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By M. K. McMullen

Mineral Development Agreements (MDA?s) are a cooperative mechanism in Canada by which the federal and individual provincial governments can coordinate their scientific, techno- logical and market development resources in order to implement measures designed to stimulate mineral exploration and development by the private sector; the objective, ultimately, being to increase the mineral industry?s contribution to provincial economies. In the latest round of MDA?s, which was initiated in 1984, a significant number of planned activities relate to industrial minerals. This paper will describe the nature and importance of MDA's in Canada and will outline the wide range of activities taking place with respect to industrial minerals.

Jan 1, 1987

By W. D. Hausel

The Wyoming craton in the western United States is a favorable terrane for diamond deposits. The craton hosts a variety of ultramafic, ultrabasic, and ultrapotassic rocks. Additionally, a few hundred 'kimberlitic' heavy mineral anomalies and some geophysical and remote sensing anomalies indicate the presence of undiscovered, mantle-derived, pipes in the craton. The Wyoming craton is separated into a Wyoming 'archon' known as the Wyoming Province, and the Colorado 'proton' known as the Colorado Province. The 'archon' underlies much of Montana and Wyoming and continues north into Alberta and Saskatchewan; the Colorado 'proton' underlies much of Colorado and a small portion of Wyoming. Although most exploration geologists would consider the 'archon' the most favorable terrane for commercial diamond deposits, the 'proton' has produced more than 120,000 diamonds, while the 'archon' has not been very productive.

Jan 1, 1996

By Robert W. Bruhn

Ground movements associated with high extraction underground coal mining, such as pillar retreat and longwall, are sometimes large enough to disrupt the ground water regime as well as damage buildings and other surface structures. A U.S. Department of Energy/Bureau of Mines- sponsored subsidence study currently underway at Kitt Energy Corporation's Kitt No. 1 Mine near Philippi (Barbour County), West Virginia has provided an opportunity to monitor the ground water response above a mine panel during both developmental and pillar retreat mining. The initial findings concerning ground water effects presented in this paper indicate that total extraction mining produced significant water level declines in deep-lying strata but had little effect on water bevels at shallower depths.

Jan 1, 1985

By R. Jin

The hydrophobicity of six coals ranked from lignite to anthracite is studied through contact-angle measurements, bubble attachment-time measurements, FTIR spectroscopy, and Hallimond-tube flotation. The preliminary study shows that the hydrophobicity of coals can be told by the bubble attachment times of coals (a kinetic criterion) or by the contact angles (an - equilibrium criterion). A general agreement between flotation response of coals and measured bubble attachment times or contact angles is observed in the present study. However, the study also shows that the hydrophobicity of coals can be predicted by FTIR spectroscopy work with proper manipulation of the spectra. Both hydroxyl and carboxyl groups in the coals are proven by FTIR work to be responsible for the change of coal hydrophobicity. A new criterion for the hydrophilicity index of coals from FTIR spectra is introduced through the study.

Jan 1, 1987

By W. Gibson Jaworek

It has become apparent in recent years to everyone intimately concerned with the future of the American fuels industries that the growth in demand for energy has become a topic receiving considerable attention, and that investigators are leaning more and more toward a mathematical approach to deduce what pattern that growth will follow. Though coal has been included by necessity In all-studies of future energy markets, it has not been the subject of mathematical analysis or description as frequently as has been total energy or some of the other fuels, particularly petroleum, It is the intent in this particular paper, to subject bituminous coal consumption to a preliminary mathematical scrutiny which can lead to a more logical estimation of the general level of bituminous coal consumption for the next decade, as well as formulating an approach toward describing how coal consumption may vary as the result of the annual variations in activity in the United States, economy, The approach utilized is more sophisticated than the mere projection of the historical trend of bituminous coal consumption. Such a projection would lead to a continuation of the recent decline, indicating that coal consumption would reach zero some thirty years from now. On the other hand, the mathematical analysis described here is a relatively simple, straightforward approach and- is not intended to represent the-ultimate in mathematical economic analysis as now practiced, It is hoped that this will contribute to our knowledge of bituminous coal markets. Even more, it is hoped that it will help arouse a greater interestin utilizing mathematical and statistical analysis when studying the bituminous coal industry. - Since this is a preliminary study, comments and criticisms are anticipated.

Jan 1, 1960

By H. Colijn

The design of bulk materials handling facilities is greatly influenced by the handling characteristics of the bulk solids. For instance, free flowing materials need only small discharge openings in hoppers, while cohesive materials require large discharge openings. Chute and hopper slope angles are affected by the sliding friction coefficients. During the past ten years, large lignite deposits in Texas are being opened up for energy production, both in generating plants as well as in synfuel projects. The early plants have encountered many problems in handling and storing this lignite. This paper will provide some information about the handling characteristics of Texas lignite.

Jan 1, 1982

By Paloma Lazaro, Moe Momayez

Interactions between human beings and their work environment require the body to regulate its temperature by balancing heat production and loss. Comfortable environmental conditions are crucial for keeping workers safe and healthy and to maintain a suitable level of productivity. However, achieving a proper core body temperature may become challenging under different conditions, especially in high heat-generating workplaces such as hot underground mines. Because hot underground mines have the potential to expose workers to heat stress, compliance with standardized and regulated indices and criteria is distinctly required. The objective of this paper is to provide an overview of the current research on heat stress and strain in hot underground mines, collected from published and specialized literature. General definitions, statistics of heat-related accidents in mining, overview of the indices, standards, and recommendations for heat stress are provided herein.

Oct 6, 2020

By Joseph L. Condon

The U.S. Department of the Interior, Bureau of Mines, is doing research on methods to obtain premining information on problems such as detection of old mine workings, abandoned oil wells, channel sands, faults, and other geologic features that are undesirable from a production or safety aspect. Techniques being developed to acquire the necessary information include seismic and electromagnetic. The seismic methods include high-resolution seismic and acoustic methods applied from the surface and inseam channel waves applied under- ground. The electromagnetic, or radar, methods are applied from the surface, from boreholes, and from the working face underground. All of these methods are useful under certain site-specific conditions, but none of these methods is universally applicable for all mining conditions.

Jan 1, 1980

By Fitzhugh T. Lee

Results from the first part of a two-part investigation of the stability of highwalls in open-pit coal mines in the Paleocene Fort Union Formation of the western Powder River Basin of Wyoming and Montana indicate that these highwalls are subject to time-dependent deformation. Field investigations and laboratory physical properties tests of coal and overburden rocks suggest that several factors influence highwall stability. Some of these factors are rebound of overconsolidated rocks, desiccation, water, orientation and spacing of fractures, and strength and deformation properties. Factors of safety for a typical highwall in the study area (calculated by the finite element method) may be less than 1.0 when open fractures are present and the highwall has degraded. Although it is concluded that most open-pit highwalls in the Fort Union Formation within the study area have adequate short-term stability, these highwalls do deteriorate and become progressively less stable. Because of this, postmining failures are common and stability conditions could become critical if mining were delayed and then resumed after a period of several months. The second part of the investigation will utilize field measurements of rock-mass properties and instrumentation of actively mined highwalls to obtain data for comparison with the results of the initial investigation. Because the height of highwalls will increase as the more shallow coal is exhausted, these data will also be used to predict the behavior of slopes higher than those presently found in the western Powder River Basin.

Jan 1, 1977

By D. J. McParland

This paper will deal with some of the considerations which, were involved in the design and construction of the uranium mills in the Elliot Lake area . These plants, eleven in number, range from 1500 to 6500 tons per day milling capacity. Most references are with respect to the seven plants in the Rio Tinto Group which have a combined milling capacity in excess of 20,000 tons per day. In dealing with such abroad subject as mill design, one has the choice, of covering a few specific problems in great detail, or else attempting to cover many subjects superficially and briefly. In preparing this presentation, an attempt has been made to compromise on these extremes, and to select some interesting illustrations which are of general interest in the field of mill design, and of value to persons concerned with mill design broadly, beyond the field of uranium mills.

Jan 1, 1959

By C. L. Karr

Establishing suitable control of pH, a requirement in a number of mineral and chemical industries, poses a difficult problem because of inherent nonlinearities and frequently changing process dynamics. Researchers at the U.S. Bureau of Mines have developed a technique for effectively controlling such systems. This technique successfully combines the process control capabilities of fuzzy logic and the search capabilities of genetic algorithms. Fuzzy logic offers an effective mechanism for handling nonlinearities, while genetic algorithms can provide fuzzy logic controllers with real-time adaptive capabilities. This Bureau-developed technique is applied to a laboratory acid-base neutralization experiment. Nonlinearities in the laboratory system are associated with the logarithmic pH scale and the changing process dynamics are due to alterations in pH and buffering capacity input solutions. Results indicate fuzzy logic controllers augmented with genetic algorithms offer a powerful alternative to conventional process control techniques in such nonlinear, rapidly changing systems.

Jan 1, 1992

By B. Li

"Sepiolite is a magnesium-rich, porous, and fibrous clay mineral with broad applications. These applications take advantage of sepiolite’s high specific surface area and unique nano-sized channel structure. Over the past years, numerous materials and techniques based on the structure and property of sepiolite have been developed. This article reviewed the recent achievements in developments and applications of sepiolite in environmental protection, catalysis area, and nanocomposites. The prospectives of sepiolite applications is also discussed. INTRODUCTION Sepiolite is a magnesium-rich, porous, and fibrous clay mineral. The typical chemical formula of sepiolite is Si12Mg8O30[OH]4[OH2]4·8H2O [1]. Sepiolite has a high specific surface area and nano-sized channels because of its special structure [2]. This unusual crystal structure projected onto the [001] plane is shown in Fig.1 [3]. As it can be seen, silicon and oxygen atoms make up for the tetrahedral structure and magnesium and oxygen atoms form octahedral structure, respectively. Those tetrahedral-octahedral-tetrahedral ribbons expand boundlessly in one direction, leading to the special fibrous structure of the sepiolite. Every tetrahedral-octahedral-tetrahedral ribbon is combined to the next by an inverted Si–O–Si bond, which causes an interlaced layer with a continuous tetrahedral sheet and a discontinuous octahedral sheet. Terminal MgO at the edges of the ribbons is coordinated with two structural water molecules, which can form hydrogen bonds with zeolitic water molecules that are located in the channels running parallel to the fiber axis [3,4]. The Mg2+ ions inside the channels can be exchanged with other cations in solution. Therefore, sepiolite can be used to remove metal cations from aqueous solutions [5,6].It can be seen from Figure. 1 and Table 1 [7], the unique structure endows sepiolite with a substantial surface area and nanoscale channels. Its specific surface area reaches 320 m2/g and channel dimensions up to 3.7×10.6 Å. There are three active adsorption sites on the surface of sepiolite: one is oxygen atoms of the Si-O tetrahedron. The second is the structural water molecules paired with magnesium ions at the edges of the ribbons, which can form hydrogen bond with adsorbent. The last one is the Si-OH groups due to the breaks of the Si-O-Si bonds on the surface of Si-O tetrahedron. Thus, sepiolite has strong adsorption ability which has been widely used in environmental protection. Moreover, sepiolite has many significant features such as good mechanical and thermal stability, rheological property, porous, and easily modification, making it be a hotspot in chemical and biological researches. However, with the development of technology, broader and more advanced applications of sepiolite have been carried out in recent years. In this study, the recent achievement in sepiolite applications is summarized, the further tendency is also discussed."

Jan 1, 2018

By T. J. Malterer

Peat has unique physical, chemical, and biological properties. These include high porosity and water retention, high absorption and adsorption properties, high buffering capacity, and it is a rich medium for microorganism activity. Peat has traditionally been used for horticultural purposes. However, in recent years, peat is increasingly being used for waste treatment purposes. This paper reviews North American literature on the use of peat for waste treatment applications. The literature indicates promising use of peat in treating municipal and on-site effluent, removal of low concentrations of heavy metals from wastewaters, and adsorption of liquid and gaseous hydrocarbon pollutants.

Jan 1, 1995

The need for an integrated approach to optimization of unit operations in both the pit and the mill has long been recognized, but the complexity and nature of the overall problem has up to now resisted solution. This paper reports on a modeling methodology which couples symbolic and numeric computing to unify operations in both the pit and mill. The ultimate goal of this work is to optimize all operations that are influenced by blasting. Blasting plays a key role in all facets of operations. Obviously, drilling and blasting costs are determined by blast design, but the down-stream costs that are closely related to blasting results are often treated as separate functions: loading, hauling, cleanup, and crushing and grinding are all heavily influenced. Diggablilty and bucket fill factor are a function of fragmentation, the condition of the floor and uniformity in the shape of the muck pile. Likewise, cycle times and loading delays partially determine haul cycles, while fragmentation distribution and size determines the efficiency of truck loading. Removal and breakage of oversize causes loading delays and increases cleanup costs. The influence of blasting doesn't stop at the crusher. Mill productivity, power consumption, and maintenance are a function of the feed. Even at the SAG mill a reduction of a critical particle size during blasting can increase throughput. Thus, a bottle-neck for production far removed from unit operations in the pit can be alleviated by a modification in blast design. The question is: how do we optimize blasting with respect not only to itself but to al\ related mining and milling operations? For that matter, how do we even model blasting so that we can control the results of a blast?

Jan 1, 1991

In early June, Rio Tinto?s chief executive officer Tom Albanese said that he expected demand for iron ore, aluminum and copper to double in the next 15 years. Driven by global industrialization and urbanization, Albanese said during his company?s annual general meeting that to meet the demand in 2030, the additional supply required will be equivalent to replicating the iron ore output of Australia?s Pilbara region every five years, adding another aluminum production complex the size of Canada?s Saguenay every nine months and developing another copper mine the size of Escondida, in Chile, each year.

Jan 1, 2010

By J. W. Hawkins, K. B. C. Brady, M. W. Smith

The Pennsylvania Department of Environmental Protection (PaDEP) has been issuing surface mining permits since 1984 that authorize remining in areas that will affect preexisting pollutional discharges. These permits require the mine operator to employ best management practices to reduce pollution loading from abandoned mine discharges. A total of 110 completed mining operations with 233 discharges were evaluated to determine the impact to water quality. Overall, acid loading from these discharges was reduced by 7, 200 kg (15, 900 lbs) per day or 61%. Metal loadings were also reduced. For acidity, 49% of discharges improved or were eliminated, 52% showed no significant change and fewer than 1 % got worse. Loading reductions resulted from a combination of reduced concentrations and lower flows.

Jan 1, 2003

By J. D. Cooper

Previous research developed guide- lines to restrict the placement of air velocity sensors to areas of Low turbulence in underground nines. Even though these guidelines are theoretically correct, and may be easy to follow in underground coal mines, their application in small underground metal mines is difficult. As a result, study was undertaken at the Colorado School of Mines Experimental Mine to determine if an air velocity sensor could be placed in other locations with acceptable results. It was found chat by applying a variable calibration function to correct for changes in amounts of turbulence, instead of the previously used calibration factor multiplication, the sensor could be used successfully in areas of moderate turbulence.

Jan 1, 1984

By James W. Bass

Atmospheric fluidized bed combustion (AFBC) is an improvement in coal-fired boiler design that offers several advantages over conventional boilers. AFC can meet sulfur and nitrogen oxide emission regulations without the need for add-on flue gas treatment equipment. The relatively low combustion temperature inhibits ash melting, thus reducing slagging and fouling which can, in turn, increase a boiler's fuel flexibility. This report discusses, in general, AFBC technology and, in particular, progress at the 20-MW Pilot Plant built by the Tennessee Valley Authority (TVA) at its Shawnee Power Station near Paducah, Kentucky.

Jan 1, 1985

By J. Drelich

The wetting behavior of liquid polymers at solid surfaces and the adhesion forces involved at polymer-filler interfaces should always be considered in the fabrication of high quality polymer composites, including those made with mineral fillers. Spontaneous polymer spreading over the filler surface is a basic condition in the fabrication of the polymer-mineral composites. In this regard, the wetting and adhesion characteristics of polymer-mineral systems are reviewed in this contribution. It appears that several aspects of wetting phenomena at mineral filler surfaces are not well described in the literature and require further systematic study. Specifically, it is clear from this review that efforts should be made to determine the effects of mineral surface contamination (including surface hydration) on wetting and adhesion phenomena, and to determine the wetting characteristics of molten polymers at mineral filler surfaces. It is expected that any improved fundamental understanding of wetting and adhesion phenomena for the polymer-mineral composites will provide the basis for further technological development.

Jan 1, 1995

By Elham Najafi, Sina Ghassa, Ata Akcil, Hadi Abdollahi, Sandeep Panda, Zohreh Boroumand

The present study investigates the influence of ferrous iron (as FeSO4) and ferric iron (as Fe2 (SO4)3), and pyrite (FeS2) on the ability of bacterial leaching of a high-grade sulfide Zn–Pb ore. In this regard, shake flask experiments were carried out at 5% (w/v) pulp density of the ore sample (having 40.7% Zn and 12.4% Pb initial metal content) using a consortium of mesophilic iron and sulfur-oxidizing acidophiles. A concentration of 0.04 mol/L of ferric iron in the leaching media was found to be optimum for zinc extraction without affecting growth of the microorganisms. Under this concentration, the dissolution of Zn, Pb, Cd, and As was found to be 57%, 0.2%, 0.03%, and 9.9% in 25 days. Using ferrous iron in the media, 0.16 mol/L of Fe2+ was found to be the optimum concentration for efficient bacterial growth and metal dissolution (54.6% Zn, 0.08% Pb, 0.03% Cd, and 10.2% As) from the sample in 25 days. On the other hand, using pyrite as the source of energy for bacterial growth, an initial 12-day lag period was observed when compared to the effect of ferrous iron in the media. Under the optimum concentration (test with 0.24 mol/L iron in the form of pyrite), the dissolution of Zn, Pb, Cd, and As was found to be 39.8%, 0.1%, 0.03%, and 10% in 25 days. The surface chemistry analysis indicated formation of a sulfur layer over the particle surface that hindered reagent diffusion and affected metal recovery through bioleaching.