Closer to the deepest ore deposits

Closer to the deepest ore deposits

Published 30 June 2008

PeBeKa has on this day started the drilling of shaft SW-4. It is one of the priority investments of KGHM Polska Miedź S.A. The shaft will allow for access to a new mining zone, the so-called Deep Industrial Głogów.
SW-4 is the thirtieth mining shaft built in the Copper Industrial Area. All were built by the PeBeKa Mine Building Company from Lubin. Total length of all mining shafts realized by the firm reaches 27 kilometers. The R XI shaft built for Rudna mine was, at the time of its construction, the deepest structure in Europe. The company’s achievements in horizontal mine works are just as impressive. The total length of underground galleries executed by the company is 650 kilometers.

- The firm has almost 50 years of experiences in mining works realizations. The first shaft for the Lubin Mining Facility was open for use in 1963 – says Ryszard Janeczek, president of PeBeKa Mine Building Company. – Since that time, our specialists have constantly honed their skills and acquainted themselves with new engineering technologies. PeBeKa has worked on many continents, realizing tunnel and underground tasks, we are also one of the main contractors of the Warsaw Metro. I am glad that we can put the experiences to use at the great constructions of the Copper Industrial Area.
Shaft SW-4 is currently the largest mining investment of KGHM Polska Miedź S.A. The shaft will function as part of the Polkowice-Sieroszowice Mining Facility structure. Its opening will allow access to hitherto unexploited copper ore deposits. Construction works at the shaft lying in Jakubowo, near Głogów, have been under way since 2005. Until fall 2006 PeBeKa has finished area reinforcement, infrastructure installation and freezing hole drilling around the planned drilling area. The company from Lubin holds a world-scale unique technology of ground freezing. It is mainly thanks to it that the copper mines of Lower Silesia could be built. The area’s Tertiary and Quaternary loose sands along with ground waters are inhospitable for mining works. Ground freezing helps avoid the most serious danger for the shaft – underground water leaks. The ground, frozen with saline under minus 30 degrees Celsius, makes for proper isolation from ground waters.

The freezing installation at the SW-4 construction site was finished in September 2007. Since that time aggregates with total power of 4 MW have uninterruptedly been freezing rock formation around the shaft. After seven months of this process, after the creation of an icy protective jacket, it will be possible to break into the watery rocks and start drilling the shaft. Simultaneously with the freezing, works were executed at the shaft square to provide complete investment infrastructure: a pithead, two powerful elevators for ore transport and turnstiles enabling installation of platforms in the shaft were installed, among other elements.
The extraction of first ore tray was the start of a many-month process of shaft deepening. In the frozen area down to roughly 650 m works will be executed with the use of a combine extracting the frozen rock. Lower than that, where special rules of freezing installation protection no longer apply, construction will be continued with the use of explosives. Planned depth of SW-4 is 1,244 meters, and its internal diameter will be 7.5 meters. Final casing, depending on the depth, will be made of cast iron tight rings 13 centimeters thick or monolithic concrete 60 cm thick.

After finishing, the shaft will act as a ventilation inhale shaft, supplying proper amounts of fresh air to the newly accessed areas in the Polkowice-Sieroszowice mine.

All rights reserved