Degradation losses

As mining losses is known in mining the contents of a mineral resource within a mining area that is not different reasons mined or can be. The mining losses are given as a percentage of the pending deposit . The mining losses are to be kept as low as possible , taking into account the completeness of the extraction of the deposit and the profitability of the mining.

causes

The causes of the mining losses can be divided into deposit-related mining losses, operating-related mining losses and safety-related mining losses.

Due to the geology of a deposit, not every part of the deposit can be mined. Reservoir contents impaired by clouding , narrowing or other geological disturbances cannot be dismantled or only with considerable effort. The mining losses caused by the deposits arise due to the different shape and structure of a deposit. But parts of the deposit that are not worth building also ultimately lead to corresponding mining losses.

Operational mining losses arise mainly from the selected mining method . In particular, mining processes without backfilling force the miner to abandon mountain festivals for reasons of protection. These mining methods result in large mining losses due to the non-degradable mountain forts. But even if the mountain festivals can be dismantled afterwards, slight mining losses occur when the mountain festivals are dismantled. The ruthless exploitation of deposits results in very large mining losses, depending on the deposit. But also the no longer recoverable stocks of closed mines count among the operational losses.

To protect mines or daytime facilities , safety pillars must remain in place in certain areas . These safety pillars lead to further mining losses. In particular, the mining losses caused by the shaft safety pillars are considerable. Since these piers get larger with increasing depth due to the angle of fracture to be taken into account , the mining losses also increase with increasing depth.

Amount of losses

The first calculations about the amount of the individual mining losses were already carried out in the 19th century on the Königsgrube. Taking into account the thickness of the seams, the height of the piers and the width of the section, initial conclusions could be drawn about the mining losses in the hard coal industry. The degradation losses are particularly influenced by the respective degradation process. The mining losses are around 30 percent when building piers . High degradation losses also arise in transverse construction. Particularly in the case of mighty seams with mild coal and heavy hanging walls , these losses increase to up to 50 percent. In chamber construction, the losses are over 50 percent. In the case of hollow construction , degradation losses of up to 54 percent occur. Due to the safety pillars, mining losses of 44 to 60 percent occur during the excavation. There are very little mining losses when building floors, averaging 11 percent. When the mountain fortresses are dismantled, mining losses of almost 10 percent remain under favorable circumstances. The premature collapse of pier sections or the premature abandonment of entire construction departments due to excessive rock pressure results in mining losses of 20 to 30 percent in hard coal mining.

Reduction of degradation losses

By choosing other degradation methods, the degradation losses can be reduced considerably. The mining losses can be reduced significantly by using mining methods with backfilling. By using offset, it is possible to subsequently dismantle the mountain festivals that were previously left standing. Targeted excavation can also reduce degradation losses. By widening the basic routes , the mining losses caused by leaving the security pillars in place can be avoided. The mining losses caused by brake mountain safety pillars can be avoided by driving up the brake mountain accordingly. A further reduction in mining losses arises from the mining of parts of the deposit that are conditionally exploitable. In seams, thin seams or seams with heavy contamination are usually only conditionally worth building. Depending on the state of the art and the market situation, these seams are then either worth building or not. But the demand for a certain mineral also means that parts of the deposit that are only partially worth building or even unworthy of building are mined. This measure was increasingly carried out in the English coal mining industry at the beginning of the 20th century, by mining seams that had previously been considered unworthy of construction. A further reduction in mining losses is the mining of parts of the deposit that have been left standing and that have already been built under. In the Ruhr mining industry, parts of the deposit that had already been built under were subsequently dismantled in several mines for cost reasons.

Individual evidence

^ ^A ^b ^c ^d Walter Bischoff , Heinz Bramann, Westfälische Berggewerkschaftskasse Bochum: The small mining encyclopedia. 7th edition, Verlag Glückauf GmbH, Essen 1988, ISBN 3-7739-0501-7 .
↑ 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 .
↑ ^a ^b ^c ^d 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.
↑ ^a ^b ^c ^d ^e ^f Carl Hellmut Fritzsche: Textbook of mining science. First volume, 10th edition, Springer Verlag, Berlin / Göttingen / Heidelberg 1961.
↑ ^a ^b ^c ^d Albert Serlo: Guide to mining science. First volume, fourth revised and up to the most recent edition supplemented, published by Julius Springer, Berlin 1884.
^ ^A ^b Fritz Heise, Fritz Herbst: Textbook of mining science with special consideration of hard coal mining. First volume, published by Julius Springer, Berlin 1908.
^ Carl Friedrich Alexander Hartmann: The advances in hard coal mining in recent times . Published by Julius Springer, Berlin 1859.
^ ^A ^b Gustav Köhler: Textbook of mining history. 6th improved edition, published by Wilhelm Engelmann, Leipzig 1903.
↑ Carl Hartmann: Conversations-Lexicon of mining, metallurgy & salt works and their auxiliary sciences . Second volume, J. Scheible bookstore, Stuttgart 1840.

[Quelle_1-1] A ^b ^c ^d Walter Bischoff , Heinz Bramann, Westfälische Berggewerkschaftskasse Bochum: The small mining encyclopedia. 7th edition, Verlag Glückauf GmbH, Essen 1988, ISBN 3-7739-0501-7 .

[Quelle_7-2] 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 .

[Quelle_4-3] 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.

[Quelle_2-4] ↑ ^a ^b ^c ^d ^e ^f Carl Hellmut Fritzsche: Textbook of mining science. First volume, 10th edition, Springer Verlag, Berlin / Göttingen / Heidelberg 1961.

[Quelle_3-5] Albert Serlo: Guide to mining science. First volume, fourth revised and up to the most recent edition supplemented, published by Julius Springer, Berlin 1884.

[Quelle_8-6] A ^b Fritz Heise, Fritz Herbst: Textbook of mining science with special consideration of hard coal mining. First volume, published by Julius Springer, Berlin 1908.

[Quelle_5-7] Carl Friedrich Alexander Hartmann: The advances in hard coal mining in recent times . Published by Julius Springer, Berlin 1859.

[Quelle_6-8] A ^b Gustav Köhler: Textbook of mining history. 6th improved edition, published by Wilhelm Engelmann, Leipzig 1903.

[Quelle_9-9] Carl Hartmann: Conversations-Lexicon of mining, metallurgy & salt works and their auxiliary sciences . Second volume, J. Scheible bookstore, Stuttgart 1840.