On December 22, the project R&D and Demonstration of Biological Carbon Fixation Technology Coupled with Soil Structure Reshaping jointly developed by Yanbao Energy and CHN Energy New Energy Technology Research Institute successfully passed acceptance. By integrating microalgae carbon fixation, soil remediation and resource recycling, the technology achieved new breakthroughs in China’s mine ecological governance. It provided replicable and scalable systematic solutions for ecological restoration of similar mines and regions.

The project focused on the high-efficiency carbon fixation and ecological restoration functions of microalgae. The research team leveraged microalgae’s characteristics, including high photosynthetic efficiency, strong adaptability, rapid reproduction and excellent carbon fixation capacity. It used raw water from coal mine pits and carbon dioxide from agricultural and animal husbandry solid waste as culture substrates. The team built a tripartite technical system of “microalgae carbon fixation—mine pit water purification—soil regeneration”, achieving the coordinated advancement of carbon emission reduction and ecological restoration.

Direct ecological restoration tests without topsoil covering were conducted on the sandy waste dumps of Baorixile Mining Area. Traditional restoration methods required 0.3–0.5 meters of soil covering, with high costs and large consumption volume. By spraying microalgae biological soil remediation agent, the vegetation coverage in the 2,100-square-meter test area increased by 38–54%. Soil moisture content rose by 14–85%. The total soil organic carbon content increased by up to 613.2%. This significantly improved soil structure and water-fertilizer retention capacity. It provided a new path for ecological restoration in arid and soil-deficient regions.

Meanwhile, the project also achieved resource recycling in the mining area. Mine water inflow was used for microalgae cultivation. During growth, microalgae absorbed pollutants including nitrogen and phosphorus in water and immobilized heavy metals, effectively purifying water quality. The restored vegetation system continued to perform carbon sink functions, enhancing the carbon fixation capacity of terrestrial ecosystems, and forming a holistic restoration and carbon cycle model of “water—soil—vegetation”.

The successful testing and practical application of the project not only improved the land utilization value and environmental quality of the mining area, but also provided feasible technical solutions for China’s ecological civilization construction and the practice of carbon peaking and carbon neutrality goals. It marked that mine ecological restoration is striding forward toward resource-oriented, systematic and low-carbon development.