Schrämen

from Wikipedia, the free encyclopedia

As Schrämen is called the slot-end type of rock work in mining . The rock is chiseled out with a pointed iron (called a mountain or cutting iron ) and a hammer ( fäustel ) in order to cut a narrow slot, the so-called Schram (also Schramm ).

Basics

The face or the working face usually only offer a free area on which the miner can start to work the mineral. In order to be able to work on this area better, he must create a second free area in the seam level. For this “preparatory work” in the mining of harder materials such as ore or hard coal , cutting is used. After cutting, larger pieces can then be obtained; tools such as a pick hammer or other tools are then used for this purpose. The cutting is not only at the beginning with the extraction of the required mining material, but of course also with the driving of roads and the construction of tunnels . By cutting, the tension in the deposit is released and the internal cohesion of the deposit block is released. Another method of creating an additional free area is to make a notch perpendicular to the seam plane. These notches are also called slots and two notches are always made. While the scraper is first made parallel to the seam level, the notches are then made at right angles to the seam level. Based on this basic preparatory work, miners used to be referred to as scrapers ; however, this term is no longer common today. Correspondingly, a cutter who limited himself to cutting work was also called a cutting tool . Cutting was usually used in lignite and hard coal mining , but cutting was also used in softer material, such as the mining of salt from the salt dome. In ore mining , cutting was only used occasionally, due to the solid rock, other techniques such as setting fire or blasting were used here.

Manual cutting

manual cutting

A miner needs a lot of experience for manual scraping, especially when it comes to optimally guiding the scraper. The delivery rate per unit of time depends on the correct choice of Schram. The proportion of lump coal also depends on the correct position of the scraper. When selecting the Schram, the respective conditions of the deposit must be taken into account. The strength of the mineral to be mined also plays a major role in the choice of Schrams. The position of the Schrams is usually coordinated with the riser . In seam-like deposits, the scraper is usually placed in the middle of the seam. In order to optimally apply the scrape, the miner first selects the softest and most decomposed intermediate materials ( slate ) in the seam . These are then removed first so as not to contaminate the coal that has been mined too much. In seams without intermediate means, the scraper is made in the area of ​​the softest seam parts. In the case of seams with uniform strength, the scraper is made in the area of ​​the lying. So that only a small amount of dust coals accumulate, the scrape is made as narrow as possible in this position.

Tough

Three different teeth were used by the cutting tools, the cutting hammer, the cutting tool and the cutting spike . The cutting hammer is also called a pointed hammer, rock hammer, hoe iron or miner's iron. In principle, the cutting hammer is a kind of wedge pick , which is also provided with a hammer at the rear end. The cutting hammer is mainly used for cutting. The Schramhaue is a light wedge pick that is used exclusively to make the Schram. The skewer consists of a square, straight iron rod that ends in a point at one end. The skewer replaces the function of the crowbar and the sky , it is used in wedge-cutting work.

Machine cutting

Since manual sharpening is very difficult and time-consuming, manual sharpening was replaced by machine sharpening as early as the 19th century. With mechanical cutting work, greater mining progress is achieved. Through the targeted use of machine cutting, the shooting work could be reduced. This also reduced the ripping of the roof after firing . It also reduced the number of accidents caused by falling rocks and coal. Mechanical cutting was used up to a seam thickness of 2.5 meters. With larger seams, the machines could be buried by the falling coal. Mechanical cutting was best for seams with a shallow dip of up to 25 gons . In the case of higher seams or seams with a larger collapse, the operating teams were also at greater risk from falling coal. The position of the scraper is also important for machine cutting. The Schram must not be placed too close to the sole area. If the scratch is placed too close to the sole area, the chain pulls the coal back into the scratch. This again requires additional work, as the coal has to be laboriously shoveled away by hand. If a scraper cannot be placed in any other way, a scraper scraper is required for scraper positions below 100 millimeters.

The machines used

Korfmann cutting machine in the Bochum mining museum

There have been cutting machines since 1862 . They were operated by means of air or water pressure, so that the scrapings could make a hacking or cutting movement. The engine of the cutting machine from Carrett, Marshall & Co in Leeds was a water column machine with a flying cylinder that rested on an iron cart.

Today's cutting machines are not limited to cutting out rock, ore or coal. They have been further developed into cutter loaders and - as the name already suggests - are also used for their removal and onward transport.

Machines that make a cut parallel to the horizontal or hanging wall are called cutting machines, machines that make a cut perpendicular or at right angles to the horizontal are called slotting or notching machines.

In the extraction of natural stone (marbles, tuff, soft lime and clay-bound sandstones), cutting machines are used that use cutting blades with a blade length of up to 5.0 m at a working depth of approx. 2.5 m.

literature

Individual evidence

  1. ↑ Explanatory dictionary of the technical terms and foreign words that occur in mining in metallurgy and in salt works and technical articulations that occur in salt works. Falkenberg'schen Buchhandlung publishing house, Burgsteinfurt 1869.
  2. ^ A b c Carl Hellmut Fritzsche: Textbook of mining science. First volume, 10th edition, Springer Verlag, Berlin / Göttingen / Heidelberg 1961.
  3. ^ Gustav Köhler: Textbook of mining science. 2nd edition, published by Wilhelm Engelmann, Leipzig 1887.
  4. ↑ a b Moritz Ferdinand Gätzschmann: Complete guide to the art of mining. Third part; The mining theory, published by JG Engelhardt, Freiberg 1846.
  5. ^ Emil Stöhr, Emil Treptow: Basics of mining science including processing. Spielhagen & Schurich publishing house, Vienna 1892.
  6. ↑ Mining dictionary. Johann Christoph Stößel, Chemnitz 1778.
  7. ^ Carl Hartmann: Handbook of mining and metallurgy. Publishing house, printing and lithography Bernhard Friedrich Voigt, Weimar 1858.
  8. ^ Heinrich Veith: German mountain dictionary with evidence. Published by Wilhelm Gottlieb Korn, Breslau 1871.
  9. ↑ Fritz Heise, Fritz Herbst: Textbook of mining science with special consideration of hard coal mining. First volume, published by Julius Springer, Berlin 1908.
  10. ↑ Berg- und Huettenmaennische Zeitung 1863. Twenty- second year, bookstore JG Engelhardt, Freiberg 1863.
  11. ↑ Heinz Kundel: coal mining. 6th edition, Verlag Glückauf GmbH, Essen, 1983, ISBN 3-7739-0389-8 .