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By D. Baker

Alternative material handling methods are allowing material handling operations to be performed with increased cost savings. This allows for higher production levels with better returns. RAHCO International Inc.'s Continuous Mining Excavator (CME) has recently received a lot of attention due in part to its operating efficiency, flexibility, and associated low operating costs. The CME is designed to perform three primary functions. These include material excavation, sizing and loading operations. In many applications, a drilling and blasting process can be eliminated. The CME was developed originally in 1985 for open pit coal mining. See figure I. Since this time, it has been proven an effective system for excavating many other types of materials including friable and sticky materials. It has also been shown to suitably handle hard rock in certain site conditions.

Jan 1, 1998

By T. Reed Scollon

Major interrelated factors to be considered in assessing the impact of air pollution control regulations on coal are: (I) the fuel and fuel-related limitations of such regulations; (2) the rate of adoption and areal scope of the regulations; and (3) the availability of fuels and fuel-burning equipment to meet the requirements. A growing number of regulations contain provisions limiting the emissions of sulfur oxides or the sulfur content of fuels or both. With few exceptions, these limitations have not yet become fully effective in those areas which have already adopted regulations, and pertinent details of future regulations or legislation for most other areas are unknown at this time. Sufficient information is not avail- able to determine the availability of low-sulfur fuels at various demand and price levels, and large-scale commercial feasibility of sulfur-oxides removal processes and equipment is believed to be some years away. Accordingly, with the many uncertainties and unknowns, it is possible at best to make only a rough assessment of the impact of such regulations or legislation on coal.

Jan 1, 1969

By R. Fernando

"The Office of Mine Safety and Health Research (NIOSH-OMSHR) currently is leading an effort in the development of the next-generation self-escape apparatus as part of the research imperative directed by the MINER Act of 2006. A multifaceted contract program over the past 3 years delivered key components and base breathing modules to form the basis for developing backpack and vest-style versions of dockable self-contained (closed-circuit) self-escape respirators with hoods (CCMERs). This paper outlines the current status in developing the CCMER that incorporates a docking and switch-over valve (DSOV) for seamless transfer from one breathing device to another, and a hood with an inner mask and speech diaphragm (HMC) for ease of donning, ease of use, and communication ability. Three versions of the CCMER are being pursued, namely: the CCMER-B, which can be worn as a backpack and incorporates the features of a miner’s belt; the CCMER-V, which is worn similar to a miner’s vest and attaches to a miner’s belt; and the CCMER-C, a breathing module cached along the escape route that can be docked to the -B and -V versions. Human factors considerations are a key element in the CCMER design, as it is to be continually worn by the miner while underground, and must be readily accessible for deployment when needed. The CCMERs are designed to be capable of being certified to 42 CFR part 84 standards, including sub-part O for mine use, and to meet MSHA permissibility regulations for use in underground mines. They are sized for sufficient oxygen capacities (Cap 2 and Cap 3 as defined in sub-part O) to yield a duration that is of practical use in a mine escape scenario. INTRODUCTION The National Institute for Occupational Safety and Health (NIOSH) Office of Mine Safety and Health Research (OMSHR) is leading the development of self-escape apparatuses to provide breathing gas to mining personnel operating in the event of an emergency in various capacities underground in environments containing hazardous gas components. The Mine Improvement and New Emergency Response Act of 2006 (also known as the MINER Act) and input from the mining community called for the need to move Self-Contained Self-Rescuer (SCSR) technology to a next-generation status. In response to this need, NIOSH’s Office of Mine Safety and Health Research (OMSHR) established a strategic plan to develop key components and devices with help from external experts knowledgeable in breathing apparatus designs. The US Navy was identified as a key expert in this field through its extensive experience in diving apparatus and life support systems, and development work commenced through Inter-Agency Agreements with OMSHR. A contracts program was also launched with industry experts specializing in this field. This paper outlines the current status in developing the Next-Generation Closed-Circuit Mine Escape Respirators (CCMERs) that could be used for surviving and escaping from a mine following an emergency that renders the mine atmosphere irrespirable."

Jan 1, 2016

By S. Nunoo

The shape of particles has a significant effect on the shear strength and deformational characteristics of granular materials. Weathering can change the grain shapes. For example, more weathered sands tend to be rounder regardless of particle size. Particle shape analysis was performed on samples collected from the Questa mine rock piles, a debris flow and the pit alteration scar. In order to increase the validity of the particle shape analysis, 4 persons including 2 geologists and 2 mining engineers were involved in describing the particle shapes. The results of this analysis indicate that rock fragments in the collected samples are mainly subangular, subdiscoidal and subprismoidal. The sphericity and angularity of the rock fragments of the older analogs are similar to those of the rock piles. This suggests that short-term weathering (<100 years) has not noticeably changed the particle shapes at the test locations. Rock piles made of more angular particles are more stable compared to rock piles with rounded particles.

Jan 1, 2009

By J. P. Earnhardt

Recycling of such municipal solid wastes as glass containers, metal cans, and newspapers has received increasing attention recently. However, municipal solid wastes account for only 1% of the total solid waste stream in the United States. The remainder includes hazardous and non-hazardous industrial wastes. Generators of industrial wastes are facing higher landfill costs. Future liability potential, and public image concerns which are forcing them to seek innovative and often profitable solutions to minimize, reuse, and recycle their waste streams. Opportunities for the mining industry in industrial recycling include recovery of mining wastes and by-products, and utilization of mineral products for treating waste streams.

Jan 1, 1993

By M. Nichols

Where am I? Where are they? Where is it? These are the fundamental questions that need to be answered in managing people and resources. This paper explains how GPS positioning technologies answer those fundamental questions and provide better information management from initial exploration work through daily mine operations to reclamation work and environmental monitoring.

Jan 1, 1998

By T. A. Gray

There are several potential large-volume uses for coal ash in mining-related applications that could be environmentally and economically beneficial to mining companies. Actual usage, however, may be constrained by regulations or by perceptions of coal ash and the potential uses. To identify currently allowed uses and to assess constraints to coal ash use in the eastern coal fields, questionnaires were sent to state coal mining agencies to determine their policies on coal ash utilization and to mining companies to solicit their viewpoints on coal ash utilization. Identifying and understanding the constraints will allow for the development of a coordinated and consistent approach to remove or reduce these constraints and possibly allow for increased utilization of coal ash by the mining industry. This paper summarizes the findings of our investigation.

Jan 1, 1995

By S. S. Szoke

The concrete masonry industry, represented by the National Concrete Masonry Association has significantly expanded its markets since the industry&apos;s inception. The concrete masonry industry has developed and refined concrete masonry units by producing a variety of quality products on automated machines. In the sixties, architectural concrete masonry units gained popularity. In the seventies, the concrete paver market expanded. In the eighties, segmental retaining wall units became popular. The industry continues to research and develop new products and applications for concrete masonry to satisfy the needs of designers, specifiers, installers and owners. Both existing and innovative technologies in the concrete masonry industry are discussed.

Jan 1, 1993

By M. Robson

Water & Earth Technologies, Inc. (WET), Habitat Management, Inc. (HMI) and Chevron Mining, Inc. (CMI) together developed a solution for reclaiming steep southwest facing slopes in mining Area 12C that have historically been prone to excessive erosion, low vegetation establishment and continuing maintenance. Area 12C is located in the east wing of the Chevron McKinley Coal Mine, 27 miles northwest of Gallup, New Mexico, on Navajo Nation land administered by the Office of Surface Mining (OSM). Mining in this area was completed in May of 2007. Challenges encountered for this reclamation project included the need to reclaim graded material on a slope of 18-35% with southwest facing aspect, the presence of undisturbed rock outcropping that needed to be avoided during reclamation, the operational need to limit bulldozer pushes and the inability to import or export additional materials for construction. Two different reclamation alternatives were considered for Area 12C. The first alternative would use a traditional reclamation approach including three levels of draining terraces designed to convey water on a 3% slope to a single riprapped down drain. Terracing and down drains have been used to reclaim areas with similar terrain conditions elsewhere at the McKinely Mine and have failed to adequately control erosion (Williamson 2006). Terrace overtopping and down drain blowouts have been issues in maintenance and functionality for the mine. Maintenance routines consist of cleaning out terraces where they have filled in with sediment and repairing damaged or blown out terraces and down drains.

Jan 1, 2010

By Stefan Mede

Robot Supported Moulding—this is the name of Herrenknecht Formwork’s entry to the world of automated segment production. What had been considered impossible for a long time, has been achieved by Herrenknecht experts together with the Swiss company Marti AG: unmanned segment production on the working line. The moulds open and close autonomously with the help of a hydraulic system. A robot cleans and greases the moulds at one work station and inserts the injection sockets at another. The next step will include further automation and digital networking of all processes from production to installation in the tunnel.

Jun 13, 2021

By Terry I. Mudder, Michael M. Botz

Discharge regulations for mine waters require relatively low concentrations for cyanide and metals, and the trend is for discharge limits to be lowered. In the event conventional treatment practices are not sufficient to meet discharge limitations, advanced treatment technologies such as ion exchange and reverse osmosis may be considered. Though these technologies will provide discharge quality waters, they also require the disposal of a concentrated brine and are relatively complex and costly to operate. Many mine sites currently using activated carbon in precious metals recovery present the opportunity to economically operate an activated carbon water treatment plant for polishing of effluents. This paper presents summaries of six ( 6) mining operations which have evaluated or use activated carbon for treatment of water and which also use carbon in precious metals recovery processes.

Jan 1, 1997

By Majid Ataeepour, Ernest Y. Baafi

High level programming languages such ass C, FORTRAN and BASIC have been used in the mining industry to simulate truck-shovel systems. In addition, some special languages for simulation such as GASP, GPSS, SLAM, PROOF and SIMAN are commonly used. The most recent simulation system ARENA uses graphical modelling approach as well as animation notion. In this paper, the main elements of ARENA required to perform a truck- shovel simulation and to view the simulation results by means of the model animation are presented. The layout of the haulage system including shovels, trucks and dump sites was generated using draw tool in ARENA. All the components of the haulage system were represented by graphical modules. Animation tool was used to depict the performance of the haulage system as the simulation progressed.

Jan 1, 1996

By S. Mathur

Future Florida phosphate reserves contain higher MgO than presently mined deposits. The high MgO content is contributed by dolomite and Mg-rich clay, palygorskite. Selective flocculation was attempted to reduce the MgO content of apatite in synthetic mixtures of apatite with dolomite and palygorskie. Mixed mineral selectivity was predicted in the apatite-dolomite and apatite- palygorskite systems with Poly(ethy1ene oxide) (PEO) flocculant. Loss of selectivity in the mixed mineral systems was primarily attributed to heteroflocculation, which was minimized by addition of a Site Blocking Agent (SBA), a lower molecular weight fraction of PEO, prior to addition of the flocculant. A 80:20 mixture of apatite-dolomite (or palygorskite) was upgraded as 95% apatite at more than 80% recovery level in the product fraction.

Jan 1, 1995

By D. Duvris

The main objective of this work was to quantitatively investigate exhaust emission levels relative to maintenance (service) intervals during the operation of diesel-powered equipment at an underground bauxite mine in Greece. Such emissions depend on a great number of parameters, including the type of engine (technology) and its tuning, the type of work performed (as related to the engine workload), the suggested maintenance intervals, the altitude, the temperature and humidity of the atmosphere in the underground mine, the properties of the fuel and the operator&apos;s training and experience levels. The necessary ventilation quantities were calculated based on exhaust gas-concentration measurements and site-specific relationships between pollutants and adjusted air-quality indices. Diagrams comparing the necessary and recommended airflow for several equipment groups, featuring two engine types and different maintenance intervals, are presented.

Jan 1, 2000

By G. Zandt, H. R. Pratt, W. A. Hustrulid, M. Bouchon, D. E. Stephenson

PREFACE The National Waste Terminal Storage Program was initiated to conduct the research to select a site for the disposal of high level radioactive waste in deep geologic formations. As part of this program, the Savannah River Laboratory at Aiken, South Carolina, is conducting geologic research of generic applicability on the potential subsurface damage to a repository from an earthquake. Part of this study involved the collection of data on subsurface damage due to an earthquake, and another part involved the calculation of displacement fields as a result of an earthquake. Both of these studies were conducted at Terra Tek of Salt Lake City. This report is an abridged and combined version of both studies which was presented at the Rapid Excavation and Tunneling Conference in Atlanta, GA, on June 19, 1979.

Jan 1, 1979

By L. B. Rothfeld, R. L. Dolzani

This paper presents preliminary results of a US Bureau of Mines (USBM) study of potential costs of compliance with possible federal regulations for copper heap and dump leaching. The regulations could arise under amendments to the Resource Conservation and Recovery Act (RCRA) and/or the General Mining Law. Estimates are given for the cost of compliance with possible technology standards that would require the use of liners and closure caps regardless of terrain and underlying geology and hydrology. This cost is compared to the cost of compliance with 1992 state requirements for terrains typical of those found at existing copper leach sites in the southwestern United States. Incremental compliance costs are found to widely exceed screening criteria used by the US Environmental Protection Agency (EPA) to denote significant economic impact.

Jan 1, 1995

By L. F. Nicolai, W. J. Schlitt

Lateral migration of leach solution in heaps and dumps is attributed to two phenomena. One is site-specific anisotropic conditions that exist on a macroscopic scale on the surface or within the rock piles. The second is associated with a random walk phenomenon that causes dispersion of solution, especially at gradients in flow or hydrostatic pressure. The latter phenomenon is a general condition that will occur in any leaching operation. Its effects are modeled by computer analysis and are compared with available field data on heap leaching. Under appropriate assumptions, the observed 58° angle of solution dispersion can be reproduced by the model. The combined effects of both anisotropy and random walk are also discussed. Finally, the impact of lateral solution flow on actual leaching operations is considered.

Jan 1, 1988

By R. Simon

Strain-burst phenomena are generally characterised by sudden releases of energy in a volume of highly stressed rock. Strain bursts are encountered in situations such as crown pillar bursts during cut-and-fill mining, face bursts at development headings cord floor bursts in deep shaft sinking. This paper describes a simple two-dimensional linear elastic FE modeling approach that leads to the calculation of the energy-release rate (ERR) and the total energy storage rate (TESR) in the rock-mass around the openings. The merits of using such energy parameters in the analysis of strain-burst problems for identifying areas of high energy release/storage are discussed through a case stud v. However, much site-specific back analyses are needed to better understand how strain bursts and energy parameters are interrelated.

Jan 1, 1999

By Robert J. Timko, R. Lincoln Derick

This report presents a Bureau of Mines evaluation which examined the extent of gas leakage from sealed areas in underground coal mines and measured the effectiveness of commonly used structures for controlling the quantity of gas exchange from these areas. Evaluations were performed on five abandoned areas in two operating underground mines within the same coal seam. Methane and oxygen levels inby the seals were monitored to determine if the gas leakage was unidirectional or bidirectional. Results from this and prior work dealing with minimizing gas leakage were then applied to a newly abandoned area. Also discussed are bulkhead site preparation, construction plans, techniques for monitoring the status of the atmosphere within the sealed volume, and a modified European method for controlling gas migration from the sealed volume to the active mine.

Jan 1, 1991

By R. D. Herron

Mining coal under deep cover conditions is certainly the proper phrase to use in describing one of our newest operations. Located in the southwest corner of Virginia is this operation which is the Beatrice Mine of the Beatrice Pocahontas Company, a joint venture of Republic Steel Corporation and Island Creek Coal Company. The mine is working in the No. 3 Pocahontas seam in an assigned area of over 9500 acres containing over 60 million tons of recoverable, high quality, low volatile coal. The site of the mine opening was at Keen Mountain, Virginia, where the seam lay 1350 feet below the surface. This depth, greater than anything attempted thus far in the coal industry on this continent, would pose some problems, we felt, with which we had not previously had to contend.

Jan 1, 1968