On August 28, the No. 3 return air shaft of the Xi'anshan Iron Mine project in Liaoning, the largest single underground iron mine project in China, was excavated to a depth of 773.2 meters underground. This is the first shaft of the Xi'anshan Iron Mine to complete excavation, laying the foundation for the project's drift (horizontal roadway) construction.

The Xi'anshan project is located in Tiexi District, Anshan City, and features 8 vertical shafts and 2 inclined shafts. The No. 3 return air shaft is the deepest underground vertical shaft of the entire project, with a net shaft diameter of 8 meters and a depth of 773.2 meters. The cumulative excavation volume is 1.23 million cubic meters, making it a major and difficult control project.

The geological conditions in the construction area are complex, with prominent sudden water inflow. After entering the site, the contractor optimized and adjusted the sequencing of each process, shortening the process transition time. The blasting design was optimized, raising the blasting utilization rate from 80% to 90%. In addition, the project team introduced digital construction into the traditional mining construction field. Using IoT technology and AI technology, they achieved linkage between data and drawings, ensuring high-quality shaft excavation and lining.

The Xi'anshan project is a key project of the national "Cornerstone Plan," with retained resource reserves of 1.3 billion tons. The Xi'anshan Iron Mine has 30 million tons of mixed iron ore and over 10 million tons of iron concentrate, with a cumulative excavation length of 92.8 kilometers, an excavation volume of 2.978 million cubic meters, and a support volume of 370,000 cubic meters. It is currently the single iron mine with the largest undeveloped resource reserves and the best endowment in China. The project practices the "Two Mountains" concept and, in line with the direction of deep mining, intelligent mining, efficient beneficiation, and green development, adopts an underground mining and transport construction scheme. Compared with traditional open-pit mining, it preserves the natural landscape of Xi'anshan to the greatest extent, reduces dust and soil erosion, and ensures that the surrounding environment is not damaged.