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By Richmond Bennett

Airborne geochemistry became a reality with the advent of a high-sensitivity airborne gamma ray spectrometer with large volume NaI (TI) crystal detectors. Small variations in the concentration of potassium (as K40), thorium (as T1208) and uranium (as B1214) along the flight lines can be determined by measuring the gamma radiation with a sensitive airborne spectrometer. Small volume crystal spectrometers are useful only for detection of major surface uranium (Bi214) variations, but the large crystal volume system is an airborne geochemical exploration method capable of locating hydrothermal mineral deposits. Radioactivity as a guide to ore has been discussed in the literature by Damon (1950), Gross (1952) and others. The theoretical basis is that potassium, thorium, and uranium are concentrated in late stage solutions during magmatic crystallization. Thorium and uranium are concentrated in late stage liquids because their large atomic radius and high ionic charge prevent them from entering into the crystal lattice of common rock-forming minerals (Rankama and Sahama, 1950). Potassium, which has a large ionic radius and small charge, also can be concentrated in the high water content late stage fluids (Heier and Adams, 1964). A large proportion of uranium and thorium in rocks occurs around grain boundaries of the essential rock-forming minerals (Hurley, 1950). Uranium and thorium substitute for zirconium in zircon, a comparatively early forming mineral. However, most of the thorium and uranium is concentrated in residuals where they can be fractionated and incorporated into allanite, monazite, xenotime, and other minerals.

Jan 1, 1970

By Harold D. Palmer

The marine geologist and coastal engineer have at their disposal a wide variety of geophysical tools with which to investi¬gate sea floor topography and structure. Such devices include towed magnetometers, shipboard gravimeters and a variety of acoustical systems for recording the relief of the sea floor and buried structural features. The versatility of this latter group of systems lends itself to a variety of applications essential to those projects where excava¬tion of the sea floor is required. This paper describes the use of several acoustic devices and their Limitations and presents a case history in which a rapid survey from a small vessel provided detailed information critical to the planning stage of a specific coastal project. In this discussion, shallow water is defined as depths less than 150 feet. At present, this limit includes the maximum depth of economic dredging and most other offshore activities. To be sure, the maximum depth at which routine useful work can be accomplished is rapidly increasing, but the majority of current marine activities are located in water depths here defined as shallow.

Jan 1, 1968

By Victor F. Hollister

This section on case histories of discoveries of volcanic-associated and volcanogenic massive sulfide deposits is divided into a preliminary discussion of models and then into three parts: Kuroko- type, Anyox-type, and shale-hosted. The separation is made to accommodate the use of exploration models, and these may not coincide with genetic models discussed in the literature. The exploration models grew as knowledge was gained concerning ore guides and ore controls in the volcanic-related deposits. The evolution of the genesis of massive sulfide deposits in volcanic terranes from a replacement to a syngenetic hypothesis in the 1950s and 1960s necessitated changes in exploration approaches in ore search. The acceptance of a syngenetic origin for conformable or concordant sulfide masses led to more widespread adoption of stratigraphic ore guides. 'The occurrence of epigenetic stringer ore with and stratigraphically below many conformable massive sulfide deposits did not diminish the importance of stratigraphic ore controls. Proximal conformable sulfide masses were formed near their seafloor hot spring source and normally are underlain by epigenetic sulfides: whereas. distal conformable sulfide masses were deposited away from the hot spring and may have no associated feede; zone. Industry groups that early recognized the syngenetic nature of volcanogenic massive sulfides were responsible for discovery of some of the large and economically significant deposits. Ultimately, the rest of the geological profession accepted the leadership of the early iconoclasts.

Jan 1, 1991

By John B. Rigg

The title of my paper today is "public relations challenges for the pending minerals crunch". There isn't anyone in this room who would dispute. That the minerals industry has always had public relations challenges . . . No matter what the circumstances, mineral shortage or abundance. The industry suffers from an image that is second to none in longevity. It defies all actuarial formulas of the past or the future. Never mind that such an image is outdated, distorted, overstated, and reiterated. I submit that the minerals industry had public relations challenges long before there was anything called public relations. This account of egyptian mining practices, recorded for posterity by Diodorus Suculus at the end of the second century, b.c., is indicative. "On the confines of Egypt . . . And Ethiopia is a place which has many great mines of gold, where the gold is got together with much suffering and expense. The kings of Egypt collect together and consign to the gold-mines those who have been combined for crime, and who have been made captive in way . . . Sometimes only themselves, but sometimes likewise their kindred. "Those who have been consigned to the mines, being maw in number and bound with fetters, toil their tasks continuously both by day and all night long, getting no rest and jealously kept from all escape.

Jan 1, 1975

By Diane M. Jordan Tom M. Malloy

As part of the Mine Waste Technology Program (MWTP), a large-scale column test utilizing bacteria and a sulfide ore was conducted at McClelland Laboratories, Inc., in Sparks, Nevada. The MWTP is funded by the U.S. Environmental Protection Agency (EPA) and is jointly administered through an interagency agreement with the U.S. Department of Energy (DOE). The project was intended to illustrate the viability and feasibility of biodegradation technologies to reduce the cyanide to the regulatory level of 0.2 parts per million (ppm) within an acceptable time frame and with low operational costs.

Jan 1, 1999

By Jaime Lomelin

[First of all I want to thank the Society of Mining Engineers of AIME for the opportunity to present what Industrias Penoles, S.A. is doing in Mexico to reach the basic objetive of the enterprise without compromising, in short or long term, the living conditions of the community or attempting in an irreversible form against Nature. Industrias Penoles, S.A. is one of the largest mining and metallurgical companies in Mexico. It was founded in 1887 and at the turn of the century installed a lead smelting operation close to the village of Torreon, which became city five years after the start up of the Penoles smelter. Now Torreon has a population close to 300,000 inhabitants. In 1974 Penoles is still the largest industry in Torreon and the dynamic growth of the city is close related to this factor. Today Penoles in Torreon has a lead smelter with a capacity of 130,000 metric tons/year of bullion, an electrolitic zinc plant of 105,000 metric ton/year, and it is modernizing its lead smelter to control pollution and expand it to 190,000 metric ton/year of bullion including all the services and refinery. The Penoles complex in Torreon is the biggest in the non-ferrous metals field in Latinoamérica.]

Jan 1, 1974

By J. R. Caylor

The Mine Safety and Health Administration (MSHA) advanced several initiatives last year to further protect miners' health. Regulatory efforts included the implementation of a Hazard Communication rule for all mines, work on the Single Sample rule for all coal mines, and the Plan Verification rule for underground coalmines. Development and application of new technologies are actively encouraged in preventing miners' hearing loss and respirable dust overexposures. MSHA's successful x-ray program for screening of black lung among coal miners completed its third year. Compliance Assistance efforts are focused on Best Practices, outreach, and technical support for operators' specific challenges.

Jan 1, 2003

By Dennis C. Drehmel

Because of their relatively low cost, carbonate rocks are desirable in abatement of air pollution by acid gases. Although many processes and types of equipment have been proposed to control or prevent the emission of acid gases, this paper considers only three: dry-limestone injection, wet-limestone scrubbing, and chemically active fluid beds. For the dry-limestone-injection process, surface area-especially from pores in the 0. 2- to 0.3-micron range-is one of the important parameters which will discriminate between less and more reactive carbonate rocks. Marls, chalks, oolitic calcites, and other fine- grained limestones show larger-than-average surface areas and better- than-average removal efficiencies. Inert chemical impurities such as silica detract from reactivity. A dolomite is not necessarily less re- active than a calcite. For the wet-limestone-scrubbing process, dissolution rate of the carbonate rock controls the differences in stone reactivity. In this process the dolomites are less reactive than the calcites. In addition, more than 90 percent of the dolomitic impurity in Fredonia white lime- stone is inert during limestone scrubbing. Dissolution rate is also a function of particle size for large-grained carbonate rocks. Fine grinding of such rocks will increase the dissolution rate to that of a fine-grained rock. Hence the requirement of high dissolution rates may be met by some grinding of fine-grained material (e. g., marl, chalk, or other limestone) or by fine grinding of coarser grained material. For chemically active fluid beds, chalks have the best capacity to absorb both SO2 and H2S. However, most chalks are probably unsuitable for fluid beds because of high attrition rates. Because dolomites are generally more reactive than calcites with both SO2 and H2S, a dolomite would be the feed material of choice for a chemically active fluid bed.

Jan 1, 1974

By Khosrow Badiozamani

Depletion of easily accessible coal reserves and stringent competition in coal marketing has led to the coal industries' need to more accurately assess alternate development scenarios and to develop well-conceived produc¬tion plans. This, in turn, has encouraged the active use of the computer during resource eval¬uation and mine planning. Morrison-Knudsen, (M-K) has developed proprietary software, known as "EAGLES", to support not only its own mine planning and development activities but also the mining industry in general. The EAGLES system provides complete geologic modeling, mine planning, production modeling, equipment modeling, and cost and financial modeling capabilities. In addition, EAGLES can be used for geotechnical studies, environmental assessments, and surface and groundwater hydrological evaluations. Another important tool used in today's mine development is Landsat (remote sensing). Landsat is especially useful in the evaluation of mining activities at remote mine locations and for megascale assessments of geologic structures and hydrologic regions. The use of scientific systems in the development of surface mines is being well integrated into today's mining operations and will be a major factor in the planning, development, and operation of mines in the future.

Jan 1, 1985

By B. A. Bancroft

A quality assurance program consists of all those activities aimed at providing confidence to the purchaser that the suppliers quality system will provide a product that will satisfy the purchaser's stated quality requirement. An organizing principle is necessary for prioritizing the quality control activities of quality personnel in the face of a myriad of technical possibilities, data-analytic applications, and an overwhelming number of possible activities promoted in the literature and by quality "gurus". The organizing principle I like is that quality assurance exists when those involved in the quality process: (1) know what they are supposed to do, (2) can tell if they are doing it and are set up to continue doing it and, (3) if they are not, they can remedy the situation in a timely fashion. Any incremental activity which facilitates this organizing principle is a continuous improvement activity. That activity which has the chance to facilitate this principle to the greatest extent is the next one to work on. In these days of lean corporate and regional staffs it is as important to know what not to work on as it is to know what to work on. In this paper I shall discuss in general terms the implications of this organizing principle for the design of Quality Assurance (QA) Programs for coal mines and also provide some comments about the application of Statistical Process Control (SPC) methodologies in the coal industry.

Jan 1, 1994

By R. E. Gertsch

A mobile-modular carbon adsorption mill design and operation for small to medium sized heap leach precious metal mines is presented. In the mobile-modular strategy, charcoal columns with adsorbed metal move from small strategically located carbon adsorption loading stations to a central stripping facility and back. The design has many advantages: 1) It scales-up from pilot plant to full production. 2) It has low capital requirements. 3) Operational costs are competitive with other systems. 4) Mill production can react quickly to changes in ore grade or property area. 5) The solution circuits are simple and easy to maintain. 6) Charcoal damage is reduced.

Jan 1, 1993

By P. Somasundaran, T. Chen, Diptabhas Sarkar

We have developed a layer-by-layer deposition technique for preparation of nanocomposite particles. Using this process, it was possible to make nanocomposites of various oxides with desired local composition and microstructure. The attachment of the shell particles to core particles was achieved using controlled polymer adsorption. Removal of excess polymer was accomplished without detaching the pre-adsorbed polymers by a specific stepwise washing scheme. The inherent chemistry of the process makes it easy to incorporate functional fillers over core particles. The nanosized filler materials will replace the shell particles in the present process and the polymer bridge would be chosen by taking into consideration the respective surface chemistries of various shell and core particles.

Jan 1, 2003

By R. L. Grayson, T. L. Dickinson, C. G. Anderson

Sponsored by the EPA, USGS, DOE, and NSF through the Committee on Earth Resources, the National Research Council’s Committee on Material Flows Accounting of Natural Resources, Products, and Residuals, created in August 2002, studied the value that material flows accounting, which can track the flow of a material from the time it is extracted to its ultimate disposal, may provide for making better integrated economic, social, and environmental policy decisions. This could be a crucial technology for the mining industry to incorporate. This paper will recount the statement of tasks, the study process, and the science-based conclusions and recommendations reached.

Jan 1, 2004

By P. C. Clark

This paper is an overview of the requirements and concerns for minerals and pigments used in papermaking. The first part of this paper deals with mineral or pigment filling in the actual papermaking process. The second part deals with the pigment or mineral properties that are important in today's coating processes.

Jan 1, 1993

By W. Jacobi, B. Haider, D. Regulla, J. Huber

[Introductory Remarks] Thermoluminescence (TL) detectors are widely used for the dosimetry of X- and[ y]-rays. Also filter devices for radon daughter monitoring have been developed in which the a activity on the filter was measured with TL-detectors (Breslin et al., 1977). For this purpose normal LiF-tablets with a thickness of 0.4 - 1 mm were used. However the lower detection limit of such TLmonitors for radon daughters is relative high, especially in areas with a high [y]-background, due to the low [a /-y]-sensitivity ratio of such thick LiF-detectors. This [a/y]-sensitivity ratio can be increased if TL-detectors are used whose thickness is comparable with the range of [a]-particles. On the basis of this consideration we have developed a simple light weighted and sensitive TL-monitor for the measurement of the cumulative radon daughter exposure in air. [Description of the "Monitor] The monitor consists of two parts: The sampling pump with the accumulator, and the sampling probe which contains the air filter and TL-detector system. Both parts are connected with a plastic tube. For operation in mines a light weight, portable air sampler with a built-in accumulator (DuPont model 125 and 200, 400 g) is used which enables an adjustable, constant flow rate in the range of 7.5 -12 1/h. These air samplers allow a sampling period of 10 hours before recharging is necessary. For radon daughter measurements in houses this pump is replaced by a larger, netoperated pump with a flow rate of 180 1/h. Figure 1 shows a schematic cross section through the sampling probe whose weight is 40 g. The radon daughters are collected on a hydrophob membrane filter (Sartorius) with an effective filter diameter of 11 mm and a pore diameter of 3 µm; its collection efficiency for radon daughters is [>] 95%. Above the filter the detector system is mounted. It consists of two thin Tm-activated CaSO4-TL films of 8 mm diameter on a Al-carrier foil manufactured by Matsushita Inc., Japan. The thickness of the TL-film is 6 mg/cm2, which is comparable with the range of a rays. The first detector is faced in 3.5 mm distance above the filter; in addition to the ambient y background this detector is exposed to the [a] and ß radiation from the radon daughters on the filter. Between the first and the second TL-detector is an Al-absorber of 0.5 mm thickness which shields this detector against the [a] radiation and partly also to the ß radiation from the filter. Both detectors have the same [y] shielding. After air sampling both TL-detectors are read-out with a commercial, hot-air reader (Matsushita Inc. / Japan, Model 505 A). The glow-curves are identical for [a and y] rays (Regulla et al., 1980). The integral TLsignal from both detectors is displayed in mR-units (or mR-equivalent). The difference between the response of the unshielded TL-detector above the filter and the shielded TL-detector is proportional to the time-integral of the filter activity, integrated over the sampling period. Calibration and Intercomparison Measurements] The linearity of the a response was checked with a 241Am-source for an [a] fluence on the detector surface of 5400 [a's/cm2•s] in the range of 102 -105 mR-equivalent. Within the experimental error of 15% the response function is linear. The TLD-monitor was calibrated for radon daughters in air by comparison with a calibrated integrating, monitor (WLM-meter) equipped with a Si-surface barrier detector and a direct electronic read-out; this instrument was developed by us for area monitoring some years ago (Haider et al., 1976). The results of simultaneous measurements with the TL-monitor and the electronic WLM-meter in mine areas and in indoor air of houses are shown in figure 2. On the abscissa the mean potential [a] energy concentration (in WL) during the sampling period is given which was derived from the measurements with the electronic WLM-meter. On the ordinate the corresponding response of the TLDmonitor to radon daughters (difference between both TL-detectors) is displayed, expressed in terms of mRequivalent per liter sampled air. It follows from this comparison a linear relationship over the whole range of 0.005 - 5 WL with a standard deviation of 10%. The resulting calibration factor for the TLD-monitor is 18± 2 mRequiv per WL • 1.

Jan 1, 1981

By Donald L. Gaughenbaugh

Under the terms of the 1970 amendments to the Clean Air Act, the EPA established national ambient air quality standards for a number of pollutants. Sulfur dioxide (SO2) was one of these pollutants. These ambient air quality standards have had perhaps their biggest impact on the power utilities. In an effort to meet the air quality standards set forth by the EPA, utilities using high sulfur fuels have been forced to install flue gas desulfurization (FGD) systems. The majority of FGD systems in operation today are nonregenerable systems, that is the by-product of the system is disposed of, usually into settling ponds. Limestone slurry is the most common reagent used to remove SO from the flue gases. The calcium carbonate (limestone) slurry interacts with the flue gas, absorbing the SO2 and forming a by-product of calcium sulfate/sulfite which is disposed of.

Jan 1, 1986

By Ryota Kasahara

In 1981, a gas outburst accident occurred in the Yubari Shintanko coal mine, the only expectant mine in Japan, it caused 93 deaths. As a result, Yubari Shintanko closed in 1982. This major disaster was a turning point for sustainability of Yubari City, the largest coalfield in Japan. Finally, Yubari City was bankrupted in 2007. This paper aims to explore how miner’s children experienced this disaster and felt about region, family, and themselves, and to explain the relation between region declining and children’s lives. The data of this paper are the archived 600 essays, written by the junior high school students at the time of the disaster. There are three findings. First, the children who lost their father were the most shocked. They faced profound sadness. But they expressed that they had decided to overcome their sadness with surviving family. Second, the children who didn’t lose their father were also influenced. They were anxious about the future of Yubari, their family, and themselves. Furthermore, they decided to strive for their future. Third, they understood the disaster as a turning point of Yubari declining and looked ahead their future outside of Yubari. In conclusion, this disaster created their hopelessness to Yubari region and, as a result, promoted the decline of the city through their migration to other city. Furthermore, it is important to clarify that Yubari City has to continue the struggle to the regeneration.

Jan 1, 2017

By H. Wagner

INTRODUCTION One of the most important tasks facing the opera¬tors of deep-level gold mines is supporting the roof strata in the immediate vicinity of the stope faces. Some of the deeper gold mines operate at depths ex¬ceeding 3.0 km; the extreme mining depths and the tabular nature of the gold-bearing reefs result in high stress concentrations at the abutments of the stope faces. These, in turn, lead to extensive fracturing of even the hardest quartzites. Although most of these fractures develop in a stable manner, there have been many instances where rock failure occurred suddenly, resulting in a considerable amount of damage to the underground workings. Such violent rock failures commonly are known as "rock bursts," and they are typical of many hard-rock mines that are operating at great depths. To safeguard mining personnel and equipment against the effects of stable and unstable rock failures, adequate support must be provided to the fractured roof as quickly and as effec¬tively as possible. Traditionally, timber props and timber packs have been utilized to provide roof support in gold mine stopes up to 1.5 m wide. Both methods of support suffer from the fundamental disadvantage of generating sup¬port only in reaction to movement of the strata. Since unrestrained strata movement often results in a break¬down of the frictional forces that preserve the stability of the intensely fractured roof strata, it is essential that stope supports have rapid load-bearing characteristics. An equally important requirement is that the roof sup¬ports be able to accommodate displacements of the rock mass. A third requirement of roof supports in gold mine stopes is that they must be able to accommodate the high rates of stope convergence typical of rock bursts. The hydraulic prop is the obvious choice for sup¬porting the stope faces in deep-level hard-rock mines. Since hydraulic props can be installed with a positive setting load, they can provide roof support that is independent of strata movement. By equipping the hydraulic props with yield valves, they meet the require¬ment of being able to accommodate rock-mass displace¬ments. However, the requirement of being able to accommodate high rates of stope convergence without overloading or damaging the rock strata was rather difficult to meet. The first introduction of hydraulic roof supports into gold mine stopes showed that conventional hy¬draulic props, such as those used in coal mines, were completely unsuitable for a number of reasons, in¬cluding: 1) Since drilling and blasting are used to break the ore in gold mine stopes, supports installed close enough to be effective are exposed to the vigor of the blast. Conventional coal-mining props suffered extensive blast damage, despite being protected by a blast barricade. 2) The environmental conditions in gold mine stopes favor corrosion. The high quartz content and the abrasiveness of the ore further aggravate the problem by damaging the protective coatings on the hydraulic surfaces. Simply changing the design of gold mine props to have the piston project from the bottom rather than from the top resulted in dramatic improvements in the service life of the props. The improvement was attributable to external water in the stope washing the fine quartz grit away from the hydraulic surfaces, rather than concentrating the particles between the cylinder and piston of the prop. 3) The most obvious deficiency of conventional coal mining props was their inability to yield rapidly enough to accommodate the high convergence rates of rock bursts without overloading the supports. As a result of the first disappointing results with hydraulic supports in narrow hard-rock stopes mined by drilling and blasting, a comprehensive research and development program was undertaken. The hydraulic props resulting from several years of research and exten¬sive field trials are described herein. To date (1978), more than 130,000 of these props have been manufac¬tured and used successfully in a number of mines and under a variety of geological conditions. Although many of the detailed specifications are directed spe¬cifically to gold mining conditions, there are a number of points that are of general importance in the design of underground support systems for tabular excavations in hard-rock mines of any type. SPECIFICATIONS FOR RAPID-YIELDING PROPS Yield Requirements The yield requirements for hydraulic props in deep¬level hard-rock gold mines are summarized in the fol¬lowing paragraphs. Slow Yield Load: The design of the yield valve must allow the yield load to be preset to between 300 and 400 kN. This flexibility is necessary to account for the differences in the strength properties of the roof and floor strata. Drop in Load Under Slow Yield: The drop in sup¬port load during a slow yield should be as small as possible, but it should not exceed 5% of the slow-yield load. Rapid-Yield Load: The load exerted by the prop during periods of rapid stope convergence should be as close as possible to the slow-yield load. The rapid-yield load should not exceed the slow-yield load by more than 15% at yield rates of 1.0 m/s. The limitation of the upper valve of the yield load is important; it deter¬mines the hydraulic performance of the yield valve. The hydraulic props that satisfy this criterion have performed well, even under severe rock bursts. Load Changes Under Rapid Load: On some of the earlier rapid-yielding props, conditions of dynamic in¬stability were observed; these conditions resulted in a complete breakdown of support resistance. It is essen¬tial that the force oscillations during rapid yielding be as small as possible, not exceeding -*5% of the average rapid-yield load at a yield rate of 1.0 m/s. Longitudinal Resilience: During rock bursts, vibra¬tions of the roof and floor sometimes are observed. To

Jan 1, 1982

The Mine Safety and Health Administration (MSHA) has conducted studies to evaluate dust control technologies on deep cut continuous mining sections. These surveys have been conducted in different mines using various mining methods, face ventilation systems and dust control systems. The surveys typically consist of respirable dust sampling combined with a time study of mining activities. Measurements of dust control and operational parameters are also made. Critical elements identified for controlling respirable dust in deep cut mining systems include controlling intake dust, dust collector capacity, face ventilation quantities and velocities, positioning of workers, work practices and selection of equipment. This paper discusses how the dust surveys are conducted in deep cut mining sections and how these surveys are used to identify specific dust generating sources.

Jan 1, 1999

By Y. H. Kim

A simulation procedure has been developed that realistically portrays aggregate growth and disintegration for particular types of floc structures in water and wastewater treatment processes. The procedure requires local dissipation rates and specification of an interaction distance between colliding particles. A principal difficulty encountered in polymer flocculation, however, arises from changes in conformation of adsorbed macromolecules. Therefore, in systems where polymer flocculation occurs by bridging, dynamic changes in the particle size distribution depend upon the interaction of nonlinear. stochastic hydrodynamics with particles whose growth results from a number of concurrent and sequential random processes.

Jan 1, 1988