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By L. A. Maseko

"As part of the mining engineering curriculum, students are required to be placed in industry for vacation work or work-integrated learning (WIL). In this paper we review work-based placement as done at the four South African mining schools: the University of Johannesburg, the University of Pretoria, the University of the Witwatersrand, and the University of South Africa.Key aspects of past and current WIL (pre- and post-graduation) practices that may need attention are highlighted for consideration by all universities that provide professional qualifications. Work-directed theoretical learning, problem-based learning, project-based learning, workplace learning, and simulated work experiences are discussed as legitimate approaches to WIL.Regardless of the choice each institution makes, commitments of universities, preparedness of university teachers, and the desire for equity and excellence will play an important role in the provision of WIL.DefinitionsAccredited Qualification: a qualification awarded on successful completion of an accredited programme.Advisory Boards (or Committees): are essential infrastructure for a WIL curriculum that is built on the integration of the workplace and the university. This requires the collaboration of experts from both environments. Workplace advisors are critical to the success of the academy as they embody expert knowledge of the ‘real world’.Assessment: the process of determining the capability or competence of an individual against standards by evaluating performance.Category: a mode of registration defined in or under the ECSA Act which has a distinctive purpose, characteristic competencies, defined principal routes to registration, and educational requirements.Experiential learning: (in South Africa sometimes used synonymously with work placement or cooperative education) is a term used with a great variety of meanings in the international literature. More broadly, it may refer to learning that has meaningful learner involvement. It is the process of generating meaning from direct experience. In the international literature, experiential learning is learning through reflection on doing, which is often contrasted with rote or didactic learning."

Dec 1, 2018

By D. J. Pyra, J. Kudelko, Korzekwam W.

Polkowice region (Lower Silesia, Poland) is an area, where the copper mining activity started about 40 years ago and new technologies were applied. There are 3 underground mines, 3 processing plants, tailings pond (the biggest one in Europe), pipelines for flotation waste transport, railways. Although new technologies were applied during the copper ore exploitation, the environment in this area were polluted mostly by dust containing copper, lead, zinc and arsenic. Estimated values of heavy metals in polluted soils were compared to the natural contents of this metals. The geochemical background for Polkowice area was defined. The pollution zones occur around mining facilities. Copper ore exploitation and processing is planned for the next 20-40 years depending on market situation. After mines and other facilities closing the most important problem will be sustainable development of this area. To evaluate the scope of revitalization activities the analysis of recent soil environment condition will be necessary as well as forecasts for pollution migration. Geostatistic methods used also in mining will be very helpful for this task.

Jan 1, 2005

By AIME AIME

AT the annual .meeting of the Minnesota Section in December, Dr. Leith characterized as a question still open the exact method of origin of Lake Superior iron ores and emphasized it as an important practical problem for the future. He welcomed the step taken last year by Dr. Gruner in presenting a new hypothesis, and asked Lake Superior geologists to meet the challenge of such multiple hypotheses by unbiased, study.

Jan 1, 1932

By Samuel A. Reipas

Introduction The ore mining industry has been successful because of technological progress and huge sums of capital investment. But new technology and plants have not come cheap. The problem now is companies will run out of money before they run out of ideas. Survival Strategies Industry survival strategies demand restructuring and new plans. Inland's prescription for the future includes: • Continued emphasis on technological improvements to upgrade pellet quality and lower costs; • Effective use of human resources resulting in employee satisfaction and improved planning and productivity; • Deliberate, well planned, and documented cost-control programs for the short- and long-term; and • Capital investments to support the first three initiatives. Technology Technological changes are not only required by the need for operational improvements, but by product quality improvement dictated by the user - usually the blast furnace operator. Established ambient measurements of pellet quality, such as tumble index, compression strength, porosity, size distribution, and chemical composition, are no longer considered meaningful in predicting pellet performance in a blast furnace. New specifications, called low temperature and intermediate temperature properties, have been recently introduced. Low temperature specifications are characterized by disintegration of pellets in the 500°C (930°F) range in the upper portion of the granular zone during the hematite-to-magnetite transformation in blast furnace stack. Intermediate temperature properties (measured by 1000°C or 1800°F) are characterized by swelling, reducibility, and compression strength after reduction, reflecting conditions in the lower portion of the granular zone of the furnace. These new parameters are being used for pellet quality evaluation at Inland, and will be introduced at its Minorca mine for more routine analysis and correlation with the pellet furnace operation. With increased emphasis on quality, effective communication between the blast furnace operator, research, and the pellet plant operator is critical. At Inland, this is accomplished through technical meetings where the opportunity is provided to solve problems, establish a common understanding on the value of quality, and develop future quality standards and programs. With the degree of sophistication in determining pellet quality as it affects blast furnace operation, the future pellet plant operator will actually be producing a custom pellet. Human Resources Technological change has been a strong point at Inland, and will continue to be. However, human resource management is equally important. Is management giving sufficient attention to employee motivation and involvement? It is a way to improve productivity, reduce costs, and enhance employee job satisfaction. The industry is beginning to understand the principles and the potential for tapping employee brainpower. The payoff can be handsome. Management has to be willing to share both information and power if participative management is to live up to its potential. It has to become more flexible and be willing to adapt to change on the human side. Management should embrace rather than fear employee involvement. Given time, joint problem solving will replace adversarial attitudes and pay dividends for both sides. Productivity and product quality will improve and new dimensions of employee job satisfaction will be achieved. But, it will not happen overnight. Attitudinal change must permeate the organization from top to bottom. This change is needed to support the working relationships and give everyone a sense of direct and meaningful involvement.

Jan 11, 1983

By Mohsen Mohammadi, Edward Cyr

"To date, several studies have been performed on the static mechanical properties of SLM-AlSi10Mg alloy. There have also been more recent studies on the relation between scan strategy, texture, and mechanical properties of SLM metals and composites. However, there is a huge knowledge gap in the available literature regarding texture and mechanical behavior of SLM-AlSi10Mg alloy under high strain rates. Therefore, in this study, dynamic mechanical behavior of AlSi10Mg_200C alloy manufactured by DMLS technique was investigated at high strain rates ranging from 900/s to 1700/s using Split Hopkinson Pressure Bar. Texture using X-ray diffraction technique of the initial samples were measured. The yield strength, peak flow stress, and ductility increased in all samples with increase of strain rate. TEM studies have also revealed evidence of continuous dynamic recrystallization in grains after 900/s–1700/s strain-rate tests. A Taylor polycrystal crystal plasticity constitutive model was then developed to capture and predict the texture evolution and mechanical response under dynamic loading, using plastic work as a critical parameter for the onset of recrystallization.INTRODUCTION Additive manufacturing (AM) powder techniques are among the fastest advancing breakthroughs in manufacturing in recent years, defined by a bottom-up layer by layer process of joining with energy input from lasers or electron beam (Herzog et al., 2016; Gibson et al., 2015). Among alloys fabricated by SLM, AlSi10Mg is of high interest to industry and academia due to its low density, high specific strength and excellent corrosion resistance, making this alloy a viable contender for aerospace, automotive, and marine applications. Circumstances such as car crash or bird aircraft strike hazards subject potential additively manufactured AlSi10Mg parts to impact loadings. This drives an interest in understanding and predicting dynamic behaviour of these alloys. AlSi10Mg is the AM counterpart of A360 die-cast aluminum, which possess hypoeutectic microstructure (Li et al., 2015). Up to the present time, many studies have presented the mechanical properties of SLM-AlSi10Mg alloy. The mechanical properties and microstructure of AlSi10Mg produced by selective laser melting (SLM) or DMLS techniques can be controlled using different parameters, such as feedstock powder (Asgari et al., 2017), and process parameters (Olakanmi et al., 2015). The microstructure and mechanical properties of AlSi10Mg can also be controlled using post heat treatment after SLM process Li et al., 2016). The mechanical properties of SLM-AlSi10Mg are sensitive to strain rate and can both change under quasi-static (Rosenthal et al., 2017) and high strain rates (Asgari et al., 2018). However, a significant knowledge gap in available literature regarding modeling these behaviours, and especially micromechanical modeling of dynamic behaviour."

Jan 1, 2018

By Yoginder P. Chugh

Subsidence may be observed above partial extraction shallow room-and-pillar mines where the coal seam(s) is associated with weak and thick claystone in the floor. This paper presents results of subsidence studies at such a mine. During the 26-month study period, a time dependent subsidence causing a maximum vertical movement of 50 mn was observed. After a subsidence rate of 6.0-6.5 m/month for the first two months after development of mine workings, the rate decreased to 0.8-0.9 mm/month after 17 months. However, presumably due to settlement of barrier pillars, it increased therafter to 1.7 mm/month for the next 9 months. Angle of draw, based on zero subsidence, was calculated to be about 29 degrees. Maximum tensile strain and compressive strain values observed were 0.040 pct and 0.039 pct respectively. A hypothesis was fomlated to correlate surface subsidence movements with observed underground movments. The data collected to date fits reasonably well within the formulated hypothesis.

Jan 1, 1989

By S. F. Emmons

Jan 1, 1899

Jan 1, 1987

By Iina Vaajamo, Jani Jansson, Lauri Pesonen

In pyrometallurgical operations, structural integrity of a high temperature furnace plays a crucial role in the overall safety, profitability and ecological footprint of the plant. Furnace integrity is related to how reliable a furnace is and it can be compromised, for example, by having poor operating and maintenance practices, an inefficient cooling system and flaws in the overall furnace design. These flaws and poor practices might lead to unexpected shutdowns, production losses, increased emissions, or worse. This paper presents the main factors to consider when engineering a furnace and developing its operating practices, while ensuring safe and reliable operations without compromising process efficiency and quality of the final products. In this respect, Outotec’s solutions for the cooling system and for automation systems like PROSCON, Process Advisor, Sentinel and our Smelting Information Management System, are also introduced.

Jan 1, 2015

By AIME AIME

L H. DUSCHAK gave an interesting talk at a recent meeting of the. San Francisco Section, based -011 experimental work with a variety of ores at the laborator of the Treadwell-Yukon Co., in Berkeley, Cal. He was of the opinion that the customary "cut and try" method of flotation testing was still in evidence and that the flotation process was more of an art than an exact science. Propounded theories have enabled investigators to' classify reagents as well as to suggest new ideas both in the metallic and nonmetallic fields, but the application of theory has riot as yet been able to solve many of the unknown factors in operation.

Jan 1, 1932

By P. M. BIDDISON, G. G. Oberfell, George A. Burrell

The Bureau of Mines is conducting a series of investigations, with a view to ascertaining the most efficient methods of obtaining gasoline from petroleum and natural gas. This report deals with a method of extracting gasoline from natural gas by absorbing the gasoline in oil and subsequently separating it from the oil by distillation. The process is quite different from those of compression and condensation which have been used for a number of years for extracting gasoline from casing-head natural gas, and has not heretofore been described in the literature. MANUFACTURE OF GASOLINE FROM CASING-HEAD GAS. The extraction of gasoline from casing-head natural gas by compression and condensation methods has become a large and lucrative industry in this country. In the year 1915 about 65,000,000a gallons of gasoline prepared by these methods was placed on the market. In addition, in marketing this gasoline, at many plants an equivalent quantity of naphtha was blended with the gasoline, thereby utilizing for automobile fuel and other purposes a large quantity of naphtha that otherwise would have been unsuited for these purposes. The increase for the year 1915 over 1914 was about 22,000,000 gallons. For the year 1916 the production should be more than 100,000,000 gallons. The quantity of casing-head gas treated in the year 1915 by compression and condensation methods amounted to about 24,000,000,000 cubic feet; the average yield of gasoline was 2.57 gallons per 1,000 cubic feet. b This casing-head gas represents natural gas that formerly went largely to waste; hence the process represented a distinct and important step in the utilization of the natural gas produced in this country.

Jan 1, 1917

By D. Chetty

Process mineralogy forms an integral part of geometallurgy, with ore body characterisation being but one piece of the puzzle in optimising value derived from ore. This value is not only financial, but importantly speaks to sustainability from environmental and social standpoints. The reactive approach of traditional process mineralogy is increasingly being replaced by predictive methods in the geometallurgical sphere, for which mineralogical information must be timeously acquired on judiciously selected sample sets to understand ore variability and its impact on orebody processing. Such processes are not only metallurgical, but must incorporate mining and waste management protocols. Dwindling resources like water and energy also demand innovative approaches for lowering consumption and/or promoting recycling along the value chain. Addressing such challenges relies on appropriate characterisation of ore behaviour under different process regimes. Coupled with this, emerging characterisation tools are increasingly applied to understand the mineralogy of unconventionallypresented and difficult-to-process ores to meet societal and technology demands. Such tools are often accompanied by the generation of large, computationally intensive datasets, for which data management and storage are key requirements, particularly when deciphering temporal trends in ore and process variability. This paper will elaborate on these themes with examples that highlight the importance of process mineralogy throughout the minerals value chain. Keywords: Process mineralogy, ore characterisation, geometallurgy

Jan 1, 2020

By Mayo D. Hersey

This problem was taken up by the Bureau of Mines as a result of the oxygen explosion at the Jefferson Physical Laboratory of Harvard University , and other similar explosions , in order to supply technical information which would serve as a basis for safety precautions in the future . At the Harvard inquiry the fact was emphasized by the Massachusetts State Chemist , Mr. Walter M. Wedger , that we do not know the limiting pressures and temperatures above which compressed oxygen and lubricating oil are capable of spontaneous explosion . The problem is also of importance to the Army and Navy and to the Bureau of Mines in connection with the hazards incurred in the use of compressed and liquified gases in the repurification of helium. In fact , the risk of fires and explosions due to traces of lubricating oil coming into contact with high pressure oxygen is of serious interest to all concerned with the manufacture and use of oxygen , a commodity which is now being produced and distributed on a rapidly increasing scale . Part of the money expended on this investigation was from Army and Navy funds . The problem was undertaken by the Bureau of Mines at the suggestion of Dr. Charles E. Munroe , Chairman of the Committee on Explosives Investigations of the National Research Council , and referred to the Pittsburgh experiment station of the bureau.

Jul 1, 1923

By Raquel Costa, Aldino Campos, Frederico Carvalho Dias, Pedro Madureira, Patrícia Conceição, Ana Filipa Marques, Andreia Afonso, Maria Ana Martins, António Calado, Luísa Pinto Ribeiro

Since its formation in 2004, the Task Group for the Extension of the Continental Shelf (EMEPC) has been collecting hydrographic, geological and geophysical data to support the extension of the continental shelf beyond 200 NM. In 2008, the EMEPC acquired a 6,000 m rated ROV named "Luso" and has been cooperating with several national and international institutions to increase and improve its operational capabilities to conduct research on deep-sea minerals. The Portuguese continental shelf corresponds to a broad area of the seafloor encompassing different physiographic domains: the mid-Atlantic ridge system, abyssal plains and numerous seamounts. From 2008 to the present, the mid- Atlantic ridge and seamounts have been the most visited sites with the ROV "Luso". Several hydrothermal vent sites are known to occur along the mid-Atlantic ridge to the south of the Azores archipelago and mostly within the Portuguese EEZ. Vent fields were also discovered in the extended continental shelf, namely the Rainbow and the Moytirra sites located to south and to the north of the Azores archipelago, respectively. The most studied seamounts correspond to those forming the Great Meteor chain and the Madeira- Tore rise. All these visited sites are related either with the occurrence of polymetallic sulphides or cobalt rich Fe-Mn crusts and the opportunities to further pursue their exploration will be discussed.

Sep 1, 2014

By Mike Watts

Since the first longwall panel development started in the new mining, (Southern) area, a number of roof falls have occurred in L1 and L2 gate-entries. The longwall was delayed for a total of two months due to roof falls in the gate-entries. To prevent roof falls in future gate-entries, an extensive ground control analysis has been conducted which incorporated regional horizontal stress and panel orientation, tectonic stress, roof strata, surface stream valleys, etc. Results of the analysis indicate that a combination of these factors caused the roof falls. Therefore, a Roof Instability Rating (RIR) system was constructed to predict the roof condition and identify areas where supplemental support should be implemented. The L3 gate-entries, supported by the prediction using the RIR system, have not experienced any roof problems.

Jan 1, 2000

By James L. Ash

This report contains the results of a technical and economic evaluation of conceptual systems for the underground mining, rubblization, and in situ retorting of deep oil shale deposits. Study efforts were first directed towards evaluation of the applicable geology, associated minerals, rock mechanics, in situ retorting, access mining, ventilation, rubblization, safety, and environmental impact factors. Conceptual systems were synthesized and then evaluated against these factors from both a technical and limited economic viewpoint. The results of these evaluations were then analyzed and, based upon this analysis, the following two systems were selected for further study: System II: Room and Pillar-Vertical Drill and Blast System IV: Tunnel Boring-Horizontal Ring Drill and Blast Due to the large number of variables to be considered, a computer program was developed and utilized to provide data for the cost trade-off studies and economic analysis. Results of the early computer runs indicated the value of the tool available? in the computer program and led to an extension in the contract to determine the sensitivity of the systems to several of the more apparent significant variables. These results in turn led to a refinement in the design assumptions and a better understanding of the technical and economic options available to an owner-operator of a Vertical Modified In Situ Shale Oil Extraction System. This report is submitted in fulfillment of the requirements of Contract Number 50241073 by Fenix & Scisson, Inc. to the Denver Mining Research Center, United States Department of the Interior, Bureau of Mines. Work was completed as of November, 1976.

Jan 1, 1976

By Dennis Ofiara, Michael Lewis

An experimental 1.75 meter Shaft Boring Machine was designed and manufactured by The Robbins Company. The drill was used by contractor Drillcon Raise AB to drill test shafts at an SKB underground test facility. SKB is the Swedish authority responsible for safe management of nuclear waste materials. This “SBM1.8” Shaft Boring Machine was used to drill shallow test shafts ingranitic rock at SKB’s Aspo underground laboratory. The drill used a unique vacuum mucking system. The bored shafts were held to very strict tolerances for bore diameter, straightness, and verticality. This drill was launched and operated from a mobile launcher. Headroom and working space were limited. The SBM1.8 drill produced acceptable test holes. SKB will carry out several studies to determine the suitability of this geology, and of this technique, for safe nuclear disposal. In addition to future use at SKB, many applications are foreseen, particularly in the civil construction industry.

Jan 1, 2005

By D. Christofferson

This final report documents the cooperative efforts of the Engineered Systems Division and the Mining Equipment Division of FMC Corporation during performance of Bureau of Mines Contract H0252091. Improved operator compartments incorporating overhead canopies, logical arrangements of controls, and design features offering greater operator comfort were developed and retrofitted to the FMC 320A roof bolter and 6L shuttle care The vehicles were evaluated in underground operations at separate mine sites. The successful evaluation has resulted in incorporation of the designs as standard features of the 320A roof bolter, and the 5L, 6L, and 10L shuttle cars.

Jan 1, 1978

By W. M. Pytel

The applicability of the beam theory in analysis of roof- pillar-weak floor interaction in partial extraction room-and-pillar mining is presented. The mine structure is modeled as an equivalent multi-indeterminate overburden elastic beam supported by elasto-plastic pillars; resting on a viscoelastic layer of immediate weak floor strata underlain by a competent rock mass. The developed analytical model was initially utilized to conduct sensitivity analyses of different variables affecting the mining system, such as the deformability of coal and weak floor strata, thickness of weak floor strata, number of pillars in a panel, width of pillars, width of panel etc. These analyses were then extended to three overburden strata - coal pillar - floor strata lithologies typical of active coal mining areas in Illinois.

Jan 1, 1989

By Julie N. Walker

This U.S. Bureau of Mines report reviews the first 2 years of the agency's progress in implementing total quality management (TQM), which the agency refers to as Quality Improvement (QI). All employees have been trained in basic TQM concepts, a cadre of facilitators has been selected and trained, and 13 Bureauwide teams are addressing specific issues that were identified by Bureau employees nationwide as problem areas. Also in place are a Quality Council composed of the Bureau's top executives, a Quality Management Board, and eight QI Working Groups to provide a national 01 infrastructure. There are also Quality Steering Groups at each Bureau location nationwide to address local concerns. In addition to the narrative text, the texts of salient memoranda and other documents are included as appendixes.

Jan 1, 1992