A complex of sub-vertical skip shaft (no direct access to the surface) was commissioned at the 'Internatsionalny' mine of ALROSA Mirny Ore Mining & Processing Plant, designed to deliver ore more efficiently from deep workings. It will allow to optimize the scheme for issuing kimberlite ore and reduce the costs of technical and material resources.
The construction of the blind skip shaft complex began in 2013. The complex includes a shaft, a lifting machine, two mill holes, two bunkers, a conveyor line, as well as skip loading and unloading complexes. At present, the blind skip shaft is traversed in elevations from -832 m to -525 m. It is designed to lift the rock mass from deep levels to the main skip shaft, through which the ore is then delivered to the surface.
"Earlier, transportation of ore from the deep workings of the mine was carried out by underground dump trucks. For this they had to overcome up to 4 km, which took about 40 minutes only in one direction. The length of transportation of the rock mass to the commissioned blind skip shaft is 300 meters. This simplifies the delivery of rock mass by dump trucks, reduces the costs of technical and material resources. This shaft will transport up to 950 tons of ore per day,” noted ALROSA Chief Engineer Andrey Cherepnov.
Currently, the possibility of deepening the blind skip shaft to a mark of -950 m is being considered.
The 'Internatsionalny' mine was put into operation in 1999. As of the beginning of 2018, the ‘Internatsionalny’ mine reserves of diamonds according to the standards of the State Commission for Mineral Resources are 51.3 million carats. Approved stocks of the ‘Internatsionalnaya’ pipe are characterized by a high content of diamonds in the ore, an average of about 7.3 carats per ton. Expected completion date of the deposit is 2033.