Mine dewatering

Mine dewatering is the action of removing groundwater from a mine.

History

The act of taking water from a mine that is being operated has been done since Neolithic times. In the past it was done by using a shadoof, digging deeper dikes so that gravity would remove the water, by mounting leather water-filled buckets on water wheels[1] or, if nothing else, carrying water-filled buckets manually. The Archimedes' screw was also historically used to pump water out of mines. Where no dewatering techniques were effective the mine had to be shut down due to flooding.[2]

It was only in the 15th and 16th centuries that mine dewatering techniques had some technical advancements as the first mechanized pumps were made available, first in the German mine of Rammelsberg/Goslar, in the 15th century, and then in the also German mine of Ehrenfriedersdorf/Erzgebirge, in the 16th century.[3][4]

With the dawn of the Industrial revolution, the demand for more coal also demanded more dewatering of the ever-deeper mines. Water was put in buckets and removed using rope conveyors powered by horses on treadmills.[5]

Thomas Savery was the first to realize that a steam engine could be used to pump water out of mines, so he patented an early form of a steam engine. He described the device in his book The Miner's Friend; or, An Engine to Raise Water by Fire. His proposed engine however, was very ineffective and problematic in design. It could not pump water higher than 30 feet (9.1 m) above the water level.

The machina pyraulica, invented by Thomas Newcomen in 1712, combined the ideas of Thomas Savery, who he was forced to go into partnership with due to Savery's patent, and Denis Papin, using his invention of a piston. It was the first practical application of the steam engine and it was used to dewater coal and tin mines. The first reliable metal pump was created by József Károly Hell and used in the Schemitz mine in 1749. Almost 40 years later, in 1788, the first water-independent system appears that uses a metal pump. It was installed in the German lead and zinc mine of Tarnowitz.

Newcomen's design was later improved by James Watt in his steam engine, which doubled its efficiency.

In the 20th century submersible pumps offered another innovation in mine dewatering. In the current days the dewatering techniques and systems are so advanced and well defined for each type of mine - open pit or underground - that even mines with thousands of meters deep can be successfully dewatered.[6][7]

Problems with mine dewatering

Dewatering a totally or partially flooded mine, or even as a normal procedure in normal mine activity, may carry a number of problems, most of which are environmentally related. This can happen in open pit mines as well as in underground mines.

The most relevant concerns with mine dewatering are related to acid mine drainage and the dispersal of contaminated water into other water fonts and the general environment becoming a serious source of pollution.

Types of dewatering techniques and systems

Dewatering open pit mines and underground mines is different. Each method relies on different apparel and techniques.

For dewatering open mines the following are used:[8][9][10]

  • Filter wells
  • Disposal wells
  • Inverted wells
  • Vacuum drainage
  • Horizontal drains
  • Sealing walls
  • Cut off walls
  • Guard wells

Underground, the following methods are used:[11]

See also

References

  1. ↑ Younger, P.L. (2004). "Making water": the hydrogeological adventures of Britain's early mining engineers. Spec. Publ., Geol. Soc. London, 225, p. 121-157.
  2. ↑ Sheperd, R. (1993). Ancient Mining. Elsevier, London. 494 pp.
  3. ↑ Agricola, G. (1556). De re mettalica libre XII. Holzschnitte, Basel, 273 pp.
  4. ↑ Kreibich, M & Eisbein, M. (ca. 2003). Georgius Agricola und die Ehrenfriedersdorfer Radpumpe. Ehrenfriedersdorf, 34 pp.
  5. ↑ Construction Dewatering: New Methods and Applications, page 7
  6. ↑ Vutukuri, V.S. & Singh, R.N. (1993): Recent Developments in Pumping Systems in Underground Metalliferous Mining. Mine Water Env., 12, p. 71-94.
  7. ↑ Duane, M.J., Pigozzi, G. & Harris, C. (1997). Geochemistry of some deep gold mine waters from the western portion of the Witswatersrand Basin, South Africa. J. Afr. Earth Sci., 24, 1-2, p. 105-123.
  8. ↑ Plotnikov, N.I., Roginets, I.I. & Viswanatan, S. (1989). Hydrogeology of Ore Deposits: Russian translation serie, 72, Rotterdam, 290 pp.
  9. ↑ de la Vergne, J. (2003). Hard Rock Miner's Handbook. 3rd edn., Tempe, 314 pp.
  10. ↑ Kecojevic, V.J., Mrugala, M.J., Simic, R.D. & Stankovic, R.M. (2003). A Computer-Aided System for Design of Drainage Facilities in Surface Mining. Mine Water Env., 22, 3, Berlin, p. 149-154.
  11. ↑ Wolkersdorfer, C., 2008: Water Management at Abandoned Flooded Underground Mines – Fundamentals, Tracer Tests, Modelling, Water Treatment, 465 pp.
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