Broken structure

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Mining operation in the quarry field
Bruchbau (illustration from the beginning of the 19th century)

As caving is known in mining , a mining method that is applied to so-called residual pillars that after completion of mining have remained still stand and still have sufficient strength in recovering. The method is also used for partially penetrated deposits .

Basics

The miner differentiates between a standing break and a living break. When an upright break that takes rock mass one the original position and is only through crevices torn and columns that have arisen as a result of breaking. In the case of a living fracture, the rock mass is splintered into individual pieces, so that the rock mass is no longer in its original position. Due to the excavation, the hanging wall will be thrown open as planned after the dismantling. The cavities created by the extraction of the mineral wealth are to be filled by increasing the volume of the debris created when the hanging wall collapsed. This measure creates a new abutment for so-called main hanging people. The miner calls the line at which the hanging wall layers tear off. A distinction is made between two main types of fracture construction, the floor fracture construction and the actual fracture construction. Other methods are broken block construction and crosscutting partial base pile construction. In addition, quarry construction is used as a form of hanging wall treatment . The reinforced quarry structure in Altenberg in Saxony resulted in a massive break in the pewter-hermaphrodite level, which caused the formation of the approximately 400 m tall Altenberger Pinge .

Floor break construction

Partial break construction

The floor break construction is also known as partial floor break construction and is a universal mining method. The mining process is used to dismantle mighty, steeply upright sticks and bearings whose masses no longer have sufficient strength. But also to work with large expansions. The broken storey building is in certain areas similar to the pier building . The difference with the pillar method is that the pillars not the Etagenbruchbau between ridges and sole are, but the deposit as such forms the boundary. There are two different methods, the application of which depends on the nature of the deposit. In the case of plate-shaped deposits, the sites are brushed or driven across. Crossed locations are generally better because they create more win points rather than as long locations. This method is mostly used on fragile rock. Another method is the targeted breaking of the higher masses through local operation. In the process, new locations are obtained, which then go into the actual quarry.

The partial soles are dismantled from top to bottom. After one level or part of the floor has been dismantled, the next lower one is dismantled. Thus, the degradation is staggered downwards and the lowest partial sole holds the entire fracture offset above itself. With this procedure, the deposit can be fully exploited. When building a broken storey, one first drives several places and then the pillars in between are won. The roof, which remained in place due to the higher floor, is also won over. The pillars and levitation are weakened by so-called thin shooting until the remains of the piers collapse under the pressure on the hanging wall. At the same time, the upper pile rolls down, from which ore chunks can then be extracted. Where it is necessary for the purpose of stabilization, the cavities that arise when the piers are dismantled are filled with lean concrete from the respective upper sub-base.

The mining method is still used today as a partial break because it does not place great demands on the adjacent rock and the mineral. It is also relatively independent of the collapse of the deposit. In this mining process, the necessary operational concentration is achieved through the use of high-performance LHD devices. The extraction is achieved by means of drilling and blasting work, the blasted debris is picked up and removed using LHD devices. The debris is conveyed to the bottom through previously created roll holes . Here the rock is transported on by conveyor belts.

Actual broken structure

The actual quarry construction is not a special mining method, especially since the floor break construction merges into the actual quarry construction. Since the actual quarry is more of a construction in broken masses, the extraction of lignite is also referred to as quarrying . In the hard coal mining industry in the 19th century the carpentry was stolen from the mining industry , which caused the baked-on finest coal to break in in the mighty hard coal seams. In some mines this process was also referred to as quarrying. The actual quarrying was also used in some mines with storeys . Due to previous expansion or multi- storey buildings in mighty deposits, accidental and deliberate rupture of the disrupted masses occurs. These deposits were then processed further through quarrying and abortion work. If quarrying continues to be carried out regularly in a deposit that has already been worked on by multi-storey construction, the lowest level is started. To this end, a distance is in an arbitrary direction from the stable rock starting ascended to seek to bauwürdige masses. The track room had to be strengthened for this work in the area of ​​the so-called break point, the miners stood under the protection of the carpentry.

The fracture location or search location is used to drive into the already broken masses. In the process, as much broken mass is gained as falls into the search location by itself. In the past, some of the rock masses were extracted with hammer and iron work , and fire- setting was also used . As the loosened broken masses are brought in and then conveyed away, a cavity gradually forms in the area of ​​the face. When the loose masses no longer rolling by itself in the search location, by means of crowbars new break-ins created. As soon as such incursions occur, the miners again seek protection from falling rocks behind the track room. When no more masses could be loosened with the crowbars, the track room was converted into a so-called abortion room by means of further wood reinforcement and cover layers of tailings. As a result, the search location now became a push location. The miners stood under the protection of this abortion room to loosen up the masses with so-called abortions. Such shunt locations often stood for up to 12 years. If a standing fracture had formed, the carpentry did not have to be as stable as with a living fracture. Problems could arise if cavities formed behind the expansion.

Broken block construction

Block quarrying is a mining method that is used in massive ore deposits with little self-stability. The prerequisite for this, however, is that the deposits expand in all directions. Another prerequisite for using this mining method is the behavior of the ore with regard to its solubility from the deposit. So it is necessary that a hereingewinnbarer Erzblock be solved properly from its lateral surrounding area. Deposits that have such properties tend to collapse over a cavity excavated by miners. In addition, the released mineral must not stick together and have no tendency to self-ignite. For these reasons, block quarrying is only suitable for ore mining. The process as such is one of the cheapest mining processes. The costs for block quarrying are approximately the same as the costs that are required for opencast mining . The process was developed in the iron ore district on the Upper Lake. Here, the distances between the partial floors were increased when building partial floors. The alignment work was carried out in the winter months so that the broken ore could then be transported away by water in summer.

Before the deposit can be exploited with this extraction method, a considerable amount of input is required. The storage facility is to be subdivided into suitable fixtures . First of all, an extensive route network must be opened up for dismantling. This divides the entire deposit into individual blocks. In order to remove the ore later, discharge hoppers are created under the ore blocks at regular intervals. A deposit block is now bypassed with the alignment structures. With this procedure, the respective block is now released from the entire mountain range at its vertical boundary surfaces. Then the lowest disc of the ore block is removed by means of drilling and blasting . As a result, the abutments of the ore block are removed and the ore block collapses due to gravity. The ore extracted is conveyed through the discharge funnel to a loading station by means of truck loaders . After the bottom pane has been detached, the content of the block above collapses over the resulting cavity without additional effort. This recovered ore is also conveyed under the discharge hoppers to a loading station by means of loaders. Larger ore chunks are crushed by means of impact roll crusher before they are transported further, then the ore that has been extracted and crushed is transported away via conveyor systems.

Quarry construction for hanging wall treatment

The quarry is also used as a form of hanging end treatment in longwall and pillar construction. This is not a process for extracting the contents of the deposit, but a systematic lowering of the hanging wall. This planned collapse prevents a large space from remaining open after the usable deposit parts have been won. At the boundaries of this area, excessive stresses can form due to the rock pressure . Thus the hanging wall is brought quickly to tear that needs expansion as evenly as possible in a straight line removed. The expansion is expediently stolen from the center of the joint on both sides . The basic idea of ​​quarrying for the treatment of hanging walls is based on the idea of ​​building the deposit free without leaving residual pillars lying around . The aim is to prevent tension from building up. Until the 1950s, the applicability of the limit was broken in construction trending working direction with a dip of 33 Gon and floating working direction at 22 Gon. Using shield support , the limit is a striking mining direction at a dip of 55 gons and a floating mining direction at a dip of 40 gons. When Strebbruchbau the degradation can be both means of stem as well as dismantling lead .

Individual evidence

  1. ↑ a b c d e f Gustav Köhler: Textbook of mining science. 2nd edition, published by Wilhelm Engelmann, Leipzig 1887
  2. ↑ a b c d e f Albert Serlo: Guide to mining science. First volume, third revised edition, published by Julius Springer, Berlin 1878
  3. ^ Walter Bischoff , Heinz Bramann, Westfälische Berggewerkschaftskasse Bochum: The small mining dictionary. 7th edition, Verlag Glückauf GmbH, Essen 1988, ISBN 3-7739-0501-7
  4. ↑ a b c Karl Heinz Wennmohs: Loading and transporting in underground mining - a challenge for operators and manufacturers. In: Hossein H. Tudeshi (Ed.) AMS Online GmbH: Advanced Mining Solutions. 2012, No. 1, pp. 13-16
  5. ↑ a b c d e f g h Ernst-Ulrich Reuther: Textbook of mining science. First volume, 12th edition, VGE Verlag GmbH, Essen 2010, ISBN 978-3-86797-076-1 .
  6. ^ A b Fritz Heise, Fritz Herbst: Textbook of mining science with special consideration of hard coal mining. First volume, fifth improved edition, published by Julius Springer, Berlin 1923
  7. ↑ a b c d Carl Hartmann: Handbuch der Bergbaukunst. Second volume, Verlag Bernhard Friedrich Voigt, Weimar 1852
  8. ^ A b c Wirtschaftsvereinigung Bergbau eV: The mining manual. 5th edition, Verlag Glückauf GmbH, Essen, 1994, ISBN 3-7739-0567-X
  9. ↑ a b c d e Jens Steinberg, Detlef Hahn: Development of a continuous conveyor system. In: Ring Deutscher Bergingenieure eV (Hrsg.): Mining. 2008, No. 3, Makossa Druck und Medien GmbH, ISSN-No .: 0342-5681, pp. 130-131
  10. ↑ a b c H. Tudeshi: Extraction of solid mineral raw materials in underground mining. In: Hossein H. Tudeshi (Ed.) AMS Online GmbH: Advanced Mining Solutions. 2013, No. 2, pp. 6-13
  11. ^ A b c d Carl Hellmut Fritzsche: Textbook of mining science. Second volume, 10th edition, Springer Verlag, Berlin / Göttingen / Heidelberg 1962
  12. ↑ a b Heinz Kundel: coal production. 6th edition, Verlag Glückauf GmbH, Essen, 1983, ISBN 3-7739-0389-8 .
  13. ↑ a b c d Georg Spackeler, Waldemar May: Bergbaukunde . 8th training letter for dismantling II. Ed .: Main Department of Distance Learning at Bergakademie Freiberg. 2nd Edition. Deutscher Verlag der Wissenschaften, Berlin 1957, p. 8 / 13-8 / 20 .

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