POWER UP

摘要

Restructuring of the Polish mining industry forced mines to struggle to make a profit. Reductions in investment funds led to limiting works in vertical excavations. This resulted in more frequent use of sublevel systems. The excavation depth increases at a steady rate: on average 5-8 m/year. As a result, mining of sublevel walls made up 57% in 2008. In four mines, 100% of the output came from the sublevel excavation. In 123 longwalls, as many as 53 lay below 800 m, and in seven cases excavations were carried out below 1000 m.