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By TONY CICINELLI

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Jun 13, 2021

By Renee Fippin

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Jun 13, 2021

By Andrew Bursey, Colin Lyons

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Jun 13, 2021

By Aaron McClellan, Eric Levonas

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Jun 13, 2021

By Jesse Salai, Colin Sessions

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Jun 13, 2021

By Mike Stolkin, Julio Martinez

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Jun 13, 2021

By Will Hodder, Martin Mancini

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Jun 13, 2021

By Dillon Tew, Kush Chohan

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Jun 13, 2021

By David Watson, Steve Price

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Jun 13, 2021

By Stephen Njoloma, Amitabha Mukherjee

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Jun 13, 2021

By Mohamed Younis, Keith Ward

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Jun 13, 2021

By Dave Dorfman, Ben DiFiore

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Jun 13, 2021

By Malcolm J. McPherson

The highest recorded loss of life due to the collapse of mine workings occurred at the Coalbrook North Colliery in South Africa on 21st January, 1960. A total of 437 persons died when bord and pillar workings collapsed over an area exceeding one square mile The whole mass of strata from the 470 ft (143 m) deep seam to the surface being affected. Although the Coalbrook disaster was unique in its scale the problem of pillar failure, particularly in old workings, is by no means uncommon nor confined to recent history. Indeed, the collapse of large pillared areas was a regular feature of mining in the north of England in the early part of the nineteenth century. When a section of underground workings collapses, the air under the descending roof is compressed very rapidly. The pressurised air is dissipated subsequently at a rate governed by the leakage paths available. If the collapsing area is small, such as the case of a local fall of roof, then there will be little danger of an air blast. If, however, an extensive area collapses suddenly then the rapid compression of air will give rise to a pressure shock wave that will be transmitted through the remaining workings as an air blast. If worked out areas are connected to current workings via unstopped airways an air blast caused by pillar failure in the old workings will be extremely hazardous to personne1 and may cause extensive damage to equipment, perhaps even reaching to surface plant. At Coalbrook, the air blast blew out a wall in the surface fan house. Areas that are considered liable to sudden collapse may be isolated from current workings by the construction of stoppings. However, such stoppings must be capable of withstanding the 'hammerblow' effect of peak air pressures developed during the collapse. The work described in this paper was undertaken in order to determine the maximum air pressures that stoppings must withstand during a major pillar failure. The result has been a method of establishing peak air pressures that is quick and simple to use. Readers who are concerned primarily with the practical application of the method are advised to turn directly to the last main section of the paper.

Jan 1, 1980

By E. Yiğit, M. N. Saridede

Correction to: Mining, Metallurgy & Exploration. https://doi.org/10.1007/BF03402385 The original online article has been revised to correct the author names. Publisher’s Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. The online version of the original article can be found at https://doi.org/ 10.1007/BF03402385 * M. N. Saridede theng@smenet.org 1 Metallurgical and Materials Engineering, Yildiz Technical University, Istanbul,

Dec 23, 2021

By Niall Weatherstone

Introduction Risks & Rewards of a Mineral Reserve Life History of a Mineral Reserve Estimate Risk Assessment & Management Mineral Resource & Reserve Estimation Good Practice Mineral Resource & Reserve Reporting Conclusions

Jan 1, 2003

By G. Orhan, C. Arslan

The possibility of producing metallic chromium from Cr2O3 via the aluminothermic route, with no external energy supply, was the subject of this laboratory-scale research. The experimental study focused on investigating the individual effects and quantitative optimization of the charge contents, i.e., the additions of CrO3, Al powder and CaO (or BaO). The highest chromium recovery of 98% was attained with the additions of 12% CrO3 and 1.2 times the stoichiometrically required amount of Al powder. The optimum CaO addition giving the highest chromium recovery was found when the CaO/Al weight ratio in the charge was equal to 0.3. When BaO was used, however, 95% Cr extraction efficiency was obtained at a BaO/Al weight ratio of 0.15.

Jan 1, 2000

By D. Elsworth, M. Bai

The influence of mining on the hydro-geo-mechanical environment can be greatly modified by alternating mining geometries. The limiting magnitudes of surface subsidence and groundwater flow over the mining area, as a result of mine geometric changes, can be reasonably predicted through the coupled finite-element model introduced in this paper. The model has been verified using real and conceptual case studies which reveal that changes in strata conductivities are strongly related to the strata deformation induced by mining. The greatest modification of hydraulic conductivities occurs within the caving or severely fractured zones. The study indicates that narrowing the panel face width will substantially reduce both the intensity and extent of mining damage to the overlying strata, limit surface subsidence and constrain the change in hydraulic conductivity to a reduced scale and smaller extent, particularly as mining depth increases.

Jan 1, 1995

By R. A. * Russell, J. R. * Brooks, E. J. Griffith

In 1967, a major impoundment to contain phosphate tailings was built near Columbia, TN. Precise records were maintained on the behavior of the impoundment throughout its 20-year active life. The volume of the impoundment was determined. The DNT (dry net tons) of solids added to the impoundment were continuously measured. The rise of the mud line in the impoundment was measured monthly. The density of the settled strata was determined, as required to understand the behavior of the settled tailings. And experiments were per formed to increase the settled density of the clays. The impoundment is currently being retired and stabilized. It covers more than 400 acres and the settled muds are almost 200 ft thick. The clays have been sufficiently solidified with electroendosmosis to support the growth of cypress trees. More than three milllion trees are being planted.

Jan 1, 1992

By Thomas Schultheis, William Heron, Paul Watson, Colin Warren

This paper describes the geology and geotechnics associated with construction of the Thames Tunnel, part of the UK’s Channel Tunnel Rail Link (CTRL). The 2.5km long twin tunnels run beneath the river Thames at depths of up to 40m and are currently under construction. They pass through varying geology comprising alluvium, terrace gravels and chalk with flints and are currently being bored using Herrenknecht mixshield slurry tunnel boring machines (TBM’s). This paper outlines the lithology and engineering properties of each geological formation and describes the geotechnical processes, potential hazards and difficulties experienced in the works. A summary is given into the extent of the investigative work in terms of route selection, tunnel design, TBM optimisation and further details are provided on the geotechnical aspects associated with the construction of the tunnel approach structures and the tunnels.

Jan 1, 2003

Due Dilligance does not only lie in the statistics, but rather in the practical process aspects, which is the window to understanding the statistics.

Jan 1, 2005