By rosebell
With the aim of completing excavation of a lithium ore transport tunnel in Chijiaoshan in Hunan, a TBM has broken through on the final rock face.
This 7.3km tunnel through complex geology in the Nanling Mountains was dug by TBM Longyuan.
As the world’s first TBM purpose-built for lithium mining, Longyuan has a diameter of 6.3m and a total length of 155m, and was designed to handle hard rock and challenging geological transitions, as China Railway Engineering Equipment Group (CREG) says.
A a wear-resistant cutterhead, steel arch erector, rock bolt drill, s well as asystems for floor preparation, side cutting, shotcreting, and material transport – enabling continuous, fully mechanised operations, are the options of this machine. whereas the entire route was excavated uphill at an average gradient of 5.7%.
Considering that the monthly advancement record of this project in September last year was 1,186m, which CREG says set a new global benchmark for hard rock mining tunnels, the TBM significantly improved excavation efficiency and shortened the construction timeline compared to traditional drill-and-blast methods.
While the planned date for completion of this tunnel was the end of August 2025, it was successfully delivered three months ahead of schedule.
