Recently, at the Dunde Iron Mine in Hejing County, Xinjiang, located at an altitude of 3788 meters, the AT-2000 Raise Borer Machine successfully completed the construction of a drainage shaft with a depth of 214 meters and a diameter of 1.4 meters. This achievement not only fills the technical gap in the construction of large Raise Borer Machines under complex high-altitude geological conditions but also demonstrates the robust strength of Chinese mining equipment with the efficient performance of "completing a 214-meter reaming in 19 days."

The Dunde Iron Mine is located in the heart of the Tianshan Mountains, with harsh natural conditions and complex geological structures. The permafrost layer has a high ice content and rheological properties, making it a typical high-cold, high-altitude mining area characterized by "high altitude, poor terrain, poor transportation, and harsh climate." Equipment operation efficiency is easily affected by low temperatures, and the project's rock type is hard granite. The presence of permafrost further increases the risks to foundation stability and pilot hole operations.

Facing the construction challenges encountered in high-altitude operations, the Yier Technology after-sales team has formulated the following measures and plans:

1. Foundation Treatment: Building a "Safety Cornerstone" for Construction

The high-altitude permafrost layer is characterized by strong rheology and high ice content. Under equipment load and construction vibrations, it is prone to slow deformation, which may cause drilling rig foundation settlement and collapse of the working surface. Additionally, melting permafrost and rock fissures can cause "no water return and no cuttings return" phenomena during pilot hole construction, affecting drilling efficiency and safety.

To address the hidden dangers of the permafrost layer, the Yier Technology after-sales team first used excavators and loaders to clear the surface permafrost, then poured a 1-meter-thick concrete layer, embedding No. 30 national standard I-beams to form a solid and stable drilling rig foundation. This measure not only resists the impact of permafrost deformation on the equipment but also prevents collapse risks caused by surface erosion during subsequent construction, providing a solid guarantee for rig erection and drilling operations.

2. Technical Breakthrough: Ensuring Precision in Deep Shaft Construction

The project requires constructing a vertical shaft with a diameter of 1.4 meters and a depth of 214 meters from the 3788-meter level to the 3568-meter level. The rock type is hard granite. Due to large rock fissures, water seepage channels easily form between the concrete layer and residual permafrost. Rising water temperature and continuous erosion of the permafrost layer can cause small-scale collapses and gaps, leading to difficulties in water and cuttings return during pilot hole operations.

To address the difficulty in cuttings return during pilot hole drilling, the team implemented real-time monitoring of water return and performed "segmented grouting" on fissure sections, using high-pressure injection of cement slurry to seal gaps and ensure continuity of pilot hole operations. During the pilot hole phase, a "low pressure, high speed" "suspended drilling" technique was used, slowly grinding the rock to reduce drill bit deviation risk, effectively ensuring precision and laying the foundation for the subsequent 214-meter deep reaming.

3. Efficient Construction: Breaking Through 214 Meters of Reaming in 19 Days

The oxygen content at high altitudes is low (oxygen content decreases by about 10% for every 1000 meters increase in altitude), which easily causes power reduction in drilling rig engines and hydraulic systems, leading to insufficient power, increased fuel consumption, and reduced cooling efficiency.

However, in this project, the AT-2000 Raise Borer Machine demonstrated excellent adaptability: starting reaming on June 28 and successfully completing it on July 17, finishing the reaming operation in just 19 days with an average daily advance exceeding 11 meters, efficiently and excellently completing the 214-meter vertical shaft construction task.

4. Human-Machine Collaboration: Scientific Prevention and Control of Plateau Risks

At an altitude of 3788 meters, the reduced oxygen content can cause construction personnel to experience acute altitude sickness symptoms such as headaches, dizziness, and difficulty breathing, which can lead to life-threatening conditions like high-altitude hypertension and pulmonary edema. Intense exercise or overexertion can exacerbate physical strain, posing safety risks to construction.

To alleviate workers' acute altitude sickness, the project team formulated a "three-level adaptation plan": adopting a "machine replaces human" strategy during operations. The AT-2000 Raise Borer Machine has a high degree of automation, reducing manual handling and requiring only parameter monitoring, significantly lowering labor intensity and laying a solid foundation for plateau construction.

The successful construction of the AT-2000 Raise Borer Machine at the Dunde Iron Mine not only verifies the reliability of Yier Technology's Raise Borer Machine in extreme environments but also marks that our independently developed mining equipment has the capability to operate under complex high-altitude geological conditions. Yier Technology will summarize this experience to further optimize the adaptability design of high-altitude models, providing more reliable equipment and technical support for mineral resource development in the western region and plateau engineering construction.