Hundreds of meters underground in Anshan, Liaoning, a silent technological revolution is rewriting the history of China’s mining construction.
Faced with world-class problems such as ultra-deep shafts and complex geology, Xi’anshan Iron Mine – the largest single underground iron mine in China – relied on two domestic boring machines “Cornerstone” and “Steel Spine” to not only successfully overcome technical restricted areas, but also increase construction efficiency by 3 to 5 times while significantly reducing safety risks.
This breakthrough marks China’s key leap from following to leading in the field of deep earth engineering equipment.
The Xi’anshan Iron Ore Project is a major national mineral resource guarantee project with a total investment of 22.9 billion yuan, retained resource reserves of 1.3 billion tons, and a designed annual mining capacity of 30 million tons of iron ore. It is planned to be completed and put into operation by the end of 2027.
However, its geological conditions are extremely complex: the excavation line spans long, and there are multiple challenges such as large longitudinal slopes, small radius turns, and interweaving of hard rock and soft rock fracture zones. The traditional drilling and blasting method is difficult to make progress here.
The “Cornerstone” responsible for opening up the main underground horizontal transportation channel is the first domestic hard rock TBM boring machine for mine tunnels.
This equipment is 188 meters long, has an excavation diameter of 7.03 meters, and weighs 1,200 tons. It was jointly developed by Anshan Iron and Steel Mining, China ENFI, China Railway Tunnel Bureau and other units. It has filled the gap in the construction of full-section hard rock tunnel boring machines for domestic underground iron mines.
In terms of efficiency comparison, the traditional blasting method can only achieve 60 to 80 meters of footage per month, requiring more than 40 people to work together; while the “Cornerstone” can achieve 300 to 400 meters of footage per month, requiring only 10 people to operate, and the efficiency is increased by 4 to 5 times.
In terms of safety improvement, the equipment simultaneously tightens the cave wall through the main and auxiliary support shoes to prevent the surrounding rock from collapsing, effectively cope with the soft rock fracture zone, and significantly reduce safety hazards such as landslides.
Since its launch in December 2023, the “Cornerstone” has completed 5,420 meters of auxiliary ramp excavation.
Dangerous situations such as the cutterhead jamming were encountered during the construction, but the team debugged and recovered through the “one danger, one strategy” plan, which highlighted the stability of the equipment in complex geology.
The “Steel Spine”, which specializes in thousand-meter deep vertical shafts, is the world’s first thousand-meter shaft hard rock full-section boring machine.
Led by Railway Construction Heavy Industry and developed in conjunction with 10 units including the University of Science and Technology Beijing, it completed the 1,004-meter tunneling task and built the world’s first thousand-meter-deep vertical shaft constructed using the full-section boring machine method.
Designer Ding Zhangfei said at the construction site: “The shaft is the throat of the deep earth. The traditional drilling and blasting method is slow and dangerous. ‘Drilling a well without going down’ is the dream of generations of well builders.” The technical team overcame three core difficulties: innovating the cutterhead configuration, drawing on the principle of “pencil sharpening”, changing the cutterhead from a V-shape to a W-shape, and optimizing the hob inclination angle.
, to solve the problem of hard rock excavation equipment loss; the intelligent slag discharge system refers to the keel waterwheel principle and develops a vertical slag discharge system, equipped with a 360° annular slag receiving device, with a maximum slag output of 120 cubic meters per hour; the suspended support technology adopts a cast-in-place concrete support solution to achieve non-interference between excavation and support, turning high-risk underground operations into standardized construction.
This achievement has been selected as one of the top ten state-owned enterprises in 2025, and won the Geneva International Invention Patent Gold Award.
Technological breakthroughs not only rely on hardware, but also benefit from the empowerment of smart management platforms.
Technologies such as the Internet of Things, AI intelligence, and digital twins are deeply embedded in the entire construction process. The intelligent command center uses global sensors and high-definition imaging systems to achieve millimeter-level precise control of the 773-meter underground working surface.
In terms of data integration, the platform has built a digital three-dimensional model that integrates mining, geology, engineering, safety and other fields, and displays the details of 8 shafts with an average depth of 700 meters, 6400 meters of auxiliary ramps, and equipment operating parameters in real time.
In terms of collaborative efficiency, it breaks the data barriers between traditional project participants and enables efficient collaboration among construction, design, construction, supervision and other parties on the same platform.
This system reduces safety risks by 60% and increases construction efficiency by 35%, truly realizing “less manpower underground, automation on the ground, and intelligent dispatching.”
The successful application of Xi’anshan Iron Mine has a significance far beyond the construction of a single mine.
It provides hard-core support for the country’s iron ore resource supply guarantee and helps reduce iron ore’s dependence on foreign countries.
At the same time, the project has authorized and applied for 41 patents and formulated 2 industry standards, setting a technical benchmark for deep underground resource development.
From the horizontal breakthrough of the “Cornerstone” to the vertical breakthrough of the “Steel Spine”, China’s equipment manufacturing has demonstrated its technological dominance under extreme working conditions.
Enterprises such as China Railway Construction Heavy Industry have promoted the export of similar equipment to Macau, Türkiye, Italy and other projects, demonstrating their international competitiveness.
As the development of deep underground resources becomes a global trend, the practice of Xi’anshan Iron Mine provides a replicable Chinese solution for the future utilization of underground space.
