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(Upload on May 22 2015) [ 日本語 | English ]

Revegetation after mining (採掘跡地における植物群集動態)






Mount Usu / Sarobetsu post-mined peatland
From left: Crater basin in 1986 and 2006. Cottongrass / Daylily

Revegetation after mining (採掘後の植生回復)


For the restoration, we have to mention chemical and physical soil properties.

Coalfield (炭田)


There are many coal-slag heaps (small mountain made by coal slag) aound abandoned coal mines not only in Japan. We have to consider the revegetation.
Soil
Contamination of Cr, Ni, Zn and As from coal combustion (Botswana) (Zhai et al. 2009)
V, Cr, CU, Mn, Zn and Pb, measured by X-ray fluorescence spectrometer (stone coal mine in Hubei Province, China) (Li et al. 2016)

→ V, Dr, Cu and Zn originated from stone coal slag

Coalfield in Hokkaido


distribution
Distribution of coalfields in Hokkaido, Japan (Hokkaido Government 1993)

Now, there are only one company mines coal in eastern Hokkaido (except minor mining).

Mikasa Memorial Park Bibai
Mikasa (July 19 2003). A coal-slag heap showed low vegetation cover. A residential talked that the heap had almost no vegetation cover a couple of years before now. Bibai (July 20 2003). Coal-mining Memorial Park. Bibai (July 20 2003). Close to Coal-mining Memorial Park. The black part is coal.

Terminology


  • Acid mine drainage: Water mixed with sulfuric acid and having a pH of < 6.0, due to minerals containing sulfides, etc. The sulfuric acid mixes with water and flows out of the mine into surrounding areas as acid mine drainage
  • Adit: A horizontal entrance to go an underground mine
  • Dump: A pile or heap of waste rocks, etc.
  • Gangue: Low-valuable minerals
  • Gob: Rock or other coarse materials sorted out of coal either during mining or processing
  • Hard rock mine: Mining metallic minerals, e.g., copper, lead, zinc, silver, and gold. The mining is undertaken to rocks that require drilling and blasting to extract the ore
  • Heap leaching: A process whereby valuable metals, e.g., gold, silver, and copper, are leached from a heap of crushed ore by solutions percolating down through the heap
  • Impoundment: A natural or artificial, closed basin that is dammed or excavated for retaining water, sediment and/or waste
  • Leachate: Liquid that has percolated through a medium, and has extracted dissolved or suspended materials from it
  • Mill: A mineral processing facility for grinding, pulverizing, and extracting metals and/or producing a product
  • Mining: The process to obtain useful minerals from the underground and surface of earth
  • Open pit mining: A type of surface mining used to extract belowground metallic mineral deposits
  • Ore processing: Milling, heap leaching, flotation, vat leaching, adn/or other standard hard-rock mineral concentration processes
  • Pitting: Making shallow pits and/or basins to reduce overland flow. (Also used for seedbed)
  • Processed mined materials: The materials remaining after the valuable minerals have been removed from the ore
  • Scalping: Removal of vegetation before mining
  • Shaft: A vertical entrance to an underground mine
  • Slag: When smelting is done, The non-metallic materials float on top of the heavier metallic constituents in the molten state, and remains in that position when it cools and hardens
  • Smelting: The chemical reduction of a metal from its ore and certain fluxes by melting at high temperatures
  • Spoil: Overburden material disturbed or removed from its natural state, or non-ore material removed in gaining access to the ore or mineral material during the mining process. Spoil is specific to coal mining and overburden to more specific to hard rock mining
  • Waste rock dump: Waste rock that was mined and then was disposed

Japan (Hokkaido)


Toyoha mine (豊羽鉱山)

mine mouth = 550 m elevation
officially closed on March 31 2006
produced metals: Ag, In, Zn, Pb, etc.

Bauxite (ボーキサイト)


ALCOA (alminium company of America of Australia)
1963: started mining in Wagerup, Burbury, WA
Huntly, Worsley

Natural vegetation = jarrah forest
Soil Topsoil = 10-20 cm deep → seedbank (germination test) > 1000/m²
Caprocle
Friable zone
Clay
Base rock = mostly granite

caprocle and friable zomne → accumulated bauxite

Process of mining: clearing → double stripping → mining

double stripping → high similarity to natural forest

Succession: early stage = orchids → gradually increasing Eucalyptus

Need to consider the effects of fire in WA → Exp. artificial fire at Jarrahdale

Restoration:
1) reduce the herbivous damages by kangaroo
2) stock-piling

a) stock-piling: remaining the debris
b) direct whole-return: retuning the topsoil
c) double-stripping: remaining debris and cover the debris by the topsoil collected from the adjacent areas

References

(Western) Australia
  • Loneragan WA, Tsuyuzaki S, Vlahos S. 2007, Early vegetation development of rehabilitated bauxite mines in the eastern jarrah forests of southwest Western Australia. MEDECOS, Perth
Mines in Australia
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