Recently, exciting news came from the Chongli Zijin project site—Yier Technology's AT-2000T Bore Machine successfully completed the smooth breakthrough of a 100-meter inclined shaft at a 30° angle. The shaft deviated by just 97 centimeters, resulting in a deviation rate of only 0.97%, perfectly meeting the expected outcome!

This milestone achievement not only highlights Yier Technology's outstanding technical expertise in constructing inclined shafts under complex geological conditions, but also lays a solid foundation for the smooth advancement of subsequent tasks such as ore block extraction.

The inclined shaft construction for the Chongli Zijin Project is highly challenging, involving three different angles—60° (with a shaft depth of 48.85 meters), 42° (depth: 67 meters), and 30° (depth: 100 meters)—all of which are along-pulse shafts.

These inclined shafts provide critical pedestrian access and ventilation support for the mining block extraction, ensuring safe and efficient operations in the mine. The project is located in an area with complex geological conditions, characterized primarily by potassic altered rocks and silicified-potassic + altered rocks. The true thickness of the vein bodies ranges from 5.0 meters to 1.0 meter; however, the surrounding rock at both the roof and floor remains relatively stable, offering some favorable conditions for construction. At the same time, the intricate geology inevitably complicates the construction process, adding significant challenges along the way.

The entire construction process took 44 days, with each stage seamlessly coordinated and efficiently advanced. The rig-erection phase completed the foundation setup in just 3 days, securing valuable time for subsequent work. Drilling the pilot holes took 10 days, achieving an impressive average daily advance of 9 meters, showcasing highly efficient drilling capabilities. Installing the cutterhead was smoothly accomplished within a single day, perfectly preparing the site for the reaming phase. Reaming, the project's most critical and challenging step, lasted 30 days, with an average daily progress of 3 meters. The orderly connection and rapid advancement across all phases resembled the synchronized operation of intricate gears, ultimately leading to the successful completion and smooth breakthrough of the inclined shaft.

The foundation layout for the 30° inclined shaft is critical to construction, and ensuring the drill rig remains stable has become the primary challenge. To address this, the project team adopted a method of hardening and leveling the ground with cement, providing the drill rig with a firm, stable base plane. Additionally, they constructed a 60°-inclined frame and securely welded the shoe plate to the frame, guaranteeing that the drill rod maintains a precise 30° angle with the ground—thus offering the drill rig a stable, angle-based foundation for optimal operation.

Construction accuracy is the lifeline of inclined shaft construction, directly impacting the quality and safety of the project. During the recent 30° inclined shaft construction, the project team implemented a series of scientific and rigorous measures to ensure precision. They used laser levels to precisely position points—covering the four cardinal directions (north, south, east, and west)—as well as the center point of the drilling rig, providing a reliable benchmark for accurate alignment. After adjusting the machinery to a 30° inclination angle, they carefully aligned the laser level's beam (running north-south) with the center of the machine's gearbox and motor, guaranteeing perfectly straight vertical positioning without any deviation.

By aligning the center hole of the floating seal in the gearbox with the center point of the laser level, precisely determine the center position for the opening. Additionally, use the laser level's east-west beam to calibrate the machine’s placement, ensuring it remains relatively horizontal. If significant left-right deviations are detected, adjust using tire shims until the machine achieves a balanced, horizontal state. Once the machine’s alignment with the laser beam and its tilt adjustment have been confirmed as accurate, drill rig positioning is complete, guaranteeing high precision during construction.

Meanwhile, the drilling rig is securely fixed by anchoring through support frames, enhancing its stability during construction. This effectively prevents shaking or shifting of the rig caused by inclination issues, thereby ensuring both construction safety and quality. Additionally, during the process, a gentler inclination angle also has a noticeable impact on work efficiency and equipment performance.

During the reaming process of the 30° inclined shaft, the issue of muck removal became a major "obstacle." The Yier Technology team had previously implemented a specialized design for the cutterhead—carefully optimizing and utilizing components such as tie rods, stabilizing blocks, and muck-scraping plates. However, during actual construction, while natural muck discharge allowed small rock fragments to occasionally escape through the gaps in the cutterhead, most of the debris ended up falling and accumulating at the bottom of the shaft. This resulted in repeated crushing actions, frequent drill bit jams, and a significantly slowed penetration rate.

Facing this challenge, the project team conducted multiple experiments and practical trials, discovering that after directly discharging water through the site's pipes, the sediment accumulated at the bottom could be washed away by the water, enabling smooth borehole expansion while ensuring no residue remained inside the well.

When encountering hard rock layers, the excessive propulsion pressure causes the entire support frame to shift forward and deviate from the center point, resulting in a slower penetration rate. Fortunately, however, the carefully designed and properly selected equipment performed well under these challenging conditions, sustaining no substantial damage and maintaining a relatively stable operational state—thus providing reliable equipment support for the continuous advancement of construction work.

The equipment used in this construction project is the Yier Technology AT-2000T Bore Machine, a compact Raise Borer Machine specifically developed for domestic gently inclined shafts (with drilling angles ranging from 15° to 90°). The machine features a modular design and offers two transportation options: tire-based self-propelled movement or rail-guided traction. This design ensures convenient positioning and quick assembly/disassembly, making it better suited to meet the development needs of China's small- and medium-sized mines.

The successful breakthrough of the 30°, 100-meter inclined shaft in Yier Technology's Raise Borer Machine project for the Chongli Zijin Project is a testament to the wisdom and hard work of the entire Yier Technology team. Amidst challenging geological conditions, they relied on their exceptional expertise, meticulous approach, and innovative spirit to overcome formidable obstacles and achieve seamless completion—creating yet another engineering marvel.

We believe that in the future, Yier Technology will continue to uphold the philosophy of "surviving through quality, conquering the market with technology, and winning customers through service," relentlessly scaling new heights in innovation and making even greater contributions to the advancement of the mining engineering sector.