Bunker (mining)
In mining, a bunker is a mine or operational facility in which bulk materials such as raw coal, raw ore or mountains are temporarily stored (bunker) until they are returned for further processing above ground or in the exploited parts of the deposit .
Basics
In the case of underground conveyance using conveyor belts , disruptions have a detrimental effect on the conveying flow. These disruptions are often so serious that the complete dismantling comes to a standstill at times. In order to achieve a good flow of conveyance, it is therefore essential to build buffer options in the form of bunkers into the conveyance. Bunkers are also used to compensate for fluctuations in delivery. If bunkers are traversed by the entire flow of conveyed goods from the upstream conveying means, they are referred to as main terminal bunkers. There are also bunkers that are used when the conveying capacity of the downstream funds is insufficient. In the case of peaks in the feeder funds, it is then not possible for the downstream funds to cope with these peaks in funding. For this case, shunt bunkers are used to bunker the peaks.
Bunker types
In mining, a distinction is made between three types of bunkers: Seiger bunkers , blind shaft bunkers and inclined bunkers . The capacity of the respective bunkers is between 200 and 1500 cubic meters, sometimes even more. In order to avoid bridging or caking, the discharges of the bunkers must be designed accordingly. The discharge slope is designed in such a way that it has an inclination about 15 degrees greater than the natural slope angle of the bulk material. This also enables the material to be conveyed to be withdrawn quickly from the bunker.
Seiger bunkers are the most common bunkers. There are bunkers with round, angular or elliptical cross-sections, mostly a round cross-section is chosen. The walls of the Seiger bunkers are usually bricked. Concrete blocks, concrete or bricks are used as materials. So that the bulk goods do not stick, the wall is designed as smooth as possible. The minimum diameter of these bunkers is two to three meters. Large central bunkers can be accessed by means of a reel in the event of operational disruptions . They have a spiral chute as a means of conveyance; this is designed either as an inner or outer spiral chute .
Blind shaft bunkers consist of a separate part of a blind shaft . A brick or molded concrete wall is usually used as a partition wall. The masonry can be provided with steel lines for stiffening. In the case of blind manholes where the cross-section is insufficient, an additional run must be created. It does this by creating a side extension.
Inclined bunkers are occasionally used with steep storage . These bunkers are usually driven in the seam . However, inclined bunkers are also driven in solid rock. These bunkers are more expensive than seam bunkers, but they are also more durable. Inclined bunkers have no special funding, they are usually created with a rectangular cross-section.
Mountain bunker
If work is carried out in a mine with a backfill, it is essential that a very efficient backfill supply is available. To ensure this, the use of mountain bunkers is essential. These bunkers are used for buffering and for the quick removal of the backfill material. Mountain bunkers were increasingly used in Ruhr mining. Mountain bunkers are usually built near the departmental blind shafts. Their capacity depends on the required amount of backfill piles and the type of piles infeed. In addition, there are also centrally built mountain bunkers that buffer the daily demand for backfilled mountains. These bunkers often have a capacity of up to 1500 cubic meters. In steep storage areas, hacking is sometimes used as a mountain bunker. In some mines, different trolleys are used to bunker the backfill mountains.
Line bunker
Line bunkers are horizontal bunkers that are used in lines. They are used as shunt bunkers with a capacity of up to 250 tons of raw materials. As a rule, section bunkers are mobile bunkers, and low-rise flat silos are often used here. These bunkers are used for the central supply of building materials to the mine. The loading and unloading of these bunkers is fully automatic. The conveyed goods are transported by hydrostatic motors.
Individual evidence
- ↑ a b c d e Walter Bischoff , Heinz Bramann, Westfälische Berggewerkschaftskasse Bochum: The small mining dictionary. 7th edition, Verlag Glückauf GmbH, Essen, 1988, ISBN 3-7739-0501-7 .
- ^ A b c d Carl Hellmut Fritzsche: Textbook of mining science. Second volume, 10th edition, Springer Verlag, Berlin / Göttingen / Heidelberg 1962.