The tailings collaborative filling technology aims to treat open-pit pits and underground voids through tailings filling, achieving the recycling of tailings. The specific operation includes transporting tailings through a filling system to open pits and underground voids for filling, while considering the strength, stability, and spatial distribution characteristics of the filling material. In addition, drainage technology is also crucial. By setting tailings filling retaining walls and filter pipes at the bottom of the open pit corresponding to the top of the first and middle empty areas during the underground transition period, groundwater can be diverted to the drainage system for recycling, reducing drainage costs and minimizing the risk of flooding accidents.

Utilizing modern measurement and information technology to obtain three-dimensional spatial information of open-pit pits and underground voids, providing accurate data support for the design and construction of tailings filling. This includes the use of technologies such as drone aerial photography, laser scanning, and 3D modeling to accurately measure and model open pits and underground voids, forming 3D digital models for subsequent analysis and calculation.


Based on the fluid Froude similarity criterion and the characteristics of non-uniform tailings filling bodies, an improved tailings filling strength calculation method is proposed. By conducting similar model slurry filling tests and on-site in-situ sampling mechanical tests, the spatial distribution characteristics of the strength differences in tailings filling in empty areas are revealed. By combining theoretical analysis and numerical simulation, a strength calculation method considering the uneven characteristics of tailings filling strength is proposed, providing scientific basis for the design and construction of tailings filling.

In order to improve the efficiency of tailings filling and reduce costs, a lightweight filling retaining wall structure design is adopted. Develop an integrated process technology for the design, calculation, and implementation of lightweight retaining walls by constructing a three-dimensional model with optimized filling height and retaining wall construction position parameters. This technology not only improves the construction efficiency of retaining walls, but also reduces construction costs, while meeting the needs of tailings filling and closure.

In mines such as Shirengou Iron Mine of Hebei Iron and Steel Group Mining Co., Ltd., a demonstration project of clean technology for tailings filling in open-pit to underground mining of iron ore deposits with a capacity of 2 million tons per year has been successfully built. This demonstration project has formed a circular, sustainable, green, and clean production process for the comprehensive utilization of mining, beneficiation, and tailings resources. Through the application of tailings filling technology, the recycling of all tailings in the mine has been achieved, reducing the costs of land acquisition for tailings ponds and comprehensive utilization of tailings, significantly improving economic and environmental benefits. This successful case provides valuable experience and technical support for other similar mines.