Mine closure is the period of time when the ore -extracting activities of a mine have ceased, and final decommissioning and mine reclamation are being completed. It is generally associated with reduced employment levels, which can have a significant negative impact on local economies. It is also the period when the majority of mine reclamation is completed, making the land safe and useful again.
7-420: Panguna is a town next to the (now decommissioned ) Panguna copper mine on Bougainville Island , Papua New Guinea . It was owned and operated by Bougainville Copper Ltd , a subsidiary of Rio Tinto . Beginning operations in 1972, the company hired thousands of workers, most from other parts of the country. By the end of its operations on May 15, 1989, when the mine was closed because of an armed uprising on
14-494: Is a stub . You can help Misplaced Pages by expanding it . Mine closure In South Africa, which is a major mining country, closure planning has not yet been formalized. This has led to a range of unintended consequences that have the potential to become sovereign risk if not adequately managed. Closure planning, a relative newcomer to mine planning, continues throughout the life of a mine, starting with conceptual closure plans prior to production, periodic updates throughout
21-461: Is needed. Holes are cut into the plate to allow for drainage as well as for a bat entrance. Expanding foam is used primarily with vertical shafts where the use of the shaft is no longer desired. It forms a plug 6 feet or more thick. A 4-to-6-inch (100 to 150 mm) pipe through the plug allows for pressure equalization as well as for water drainage, or even as a bat entrance if necessary. Closure planning has two distinct components. On-site planning
28-425: The deep tunnels helps prevent subsidence. Older mines typically used wood beams, a foot or more thick, under loose rock and dirt as caps. Over time the wood rots and sinkholes can develop. These mines are typically recapped with concrete, steel plates, expanding foam, or a combination of each. Steel plates are used primarily on horizontal shafts, but are used on vertical shafts occasionally. Doors are added if access
35-533: The island, it was the largest open-pit mine in the world. It was accused of contaminating large areas due to its toxic waste, which affected land, water and air. Resentment against the environmental poisoning and the fact that most profits left the island, were major catalysts in the unrest in Bougainville in the 1970s and 1980s, leading to the Bougainville conflict , which lasted from 1988 until 1998. In 2011 it
42-578: The life of the mine, and a final decommissioning plan. This is captured more coherently in the Australian Model to mine closure. At most mines, progressive reclamation over the life of the mine is used to reduce the reclamation burden at closure. Most mine shafts are capped, meaning a large concrete plug around 3 feet thick is placed over the shaft to cover it and stop fatal accidents from occurring. Some mines are capped using large metallic grills, this usual occurs on deep level shafts so airflow through
49-481: Was reported that former PNG Prime Minister Sir Michael Somare had alleged that Rio Tinto played a role in the conflict by helping finance the actions of the PNG government in Bougainville during the conflict in an attempt to allow the mine to be reopened. 6°18′55″S 155°29′47″E / 6.31528°S 155.49639°E / -6.31528; 155.49639 This Autonomous Region of Bougainville geography article
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