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By Rodrigo Jerez

This paper describes a Mixed Integer Linear Programming model that was developed for planning the coal operations at Mountain Coals, Inc., in Kentucky. The model incorporates the use of stockpiles as practiced and allows the operator to find the least cost combination of raw coal feeds, washing densities and blending to produce the different quality coals as required by the coal contracts.

Jan 1, 1984

By Richard W. Cannon

INTRODUCTION The authors, by means of this paper, will attempt to show the role of Induced Polarization and Resistivity surveys in the discovery of the orebodies of Gibraltar Mines Limited (N.P.L.). In this paper, we will also attempt to show the importance of conducting large enough surveys in order to properly evaluate the results obtained from these surveys. LOCATION The orebodies of Gibraltar Mines Limited (N.P.L.) are located on the western slope of Granite Mountain, central British Columbia (52°30' north, 122°16' west) (See Fig. 1). The property lies approximately 28 miles north of Williams Lake, B.C. and can be reached by way of 10 miles of newly improved road from McLeese Lake, on the Cariboo Highway. The area in and around Gibraltar Mines has a moderate topographic relief with elevations between 3,500 and 4,100 feet. {EARLY HISTORY AND GEOLOGY The present Gibraltar Mines property before amalgamation consisted of the Pollyanna property (Duval-Canex) and the Gibraltar property (original Gibraltar Mines) as well as some Coast Silver and McLeese Lake Copper claims (See Fig. 2). The Pollyanna property was first described in the 1917 B.C. Minister of Mines Report which referred to it as the "Rainbow Group". The development at that time consisted of several open-cuts on copper bearing quartz veins.

Jan 1, 1972

By F. G. Miller

To improve coal flotation Bethlehem Steel Corporation's Research Department has been working on a number of related problems based on both physical and chemical factors. The ideal is of course full understanding of the interrelated effects of both sets of factors. However, detailed studies5 of each physical factor have produced immediately usable results in commercial coal flotation and are providing the bas is for our current work on the effect of chemical factors. Since these detailed studies provided the basis for the present investigation of froth sprinkling, their key results are highlighted here. For example, for a highly floatable bituminous coal, particle floatability was shown to be directly related to the percentage of coal surface available for bubble attachment and inversely related to particle mass. The data also underscored that in a given size range the addition of mineral matter to a particle makes flotation more difficult both by adding to the mass of the particle and by decreasing the amount of coal surface available for bubble attachment. Size also affects particle floatability in that as the size of particles of a given specific gravity increases, mass increases and the ratio between coal surface area and mass of the particle decreases. Flotation tests showed that any recovery of the coarsest particles in a coal feed is accompanied by progressively higher recovery of finer and finer particles. Consequently, fine high-specific-gravity particles are recovered with the coarse good coal. As a result, when the entire 14M x 0 size range is processed by froth flotation, the good coarse coal is contaminated with high-specific-gravity fines. It is the small quantities of these fines that must be rejected from the froth product if flotation efficiency is to be increased above its present level.

Jan 1, 1968

By Sidney A. Suhler

The persistent requirement for methods and equipment capable of detecting hazardous anomalies in advance of underground mining has led to the development by the U.S. Bureau of Mines of a directional radar probe. The probe operates from boreholes drilled from the surface into the underground region to be mined. The engineering model radar was completed in early 1982 and field demonstration tests were performed in May of that year at a selected coal mine. Preliminary in-situ electromagnetic tests were performed at several candidate coal mines to evaluate the radio-frequency characteristics of the coal. A coal mine in New Mexico was selected on the basis of low EM propagation losses in the coal and the presence of an extensive coal seam displacing fault as a radar target. The borehole radar was operated in two vertical boreholes which intersected the coal seam at approximately 25 and 40 feet from the fault interface. Radar reflections from the coal/ rock interface were detected in both tests. Underground tests in a horizontal borehole in the coal were less successful because of interfering reflections. Additional borehole-to-borehole tests were performed with a separate ground penetrating electromagnetic system to obtain radar range calibration data. The coal was found to be bounded by very lossy roof and floor sandstone and shale while propagation through the coal seam was obtained at distances up to 175 feet between test boreholes. Coal seam continuity was indicated by the hole-to-hole experiments through a section of the seam previously thought to be completely cut off by the fault.

Jan 1, 1983

By M. S. Celik

Unlike most other minerals, electrokinetic measurements of calcium montmodonite (a clay mineral) and u1exite (a boron mineral) exhibit an unusual behavior. While the addition of monovalent salts such as NaCI and KCI is expected to compress the electrical double layer with a resultant less absolute charge, an opposite trend is observed. A set of systematic experiments with monovalent and multivalent ions has been carried out to understand the mechanism of this phenomenon Examination of the results reveals that the behavior of montmorillonite is dictated by the exchangeable divalent cations at the edges which undergo an exchange process with monovalent cations resulting in the reduction of positive charges. The solubility of ulexite, on the other hand, is found to decrease with increasing monovalent cation concentration leading to again an increase in the absolute negative charge.

Jan 1, 1996

By Charles J. Johnson

The United States is totally dependent on imports for all primary chromite and most ferrochrome supplies. Although the United States imports chromite and ferrochrome from a number of countries, the long-term future of chromite supplies appears to lie in southern Africa (Republic of South Africa and Zimbabwe) where 88 percent of known world reserves exist. Floreover, low mining costs and the availability of low-cost electricity for ferrochrome production gives South Africa a comparative advantage over most other chromite and ferrochrome-producing nations. A well-known problem faced by the United States is that when viewed from a longer-term perspective, the major sources of supply of metallurgical grade chromite and ferrochrome may be subject to disruption. The three countries that have caused the greatest concern have been the Republic of South Africa, the Soviet Union, and Zimbabwe. South Africa presents a particularly difficult problem because it may be subject to internal political unrest and/or U. N, economic sanctions. South Africa has increased its share of world chromium production from about 30 percent in 1968 to 62 percent in 1978.1

Jan 1, 1982

By Robert Rennie, Taylor Davies, Ahsanul Rafi

Electric locomotives powered by extensive electrical cabling systems were prevalent in the mining industry in the early days of the 20th Century [1]. Since the movement of tethered electrical mining locomotives was limited, the advent of diesel-powered mobile mining equipment provided more flexibility. This led the mining industry to be dominated by diesel-powered locomotives for most of the 20th Century and the entire 21st Century, to date. However, diesel power has certain drawbacks. Diesel-powered vehicles produce tailpipe emissions such as diesel particulate matter, carbon dioxide, sulfur dioxide, and nitrogen oxide. Mine workers exposed to these emissions were, and continue to be, subject to health issues such as respiratory problems, increased risk of lung cancer, and cardiovascular disease. [2][3]. Extensive ventilation systems are required to dilute the diesel exhaust and dissipate the heat generated by these vehicles. Moreover, as mines are getting deeper due to depleting resources, ventilation costs in diesel-powered mines are becoming increasingly high. These factors, coupled with the trend towards greenhouse gas (GHG) reduction in mine operations, has allowed zero-emission electric locomotive systems to gain traction. As lithium-ion battery technology is becoming more advanced, battery-powered electric vehicles can now perform duty cycles comparable to those of diesel-powered vehicles. Although battery-electric vehicles (BEVs) are comparable to diesel-powered vehicles in terms of mobility, they have certain limitations. For instance, the amount of onboard energy is limited by the battery energy density and specific energy. The MT42 diesel haul truck from Epiroc, for example, has a fuel tank capacity of 580L, which is equivalent to around 1450 kWh of net electrical energy [4]. The electrified version of the MT42, on the other hand, has an onboard battery with 375 kWh of usable energy weighing around 4.9 metric tonnes [5]. Moreover, storing and refueling of diesel-powered vehicles is simple and quick, whereas battery energy storage and charging systems require extensive infrastructure development. Charging time is mostly limited by battery chemistry and design. Due to these limitations, the benefits of battery-powered mining vehicles are more likely to be realized with proper planning and optimization of the BEV fleet. This includes optimizing mining layouts for BEV use, charging infrastructure design, and management of onboard energy storage systems.

Jun 25, 2023

By W. L. Price

Recent publication of United States Bureau of Mines figures showed that the sand and gravel (3) industry is the largest single mining industry in the United States in term of yearly tonnage produced. The yearly production of over 500,000,000 tons per year now exceed bituminous coal production. This disclosure caught unawares many observers who have not been following closely the rapid-growth of this phase of mining. Along with this steady growth in production, the sand and gravel industry has gone through an accelerated and varied program of beneficiation in a period of the last ten years.

Jan 1, 1958

By R. W. Wittkopp

The Relief Canyon gold deposit is located approximately twenty- four kilometers east of the town of Lovelock in Northwestern Nevada. At Relief Canyon, the Late Triassic Grass Valley Formation has been thrust over the Late Triassic Natchez Pass Formation. The lower plate Natchez Pass Formation is composed of massive gray dolomitic limestone which is locally silty and sandy. The upper plate Grass Valley Formation is composed of shale, siltstone, argillite and quartzite. Gold mineralization at Relief Canyon occurs along the highly brecciated thrust contact between these two formations. Weak gold mineralization often occurs above the thrust in the Grass Valley Formation, however, most of the ore grade mineralization is present below the thrust in the brecciated Natchez Pass Formation or where the two formations are mixed as a result of movement along the thrust. Several types of gold mineralization have been recognized at Relief Canyon. A large amount of the ore is present as a jasperoid breccia, however, significant amounts of ore occur as a mixed breccia composed of upper plate rock, fresh limestone, clay and jasperoid breccia. Gold ore also occurs in a fresh limestone breccia which contains a large amount of clay. Below masses of jasperoid, jasperoid stringers containing gold extend into the fresh limestone. Gold mineralization at Relief Canyon appears to be truly disseminated and has the typically associated trace elements of arsenic, antimony, mercury and fluorine. The Relief Canyon deposit can be classified as a structurally controlled disseminated gold deposit. Other deposits that fit this classification are the Pinson and Dee gold mines.

Jan 1, 1984

By J. Kemeny, K. M. Kim

A site-specific blasting model has been developed for the Asarco Mission mine. The main inputs to the model are the in situ block size (F80), the post-blast fragmentation (P80) and the intact tensile strength (To). The output from the model is the specific blast energy (ESE). Modern techniques are being used to obtain the input parameters for the site-specific blast fragmentation model. In particular, image processing software is used to obtain both the in situ block size and the post-blast fragmentation, and the Schmidt hammer is used to obtain the tensile strength at numerous locations throughout the rock mass. An initial model was developed using five test shots in an area of the mine that contains argillite and is relatively homogeneous. This process also included calibrating Schmidt hammer readings against actual Brazilian tensile measurements. The model for argillite will be updated as more tests are conducted, and the model will be extended to the four other primary rock types at the Asarco Mission mine.

Jan 1, 2011

By Christopher Mark

Area wide pillar failures, or “squeezes,” were once fairly common in underground coal mines. While rare today, they do occur. This paper describes seven case histories that were investigated by MSHA Technical Support. They occurred across the range of US coalfields, in both longwall and room-and-pillar mines, and involved development mining, pillar recovery, longwall panel extraction, and multiple seam interactions. Significant lessons from each are discussed.

Jun 25, 2024

By Donald J. Worth

When Eugene Bailey asked me to contribute to this session on "Canadian exploration - 1976", it took a little coaxing before he got me to agree. My immediate reaction was, what could i say about Canadian exploration that already had not been said a hundred times in the past few years; secondly, why include a banking person in such a discussion? Everyone knows banks only come into the picture after the discovery has been made and feasibility well established and validated. Rather than wrestle with these misgivings, I decided to take the easy way out and go on blind faith in Eugene - that is, he asked me so he must think that I could come up with some useful thoughts and at least touch upon some of the pros and cons of exploration in Canada. The object of the whole exploration exercise is to Find economic deposits, once they are found, one cannot really move them elsewhere to mine them. It follows, therefore, that we should really be speaking about the pros and cons of mining In Canada and my treatise will eventually lean in this direction. In any event and before getting down to the pros and cons, let us take a quick look at the history of mineral resource development in our country since the end of world war II. At that time, we were producing well under one billion dollars worth of mineral products including hydrocarbons.

Jan 1, 1976

By J. -B. C. Varnier, J. A. Cremeens, D. D. Overton

"Slope failures that occurred in 2008 and 2009 at the Pikeview Quarry in El Paso County in Colorado in the United States were investigated using three-dimensional discrete element modeling methods. Large-scale block sliding failures occurred along weak bedding planes that dip steeply into an excavation located at the toe of the slope. Several mining sequences at the toe of the slope were simulated to evaluate the effects of various degrees of extraction and backfill on slope stability. Slope stability back-analysis was conducted using prefailure and post-failure conditions to determine the joint shear strength properties. Laboratory testing was also conducted to determine intact rock properties. Three-dimensional discrete element analysis was uniquely applicable to this evaluation because it allowed representation of shear stress of the basal sliding surface and afforded evaluation of several scenarios of extraction and backfill at the toe of the slope. IntroductionThe Pikeview Quarry is an aggregate quarry located approximately 8 km (5 miles) northwest of Colorado Springs in El Paso County, CO, USA. The quarry has been operated by several owners since the early 1900s. According to the U.S. Mine Safety and Health Administration (MSHA, 1986), the quarry has been a major source of construction aggregate for the Colorado Springs area for many years. In the 1950s, the site was mined by Peter Kiewit and Sons to provide limestone for the construction of the nearby Air Force Academy.A large-scale slope failure occurred on Dec. 2, 2008, which stopped mining activity at the Pikeview Quarry. A second, related slope failure occurred on Sept. 13, 2009. The second slope failure was located immediately adjacent to the initial December 2008 failure.The objective of this paper is to discuss the three-dimensional slope stability evaluation. The causal relationships of slope instability are not within the scope of this publication. However, omitting the precursors to slope failure would limit understanding of the nature of the slope stability evaluation. The regional and local geology and the history of slope instability at the Pikeview Quarry aid in understanding these precursors. Two main failure mechanisms were hypothesized during the failure investigation to explain the triggering of the 2008 and 2009 large slope failures at the Pikeview Quarry, and both of these mechanisms were given equal credence in the present study. Quarry excavation and backfilling was a key factor in the slope instability for both failure mechanisms. The excavation was backfilled in stages in an effort to provide slope support. The objective of the three-dimensional model was to evaluate the effects of extraction and backfill at the toe of the slope with respect to slope stability."

Jan 3, 2018

By O. P. Sinha, Biswajit Mishra, A. K. Mandal, Raj Kumar Dishwar, G. S. Mahobia, Ram ji Omar

Most of the mineral deposits found in North-East India remain unexploited due to inadequate knowledge on their status, economic viability, and requisite mining technologies. The aimof this study is to characterize the multimetallic magnetite mineral deposit from the Nagaland area in India. The quality of iron ore was evaluated to establish its suitability as a raw material for iron production. Detailed studies were conducted to establish the composition and properties of the samples. X-ray diffraction (XRD), X-ray fluorescence (XRF), electron probe micro-analyzer (EPMA), and petrographic microscopy techniques were employed in the investigation. Shatter and tumbler test was performed for analyzing the mechanical properties of the ore. XRD studies indicated that magnetite is the major mineral with low amounts of martite, maghemite, and quartz. XRF/EPMA results indicated that magnetite contains 35–65 wt.% of iron and 1–5 wt.% of chromium. It also confirms the presence of Ni and Al up to 1 wt.% and Si up to 6 wt.%. Chromite-rich ore contains up to 30 wt.% Cr and 15–20 wt.% of Fe.

May 10, 2021

By Paul Dean Proctor

The known northern ore zones of the New Lead Belt of Southeast Missouri extend to the drainage divide between the Meramec River draining north and east and that of the Black River draining southward. Intensive geochemical studies related to the environmental impact of the new mining area have been carried out in the vicinity of some of the newly developed mines, mills and smelter complexes (Bolter,1970; Gale, et al, 1973; Wixson, et al, 1969, 1977). Other investigations have related to fringe studies of the Northern New Lead Belt and the possible additions of heavy metals to the surface waters, stream sediments and selected aquatic life (Proctor, et al, 1975, 1976). Similar studies have been completed in the Joplin area in the Tri-State district, and in the fringe area near Springfield, Missouri (Proctor, et al, 1974). A surface geochemical study is currently underway on the lead-zinc-copper-cobalt-nickel province near Fredericktown, Missouri (Proctor and Sinha, 1977). This report summarizes some of the distribution patterns of heavy metals in the waters, stream sediments and selected aquatic life in the Upper Meramec River drainage basin just north and west of the known northern portions of the New Lead Belt of Southeast Missouri. The region studied includes the site of the proposed and somewhat controversial Meramec Dam and the reservoir site behind it. Some 3905 km2 (1508 mi2) are included within the drainage basin of the Upper Meramec River. Six distinct drainage areas are included within the drainage basin; 1) a combined, lightly industrialized and farm area around Rolla and Salem, Missouri representing the Dry Fork drainage; 2) a primitive, mostly forested area with some farms and cattle rancheseast and north of Salem, Missouri comprising the Upper Meramec River

Jan 1, 1977

By E. O. Strahl

In the search for economic mineral deposits, the need for efficient mineral or chemical assays is of prime importance. Costly analytical methods and long delays in obtaining assay results severely limit the effectiveness of an exploration program. The assay problem becomes acute once a potential ore body is located and large numbers of samples are generated in close interval drilling programs. In order to avoid the delays and high costs of extensive assays, the exploration geologist or mining engineer is likely to be required to curtail his drilling program, composite samples, or restrict the required analyses to a limited number of critical elements. As a result, the definition of the potential ore body may be less than needed for final economic evaluation. The assay requirements for bauxite exploration usually involve a considerable number of total elemental and empirical analysis. Since the Bayer process for extracting alumina from bauxite involves the selective dissolution and reaction of specific minerals from the bauxite, a direct chemical analysis for elemental composition yields only a portion of the data required to effectively describe the potential economic value of ore body or deposit. To fully characterize the economic value of a bauxite requires digestion, mud separation and mud settling tests under conditions approximating a commercial Bayer plant. A close approximation of the process behavior of a bauxite also can be calculated from a combination of the chemical and mineralogical analyses. By determining the elemental chemistry, mineralogy, and Bayer plant processing characteristics of a few samples of a given bauxite, correlations can be derived that permit defining a bauxite in terms of a given set of process conditions.

Jan 1, 1977

By D. D. Runnells

In order to establish meaningful remediation goals and monitoring programs in areas disturbed by mining, it is desirable to determine the natural metals concentrations that existed in the area prior to mining. At Iron Mountain, California, several natural sources exist for acid drainage and loading of metals to Slickrock and Boulder Creeks. This paper describes methods to determine the contribution of copper and zinc to groundwater and surface water from those sources, including natural gossan rock outcrops, mineralized bedrock, and colluvial materials. Methods used include evaluation of: 1) historical information, 2) literature values of unmined, mineralized areas, 3) analyses of water from monitoring wells, 4) leaching studies, 5) statistical analysis, 6) isotopic studies, and 7) identification of background by elimination of mining sources. Results from this natural background determination show that Boulder Creek and Slickrock Creek carried elevated concentrations and loads of copper and zinc prior to mining activities. With repeated rinsing of reclaimed and remediated mine materials by rainfall, there will be a diminishing contribution from residual waste rock and tailings at Iron Mountain, and natural background will become an increasingly larger proportion of the total load.

Jan 1, 1999

By R. K. Will

An inactive mining operation in northern California is known to be a source of acid mine drainage and heavy metals which have impacted adjacent creeks. Elevated concentrations of copper and zinc are a concern to aquatic populations, particularly steelhead trout and salmon downstream in the Sacramento River. Previous regional geological surveys of mineralization by the U.S. Geological Survey located and mapped outcrops of massive sulfides and gossan. Recent investigations indicate that a substantial amount of the metals in the local creeks are due to natural causes. The investigations include locating and mapping surface and subsurface minerals, soil and water sampling, and chemical analysis. Groundwater, seeps, and surface water were also sampled and analyzed. A water balance was conducted on a sub-basin level following delineation of surface water drainage and groundwater divides. A chemical mass balance incorporated metal concentrations and water volumes and was then used with other data to determine the contribution of metals from natural versus mining-related causes.

Jan 1, 1998

By J. R. Dyni

The lacustrine Green River Formation of Eocene age in the Green River Basin, southwest Wyoming, contains the world's large resource of natural sodium carbonate in bedded trona (Na2CO3? NaHCO3? 2H2O). In this study, 126 billion tons are estimated to be present in 22 beds, ranging from 4 to 36 feet in thickness. These 22 beds underlie areas of about 50 to more than 775 square miles at depths ranging from about 650 to more than 3,000 feet below the surface. The total resource of trona ore in the basin for which drilling information is available is estimated to be about 149 billion short tons. The undeveloped deeper trona beds in the southern part of the basin may be exploitable by solution mining. Additional unevaluated sodium carbonate resources are present in disseminated shortite in strata interbedded with the trona and in shallow sodium carbonate brines in the northeast part of the basin.

Jan 1, 1995

By Andrew Burton, Damian Schofield, Jeremy Noond

This paper will introduce and discuss a range of techniques that utilise new developments in Computer Graphics (CG) and Virtual Reality (VR) for the investigation of incidents and accidents in mining environments. The future of mining safety may not be totally led by the demands of the mine operators, but sometimes by the academics, commercial software developers and legal pioneers who generate new ideas and products and set admissibility precedents which may change the way certain traditional investigative operations are performed. In any accident investigation the outcome from the investigating team is often a complex affair and the results of the investigation are often reported in large, convoluted documents. Computer-generated forensic reconstructions allow investigators to present accident scenarios in an accessible and easily understood, visual manner. Surveys in the US have also shown that people have increased recall of computer-generated images over many other forms of evidence. The AIMS Research Unit in the UK have been pioneering the use of Computer Graphics (CG) and Virtual Reality (VR) technology for both industrial and road traffic accident reconstruction. This paper and accompanying presentation will contain examples of forensic reconstructions developed by the authors that explain some of the methodologies used to ensure admissibility of this type of digital evidence. The paper will contain a number of case studies based on UK and International industrial accidents. The paper will focus on how AIMS Research is extending the capabilities of the accident reconstructions created to take advantage of the latest developments in VR technology. As digital technology makes its impact within professional and commercial fields, computer generated forensic reconstructions will form important admissible evidence in the courtrooms of the future. The technology will also make a great impact in the way we train our workforces, with highly visual three-dimensional (3D) interactive training tools becoming the norm. Acceptance by the public, courts and workforce is an important issue, and implementation strategies must be considered carefully.

Jan 1, 2002