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Well designed and maintained haul roads are the key to minimizing truck haulage on-road hazards and costs, as well as increasing productivity. However, practically designing and managing a haul road for optimal performance is often difficult to achieve. Poorly designed and built roads exhibit high rolling resistance - a 1% increase in road rolling resistance can typically reduce speed on ramp by as much as 10% - and on the flat by up to 26%. In the current economic climate, investment and operating decisions come under scrutiny. In the long run, this scrutiny returns improved efficiencies and leaner, healthier operations. The focus of this evolving evaluation process should and will certainly fall on haulage operations ? simply by virtue of their contribution to overall cost of operations ? often in excess of 50% of total costs for deep open-pit mines. Whilst the end result - improved efficiency and reduced cost per ton hauled ? is not in itself problematic, it is the route, or process followed to achieve these savings that needs to be carefully managed. We can be guided on this journey by our understanding of how a road design is developed, and, critically, the interplay between a good design and safe, cost efficient haulage. This paper briefly summarizes the evolution of mine haul road design, from the seminal USBM work of Kaufman and Ault in 1977, through to current geometric, structural, functional and maintenance management design components. These augmented design and management guidelines have been developed over the past decade, both in response to the requirements of mine operators for more safe and efficient haulage systems, and the truck manufacturers? requirements for a more predictable and controlled operating environment. These developments have been paralleled by the need to minimize haulage hazards, both from a health and safety perspective. Whilst improved mine haul road design does indeed reduce haulage accidents, recognition also needs to be given to human factors which are a significant contributor to haulage accidents. The human factor is the most problematic to address in a road design. It is often easier break the link between the interactive effects which may lead to accidents than trying to predict and reduce human error. These human factor interactive effects include the geometric, structural and functional design components and to prevent an accident or reduce the severity of its consequences, a road should be more accommodating to human error. The more that is known about human error, the better a road can be designed to accommodate those actions or non-standard practices that would, on a poorly designed road, invariably escalate an error into an accident.

Jan 1, 2010

By William A. Gibson, Kenneth P. Neumann

In 1967, development of the Cyprus Thompson Creek molybdenum deposit began near Challis, ID. The first mining claims were staked on an intrusive rock out-crop. Exploration continued for 14 years. In 1978, the decision was made to develop the deposit. In Dec. 1980, approval was received for the environmental impact statement and facilities construction and waste rock removal began. By the middle of 1983, 126 Mt (139 million st) of rock had been removed and all facilities completed. Location The Thompson Creek project is located about 58 km (36 miles) southwest of Challis in Custer County, in south central Idaho. The mine and mill are situated between 2.2 and 2.6 km (7,217 and 8,530 ft) in elevation. The project is located in an isolated area. Surrounded by mountains, it is adjacent to the Sawtooth National Recreation Area. The Salmon river is 8 km (5 miles) south of the project. The project claim block is lo-

Jan 1, 1984

By T. E. Gray, A. W. Deurbrouck

This report describes the preparation characteristics of significant coalbeds in Kanawha County , W. Va . It is one in a series of Federal Bureau of Mines reports planned to determine coals suitable for producing metallurgical coke , either as mined or after beneficiation . Almost 9.4 million tons of coal was produced in Kanawha County , W. Va . , in 1959 , of which about 67 percent was cleaned mechanically in 10 cleaning plants . It has been estimated that more than 5,505 million tons remain in the county . Samples were collected from Pittsburgh , Stockton - Lewiston , Winifrede , Cedar Grove , Peerless , Upper Kittanning , Coalburg , Powellton , Eagle A , No. 2 Gas , and the Lower Kittanning beds . These beds were selected by the Bureau based on current production rates and estimated minable reserves . Float - and - sink tests of the samples collected from Eagle A , Peerless , Cedar Grove , Winifrede , and No. 2 Gas beds show that these coals at one location each are suitable for metallurgical use without washing . Lower Kittanning bed at four locations ; Pittsburgh , Stockton - Lewiston , and No. 2 Gas beds at two locations each ; and Coalburg , Powellton , Winifrede , Peerless , Upper Kittanning , and Cedar Grove beds at one location each can be upgraded to metallurgical quality by mechanical cleaning . Crushing the samples to 3/ 8- inch top size increased yields substantially at 1.30 specific gravity of Pittsburgh ( 17.5 percentage points ) and Upper Kittanning ( 13.0 percentage points ) beds and increased yield for the other beds sampled to a lesser amount . At this specific gravity , finer crushing caused In the 1.58 specific gravity float a general decrease in ash and sulfur . fractions of the other samples tested , most of the yields , and ash and sulfur contents , were lowered slightly by finer crushing .

Jan 1, 1963

By Tamara Nestorovic, Luan T. Nguyen

"With the aim to mitigate excavation risks and reduce the costs caused by tunnel boring machine (TBM) stoppage when tunneling under uncertain soil conditions, prediction ahead of the tunnel face has become an increasing interest in the tunneling community. Our research topic is concerned with developing effective concepts for nondestructive identification of geological anomalies ahead of the tunnel face by waveform inversion of reflected tunnel seismic waves. The authors demonstrate that this new technique is promising in providing tunnel engineers with an accurate image of the geological situation that the TBM is going to encounter thanks to the waveforms’ rich information about the geological structure that affects propagation, reflection/refraction and mode conversion behavior of the elastic waves. By setting up a 2-dimensional numerical model for simulation of tunnel seismic wave propagation influenced by a dip layer change ahead of the tunnel face, the authors show that the waveform misfit to be minimized by the inversion process is highly multimodal and therefore propose a hybrid stochastic optimization method that can quickly and robustly converge to the global minimum. DEVELOPMENTS IN TUNNEL ADVANCE EXPLORATION Conventional site investigation by drilling boreholes helps to draw a general image of geological structures along the borehole axes but that image is likely to misrepresent the detailed geological structure due to limited sampled locations. Due to high costs and restricted boring space which deep tunneling and tunneling under urban areas encounter, many industrial and academic research groups have had great interest in developing nondestructive ahead of the tunnel face prediction systems. That means only excitation sources and receiving sensors, which are usually placed on the ground surface or on the side walls or on the cutter head of the TBM, are used for acquisition of the measurement data. The recorded signals in the form of seismic or electromagnetic/ electrical waves, which travel through the geological structure or are reflected back from it, hold the signature of the geological structure of concern, such as geological layer changes, fault zones, erratic rocks, boulders, construction remnants, etc., and therefore can be used to reconstruct the spatial and material properties of those hidden geological structures. Most common nondestructive ahead-of-tunnel investigation systems to date are based on interpretation of reflected elastic/ acoustic waves (seismic waves) and analysis of electromagnetic/ electrical resistivity signals (Mooney et al. 2012). However, due to insufficient penetration depth and spread of signals generated by radar and geoelectric sources, the use of seismic waves for ahead of the tunnel face prediction (tunnel reconnaissance) is more preferable (Kneib et al. 2000; Bohlen et al. 2007)."

Jan 1, 2016

By Rob van Dorp

"AbstractThe Monitoring & Instrumentation Committee (MIC) of DFI Europe has the objective to support DFI members in concern of risk management of geotechnical matters, where monitoring and instrumentation have added value.Work of the CommitteeA study by the committee showed that there are already several existing (national) guidelines. They all have their strengths and limitations and their focus may vary a little per country due to local regulations and typical local building activities, but the main question remains what added value another new guideline would have. More likely it would add to the confusion instead of providing overview.Companies with larger experience in geotechnical monitoring (often larger consultancy firm, contractors or clients) are already quite familiar with its benefits do not really need a new guideline in how to design and effectively apply sophisticated geotechnical monitoring systems for special projects.Therefore the aim of the MIC is to focus a little more towards smaller organizations - that are less familiar with monitoring and instrumentation - and the more ‘regular’ type of project that they are mainly involved in. The MIC wants to create a tool which helps them to create risk awareness, to understand the benefits of geotechnical monitoring and to provide them information about how and where to find the right partners and equipment to setup and apply appropriate monitoring systems for their projects.Monitoring and instrumentation benefits are for example:• Risk control during construction stage;• Costs reduction in design and construction (taken limitation of geotechnical aspects into account).• Prevent of unnecessary delays in construction work• Increasing general awareness of geotechnical risks and possibilities of monitoring.The cost of monitoring compared to the cost of failure and/or the savings that can be achieved play a role in the work of the committee. DFI members benefit from the shared knowledge by the MIC on monitoring and instrumentation within their process of risk management."

Jan 1, 2014

By William M. Thornton

[Owing to the comparatively high freezing point of nitroglycerin (14, 15, 16, 17, 18, 23, 37, 38)3/ - 1.9° C. and 13.0° C. for the labile and stabile modifications, respectively, as determined by Hibbert (16) - manufacturers of dynamites have incorporated into the liquid portion of these composite explosives various substances capable of participating in an explosion, to depress the above-mentioned freezing point. Aromatic nitro-compounds, chiefly nitrobenzenes, nitrotoluenes, and nitronaphthalenes, have been used to a considerable extent (11), but such nitrosubstitution products have not proved altogether satisfactory, as has been shown clearly by Naoúm. (14). Consequently there has been a strong tendency in recent years to replace them with one or more of several nitric esters, among which the following (29, 35) have been prominent: Dinitrochlorhydrin (monochlorhydrin dinitrate); nitrosugars, for example, sucrose octanitrate (19); tetranitrodiglycerin (diglycerin tetranitrate); nitroglycol (ethyleneglycol dinitrate); and diethyleneglycol dinitrate (13, 46, 47). Of these, nitroglycol (33, 4l, 45, 48, 49, 65) is outstanding in importance. As the Bureau of fines is naturally interested in the analytical chemistry of the "explosive oils," it seemed desirable to bring together in this report the widely scattered experimental work covering the problem of differentiation that has appeared in various chemical and physicochemical publications.]

Jan 1, 1941

The 63rd Regular Meeting of the Rocky Mountain Coal Mining Institute convened at the Stanley Hotel, Estes Park, Colorado, and was in session at 10:00 a.m. The first session was called to order by Past President George A. Nugent, Vice President and General Manager, Big Horn Coal Company, Sheridan, Wyoming. He thanked and offered his congratulations to the Program Committee for a very wonderful job, namely, John Reeves, Chairman, E. G. Fox, Lee Jensen, O. F. Lewis, J. Peperakis, R. M. von Storch, J. E. Ward and R. R. Williams, Jr. He thanked the suppliers for a fine cocktail party the evening before. Mr. Nugent's Opening Address and introduction of President James Westfield, Assistant Director, U.S. Bureau of Mines, Washington, D.C., follows: It is a real privilege to call this 63rd Regular Meeting of The Rocky Mountain Coal Mining Institute to order and to say welcome.

Jan 1, 1967

The Sixty-Second Regular Meeting of the Rocky Mountain Coal Mining Institute convening at the Stanley Hotel in Estes Park, Colorado, was declared in session at 10 a.m. by Past President Oren F. Bridwell, Secretary, Northern Colorado Coals, Inc, Denver, Colorado. Mr. Bridwell thanked the Joy Manufacturing Company fer the very fine party of the previous evening. He also paid tribute to a very fine Committee - the Program Committee: O. F. Lewis, Chairman, Oren Bridwell, Edward G. Fox, Glen E. Sorensen, Joseph E. Ward, R. R. Williams, Jr., and John Peperakis. Mr. Bridwell then introduced George A. Nugent, Vice President and General Manager, Big Horn Coal Company, Sheridan, Wyoming, as follows: "It is my privilege and duty to call this 62nd Regular Meeting of the Rocky Mountain Coal Mining Institute to order and to extend to you all a cordial welcome.

Jan 1, 1966

By Anish Kumar

Keywords: Ultrasonic velocity, Poisson?s ratio, Elastic constants A new correlation has been established between two independent elastic properties, ultrasonic shear wave velocity and Poisson?s ratio, in a wide variety of isotropic solid materials, such as pure metals, ceramics, polymers and intermetallics. It has been shown for the first time that Poisson?s ratio decreases with increase in elastic moduli, E & G and ultrasonic velocities. This new correlation between two independent elastic constants may lead to the reduction in independent elastic constants for isotropic solid materials from two to one, at least for a given alloy system with different microstructural conditions.

Jan 1, 2005

By L. A. Readdy

Pilot Hole "X" was drilled to test the formations through which the ventilation shaft for the proposed U.S.B.M. demonstration oil shale mine would be drilled. The geologic formations encountered in this hole are discussed. Correlation of the geologic horizons encountered in this hole with those encountered in nearby drill holes was accomplished by the use of geophysical logs. Data on the geophysical interpretations are provided. The anticipated geotechnical characteristics of the geologic units encountered in Pilot Hole "X" are described.

Jan 1, 1977

By Edward H. Robie

Jan 1, 1971

By A. Grimod

Rockfall drapery systems are commonly used as a simple, fast and cheap measure against the rock falling trajectories affecting very steep slopes. The system basically consists of a steel mesh, which is held on the top edge with a longitudinal cable fixed by means of a suitable number of anchors. The effect of this kind of intervention is to control the falls of the rocks, which are driven toward the bottom with slow velocity, or are stabilized on place. It can be used on any kind of slope to protect sensitive target in the mining industry, roads and railways, and inhabited areas. The falling blocks, typically smaller than 0.6 - 1.0 m in diameter, pile up into a trench (or into a ?pocket of mesh?) at the bottom. In comparison to other types of rockfall interventions, the simple drapery is cheaper, and its maintenance is easier, but on the other hand it cannot be considered the remedy for shallow instabilities, because it can only mitigate the effect of the falling trajectories. The design of simple draperies requires the analysis of several factors like the slope features (height, gradient, morphology), the geological and dynamic features (nature of the ground or rock, type of instability, erosion problem, blocks size), the environmental condition (presence of vegetation, aesthetical problem), the installation problem (accesses to the slope, safety for the workers, safety for the surrounding areas) and finally the performance required (temporary or permanent intervention, required maintenance, cost). Finally the most problematic design-step is the choice of the suitable mesh, the top longitudinal cable, and the top anchors type. Because of the highly variable nature of rockfall behaviour these structures cannot be standardized, but they have to be analyzed and designed for each case. Maccaferri has developed a new software application (MacRO 2) has a practical tool to define the mesh and the related supporting structure composed by up-slope cable and anchors. The software, based on the approach proposed by Muhunthan B. et al. (2005), allows designers to verify the top longitudinal cable, the anchors, and the mesh drapery, and to plan for maintenance procedures. Even if the method seems quite simple and rough, it is effective and lets the designer correctly foresee the materials and the geometrical features to be used on the interventions. This paper analyses the condition for the simple drapery installation, the main steps for the calculations, and it will present a case study in a U.S. mine. Nevertheless, even if the software allows a quick and simple calculation approach, onsite observations are always recommended in order to achieve a good design, with the ultimate goal of protecting property and human lives.

Aug 1, 2013

By Joseph J. Wallace

1. The investigation shows that nine coal beds have been mined in Harlan County, of which the Harlan and Upper Elkhorn No, 3 are the most important from the standpoint of present production. Of less importance are the Hindman, Flag, Haddix, Wax, Fire Clay, Armburgy, and Upper Elkhorn No. 2. The Harlan, Upper Elkhorn No. 3, and Upper Elkhorn No. 2 beds contain the largest remaining known reserves. 2. Known measured and indicated reserves in all beds, based on a minimum thickness of 14 inches and 1,800 tons per acre-foot of coal in place, are estimated at 2,138 million short tons as of January I, 1932. Of this total, 1,956 million short tons is in beds 28 inches and more thick. Areas in each bed were omitted from the estimate because available data relative to the bed characteristics are too meager for making an estimate that conforms with the definitions of measured and indicated coal adopted for this study, Should future drilling or development prove reserves in these areas, such reserves should be added to the total estimated reserves.

Jan 1, 1954

By F. K. Shelton, J. C. Stah, Ruth E. Churchward

A study of the hydrometallurgy and electrowinning of cobalt from various domestic ores has been in progress at the Boulder City, Nevada, Experiment Station since February 1940. Previous reports covering certain phases of this investigation have been published. This report covers the research and pilot-plant work on the production of cobalt metal from cobalt-copper ores from the initial experimental work on crude ore through continuous operation. The ore types were from the Blackbird District, Lemhi County, Idaho. The initial tests were made with concentrated ore which was received by air mail and these experiments were expanded both in size and scope. After the laboratory was continued, improved, and extended tests were reported. Sufficiently advanced, a continuously operated plant producing 250 pounds of electrolytic cobalt per day was operated from June 15 through July 15, 1944.

Jan 1, 1948

By Galen H. Clevenger, MARTINUS H. CARON

Although there are exceptions, oxidized silver ores containing the higher oxides of manganese are generally refractory to hydrometallurgical methods of treatment. When these ores are of high enough grade they can be smelted; indeed, some rather low-grade ores of this type have been smelted at a profit because of their fluxing value. In the past, when these ores could not be smelted, they either were not treated or were treated at low efficiency, generally by cyanidation. The need for thorough investigation of the problem was therefore evident for some time before the writers began their research. The problem of treating manganese-silver ores seems to have been recognized first about 35 years ago by C. W. Goodale in applying pan amalgamation at Tombstone, Ariz. He attributed the low extraction of silver to the fouling of the mercury by manganese rather than to the presence of a refractory compound of manganese and·silver. Although definite knowledge as to the cause of the poor extraction of silver was lacking, a more or less effective preliminary treatment, that is, a chloridizing roast, was applied. E. M. Hamilton, in 1909, was perhaps the first to define clearly the problem as it affects the cyanidation of silver ores and to suggest possible methods of preliminary treatment. Most of the work done in the interval between the appearance of Hamilton's paper and the assumption of the investigation by the authors was in the nature of routine tests covering suggestions already made rather than of research directed to a fundamental study of the problem. No practical application has so far been made of any of these proposed processes. The investigation described in this bulletin has proved that there s a refractory compound of manganese and silver-probably a manganite- insoluble in cyanide solution and other common solvents for silver. Although this compound has not been isolated from natural ores, it has been made synthetically, and shows all the characteristics of the natural product. Furthermore the authors have shown definitely that heating in air a relatively small amount of a silver compound with a large excess of silica (in the proportions ordinarily occurring in a commercial silver ore) renders

Jan 1, 1925

By A. J. Barry

An apparatus and procedure have been developed for testing the anchorage effectiveness of slotted-type bolts. The apparatus consists of: (1) A hydrualic Jack assembly for loading the bolt and (2) a device (extensometer or cathetometer) for measuring displacement of the bolt as it is loaded. This apparatus and procedure permit measurment of anchor slip for loads up to the yield load of the bolt. Two representative makes of slotted-type bolts (a total of 94 bolts) were tested in typical sandstone and shale mine roof. Analysis of the test results showed that (1) anchorage capacities up to the yield load of the bolts can be developed in either rock type; (2) the shape of the slotted end of the bolt affects the ease with which the bolt can be driven; (3) all bolts for which the driving distance was more than 1.25 inches produced satisfactory anchorage in both rock types (thus, driving distance can be used as a criterion for satisfactory anchorage); (4) for the group of bolts that was satisfactorily anchored the anchor slip was unaffected by the type of bolt but was considerably larger in shale than in sandstone; and (5) the bolt expansion, that is, the amount the wedge expands the prongs in excess of the diameter of the hole, can also be employed as a criterion for satisfactory anchorage. Although the bolt-expansion and driving-distance results do not differ appreciably, the latter is recommended because it is easier to determine.

Jan 1, 1954

By C. Edward Chamberlain

A Bureau of Mines procedure was developed for the analysis of volatile matter in airborne coal dust-rock dust mixtures prior to, and resulting from, coal mine fires and explosions. Dust in the 10-to 20-mg weight range can be analyzed. Volatile matter is determined by a greatly scaled-down version of the empirical macro-scale method used by the Bureau. The alkaline earth carbonates in the rock dust are dissolved in acid prior to the volatile matter determination of the residue, and the rock dust content is calculated from the analysis of calcium and magnesium by atomic absorption.

Jan 1, 1974

By H Mischo, G Barakos, J Gutzmer

The continuously growing demand for rare earth elements (REEs), in combination with the crisis of 2009 and the price spike of 2011, has initiated a treasure hunt for rare earth deposits all over the world in recent years. Since then, commodity prices have declined and are now quite stable, yet the world is still dependent on China’s dominance of the market and its export policies. Exploration is unremitting and numerous resources of potential interest have already been revealed in many countries; however, proceeding to mining operations is not that simple, especially when it comes to the exploitation of rare earth deposits. Evaluating the feasibility of a mining project is always a unique, sensitive and rather complex process that depends on multiple criteria.This paper focuses on clarifying the present and future global situation in the development of respective deposits and on identifying rare earth-specific criteria that influence the overall feasibility assessments of any potential (especially underground) mining projects. Environmental impacts, legislation issues and the presence of radioactive pollutants are some of the notable boundary conditions that govern rare earth mining operations and need to be taken into consideration. Furthermore, the balance problem between the supply and demand of the different REEs can determine decisively whether a deposit of specific REEs is economically exploitable. For this reason, evaluations are made regarding the future strategies to be enacted in order for the rest of the world to detach itself from this situation. The ultimate goal of these evaluations is for them to be incorporated in an overall assessment tool for rare earth underground mining procedures that will be implemented in real case studies to determine their sustainability.CITATION:Barakos, G, Mischo, H and Gutzmer, J, 2015. Status quo and future evaluations of global rare earth mining (with respect to special rare earth element-industry criteria), in Proceedings Third International Future Mining Conference, pp 21–30 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

The 74th Regular Meeting of the Rocky Mountain Coal Mining Institute convened at The Mark Conference Center, Lionshead Village, Vail, Colorado, and was in session at 10:00 a.m. Past President, Ralph Moore, Vice President, Operations, Westmoreland Resources, Hardin, Montana, called the meeting to order. The membership was asked to stand and pledge allegiance to the flag. He welcomed members and guests and thanked Park Lamborn, the Program Chairman, for the excellent speakers and program he engineered. He mentioned the cancellation of our golf tournament due to the conflicting dates with the Annual Jerry Ford Invitational Golf Tournament. He thanked all of the committees with a special "thank you" to Loren Linville and Gussie Whiteside. He introduced President, Shirl C. McArthur. President and General Manager, American Coal Company, Huntington, Utah. A biographical sketch follows: Mr. McArthur, a native of Huntington, Utah, began his coal mining career shortly after graduating from North Emery High School and worked his way up through the ranks, having worked at every job available underground. For example, he dug coal with a "banjo" at the Independent Coal and Coke Company in Kenilworth. In the summer of 1941, he worked at Straight Canyon Mine as a timberman and advanced to section foreman in four years. He was face boss for part of the time. In October 1946, he received a call from the LDS Church General Welfare Board (presided over then by Marion G. Romney) and took over as superintendent of the Church Mine. He operated in that capacity until the mine became privately owned in 1971. In 1961, Mr. McArthur formed Castle Valley Mining company, and in 1970, he organized American Coal Company, which he presently owns and operates.

Jan 1, 1978

By K. Lapakko

One responsibility of the Minnesota Department of Natural Resources is to encourage the development of mineral resources within the state. A second responsibility is to ensure that mineral development does not adversely impact other natural resources, including the water resources of the state. One approach the Division of Minerals has taken to fulfill these responsibilities is to conduct cooperative research with the mining industry. To encourage mineral development the Division has cooperated with industry on projects related to exploration, mining, and mineral processing. To examine environmental issues the Division has worked in concert with iron ore, base metal, and precious metal exploration and mining companies, as well as the Western Governors' Association, US Bureau of Mines, US Bureau of Land Management, and the US EPA for the past 20 years. These projects were conducted to evaluate methods of predicting, preventing, controlling, and treating problematic mine waste drainages, as well as mine waste revegetation. This paper I) briefly summarizes cooperative projects conducted, 2) enumerates elements which have contributed to the success of cooperative projects, and 3) describes changes implemented for future projects at the Division's new field and laboratory research facilities, as well as at existing mine and plant sites.

Jan 1, 1998