become a stumbling block to the development of the alumina industry, and how to deal with it reasonably has drawn widespread attention from the international community.

Up to now, a large number of scientific researches and engineering practical applications have been carried out around red mud, including the use of red mud as an environmentally friendly adsorption material, producing the building materials such as bricks and concrete, the recovery of iron, aluminum and rare earth elements (e.g. scandium, gallium and cerium), as well as the ecological restoration of red mud soilization. These provide different ways for the comprehensive utilization of red mud, and even turns red mud from waste into treasure. However, the comprehensive utilization of red mud is not optimistic at present, with a rate of less than 15%. This is due to the fact that the historical accumulation of red mud is too large and constantly increasing, the existing technology still has problems such as immaturity, high cost and secondary pollution, and the social consumer group has doubts about its safety. Therefore, the consumption quantity is still lower than the production quantity.

How to get out of the predicament?
A. Constantly strengthening the research and development of innovative technologies. This includes: optimizing the process of producing alumina from bauxite, controlling the generation volume and properties of red mud from the source, and reducing its subsequent disposal and hazards; Exploring more scientific source classification control and storage methods for red mud to facilitate its subsequent secondary disposal and potential storage risks; Focusing on solving key technologies such as large-scale low-cost consumption and high-value utilization, and promote their efficient application.
B. Conducting comprehensive analysis of the market potential and exploring the potential demand for red mud products from different industries (such as construction, transportation, chemical engineering, agriculture, and environmental protection) in society to expand the application channels and scope and promote its market-oriented development. Strengthening the construction of demonstration industrial projects, especially cultivating some key enterprises of red mud products to play a leading role, drive the industrial innovation, promote the comprehensive utilization of red mud to form a new industry, and build a new pattern of red mud industrial development.
C. Establishing complete systems of policy support, government supervision and industry standards. For example, increasing the preferential policies in terms of finance, taxation and finance for the red mud industry; Improving the law enforcement and supervision systems for different links such as the generation, storage, transportation and utilization of red mud to ensure that there are laws to follow and strict law enforcement; setting up quality standards, production process standards, pollution control standards, etc. for comprehensive utilization products of red mud to provide guarantees for the healthy development of the red mud industry.
D. Carrying out international cooperation and exchanges. How to effectively deal with red mud is a common problem faced by the world. Through conducting cross-border scientific research joint efforts and sharing experiences among multinational enterprises, It can achieve twice the result with half the effort. At the same time, efforts should be made to promote the formulation and mutual recognition of international standards, and enhance the cross-border trade and international competitiveness of red mud comprehensive utilization technologies and products.

This study was supported jointly by the Guizhou Provincial Key Technology R&D Program (QianKeHe Support [2023] general 097), the Sixth Batch of Guizhou Province High-level Innovative Talent Training Programs (ZhuKeHeTong-GCC [2022]001).