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Electromagnetic inspection of wire ropes – vertical lift bridges
Published in Khaled M. Mahmoud, Advances in Cable-Supported Bridges, 2017
Electromagnetic inspection (EM) of wire ropes has been utilized in the mining industry since the early 1950’s in gold mines in South Africa. These mine shafts are extremely deep, in excess of 8000 feet. Some method of advanced wire rope inspection was necessary to help prevent sudden hoist rope breakage. As many as 200+ mine personnel ride these rope hoisted cages to the work-place on a daily bases. Wire ropes in this application are virtually “life lines”. Wire rope hoists are also used for placing and extracting mining materials and equipment. Broken ropes cause costly downtime and damage to mine equipment and possible fatal injuries to mine personnel. EM of wire rope is also widely used for the inspection of guy strands on towers and flare stacks, lift and tram way ropes in the ski industry. Ropes on vertical lift bridges work in the same manner as ropes other applications, just much more slowly.
Tunnel support in South African mines
Published in Xia-Ting Feng, Rock Mechanics and Engineering, 2017
The sinking of vertical shafts to access deeper orebodies is a highly specialized form of tunnel development. The world’s deepest single-drop vertical shaft is the South Deep shaft complex in South Africa, which extends to 2995 meters below surface. Most gold mine shafts are more than 1500 m deep; often two, or even three sequential shafts are needed to access the deepest workings. Older timber shafts were either square or rectangularly-shaped, while today’s shafts are either circular or oval in profile, with all shaft infrastructure manufactured from steel.
Tunnel support in South African mines
Published in Xia-Ting Feng, Rock Mechanics and Engineering, 2017
The sinking of vertical shafts to access deeper orebodies is a highly specialized form of tunnel development. The world’s deepest single-drop vertical shaft is the South Deep shaft complex in South Africa, which extends to 2995 meters below surface. Most gold mine shafts are more than 1500 m deep; often two, or even three sequential shafts are needed to access the deepest workings. Older timber shafts were either square or rectangularly-shaped, while today’s shafts are either circular or oval in profile, with all shaft infrastructure manufactured from steel.
Development and use of hazard ranking system for abandoned mine entries: A case study of the mine shafts in Giyani and Musina areas of South Africa
Published in Cogent Engineering, 2018
Sphiwe Emmanuel Mhlongo, Francis Amponsah-Dacosta, Armstrong Kadyamatimba
In general, the major environmental problems of abandoned mine shafts or entries are that they are at times found discharging contaminated and acidic water. The shaft that is used to pump water for irrigation and other domestic purposes at Klein Letaba Mine was the only shaft that had relatively higher pollution potential risk score in the whole of the study area. However, the major environmental issues of most of the shafts in the Giyani and Musina areas were physical degradation of the land which also affects the aesthetic appearance of the landscape. The shafts found in physically unstable grounds in Musina had the highest score for land degradation issues (see Figure 6b). The reason for this was that the land occupied by these shafts is at the state where it cannot support even the basic post-mining land uses such as crop farming and development of animal grazing site. The comparison of the seriousness of the risks of abandoned shafts which gives an indication of what should be the focus of the efforts of treatment of the shafts in the areas of Giyani and Musina is shown in Figure 6a and b.
Fluoride-Salt-Cooled High-Temperature Reactor (FHR) Using British Advanced Gas-Cooled Reactor (AGR) Refueling Technology and Decay Heat Removal Systems That Prevent Salt Freezing
Published in Nuclear Technology, 2019
Charles Forsberg, Dean Wang, Eugene Shwageraus, Brian Mays, Geoff Parks, Carolyn Coyle, Maolong Liu
5. Heat conduction to ground: If the silo wall cooling system fails, heat is conducted to ground. Special concretes can be used to minimize high-temperature degradation and gas generation such as granite or other high-temperature aggregate and alumina cement. Alternatively, the inner wall can be made of steel rings with the cooling coils on the outside of the rings. Steel rings are used to line mine shafts. In terms of an FHR BDBA system, steel rings have the advantage of providing a high thermal conductivity structure to spread heat over the total internal area of the silo including above the salt level with more uniform temperatures to assist heat transfer to ground in an accident.