Underground mining

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As underground mining , the mining and underground mining , it refers to the production of underground cavities underground , so in the upcoming mountains . In underground mining, raw materials are extracted that occur in deeper deposits . These are raw materials such as coal , salt and potash salt , ores , hard rock and clays .

history

Underground mining and the development of modern man are closely linked. Underground mining already existed in the Stone Age . Archaeological finds from the 1984 date the Flint mine of Abensberg-Arnhofen on 5500 v. Flint was mined from about 8 meters deep shafts . The work was done with primitive tools that the Stone Age miners had previously made from deer antlers. When a shaft was dismantled, a new one was sunk a few meters further and the old one was filled with the spoil from the new one. This process represents the transition from open-cast mining to underground mining. The tunnel construction is around 3000 years old, and ore was mined at that time by means of fire . About 2000 years ago, under Emperor Claudius , a tunnel was driven to drain Lake Fucin . The first underground pits date from the 16th century. The Fugger pits near Kitzbühel reached a depth of 880 meters.

Development of the deposit

In underground mining, the differences lie in the orientation of the deposit . There are two ways of developing the deposit by means of underground mining, tunnel construction (also known as tunnel mining) and development via shafts . The depth and shape of the earth's surface are decisive for the type of development.

A tunnel is built in hilly terrain or in the mountains. To this end, horizontal, gently sloping tunnels are in the mountain ascended one of which is exploited from the deposit. The tunnel construction is not suitable for deposits that are located below the valley floor. In isolated cases, regular excavation is also carried out below the bottom of the tunnel through tunnel excavation, in which case the conveyed material must be lifted using conveyor belts and the pit water must be lifted using pumps .

In developing the deposit via shafts are first seigere or slanted wells up into the reservoir or in the vicinity geteuft . The deposit will then be aligned with main lines and crosscuts , after which the mining areas will be prepared . The miner describes the underground operation carried out in this way as civil engineering . Finally, with an appropriate reduction method , the natural resources mined and for further processing into days promoted. The mining methods are based on the natural resource (raw material), the deposit ( seam-like , tunnel-like or massive), and the stability of the mountains. Accordingly, special mining methods are used, for example, room and pillar , longwall mining , Weitungsbau or Teilsohlenbruchbau .

Different depths

Depending on the depth , a distinction is underground mining between the days the Middle mining the, near-surface mining and deep mining . There are different perspectives in the respective technical sources about the exact limit up to which depth which underground area applies. The lower the depth at which mining activities take place or have taken place, the greater the risk of day breaks .

When days Middle mining workings are designated whose outer layer is less than 30 meters. Due to the small amount of rock overburdened here, no stable condition will develop after the end of mining. These cavities are then not stable in the long run. Although the cavities created by mining remain in place for the time being, zones of degradation or loosening gradually form in the edge areas of the cavities . When day near the mining deposits were mostly over tonnlägige accessible bays. For ventilation called were similar to the tunneling mostly small bays, light holes , geteuft. A mining method that was used very often in near-day mining to extract irregularly occurring deposits with little thickness was the duck- hole mining .

Near- surface mining is a mine with a surface layer of at least 30 meters and a maximum depth of up to 100 meters. Here the surface of the day subsides frequently. There is a sustained daybreak probability. In the case of near-surface mining, the deposits are accessed via both seigere and ton-length shafts. For lignite seams with a thickness of up to twelve meters, tummel construction was very often used.

Deep mining , often also called civil engineering , takes place in depths greater than 100 meters. At this depth there is sufficient rock overburden. The overburden reduces gradually when the overburden is no longer supported. After the end of the subsidence phase, there are only minor effects on the surface area. Thus, there can be no day breaks. In deep mining, the deposits are usually accessed via seigere shafts; in some mines, the raw materials are extracted via piles of conveyor belts. The mountains usually have a rise between 9 and 15 gons and a length of several kilometers.

Problems

The underground mining usually requires the creation of heaps and thus leads to a consumption of landscape . Extensive subsidence can occur on the surface of the earth and this can lead to mountain damage . Underground mining can also cause the lowering of the water table and the pollution of surface water. Another, far greater risk arises from near-surface and near-surface mining. Insufficiently secured underground cavities can cause the overburden to collapse, which then leads to a break in daylight . In the case of old, no longer used ( discarded ) manholes, the manhole may break if the backfill is insufficient . There is a risk of personal injury through these old, no longer used pit structures.

Individual evidence

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  2. ^ Carl Hellmut Fritzsche: Textbook of mining science. Second volume, 10th edition, Springer Verlag, Berlin / Göttingen / Heidelberg 1962, p. 377.
  3. a b Günter Pilarsky: Economy at the raw material drop . The battle for the most important mineral resources, Springer Fachmedien, Wiesbaden 2014, ISBN 978-3-658-00362-3 , pp. 101-102.
  4. ^ Heinrich Otto Buja: Engineering handbook mining technology, deposits and extraction technology. 1st edition, Beuth Verlag GmbH Berlin-Vienna-Zurich, Berlin 2013, ISBN 978-3-410-22618-5 , pp. 209, 514-515.
  5. Gerhard Girmscheid: Construction and construction in tunnel construction. 2nd edition, Ernst & Sohn Verlag for Architecture and Technical Sciences GmbH and Co.KG., Berlin 2008, ISBN 978-3-433-01852-1 , p. 2.
  6. a b c Dieter D. Genske: Engineering geology basics and application. Springer Verlag, Berlin Heidelberg 2006, ISBN 978-3-540-25756-1 , pp. 414-416.
  7. a b Bavarian State Ministry for Economics, Infrastructure, Transport and Technology (ed.): From mines, huts and hammers. April 2008, pp. 9-13.
  8. ^ A b Heinrich Veith: German mountain dictionary with evidence. Published by Wilhelm Gottlieb Korn, Breslau 1871.
  9. Emo Descovich: Technique of the depth. 5th edition, Franckh'sche Buchhandlung, Stuttgart.
  10. a b c Friedrich Freise: Alignment, installation and mining of hard coal deposits. Verlag von Craz & Gerlach, Freiberg in Sachsen 1908, p. 3.
  11. a b c d Ernst-Ulrich Reuther: Introduction to mining. 1st edition, Verlag Glückauf GmbH, Essen, 1982, ISBN 3-7739-0390-1 .
  12. ^ Carl Hellmut Fritzsche: Textbook of mining science. Second volume, 10th edition, Springer Verlag, Berlin / Göttingen / Heidelberg 1962.
  13. Joachim Huske: The coal mine in the Ruhr area . 3rd edition, self-published by the German Mining Museum, Bochum, 2006, ISBN 3-937203-24-9 .
  14. ^ A b Walter Bischoff, Heinz Bramann, Westfälische Berggewerkschaftskasse Bochum: The small mining dictionary. 7th edition, Verlag Glückauf GmbH, Essen, 1988, ISBN 3-7739-0501-7 .
  15. Practical note: Is the subsoil safe? - The old mining situation in North Rhine-Westphalia ( Memento from August 16, 2010 in the Internet Archive ) (PDF; 244 kB).
  16. a b c d Günter Meier: To determine areas of influence caused by old mining . In: 9th Altbergbau-Kolloquium . Leoben 2009, VGE Verlag GmbH, Essen 2009.
  17. a b c d Melanie Niese: Dealing with mountain damage in the southern Ruhr area. Dissertation at the Ruhr University, Bielefeld 2010, pp. 60–62.
  18. Mark Mainz: Geotechnical model presentation for the assessment of hazardous areas of the old mining and shaft protection areas in the Aachen coal mining area . Approved dissertation from the Rheinisch-Westfälische Technische Hochschule Aachen, Aachen 2007, p. 4, 134–135.
  19. a b Helmut Prinz, Roland Strauss: Engineering Geology . 5th edited and expanded edition, Spektrum akademischer Verlag, Heidelberg 2011, ISBN 978-3-8274-2472-3 , p. 454.
  20. a b Günter Meier: Modification of daybreak forecasts (PDF; 1.3 MB) (accessed on September 26, 2016).
  21. May, Stutzer, Eckardt; District group of Saxony of the Zwickau hard coal mining group (publisher): 75 years of joint work by the Saxon hard coal mines. Overview of the geological structure of the Ore Mountains coal basin, Zwickau, June 1936, pp. 205–206.
  22. ^ Wirtschaftsvereinigung Bergbau eV: The mining manual. 5th edition, Verlag Glückauf GmbH, Essen, 1994, ISBN 3-7739-0567-X