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By W. A. Wright

The use and abuse of social media restate common employee relations issues. Business solutions to these issues require advanced preparation. Employers should establish and enforce social media policies to guide their reactions to employees? social media posts that reflect on the employer and its business.

Jan 1, 2011

By D. Bour, C. Nyikos, R. Curtice

Fire in a coal mine can be disastrous on many levels. In most cases, when a fire is detected, mining operations cease and all personnel are evacuated. Underground coal-mine fires are difficult to extinguish, can burn for a long time, and often result in an extended period of lost production. In a worst-case scenario, the mine is permanently sealed and abandoned, resulting in lost jobs, lost natural resources, and possible devastation of the local economy. In some cases, seals placed within the mine to isolate the fire could eliminate the need for sealing the entire mine and the subsequent extended delay in returning the mine to full operation. Previous attempts to place remote seals to extinguish mine fires in active mines have been largely unsuccessful. The West Elk mine experienced an underground fire in early 2000. The fire could not be accessed and extinguished from the active mine workings. A method of constructing seals remotely by drilling boreholes into the affected area was needed to help isolate and extinguish the fire. This paper describes the process by which remote seals were constructed that successfully isolated the fire and provided a means of extinguishing the fire by flooding the area with water. The period of lost production in the West Elk mine was considerably shorter than is typical in similar situations.

Jan 1, 2002

By L. M. English, Y. J. Wang

When plotted as head vs. volume, fan curves start high and decrease in head with increasing volume while mine head curves start low and rise with increasing volume. Their intersection is the system operating point. But wait a minute: Isn't head loss a negative number, a debit? And isn't fan head an energy addition, a credit? This, as every ventilation instructor knows, is often a stumbling block to student or audience comprehension. It is possible to use the intuitively correct curves - pressure losses as negative values and energy additions as positive values-and still obtain the correct operating point: adding the two curves produces a third curve that intersects the x-axis at the operating point, the point at which the fan energy input exactly matches air circulation energy loss. Using this technique also makes it easier to account for outside influences on the system, such as natural ventilating pressure; with the standard approach it is quite easy to add or subtract such influences to the wrong curve. This approach can be extended to the graphical solution of any series/parallel circuit or ventilation network. The results are the same, and the approach is logically consistent and less confusing.

Feb 24, 1997

By R. Thornton

Montana Tech is located in the historic mining town of Butte, MT and is adjacent to the Orphan Boy mine. This abandoned underground mine will be the heat source for a down-hole heat exchanger (DHE)/heat pump system. The mine was abandoned in the 1950?s and has since filled with water to within approximately 30 m of the surface. The shaft is composed of a 245 m vertical shaft connected with horizontal crosscut drifts at 60 m and 150 m below the water level that connect to a large stope with approximately 1250 million liters of water at a consistent 75-78°F temperature. The intent is to build this heating system to augment or fully heat a newly built 2,000 m2 building on the Montana Tech campus. As designed the system uses ?off-the-shelf? parts making the basic configuration straightforward with the exception of the DHE?s which need to be placed into the vertical shaft. Because there is little or no examples of placing the heat exchangers in a vertical shaft, the primary focus of this work was to model the heat exchanger placement and configuration in the vertical shaft such that thermal currents develop between the stope and vertical shaft in, via the horizontal crosscut drifts, in order to move the water and thereby provide the required energy. This study includes the modeling of water flow, temperature profiles, and the heat contribution from the surrounding rock walls.

Feb 27, 2013

By B. C. Litzinger

Minerações Brasileiras Reunidas S.A. - MBR is a brazilian iron ore mining company geared for the export market. It is controlled by Companhia Auxiliar de Empresas de Minerações - CAEMI through its subsidiary Empreendimentos Brasi leiros de Minerações - EBM which holds 51% in MBR and is formed by CAEMI, the six major japanese steelmills and five japanese trading companies, Universe Tankships, Inc., and Indústria e Comércio de Minérios S.A. - ICOMI. The remaining 49% of MBR's capital are held by St. John del Rey Mining Company, a subsidiary of The Hanna Mining Company. MBR iron ore reserves exceed 1.5 billion tons of high grade ore distributed in 36 deposits located in the so-called IRON QUADRANGLE in the State of Minas Gerais. The Aguas Claras Mine is the largest presently known and highest grade deposit owned by MBR. Other mines such as Pico, Mutuca and Jangada are in operation at a combined rate of production of about 2 to 2. 5 million tons per year. The project consists of mine, railroad and marine terminal (slide). The Aguas Claras deposit, which is located about six kilometers southeast of Belo Horizonte the Capital of Minas Gerais, was selected for initial development. The Sistema Regional Centro of the Rede Ferroviária Federal, through its 6th Division known as the "Central " is responsible for the transportation of MBR ore, and provided the necessary railway construction to connect Mine and Terminal. The Terminal is located on Guaiba Island near the entrance to Sepetiba Bay, at about 120 kilometers west of Rio de Janeiro.

Jan 1, 1974

By Hendrick A. D. Kirsten, A. Clayr Alexander

Stillwater Mining Company is currently developing a second underground palladium and platinum mine approximately 21 km (13 miles) west of their existing Nye operation in the Bear tooth Mountains of southern Montana. Portals for the two access tunnels required at the new site were excavated in limestone talus to accommodate4.6 m (15 feet) diameter tunnel boring machines. A review of the technical design, field conditions and construction of the portals is presented.

Jan 1, 2001

By Roy Woodall

Successful mineral exploration is the lifeblood of the mining industry. Contrary to what the environmental lobby would have the world believe, the industry is replacing the metals it is extracting. The reserve base has not changed significantly in 20 years (Fig. 1.) Mineral exploration is a research activity. First there is the idea, the vision or the intuitive thought. The experiments follow. These involve repeated phases of data gathering, data interpretation and concept testing through drilling. For many companies, exploration is the main investment in scientific research. Each mineral exploration experiment may involve years of costly work. Despite the improving tools of science and technology, the investment remains high-risk. Only the promise of high rewards, or desire to survive as a mining company, will stimulate the necessary commitment and level of investment. Confidence that an economic return can be achieved, confidence in the science and technology being applied and confidence in the people involved are the foundations upon which successful mineral exploration is built (Woodall, 1984). The challenges facing the explorationist in the 1990s fall into two categories: - the challenge to make the activity economic; and - the challenge to make the activity socially and, therefore, politically acceptable.

Jan 1, 1992

By C. E. T. White

Although trace amounts of Indium are found in many ores, commercial production of the metal has come almost exclusively from residues, flue dusts and slags generated by Zinc recovery operations. Our paper attempts to summarize the various approaches used to recover Indium from these by-products. Some comments on production and price trends are included as well as our views on future availability.

Jan 1, 1982

By M. A. Islam, H. Mischo, G. Barakos

Among the thirty-five declared critical raw materials (CRM) in the United States, there is no sustainable domestic production for the fourteen of them, while for some others domestic supply does not meet the national demand. Numerous potential critical raw material projects are in advanced exploration stages. However, the price uncertainties for many of these commodities put feasible future production into question and come into contrast with overly optimistic price forecasts published in all feasibility studies related to such exploration projects. Thus, in this work, a newly developed smart computational tool is used to evaluate the real perspectives of several CRM exploration projects implementing actual commodity prices, and to conduct reverse calculations in order to find the prices at which each project can be viable.

Mar 2, 2022

By R. W. Culbertson

During the 1920's, approximately 11,000 small gasifiers were in operation in the United States. They converted about 15 million tons of coal per year into low Btu gas. In some cases, hot raw gas was used for applications such as firing open hearth furnaces or brick kilns. In other cases the gases produced in the gasifiers were cooled, cleaned and desulfurized for various utility and industrial purposes. The steel industry was by far the largest user. The most important fact was that the conversion of coal to a usable fuel gas was demonstrated to be commercial. During the late 1940's and early 1950's, this form of energy was largely replaced by natural gas as the pipeline net work was expanded. Producer gas was no longer economically competitive. Over the past twenty-five (25) years, government controls on the interstate price of natural gas have maintained this situation. At present only three commercial small coal gasifier plants are still in operation in the United States. These facilities are operated by the Glen-Gery Corporation which is located in eastern Pennsylvania; the National Lime and Stone Company which is located at Carey Ohio; and Holston Defense Corporation which is located at Kingsport, Tennessee. There are, however, numerous operating gasifiers in other parts of the world. Recent events indicate that this situation is changing. The quantity of domestic natural gas available to the interstate market has been declining at the same time that demand for all forms of energy has been increasing. The current potential market for gas with a heating value ranging from 100 to 500 Btu per cubic feet has been estimated at sixteen (16) quads (16 x 1015 Btu) per year. This is expected to grow to twenty (20) quads by the year 2000.

Jan 1, 1978

By M. S. Enders

The McDonald deposit is a volcanic-hosted epithermal gold resource that is estimated to contain 251,000 kg of gold in 375 Mt of ore at an average grade of 0.7 g/t gold. Phelps Dodge exploration geologists, working for the Seven-Up Pete Joint Venture, discovered the deposit in 1989. By the end of 1992, 494 drill holes for over 113,000 m of drilling, bulk sampling, soil geochemistry, geophysics, metallurgical testing, engineering, and environmental studies had been completed to support feasibility studies. The discovery of McDonald required vision, persistence, and commitment of everyone from the geologist on the drill rig to the senior management of the company.

Jan 1, 1995

By R. E. Nelson

The Alton Coal project, located in south-central Utah, lies at one point just over six miles from Bryce Canyon National Park. This region of the southwestern United States has been called the "Golden Circle" of national parks and monuments. Can a mine be inserted into this region so that it does not intrude on this spectacular landscape? The Alton Coal Project is a proposed surface coal mine designed to serve as the fuel source for the Harry Allen Power Plant, a 1,000 megawatt generating station planned for a site 25 miles northeast of Las Vegas, Nevada. The mine and the power plant will be connected by an underground pipeline through which coal will be transported in slurry form.

Jan 1, 1988

By A. Lashagri

This paper presents research results on assessment of environmental impact of digging and loading equipment in surface coal mining. Environmental impact is accessed through the equipment exhaust and dust emissions, and sound level. Exhaust emission is related to carbon dioxide (CO2), carbon monoxide (CO), nitrogen oxides (NOx), sulfur oxides (SOx), and volatile organic compounds (VOCs). Dust generation is expressed through the particulate matter PM10 and total suspended particulate matter (TSP), while sound is presented through the sound pressure level. Modeling of environmental impact of digging and loading equipment is conducted in Microsoft Visual Studio.NET software package. This research is a part of a boarder project on development of software system for the selection of productive, cost-efficient and eco-friendly mining systems, which is sponsored by the Appalachian Research Initiatives for Environmental Sciences (ARIES). The research work presented here may be used by mining professionals to aid in quantifying environmental impact of digging and loading equipment and determinate strategies for reducing its overall impact.

Feb 27, 2013

By Jürgen Kretschmann

The European climate and energy framework for 2030 is highlighting the reduction of man-made CO2 by increasing the use of renewable energy to mitigate climate change. In this spirit, Germany has decided to erase the coal use as an energy source by 2038 completely. Inevitably, this strategy promises a feasible, responsible, and sustainable post-mining management, because 200 years of coal mining have created numerous challenges necessary to tend to once the mining ends. Thus, the Research Institute for Post- Mining (FZN) at the TH Georg Agricola University in Bochum, Germany, has developed a holistic approach to meet these postmining challenges including further expertise present at our university. Here, the four strategic research pillars are (1) technical geoecology and hydrogeology to avoid and mitigate risks underground, (2) geomonitoring to evaluate and protect the surface, (3) industrial heritage preservation and engineering to secure and reuse brownfields such as mine sites, and (4) economic transformation planning of mining regions to enable a prosper future for generations to come. In all efforts, we aim to achieve the fundamental goals of the UN to deal with the resources of our planet responsibly and sustainably. Furthermore, we are synergizing increasingly with national and international networks in the interest of social, economic, and environmental stakeholders.

Jul 23, 2020

By A. Ramage

Since late 2010, CH2M HILL has been working with a confidential client who holds a long-term commitment to sustainable development (SD). The commitment is aligned with all three elements of the triple bottom line: people and society, ecosystems and environment, and financial and economic systems. These commitments are carried forward by the firm?s executives, managers, and operational sites, and are evident in materials posted on the company?s public website. These materials include a formal sustainability report prepared in accordance with the Global Reporting Initiative (GRI) guidelines (GRI, 2006), a report that outlines key SD challenges and progress toward the GRI targets, and a delineation of risks and opportunities outlined in the firm?s Form 10-K and Annual Report. In keeping with its commitments to SD targets, our client wished to consider SD issues in its decision processes for facility expansion or new projects. The company engaged CH2M HILL to meet this goal, based on working relationships established through existing contracts and CH2M HILL?s leading capabilities in sustainable solutions.

Jan 1, 2012

By Hitch M.

Many mining wastes, especially those from the metal mining industry, have traditionally been treated as a matter of little or no value and in practice a cost burden. Some wastes, due to their reactivity characteristics, have emergent values that go beyond purely economic and into the environmentally beneficial realm. This paper discusses the changing paradigm of mine waste management. Such fundamental parameters such as cut off grade, and strip ratio, are positively impacted by the revaluation of waste rock material. Mine rock waste can now be seen as a commodity of value, similar to the underlying ore being mined and influences the economic performance of suitable projects. This valuable material can be used for industrial purposes including acid neutralization as well as the capture and long-term disposal of anthropogenic carbon dioxide. The Turnagain Nickel project, located in northern British Columbia serves as an example of how waste rock material can become an important matrix for carbon capture and sequestration and can benefit economically from it. By producing material that has emergent economic value as well as carbon capture and sequestration capabilities, the sequestration matrix producer is a beneficiary of new carbon credits that have a market value and is looked upon favourably by regulatory authorities and affected stakeholders.

Jan 1, 2010

By William G. Fischer

Basic laboratory tests initiated the. Rock Mechanics program. The stress-strain curve, modulus of elasticity, Poisson's ratio, the uniaxial rock strengths, Mohr's envelope, the stress at failure, and creep were investigated. A series of underground problems were then approached using this information; and various field measuring devices, most of which were developed by the Bureau of Mines. Initially, stress concentrations near mine openings were evaluated using the stress relief technique. This required an accurate determination of the pre-mining stress field. Later, stress concentrations associated with the cave line .sere studied. After about thirty stress reliefs over an appropriate time interval the effects of one type of mining could be compared against another. The microseismic technique was used to investigate a possible application of warning devices near the cave line. A study of mane reorientation was made Problems related to the shape and size of pillars and barriers were studied. Partial extraction mining systems were evaluated. The effectiveness of roof bolting patterns were examined. Control of roof stresses was attempted. A new system of mining in heavy ground has been developed using the information secured in the Rock Mechanics program without this system, mining in more than one instance would Nave been next to impossible. Indeed; from this one discovery alone, the Rock Mechanics program has paid off in improved safety as well as in dollars.

Jan 1, 1964

By Jr. Koch

Since 1882, world zinc production has increased. In contrast, United States zinc production rose until about 1915, but since then has remained nearly constant, with a slight tendency to decrease. Production from the Tri-State district, the largest early source of zinc in the United States, has gone down steadily; this decline has been balanced by a growth in the rate of other districts. These changes in United States production are due to economic, not geological, factors. Recent exploration has located large mineable ore bodies; additional deposits will undoubtedly be found in the strata-bound carbonate rock and volcanogenic environments. A statistical analysis of the exploration effort in the Middle Tennessee district indicates that new discoveries can be expected there. Thus, the United States is in an early stage of the production cycle for zinc. Of major mining districts in the United States, only the Tri-State is exhausted under current economic conditions; large zinc resources of low-grade material, which would repay mining at higher prices or improved technology, are known to exist in that district.

Jan 1, 1980

By J. Mastoris

The growing environmental awareness and the need for providing social service to the community, urge the primary sector companies (such as mining) to find new solutions, by adjusting their operations with the special, local conditions and meeting everyday problems in practical ways. We hereby present a real case of re-design of an open pit, closed-bench type industrial minerals (clay) excavation, for the purpose of rehabilitation and utilisation as a water reservoir. The potential use of rainfall water was studied on the basis of covering the irrigation needs and improving the living standard of the neighbouring farmers and also as a project or recreational development of the area by shaping a wetland. The experience from the project progress and the reservoir use has been positive to date and the reclamation plan seems to have the acceptance of the local community.

Jan 1, 2002

By D. Lynn, D. Arthur

Infrastructures continue to age and drinking water supplies are becoming scarce in the San Fernando Valley of Los Angeles, California. Frontier-Kemper Constructors, Inc. (FKCI) was engaged by the Los Angeles Department of Water and Power (LADWP) to complete the River Supply Conduit Improvement Upper Reach—Unit 7 Project (RSC7). Two tunnel sections were bored using a 2.64 meter diameter Microtunnel Boring Machine (MTBM) and a 4.12 meter diameter Earth Pressure Balance Tunnel Boring Machine (EPBTBM) to excavate approximately 3,733 meters (3.7 km) of tunnels through highly abrasive late-Pleistocene-age Quaternary alluvial deposits (Old Alluvium) and Holocene age Young Alluvium deposits above the water table. This paper discusses the challenges encountered managing the TBM’s equipment degradation, use of soil conditioners, cutterhead wear, torque and advance rates while maintaining the necessary face-pressures and parameters to limit over excavation and ground settlement.

Jun 13, 2021