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By Michael Karmis

"In December 2011, the U.S. Attorney’s Office for the Southern District of West Virginia, the U.S. Department of Justice, Alpha Natural Resources (ANR) and Alpha Appalachia Holdings entered into a nonprosecution agreement related to the explosion at the Upper Big Branch Mine (UBB) that killed 29 miners. This coal operation was owned by Performance Coal Co., an affiliate of Massey Energy Co., which was acquired by ANR in June 2011, more than a year after the UBB explosion. Pursuant to the agreement, ANR agreed to:• Establish a trust within 120 days.• Pay a total of US$48 million into the trust to be used solely to fund and administer research and development (R&D) projects to improve mine health and safety.• Administer the trust by three highly qualified individuals with academic and/or professional backgrounds in mine health and safety.In April 2012, the Alpha Foundation for the Improvement of Mine Safety and Health was created. The three directors - Michael Karmis, president; David Wegman, vice presidenttreasurer, and Keith Heasley, vice presidentsecretary - approved a plan to expend both the interest and principal of the trust, aiming at an 8-10 year research horizon. The foundation also appointed David Belden, an experienced manager of nonprofits and professional associations, as the first executive director of the foundation. The IRS approved the foundation’s tax-exempt application, as described in Section 501c(3) of the Internal Revenue Code, on Dec. 18, 2012. The board established guiding principles of the foundation, which are as follows:• Mission: to improve mine health and safety through funding R&D projects to qualified academic institutions and other not-for-profit organizations.• Vision: to enable miners in the future to be free of work related injury or disease by the implementation of the results of the projects funded by the foundation and undertaken by the best researchers from any discipline that can contribute. The foundation is now approaching its third year and regularly posts updates, including semi-annual reports, to its website (www.http.alpha-foundation.org/), which serves as the main medium for communication with the broader stakeholder community"

Jan 1, 2014

By M. Pawlik

The rheological properties of mineral suspensions affect the design and operation of transport, mixing, size classification, grinding, gravity concentration, flotation and de-watering systems. In many cases, the rheological properties can be modified to improve processing through the addition of chemical additives. These additives may be either organic or inorganic and generally affect the state of particle aggregation or dispersion. Inorganic modifiers act primarily by affecting the surface charge of mineral particles and thus control the magnitude of electrostatic attraction/repulsion between particles. The action of organic additives (polymers and surfactants) is a combination of electrostatic and steric forces – the latter being related to the molecular weight of these reagents. While low molecular weight polymers are dispersants (viscosity reducers), high molecular weight polymers are likely to induce flocculation and increase yield stress.

Jan 1, 2004

By Christopher Mark

Six decades ago, the most dangerous job in the USA was mining coal underground. Roof falls were responsible for half of the deaths, killing about 100 miners every year. Fast forward to 2016 and zero roof fall fatalities. Just three miners were killed by roof falls during the following 6 years. How did the mining community achieve this historic goal? This paper starts by analyzing the roof fall fatalities in 1968, categorizing them by their fundamental cause. Then, it shows how each type of roof fall was reduced over time, using snapshots of the fatalities occurring in subsequent decades. Along the way, it evaluates the influence of the regulatory environment, changing mining methods, and better ground control technology. The study found that in 1968 more than half of roof fall fatalities at large mines were attributable to an inadequate safety culture. The immediate effect of the 1969 Coal Mine Health and Safety Act was to reduce the riskiest activities, like needlessly going under unsupported roof. Other hazards, like large roof falls, required technological developments before they were brought under control. Roof Control Plans, which the US Bureau of Mines had been advocating since the 1920s, played a significant role throughout the process.

Mar 12, 2024

By W. Chae

The influence of solution ionic strength (IS) and electrolyte valence on the flotation behavior of malachite has been investigated. The microflotation tests were conducted over a range of solution IS (1?300 mM) at a constant speed (340 rpm), pH (9.5), flotation time (10 min), and sodium oleate dosage (5.3×10-7 moles/g). The size of malachite ranged from 45 to 53 µm, and two different types of electrolytes (NaCl and CaCl2) were employed. Electrophoretic mobility was also measured over the same IS range employed in the microflotation study. Overall, strong coupled effect of solution IS and ion valence was observed. Specifically, the flotability of malachite increased with increasing IS in the presence of monovalent cation (Na+) while the flotability increased up to 30 mM and decreased with increasing IS in the presence of divalent cation (Ca2+). Notably, the flotability of malachite was greater with the presence of Na+ compared with Ca2+ under high IS conditions (IS>30 mM). Consistent trend for Na+ versus Ca2+ was observed from the flotation results with different SO dosages. The characterization and flotation results suggested that the trend was likely attributed to the increased unfavorable interaction between malachite and bubble via the charge reversal of bubbles and malachite at higher IS in the presence of Ca2+.

Feb 27, 2013

By Olivier Kraft, Olaf Kortz

"Project-specific optimized tunnel boring machines represent the spearhead of technological progress in tunneling because with their use, very long-lasting, high quality tunnel structures in almost any geology, depth and topography can be produced with a high degree of automation. The mechanized excavation of tunnel structures ensures the greatest possible environmental protection during tunneling itself. Professional, systematic and high quality rebuilds and reuse of already proven equipment also ensures maximum efficiency in the use of materials and energy resources. It offers an enormous potential for a highly optimized environmental balance. Here the manufacturers of tunnel boring machines and their users in particular have a duty to ensure transparent, high quality and binding standards in the entire rebuild cycle and in the refurbishment management of innovative tunneling technology. This paper deals with the comprehensive processes with rebuild levels of tunnel boring machines and highlights some exemplarily implemented projects. 1 INTRODUCTION All over the world, the number of tunnel boring machines (TBM) in which equipment rebuilds from previous projects are re-used has increased over the last few years. This text presents the technical and economical aspects of this market development. It also takes a look at the practical implementation of rebuild measures. The ""ITAtech Guidelines on Rebuilds of Machinery for Mechanized Tunnel Excavation"" from 2015 lay down the requirements that the machine manufacturers must meet. 2 ECONOMICAL AND ECOLOGICAL ASPECTS OF RE-USING COMPONENTS The globalization of the construction sector and the consideration of environmental aspects promote an increased re-use of machines and machine components. Nowadays, large-scale construction projects are often carried out by international joint ventures of several individual companies that are established specifically for this purpose. After the completion of the project, the joint ventures are dissolved and they liquidate their project-specific equipment, such as tunnel boring machines. Today, it is much more uncommon for such machines to remain permanently in the possession of construction companies. Joint ventures offer TBMs on the free market, or they exercise contractually agreed repurchase options with the manufacturer. On the whole, this increases the number of re-usable components or complete tunneling systems available on the market."

Jan 1, 2016

By Samer Sadek

The Georgia Department of Transportation (GDOT) undertook an exploratory feasibility study to one of the most ambitious tunneling projects in the United States. HNTB Corporation was retained to perform the study, deemed the Atlanta North-South Tunnel, which is approximately 7 miles long and consisting of four lanes (or six lanes) starting at the southern terminus of SR 400 extending to the south connecting with the northern terminus of I-675, providing substantial relief to the Downtown Connector (I-75/I-85), the most congested portion of Atlanta?s freeway system. This paper summarizes the analysis performed during the first phase of this challenging assignment which, if constructed, would be one of the longest roadway tunnels ever built in the United States.

By D. E. Severson

The coal solution refining process under investigation is basically a modi¬fication of the German Pott-Broche Process, on which patents date back to 1927, (5, 6). This process was used in Germany during World War II for the partial dissolution of coal in hydrocarbon solvent and removal of the ash by filtration to produce a raw material for carbon electrodes for aluminum plants. At the end of World War II the German synthetic fuel program, of which this process was a small part, was abandoned as not economical. In recent times the whole field of coal liquifaction has been given a new impetus; present technology indi¬cates that the economic processing and refining of coal may be possible in the United States. A number of approaches to coal liquifaction have been investigated, and several of these are currently being funded by the U. S. Office of Coal Research. One approach is direct thermal treatment of the coal as in the FMC Project COED, in which coal is thermally cracked to produce gas, liquid products and char. Another approach is the Hydrocarbon Research Institute's H-coal process in which coal is catalytically hydrogenated. Two other federally funded projects involve the extraction of coal by solvents. The Consolidation Coal Company's Project Gasoline, now in the pilot plant stage in Cresap, West Virginia, is an attempt to produce gasoline plus a residual char by partial solution of the coal substance. The coal de-ashing process being developed by the Pittsburgh and Midway Coal Company is a modification of the Pott-Broche process. Coal derived solvent is used with hydrogen to dissolve the entire coal substance, subsequent filtration removes the ash and the solvent is recovered for recycling.

Jan 1, 1968

By J. Rao Mokka

Extensive exploration has resulted in delineation of a massive sulfide district on the north flank of the east-central Alaska range. The district covers approximately 400 square miles and contains numerous stratiform; transported and some replacement type sulfide deposits ranging in size from less than 1 million tons to 20 million tons. Five types of ores were sampled for the study. Mineralogical analysis revealed that the minerals are too fine grained for conventional grinding and beneficiation. Hydrometallurgical studies were con-ducted using ferric chloride as a lixiviant. Ore microscopic studies as well as electron microprobe analyses of minerals in the raw samples and leach residues explained the low recoveries for certain elements as well as sources of impurities that need to be eliminated from the process streams.

Jan 1, 1991

By Will B. Jamison

The most serious safety problems encountered in U. S. underground coal mines today are related to the roof bolting operation. Also, roof bolting is usually the operation which limits coal production of the section. The purpose of my paper is to review some of the research, developments, and new ideas related to roof bolting. Many of these ideas have originated at. coal mines or with manufacturers. Most of the research on fundamental improvements has been funded by, and is a part of, the excellent and broad plans of the Bureau of Mines.

Jan 1, 1977

By I. J. Duckworth

During the last twenty years computers have be-come widely used to assist with the simulation and design of large scale, primary ventilation systems. However, to date there are few computer programs available to help with the modeling of auxiliary ventilation in dead-end headings or tunnels. This paper presents the results of the first year of a research and programming study dedicated to the development of a user-friendly duct simulation tool. Included is a literature review that summarises publications on duct leakage and resistance, on previous programs developed for the simulation of airflow in ducts, and case studies on extended ductlines in mines and tunnels. The methodology behind the development of Ductsim, a Windows based simulation program is presented.

Jan 1, 2000

By Viktor Lishchuk, Olof Martinsson, Tobias E. Bauer, Elena Haller

Freely accessible and non-confidential real-life geological data sets from mineral deposits are desirable for the wide range of applications in research and education. However, publicly available statistical data are limited in their number and quality—they contain reduced information about geological, geophysical, geotechnical, chemical, mineralogical, and other relevant properties of deposits. This makes such data insufficient for scientific purposes. However, the amount of geological knowledge obtained for a variety of deposits in the past allows the construction of an idealized synthetic ore body model using analytical approach. Such a model could be used for education purposes and testing basic scientific theories, e.g., visualization of deposit structure; teaching sampling strategies; testing new algorithms for mine planning; or comparing geostatistical modeling methods. This paper presents an analytical approach to simulate volcanic massive sulfide (VMS) deposits and shows how synthetic deposit model can be constructed and further used for studying sampling with drilling and simulating folding and faulting.

Jan 14, 2021

Ceremonies for the induction of five mining industry pioneers into the National Mining Hall of Fame are scheduled for Saturday, Sept. 25, 2004 at the Las Vegas Hilton in Las Vegas, NV. The 17th Annual Mining Hall of Fame Induction banquet will begin with a reception at 6 p.m., followed by the dinner and program at 7 p.m. The five inductees are Georgius Agricola, David William Brunton, Herbert E. Goodman, David Ray Mitchell and Robert Peele. Georgius Agricola (1494-1555) wrote De ReMetallica, an original and valuable work that discussed everything known about mining during the first half of the 16th century. In De Re Metallica, Agricola reviewed practical means of finding ores, methods of surveying and mining, the assaying of ores, types and uses of mining machinery, smelting, mine administration and more. David William Brunton (1849-1927) is best know

Jan 1, 2004

By Don C. White

The Vulture mine near Wickenburg, Arizona was a major gold producer from 1863 to 1942, having yielded about 11t(12.1 st) Au and 8t (8.8st) Ag. Gold occurs as coarse native metal and electrum in quartz veins and also finely dis¬seminated within a quartz monzonite sill and its silicified wall rock. The sill is semi-conformable within a Proterozoic volcaniclastic-dominated sequence, all dipping north about 35°. Early mining focused on the vein-hosted gold, particularly in the immediate hanging wall and footwall of the sill. Later efforts included some open-pit mining of the outcropping sill and adjacent altered and mineralized rock. Two sets of post-mineral faults have complicated the orebody geometry. The sill is a 350 m (1148 ft) long apophysis from a quartz mozonite stock to the west of the mine area. The stock has been dated at 85 my and contains abundant lesser gold occurrences in its core and about its margins. The Proterozoic rocks are notably lean in precious metals except where altered in proximity to the Creataceous stock and sill. Circumstances dictate an interpretation of epigenetic mineralization related to the Laramide intrusion.

Jan 1, 1990

A new analytical approach for characterizing and improving the performance of ball milling is presented. Individual ball mill circuit design and operating variables can be related to overall circuit performance through two distinct parameters for classification and breakage. The ball mill circuit functional performance equation is presented. Applications in the industrial plant and in the research field are discussed.

Jan 1, 1990

By S. -Y. Hwang

An ongoing problem for industry in Korea is effective removal of heavy metals from and safe disposal of spent power plant fly ash. This research endeavor attempts to develop selective separation of Ni from leach liquor using a selective chemical precipitation method. The research was conducted by changing two variables, the pH and the concentration of ions in solution. The effect of other ions present in the system on the separation efficiency of Ni species was also investigated by adjusting OH and NH3 concentrations. In the pH range of 7-9, the chemical precipitation method produced a high yield of Ni by precipitation from the fly ash leach liquor.

Jan 1, 2010

By T. I. Martinovic

A major investigative' program was conducted on the development of an acceptable substitute organic binder for bentonite for the pelletizing of the Iron Ore Company of Canada's Carol concentrate. The first phase of the program covered an evaluation of several organic binders in laboratory tire balling in order to identify the most promising potential organic binders. Based on the green ball quality obtained, Peridur C-10, Alchem 8C26 and peat moss were selected for full scale pot-grate testwork. The selected binders were tested with various pelletizing mixes (acid, dolomite, limestone and fully fluxed). The pot-grate test results showed that an acceptable pellet quality can be produced with the use of Peridur C-10.

Jan 1, 1989

By B. Berg, J. Stephenson, J. Mansanti, C. Nyikos

"Intrepid Potash, Inc.’s Carlsbad East facility has refined sylvite and produced muriate of potash (MOP) since 1965. In addition to MOP, Intrepid Potash began recovering the mineral langbeinite from a mixed ore reserve in 2005. In 2011 a new langbeinite recovery process for the coarse (+850 micron) size fraction was constructed to enhance the overall langbeinite recovery. Based on the limited mixed ore reserve and an abundance of langbeinite ore reserves the transition of the East plant to a langbeinite only facility was targeted for 2021. Due to a decreasing grade of the mixed ore reserve, declining sales pricing, and high sylvite operating costs a strategic decision was made to accelerate this transition into 2016. To enable a successful transition, a fines recovery system needed to be developed, constructed and implemented. This paper describes the advancement of langbeinite processing at Intrepid Potash and the planning, development and successful execution of the transition to a langbeinite only operation. BACKGROUND Langbeinite (K2SO4·2MgSO4) is a double salt containing potassium sulfate (K2SO4) and magnesium sulfate (MgSO4). It is used as fertilizer and in the industry is described as Sulfate of Potash Magnesia. It is attractive as a specialty fertilizer and in addition to containing a ready source of a primary nutrient potassium, it also provides two secondary essential nutrients, magnesium and sulfur. It is especially attractive for chloride sensitive crops. Langbeinite has a specific gravity of 2.8, a Mohs hardness of 4.2, and is brittle thus very friable. It is the hardest of the saline minerals, and despite its relative softness on the Mohs scale can be very abrasive in process environments and in field applications, probably due to its conchoidal cleavage. Its solubility at 240 g/l is less than the solubility of sylvite (KCl) or halite (NaCl) and due to even slower relative dissolution kinetics washing with cold water has been a common practice for upgrading langbeinite ores. The solubilization/crystallization relationship for langbeinite is different from the majority of other evaporite minerals in that once langbeinite is solubilized it does not form langbeinite again. Instead it gives up one mole of magnesium sulfate, takes on various waters of hydration and precipitates out as either schoenite (K2SO4·MgSO4·6H2O) or leonite (K2SO4·MgSO4·4H2O) depending on temperature. Due to its partial solubility and phase transitions at its surface when exposed to moisture, there is strong cohesion between wetted particles; the resulting stickiness of the upgraded products can create significant materials handling issues unless processed in slurry form or at relatively low moisture levels. Langbeinite has been produced commercially from two locations, the Kalush and Stebnik regions in the Cartpathian Mountains of former Poland and now the Ukraine and from the Permian Basin in New Mexico (Garrett, 1996; Smith 1949). Current production is from two operators in the U.S., Mosaic and Intrepid Potash."

Jan 1, 2017

By R. L. Virta

Twenty-three companies mined kaolin in nine States in 2004. Production was estimated to be 7.6 Mt (8.3 million st) valued at $912 million, based on preliminary data. This was a slight decrease from 7.68 Mt (8.46 million st) valued at $939 million in 2003.Georgia was the leading producer state with an estimated 6.5 Mt (7.1 million st) in production. It was followed, in decreasing order of tonnage, by South Carolina, Alabama, California, Texas, Arkansas, Nevada, Florida and North Carolina. Georgia accounted for nearly the entire domestic water-washed, delaminated, and pigment-grade calcined kaolin production. Consumption Sales to the paper industry accounted for 49 percent of domestic sales and 64 percent of total sales. Other major markets for domestic sales were refractory products (10 percent), paint (5 percent), fiberglass (4 percent), catalysts (3 percent) and rubber (2 percent).Paper coating and filler markets accounted for about 87percent of export sales of kaolin.

Jan 1, 2005

By Frederic Chavan, Hans Jakob Windier, Shane Yanagisawa, Willy Ritz

The Zurichberg twin track tunnel is the main segment of the Swiss Federal Railway's new expressline. A heavy concrete lining with a circular cross-section was chosen to cope with the swelling tendency of the surrounding rock. The 4,356 m (14,300 ft) long, 11.52 m (38 ft) diameter tunnel was driven using a shielded Robbins TBM. A 1.20 m (4 ft) wide, 25 cm (10 in) thick precast lining was placed from within the shield tail as the excavation progressed. Tunnel excavation and initial lining operation were completed in 18 months, averaging 11.86 m/day (40 ft/day) in two nine hour shifts. After breaking through, the final 28 cm (11 in) thick concrete arch lining was cast in place.

Jan 1, 1989

By Francis J. Quinn

The Natural Gas Act, of 1938, which put interstate pipelines under the jurisdiction of the Federal Power Commission, did not place a protective competitive shield around such companies - nor does any provision of the act guarantee them a profit. Natural-gas pipelines are competitive with each other and also with the coal and oil industries. Gas distributing companies must compete not only with the coal and oil industries, but also with the electric industry. Natural gas has captured markets from oil, which had taken them from coal. Oil men contend that gas prices have: been, held to an artifically low level by regulation. The electric industry is moving into the space-heating market, which pleases the coal people because the coal industry's largest customer since losing the railroads to dieselization has been the electric companies. The coal industry is attempting to monopolize the industrial and electric generating market through government intervention, and this is being done under the guise of concern for the national welfare through advocation of a "National Fuels Policy purporting to, further the cause of fuel conservation. Such a policy is contrary to American principles and would result in the individual's loss of freedom of choice and ultimately, in less reserves of preferred fuels because of diminished exploration efforts.

Jan 1, 1961