A congratulatory letter was sent on May 14 to Musonoi project by Metorex of Jinchuan Group, the Employer, for the successful breakthrough between the main shaft and 1# air return shaft on 400mL, in which the Employer extended sincere gratitude and respect to those who have stood fast to their post and striven to move ahead in spite of all challenges and difficulties.
Ground condition on 400mL features great complexity, with broken rock and high risk of inrush at certain areas. To eradicate such risk, by upholding the principle of “cover drilling prior to development works”, the project established a forecasting mechanism for understanding geological conditions beforehand through carrying out cover drillings. Thereby, the project overcame all adverse factors imposed by water inrush (20m3/h at main shaft and 45m3/h at 1# air return shaft), realized gyroscopic orientation survey with Leica total station, and ensured precise connection development through observation set, all together laying a solid foundation for later successful breakthrough.
Meanwhile, under the support of JCHX Overseas Division, advance equipment such as BM282 and BM281 jumbos, ST1030 LHDs and 20t trucks were mobilized, transported to UG faces in semi-knockdowns, assembled and successfully commissioned to facilitate efficient construction, to promote full-scale mechanization and to advance stable development progress.
Besides, to enable rock hoisting through the old shaft, the plan of change-over of hoisting system was adjusted, which significantly reduced cycle time. Disposable busbar and 4.3m rod were applied, contributing to the achievement of 150m monthly footage.
