Sinking work

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Sinking , sinking or stopping refers to the permanent maintenance of a route cross-section in mining , if this is reduced by the swelling of the rock in the route bottom. It serves to maintain or restore the necessary route height as well as the required gradient for the Wasserseige or the tracks for a track lift .

Basics

The expansion of the line using steel arches underground prevents the mountains from penetrating the cross-section of the line from the joints or from the roof. However, the sole is not protected during normal route expansion . This means that the mountains can swell into the free cross-section of the route at this point. On the one hand, the high rock pressure , which prevails in great depths , is responsible for the penetration of the rock into the free cross-section of the route ; This is particularly the case with stretches close to mining, where the mining effects ( convergences ) often lead to considerable cross-sectional reductions .

Sink cards

Since the swollen mountains constricts the free cross-section of the route, which hinders weather management and operations, the bottom of the route must be lowered in good time. Due to the high rock pressure at great depths, mining operations are constantly carrying out sinking work in the routes. To achieve an optimal Senkergebnis, has the total here swollen pile up for expansion bottom removed. Care must be taken that the extension segments are not lowered, as otherwise the stability of the extension is no longer guaranteed. If the extension is lowered, the extension can be deformed by the lateral rock pressure.

A distinction is made between manual sinking work and machine sinking work.

Manual lowering work

The manual lowering work is done with mining tools such as:

carried out.

With manual lowering work, the rock is first loosened using a jackhammer or wedge pick. The pile is then loaded into a conveyor with the shovel. If the shovel cannot pierce the pile directly, it is pulled directly onto the shovel or onto a loading plate by means of a scraper and then shoveled into the conveyor. The loading plate makes it possible to work more quickly with the shovel, as the shovel slides much better under the loosened debris on the plate than on the bottom.

Since this type of countersinking is very time-consuming and requires a lot of manpower, it is only used where the use of countersinking machines is not worthwhile or is not possible for reasons of space.

Machine sinking work

So-called countersinking machines are used for mechanical countersinking. There are two types of countersinking machines:

Which of the two lowering machines is used depends on various factors. With sinking machines, a multiple of the sinking work per unit of time can be achieved than is possible with manual sinking work. In addition, only a few miners are needed for these sinking operations.

Lowering work with the bottom loader

Bottom loader

Bottom loaders are used when the lowering work is carried out in parallel to normal operation. Due to their small width of less than 1200 mm and their compact design, they can be used almost anywhere, e.g. B. also in mining sections with conveyor belts. Electrically operated lowering loaders are predominantly used, but compressed air-operated lowering lowering loaders are also used occasionally. A bottom loader is equipped with a shovel located on a swivel arm, with which the loose rock is picked up and filled into the conveyor.

Both trolleys and continuous conveyors such as conveyor belts or scraper chain conveyors can be used as conveying means. In order to loosen the rock, special chisel tips are attached to the loader bucket, which work like jackhammers and literally smash the rock. In order to remove the pending debris, the loader driver drives the loader forward so that the loader shovel penetrates the pending lowering impact. As soon as the loader bucket is filled with debris it is positioned over the conveyor and emptied. With one bucket filling, 0.3-0.5 m³ of debris (sinkholes) can be removed in this way.

The lowering loader is usually brought to the job site in two transport units, the machine frame with chassis and hydraulic drive and, separately from this, the boom with shovel. The machine frame is usually designed in such a way that it can just about be transported with the monorail . As a third transport unit, the air hose and connections or electrical material and hydraulic fluid must be brought to the place of use. If the transport is not possible or too complex due to the dimensions, it must be lowered by hand.

Lowering work with the sinking helix

Due to its dimensions and the considerable installation effort, a sinking helix is ​​only used if a longer distance has to be lowered in which there are no installations such as conveyor belts. Also, the expansion must not be deformed to such an extent by the rock pressure that the route width is greatly reduced.

The heading machine is designed similarly to a roadheading machine. On the front part there are two rotating cutting heads that carry a variety of chisels. Since the cutting heads only require a few degrees of freedom, the boom on which they are located is only slightly mobile.

The bottom of the track is milled by means of the cutting heads and the loosened debris is transported to the center of the machine. There is a scraper chain conveyor via which the extracted rock is conveyed to a conveyor belt and then removed via this. The conveyor belt has to be continuously extended as the lowering operation progresses.

power

With manual lowering work, a lowering capacity of 4 to 10 m³ / man (shift) can be assumed. The use of lowering loaders becomes economical from 20 m³. In order to determine performance wages ( Gedinge ), the lowering capacity is usually offset against the pile height to be removed and the width of the bottom and stated in m / MS.

literature

Individual evidence

  1. ↑ Patent DE202004003217U1 03.06.2004 Self-advancing carrying device
  2. ↑ Information boards of the Heimat- und Geschichtsverein Sprockhövel eV ( Memento from October 12, 2007 in the Internet Archive )
  3. ↑ Lower loader information board. Heimat- und Geschichtsverein Sprockhövel eV ( Memento from October 12, 2007 in the Internet Archive ).
  4. ↑ Document WO 1992010646 Device for lowering routes in underground mining operations. PatentScope database of the World Intellectual Property Organization , Geneva.
  5. ↑ Patent DE3605448C2 08/20/1992 Device for the extraction of mineral substances
  6. ↑ Pocket book for mine officials, edition 1966, page 85, charging capacity 1964: 7.2 fm³ / day

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