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By Gregory M. Dexter

Recent litigation in Pennsylvania between three coal-mining companies and a private water company resulted in the payment by the coal companies of the equivalent of about $500,000 to buy a new water supply to replace that which had been damaged by acid drainage from strip mining. An investigation of the relevant facts indicates that the water could have been treated by spending about $40,000 on equipment and $15,000 yearly for chemicals, labor, and power until the contamination could be reduced about 80 pct. The water company's supply, furthermore, had deteriorated largely by reason of dry weather before stripping was begun by the coal companies. Payment to the water company should not have exceeded $300,000 and could have been as low as $100,000. Strip mining of coal is common in Pennsylvania. The most important objection to it in Pennsylvania is generally acid pollution of runoff water. An outline of the methods, therefore, that could be used to reduce such pollution, to compare acid-contaminated waters, and to treat such waters to make them satisfactory for public and industrial use is worth-while. The watershed of the West P~M Water Co. covers about 4.5 square miles, 20 miles west of Pittsburgh, and has two 90,000,000 gal reservoirs sup- plying about 1,300,000 gal daily for public and industrial use of which 450,000 gal daily are for two railroads. The pollution arises from weathered derivatives of typical "Coal Measures"

Jan 1, 1949

Mineral Processing Education in China

Sep 13, 2010

By Ronald E. Heuer

A 1995 RETC paper of similar title presented a method for estimating rock tunnel water inflow based on semi-empirical correlations with borehole water pressure tests. Since that time the author has found the method to be very useful, and it has been used by others in the industry. This current paper is an update which is intended to: A. More clearly explain assumptions and limitations of the method. B. Describe some case history examples. C. Respond to questions which have been raised; and extend the method to other considerations including distribution of inflow along the tunnel, panning requirements, interpretation of tunnel probe hole water inflow, and estimation of potential effectiveness of pre-excavation grouting to reduce water inflow.

Jan 1, 2005

By Kelvin K. Wu, George H. Gardner

On July 24, 2002, a nonfatal entrapment accident occurred at the Quecreek #1 Mine, Black Wolf Coal Company, when an active mining section inadvertently cut into a flooded abandoned mine. This incident, and the dramatic rescue which ensued, brought national attention to a common problem in the coal mining industry. Since 1995, there have been more than 100 inundations at coal mines in the United States. Unavailable, inaccurate, or incomplete mapping of older abandoned mines is typically responsible. Serious problems associated with accidental discharges of fluid mine waste material (slurry) and water from coal refuse disposal facilities have resulted from similar causes. Recent problems related to the inaccurate location of old abandoned mine works have increased the interest in the use of conventional and emerging drilling and geophysical techniques for detection of air-filled and water-filled cavities. The United States Congress has committed significant funding toward investigating the applicability of these technologies. MSHA actively promotes the use of the best available technology to minimize the significant adverse safety and environmental consequences associated with unplanned breakthroughs and inundations. This paper provides background information and a general summary of the MSHA-sponsored field demonstration projects which are currently in progress. Potential benefits and limitations are discussed. The need for field verification/ground-truthing is emphasized. Under appropriate conditions, geophysical methods can be effectively integrated into a comprehensive field exploration program.

Jan 1, 2005

The ERMS Process was developed during four years of testwork by Austpac Gold NL to overcome the severe metallurgical problems of the ilmenite atWestport, in the South Island. These deposits have been known for about one hundred years. They were originally mined for gold, and only later attracted attention as a possible source of titanium minerals.   The resource is of world scale and may exceed 20 million tonnes of contained ilmenite. Similar deposits occur at Barrytown further south and together these areas would constitute an important opportunity for export-oriented mineral development, if a viable beneficiation technology were available. Further processing is essential, as the composition of the ilmenite is well below market specifications.

Jan 1, 1993

By Don Z. Painter, Gordon F. Revey

Frontier/Traylor Joint Venture is presently constructing a section of the Tri-County Metropolitan Transit District of Oregon's (TRI-MET) Westside Light Rail system. This new section will extend Portland's existing transit system to the western suburbs of Beaverton and Hillsboro. The drill-blast excavations at this project include 10,000 feet of 20 foot tunnel, 18 cross passages, three shafts, an underground railway station, and a U-wall open cut. From a blast designer's perspective, this job has been extremely challenging. Blast vibration is limited to 0.5 ips at 200 feet or at the nearest structure, and airblast is limited to 129 dB -- linear peak and 96 dB -- C scale. The tunnels pass under heavily built up areas and have top of tunnel to surface cover distances as low as 70 feet. Surface blasting in the 26,000 cubic yard U-wall excavation was limited to five short nighttime periods due to its proximity to the very busy highway 26.

Jan 1, 1995

By Sean Gallagher, Thomas G. Bobick, Diane M. Doyle-Coombs, Richard L. Unger

The U.S. Bureau of Mines has developed an in-house facility to evaluate selected effects of whole-body vibration (WBV) levels experienced by underground mobile equipment operators, Vertical vibration data were collected from a coal haulage vehicle via a uniaxial accelerometer attached to the machine frame under the operator&apos;s seat. Data were analyzed and processed so a computer-controlled platform could approximate the vibration signals. Eight men (35.5 yr 2 6.5 SD) participated in a pilot study to evaluate the effects of shock and kBV on heart rate (HR), blood pressure (BP), and subjective discomfort. Subjects were exposed to vibration for 30-min periods while seated in a typical seat (backrest angle at 90° or 130°) &apos;that was plain steel or modified with 2 in foam padding. Subjects repeated the same protocol on a separate day, without the vibration. Results indicated the vibration significantly increased the HR (Q< 0.01), systolic BP, mean BP, the number of times subjects reported discomfort, and overall subjective discomfort rating (pc 0.85). When seated in the steel seat, the overall discomfort rating (E< 0,081) ad the number of times discomfort was reported (p< 0.05) increased significantly. Seatback angle had no significant effect on any of the dependent measures.

By Hisataka Sakakibara

Although the pathophysiology of vibration-induced white finger (VWF) is still under discussion, evidence has been accumulated to understand the underlying mechanism. VWF is pathophysiologically characterized by an enhanced vasospastic response to cold, which can result from an imbalance between vasoconstriction and vasodilation in the digital arteries in response to cold (i.e., vasoconstriction-dominant). The imbalance is supposed to be due to faults in vascular vessels and sympathetically mediated vascular tone. Enhanced vasospastic response to cold Narrowing of arterial lumen with medial smooth muscle hypertrophy. Possible functional factors for enhanced vasoconstriction • Increased sympathetic nervous activity to cold (e.g., norepinephrine) • Increased release of endothelin-1 (ET-1; an endothelial-dependent vasoconstrictor) from the endothelium • Increased reactivity of alpha2-adrenoreceptors to cold Possible functional factors for decreased vasodilation • Decreased release of nitric oxide (NO; an endothelial-dependent vasodilator) from the endothelium • Decreased release of calcitonin gene-related peptide (CGRP; a vasodilatory neuropeptide) from sensory afferents The question is how their interrelations or imbalances among them are Vibration and arterial damage The next question is, how does hand-arm vibration exposure induce such pathophysiological changes in VWF patients? Recent morphological evidence from animal experiments shows that vibration acceleration stress (including shear stress) and smooth muscle contraction contribute to arterial damage of smooth muscle and endothelial cells. The vibration-induced arterial damage is frequency-amplitude-dependent.

Jan 6, 2006

By Masaki Imamura

A novel hydrometallurgical process for copper concentrate treatment has been developed by Niihama Research Laboratories of Sumitomo Metal Mining Co., Ltd. The process has numerous advantages with respect to the operational and environmental aspects. For example, copper is leached effectively from chalcopyrite concentrates by chlorine gas under atmospheric pressure. The copper in the leach solution is then separated from iron and silver by solvent extraction and undergoes electrowinning for its recovery as a highly pure copper metal; this does not require any further purification. Moreover, iron metal can be produced from the purified raffinate by electrowinning without generating a large volume of goethite or hematite, which are solid wastes generated due to iron rejection in common hydrometallurgical processes. This process can also realize the efficient recovery of precious metals. The results of batch testing and continuous-operation testing are presented in this paper.

Jan 1, 2006

By Joseph A. Holmes

The investigations carried on at the fuel-testing plant of the United States Geological Survey at St. Louis in 1904-1907 included tests of the steaming and gas-producing qualities of many coals and of the possibilif3 of their improvement by briquetting, together with washing and coking tests and tests of some of the resulting coke in the cupola. These tests were part of a general inquiry into the manner of utilizing most efficiently each of the coals under investigation. The equipment used in the cupola tests of coke, the manner of conducting the tests, and the essential results have been described in publications of the Geological Survey," and only the more important conclusions to be drawn from the tests are mentioned in the following pages. The tests were made to show the fitness of the cokes for foundry purposes, but an incidentlll result was to show foundry men and the coke producers the advisability of studying the conditions of foundry practice. The present bulletin, published by the Bureau of Mines because the analyzing and testing of fuels have been transferred from the Gilological Survey to the Bureau of Mines, briefly reviews the status of the coke industry, some features of practice in the use of coke in the foundry, the probable happenings of a cupola heat, and the reasons for modifying charging practice so that a particular coke can be used to best advantage.

Jan 1, 1910

By Wang Shulan

The synthesis process of BaTiO3 from TiO2 and BaCO3 in the molten NaOH-KOH at 350oC was studied by the A.C impedance technique. The A.C. impedance of molten NaOH-KOH (xNaOH = 0.36) and the variation of the conductivity of the salt with time during the synthesized process were measured. The synthesized reaction of the BaTiO3 and the decomposition reaction of BaCO3 are fast and were finished in 10min. The interaction between TiO2, BaO and BaTiO3 and the molten salt was confirmed by the variation of the conductivity.

Jan 1, 2005

By Michael G. Nelson

Control of the feed provided to mineral processing facilities is a continuing challenge. Much effort is currently being devoted to overcoming these problems. These projects are usually described under the general headings of Mine-to-Mill Integration or Mine-Mill Optimization. It should be possible to combine the knowledge of ore type, mineralogy, and other characteristics (located in the mine modelling system), with the advanced capabilities of state-of-the-art mill control systems, to achieve an improved level of control in mineral processing, allowing optimization of the mill processes on an almost realtime basis. This is not happening because mill feed it is often treated as a uniform material, when in reality it varies in composition and characteristics. The University of Utah is investigating the use of odor sensors for maintaining traceability in ore production and processing. Odor sensors now used in food processing, environmental monitoring, and other applications can detect the presence of very small amounts (0.1 - 500 ppm) of some molecules. An assortment of such molecules could be used to ?tag? blocks of ore as they are mined, according to their respective characteristics. Then, as the ore came into the mill, an array of ?electronic noses? could be used to assess its characteristics in real time.

May 1, 2004

By Ovsei Volberg

Motion capture involves recording the position and global orientation of joint sensors of a real object, in most cases a real person performing some human activities. This information is usually recorded at uniformly spaced instances of time, or as it is often called frame-by-frame. Then the recorded motion data sets are processed and mapped into a skeleton hierarchy of a virtual, computer simulated human figure to control the motion of the virtual human in the computer simulation. In the first part of the paper we review several new techniques developed to facilitate the manipulation, noise reduction, storage and reuse of captured data, which have a potential to reduce the overall cost of motion simulation and improve its realism. In the second part of the paper we consider the real life problem of reducing a worker?s risk from being hit by underground mining machinery in a confined space. We formulate a set of requirements to motion editing for this particular task and analyze the limitation of existing techniques

Jan 1, 2000

By Peter N. Gabby

In 1992, the Bureau of Mines conducted a mineral resource investigation of the 27,034-hectare Steel Mountain/Yuba River study area and the 16,544-hectare Breadwinner study area. There were approximately 535 lode and placer claims in or partially in the Steel Mountain/Yuba River study area, and 84 lode and placer claims in or partially in the Breadwinner study area. In the Atlanta and Rocky Bar mining districts, both adjacent to and in the Steel Mountain/Yuba River study area, 30,232.4 kg (972,000 02) of gold and 62,838.3 kg (2,020,000 02) of silver had been produced. Most of this production came from outside the study area. Placer properties adjacent to (and a few in) the Breadwinner study area had production of 93.1 kg (2,992 oz) of gold and 20.0 kg (642 02) of silver. Twelve properties in the Steel Mountain/Yuba River study area have potential for resources; eleven have alteration and/or mineralization similar to that found at Atlanta with potential for gold, silver, and tungsten resources, and one has alteration and mineralization associated with polymetallic vein type deposits with potential for gold, silver, copper, lead, zinc, and tungsten resources. Adjacent to the study area, large bars of gold-bearing gravel can be found along the Middle Fork Boise River. Four properties in the Breadwinner study area have potential for mineral resources; one has alteration and mineralization associated with skarn, polymetallic vein, and, possibly, copper-molybdenum and molybdenum porphyry types of deposits; two have alteration and metal assays associated with polymetallic vein, and possibly copper-molybdenum and molybdenum porphyry types of deposits; and one has alteration and mineralization similar to that found at Atlanta. These four have potential for gold, silver, copper, lead, zinc, molybdenum, and tungsten resources Adjacent to and extending into the Breadwinner study area are large bars of gold-bearing gravel along North and Middle Forks Boise River.

Jan 1, 1993

Flotation testing has been done at laboratory scale on hematite mineral and ore samples using stage additions of various hydroxamates. Chemisorption of hydroxamate species onto the hematite surface was inferred from the results, possibly involving both the undissociated hydroxamic acid and hydroxamate ion as maximum recovery occurred close to the pKa of the hydroxamic acid. Flotation testing on a specular hematite ore containing 40 per cent Fe and 42.5 per cent silica gave highest iron grades in concentrate at pH 6, in contrast to published data which suggested pH 9 as the optimum value for ore processing. Using octyl hydroxamate, a rougher concentrate assaying 67 per cent Fe at 51 per cent recovery was obtained using four stage additions of 50 g/t at pH 6. For lower grade concentrates still meeting the chemical analysis for pigment grade micaceous hematite (minimum Fe assay 60 per cent) iron recoveries of 80 per cent were possible for stage additions of 50 g/t octyl hydroxamate in the pH range 6-8.

Jan 1, 1999

ME?s Arizona Conference was held at the Hilton El Conquistador resort in Tucson on Dec. 2 and 3, 2007. The annual conference is organized by the Arizona Conference Board of Directors, which represents SME sections in Arizona and adjacent areas. The conference provides an opportunity for individuals and corporations associated with mining in the region to get together once each year to discuss the status of the industry. The 2007 meeting featured a keynote address, a distinguished lecturer and more than 25 technical papers that were presented in seven sessions. The sessions included environmental, geology, safety, metallurgy, mining, new projects and a special session on Mexico. Topics covered included mine closure, sustainable mining, exploration methods, health and safety issues, mining equipment and drilling. Much of the discussion at the conference concerned major new developments in the region?s copper mining industry. For example, Freeport-McMoRan?s new Safford Mine and BHP Billiton?s Pinto Valley restart were the topics of technical presentations. There was also much discussion among the attendees on the current and future price of copper, community relations, education issues and recruitment concerns. At the time of the conference, the price of copper hovered around $3.30/lb, up considerably from the 61 cents/lb in late 2001, when the industry was being challenged by world market conditions and a weakened domestic economy. Since then, strong demand from China helped push copper prices to record levels that at one time reached as high as $4/lb. The general consensus among the attendees is that the current price of around $3.30/lb will continue through 2008. Most attendees also expect increased corporate investments in the industry to continue. Copper mining in Arizona has been a major industry since the 1800s. In 2007, Arizona was the leading copper-producing state in the United States and produced more than $5 billion worth of copper. The copper mining industry in Arizona also produces byproduct gold, silver and molybdenum. Arizona is the second largest molybdenum producer in the United States.

Jan 1, 2008

By Anthony J. Miscoe, William M. McKewan, Richard C. Wang

The behavior of wire ropes used in hoisting is not well understood. In an effort to improve this understanding, the structure of round-strand wire ropes was analyzed. This report provides a generalized mathematical model that completely describes the geometry of the wires. It consists of two sets of vector equations and is valid for any round-strand wire rope. One set of equations is used to trace the paths of wires that have the form of a single helix; the other is used for the paths of double helical wires. The specific model for a 33-mm 6×19 Seale, independent wire rope core (IWRC), right regular lay wire rope was presented as an example. The paths and the geometric properties of the wires, which include the path length per lay of strand, the curvature, and the torsion, were determined from this model. The effects of strain deformation were analyzed, resulting in a system of equations for determining the structural parameters of the deformed rope. In future work, the model could be used to analyze wire ropes of different constructions so that a more scientifically based understanding of rope behavior can be established.

Jan 9, 1998

By Christopher C. Jobes, Alan G. Mayton

The National Institute for Occupational Safety and Health (NIOSH) researchers have investigated seat design issues for the occupants and operators of underground mine transport vehicles relative to whole-body vibration (WBV) and mechanical shock. Considering the ergonomic and engineering improvements made to underground mine shuttle car seats, this study has focused on reducing injury risk by improving seating on transport vehicles such as scoops, mantrips, personnel carriers, and rail-mounted locomotives. Similarly, proposed seat design improvements included layering of various types of viscoelastic foam padding to isolate vehicle occupants and operators from adverse health effects of jarring/jolting exposure. This paper discusses the results obtained from laboratory vibration testing of new seat padding materials in seven configurations at the NIOSH – Pittsburgh Research Laboratory (PRL) showing that careful use of configuration and materials can reduce the operator’s exposure to WBV. In addition, results for four mine transport vehicles are presented from field data collection efforts at a Southwestern Pennsylvania mine showing that a NIOSH based design does reduce the operator’s exposure to WBV. Finally, the authors discuss efforts to develop and field test seat padding interventions using new padding materials and configurations based on the laboratory test results [The findings and conclusions in this report are those of the author(s) and do not represent the views of the National Institute for Occupational Safety and Health.]

By Ron Ketterling

We will discuss electronic and paper record keeping, what works and what doesn’t. We’ll review record keeping in light of those five sub-committees: Audit, Awards, Constitution, Ethics and Planning. You’ll come away with concrete steps you can use to improve your record keeping processes

Feb 1, 2020

By A. Salmoni, E. K. Gillin, T. Eger, A. Cann, P. Vi, M. Hunt

Kittusamy (Kittusamy & Buchholz, 2004) state that there have been few studies conducted to assess exposure to whole-body vibration (WBV) in the construction industry. They suggest that there is very little reliable data from the construction industry that characterizes exposure levels to various hazards including WBV or the health outcomes from such exposure and that there is a need for more exposure data. In a recent exploratory study of heavy construction equipment Cann (Cann, Salmoni, Vi, & Eger, 2003) looked at vibration levels for 14 different types of construction equipment. Eight of the 14 pieces of equipment tested exposed operators to levels of WBV that exceeded the recommended limits for an 8-hour period when comparing the measured VDV to the ISO 2631-1 standards. The purpose of the present research was not only to test a larger number of scrapers but also to investigate scraper operator exposure to whole body vibration (WBV) separately for each task. Methods 33 scrapers were evaluated for WBV in a variety of residential and road construction projects. Testing equipment consisted of triaxial accelerometers that allowed vibration data collection in all three orthogonal axes, with the x-axis positioned to measure vibration in the anterior-posterior direction, the y-axis in the medial-lateral direction, and the z-axis in the vertical direction. Root mean square accelerations (aRMS), vibration dose value (VDV), crest factor, and maximum transient vibration values (MTVV) were derived from this software and exported to an Excel™ spreadsheet for later data analysis. Test sessions for each piece of equipment lasted for approximately 20 minutes until at least three work cycles had been completed. Tasks included: idling while waiting for a bulldozer to push the scraper through the scraping phase, scraping, traveling loaded with dirt, dumping and traveling empty. Results Task breakdown by time reveals 25% of the work cycle was spent traveling fully loaded with dirt, 19% dumping, 21% traveling unloaded, 17% idling and 18% scraping. Calculation of aRMS vector sums gave values of 2.55 m/s2 during loaded transport, 2.46 m/s2 during dumping, 2.31 m/s2 during unloaded travel, 0.55 m/s2 during idling and 1.46 m/s2 during scraping (see Table 1). The highest acceleration values recorded were found in the z-axis during fully loaded transport reaching an average aRMS over three work cycles of 2.55 m/s2.

Jan 6, 2006