On 1 Jun 2020, successful breakthrough was achieved for waste pass at De’An Project. By then totally 5 raises with an accumulated depth of 430m were successfully completed and handed over to the owner with good quality.
Located in Pengshan woodlands, Jiujiang City, De’An Project was a new project awarded to JCHX in 2019. The scope of work mainly comprises of pilot hole drilling and reaming of raises and ore/waste passes (φ 3.0m, φ 2.5m, φ 1.4m), including without limitation to raise boring machine erection, pilot hole drilling, reaming head installation, and reaming work.
Labor and work plan were challenged due to tight construction schedule. However, best efforts were given from top down to meet key milestones and ensure the work quality.
In order to minimize the cost of machine transportation, two raise boring machines, respectively LM-120 and CY120 were mobilized for the work, and tasked with different works based on their different features and specifications.
No.1 Crew completed mobilization of labor and equipment (CY120 raise boring machine) on 22 Nov 2019, and completed the construction of ore pass as well as waste pass on 203mL in Dec.
No.2 Crew completed mobilization of labor and equipment (LM-120 raise boring machine) on 22 Dec 2019, for constructing vent raise between 271-120mL, final breakthrough for the vent raise was completed in Apr 2020.
After completion of two raises at 203mL, No.1 Crew headed to construct waste pass between 271-120mL. The first drill was commenced on 27 Mar with a depth of more than 140 meters, and it only took 13 days to complete pilot hole, reaming and breakthrough. It took less than six months to complete the 5 raises, which largely improved underground ventilation and waste disposal process.
