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By Tom H. W. Loomis

The department of the Interior is a federation or holding company of several fiercely independent bureaus which have either jurisdiction or expertise - or both - in a wide range of environmental fields. Each bureau is an advocate for its own concerns and an enforcer of its own mandates. This can be confusing to the company operating in the field. I will try to explain our concerns, help you see where we are "coming from," and give you some insight as to how we can help you. Other speakers have stressed the environmental concerns and site selection factors for uranium wastes so I will focus on the concerns of the Department of the Interior and some of the assistance we can give you in this area People are more aware and more concerned about environmental factors now than they used to be. Thus the past decade has brought about an evolution in both siting and design of uranium mill tailings ponds. Site selection criteria used to be simple - find a tract of land as near to the ore supply as possible with enough space and suitable topography for the expected volume of wastes. Site selections in the past have left a legacy of problems to be corrected - radioactive wastes on stream banks and in floodplains, mill wastes in and near established communities, and unprotected wastes subject to constant erosion. This is no longer acceptable environmentally or socially to a newly aware and concerned public. (Series of 30-35 slides showing uranium mine and mill wastes in Western United States. These illustrate environmental problems, reclamation and environmentally acceptable sites. The first group of slides are aerial shots taken in Wyoming and shows a surface mine and mill area. In the various views the pit, overburden piles, mill, and tailings pond can be seen. The next series were taken in Wyoming and New Mexico. These show various views

Jan 1, 1980

By Russell K. McFarland, Eugene L. Foster

INTRODUCTION The U. S. Department of Transportation has underway an important new program which will have a major impact on rapid excavation technology. The Transportation Tunneling Program, as it is called, is a coordinated, multi-modal research and development effort. Its goals, if realized, will significantly improve our ability to build the underground structures needed for transportation. This, in turn, will improve transport efficiency, environmental impact, and the energy consumption associated with the movement of people and goods. Tunneling technology research and development had its beginning at the Department of Transportation in the Office of High Speed Ground Transportation (OHSGT). The OHSGT developed and implemented a program in 1965 to provide the technology for underground construction needed to support future high speed ground transportation. In 1967, when the OHSGT was transferred from the Department of Commerce to the Federal Railroad Administration (FRA), the program accompanied that office. The thrust of the FRA program has been cost reduction through the development of new materials, innovative designs, and better construction methods. During the late 1960's and early 1970's, other developments were underway which would influence the future of tunneling research at the Department of Transportation. An ad hoc

Jan 1, 1974

By David E. Peterson, F. Merz

The Waihi Gold Mining Company Limited, Martha Hill Project was the first major hard rock mining operation following the resurgence of the mining industry in New Zealand. Because of its location adjoining a town and at the southern part of the sensitive Coromandel Peninsula, the operation received a high level of public scrutiny. Very srrict limits for effluent criteria had to be met and led to the necessity for advanced wastewater rreatment technology. The process technology selected was the copper catalysed oxidation of cyanide using hydrogen peroxide, with subsequent removal of heavy metals by precipitation and filrration. This paper discusses the adoption of environment limits together with the detailed description of the plant and design criteria. Data of the one year's operational history is also presented.

Jan 1, 1991

By A. L. Miller, A. J. Chambers, P. R. Griffiths, D. A. Parks

"Diesel engines are one of the primary contributors to the presence of nano and ultrafine aerosols in ambient air and occupational environments. Exposure to diesel emissions has been shown to contribute to various adverse health outcomes of the pulmonary system and cardiovascular system. Currently diesel emissions in the workplace are monitored by way of collecting the aerosol onto filters, which are then sent to a lab for thermal-optical analysis using the NIOSH 5040 method, which measures elemental and organic carbon explicitly. This process can take days or even weeks, and workers can potentially be exposed to excessive levels of diesel particulate matter (DPM) before the problem is identified. To remedy this, researchers from the National Institute for Occupational Safety and Health (NIOSH) are seeking to develop a field-portable method for measuring elemental and organic carbon in DPM aerosols. In the current study, we investigated the use of Fourier transform mid-infrared (FT-IR) spectrometry, which lends itself more readily to implementation in a real-time system than do the thermal-optical analysis methods. We have demonstrated a method for measuring organic and elemental carbon in DPM for a broad range of organic carbon (OC) to elemental carbon (EC) ratios (from 50.3 to 0.8). The ability to handle a wide range of OC to EC ratios is critical given the evolving diesel technology. INTRODUCTION Respiratory illnesses are common in mining industry workers [1] and exposures to toxic aerosols such as DPM can result in serious respiratory illness [2]. Health studies show a correlation between workplace exposure to diesel exhaust and an increased risk of lung cancer [3-8]. The International Agency for Research on Cancer (IARC) has characterized diesel exhaust as a human carcinogen [9], and similar classifications have been made by the World Health Organization and the California Air Resource Board. A recent study [10] suggests that the risk of lung cancer is approximately three times greater for heavily exposed workers. When compared to other aerosols in the mine environment, the settling time of DPM is significantly longer than that of dust due to their small particle size (typically < 1 µm) [11]. Additionally, submicron particles (such as DPM) are deposited in the lungs much more efficiently than their larger counterparts such as dust [12]. Previous studies focusing on particle morphology [13] show that the largest mass contributor to lung disease in mining is elemental carbon, which provides a solid core onto which hydrocarbons are adsorbed. In accord with those findings the Mine Safety and Health Administration (MSHA) decided on submicron total carbon as a surrogate for monitoring diesel particulate matter in the mining environment."

Jan 1, 2018

By Stanley Dempsey

Mine developers commonly undertake projects that require more funds than they can invest themselves. From that point until they are able to complete a "bankable" feasibility study, they require access to venture capital. In the United States, most venture capital has been provided to the small mining segment of the industry through tax advantaged limited partnerships. Recent changes in Federal tax law makes other forms of financing competitive, and the use of corporations and private and public offerings of shares may soon become more popular ways of securing venture capital. A number of new financial services firms have entered the mining finance business in recent years. They provide mine developers with access to venture capital.

Jan 1, 1987

By Jun Ho Lee, Dae Young Kim, Ebrahim Farrokh, Ki Chang Hyun

"The Jinhae Geoje gas pipeline tunnel project is the largest (7.8 km) and the deepest (90 m) subsea tunnel in South Korea. This tunnel will house a pipeline to carry natural gas from the mainland to Geoje Island southeast of the country to alleviate the increased demands for natural gas, especially in the winter season. Tunneling is currently underway using two slurry shield TBMs of 3.5 m diameter. This paper describes the major design elements of the tunneling machines and their performance evaluation. For this purpose, a thorough analysis of geotechnical information was performed to evaluate the tunnel elevation to reduce the risk of tunneling under high water pressure in unstable and permeable rock mass under 9 bar water pressure. TBM specification and TBM performance were also analyzed using different methods, including well-known models as well as a rotary cutting machine test developed in house in Hyundai Engineering and Construction Company. INTRODUCTION High demand for natural gas, especially in winter season was the primary driving factor for the design of the Jinhae Geoje gas pipeline project. This project is located southeast of South Korea between Jinhae district and Geoje Island and runs for over 50 km length. The mid part of this project includes a 3.5 m diameter subsea tunnel consisting of two sections of Geoje to Jiri Island (4.3 km) and Jinhae to Jiri Island (3.5 km). Figure 1 shows the tunnel project location and its layout. Figure 2 shows the geological profile along the tunnel. As can be seen, the tunnel passes mainly through three rock types: granite, tuff breccia, and andesite tuff. This tunnel was planned to be constructed by two face pressurized shielded TBMs and to be lined with a segmental lining of 2.8 m internal diameter. The major challenge for this tunnel is its maximum expected water pressure at the tunnel invert (8.83 bar). At such a high water pressure, the TBMs required special design to ensure they can handle unexpected water pressure and to ensure the risks for the TBM maintenance intervention are minimal. In this regard, a thorough analysis was conducted on the TBM design parameters and geotechnical information to define required TBMs’ design parameters and to identify the safest tunnel elevation. This paper provides a brief overview of the project geotechnical information, TBM selection and its design specification, tunnel elevation selection, and TBM penetration rate evaluation. In this regard, a rotary cutting machine testing equipment was used to perform trial tests on a similar rock type encountered along the tunnel for performance evaluation and optimization."

Jan 1, 2016

By Emily Dieckman, Claire Kincaid

"When most people think “miner,” they picture an older white man in a dusty shirt and suspenders. He’s holding a gas lamp and a pickaxe, peering at the walls of a dimly lit cavern. This image, while steeped in heritage, is no longer representative of what mining is: a global, increasingly diverse industry.It’s an industry made up of individuals like Zambian-born Chushi Mwewa, PE, president of Southlands Engineering, LLC in the United States and managing director of Southlands Engineering Limited in Zambia; Navajo tribe member Peter Denetclaw, manager of environmental programs and Navajo relations at Freeport-McMoRan; and Chinese and Jewish Alyssa Hom, a project engineer at McCarthy Building Companies.According to the Austrian Federal Ministry of Science, Research and Economics, 168 out of the world’s 195 recognized countries have some mining or mineral resources activity, and the mining industry directly employs more than 25 million people across the globe.However, according to McKinsey & Company’s 2017 “Women in the Workplace” study, white males hold 67 percent of C-Suite positions and 70 percent of senior vice president positions in the corporate world, and mining is no different. This uniformity among leadership has been tied to lower levels of employee engagement, innovation and business growth. The bottom line is this: Diversity is good for business. The question industry leaders must now ask themselves is not “Will we promote diversity?” but “How will we promote diversity efficiently and permanently?”More than 80 industry professionals, consultants and students gathered to discuss this question and share stories at the “Developing Diversity in Mining” workshop organized by the University of Arizona’s Lowell Institute for Mineral Resources (IMR), held during the 2017 SME Arizona Conference in December 2017.Brad Ross, co-director of the IMR and one of the facilitators of the workshop, said he felt diversity was important to discuss because he has witnessed its benefits throughout his career in the mining industry.“By creating a team of people with different experiences and perspectives, a company is better equipped to see the big picture and to creatively tackle problems,” he said. Speakers from industry and academia,including Mwewa, Denetclaw and Hom discussed the challenges surrounding achieving diversity and inclusion as well as the roles and responsibilities of different stakeholders."

Jan 2, 2018

By J. S. Hattrup

INTRODUCTION Tunnel boring machines in non-abrasive competent rock with little or no water have set new performance standards in the driving of tunnels. However, when the machines have hit blocky or running ground, they have encountered difficulties. The success of a tunnelling machine is usually due to a thorough geological investigation which accurately describes the rock conditions, a well designed tunnel support system, and a tunnel boring machine designed to cope with these conditions. In some cases machines have had to be modified in the tunnel after the machine had commenced boring, because geological conditions were not correctly anticipated before tunnelling began. The features described herein are not a panacea for all conditons, and some of them, like an auxiliary thrust system that thrusts off a precast invert segment requires pre-planning of work on the part of the contractor. CUTTERHEAD DESIGN Figure 1 shows typical cutterheads of ten to fifteen years ago. Note the large buckets and large openings between the buckets. These large openings were considered necessary to gain easier access through the cutterhead for cutter changes. The standard cutter in those days was an 11 inch or 12 inch cutter with small bearings, and was generally a delicate tool for the duty it was to perform. These large buckets would clog up if a formation with clay seams was

Jan 1, 1981

By Chen Bingchen, Ma Shaojian

A new magnetic liner, with unique magnetic circuit and novel structure designs, was developed. It was characterized by light weight, low noise, as well as corrosive and abrasive resistance. The wear rate of the magnetic liner was one twentieth and one ninth those of the manganese-alloy steel and rubber ones respectively. The forming mechanism of the protective layer and that of influencing factors on magnetic liners were also investigated. The research results could not only instruct using magnetic liner, but also widen their application.

Jan 1, 1995

By James H. Vignos

An optical instrument designed for the on-line measurement of the size distribution of coarse particles (3-500 mm) being transported on a conveyor belt is described. Included is a discussion of the measurement technique, as well as test data verifying the legitimacy of the basic sensing approach. Field data indicating the instrument&apos;s ability to make useful measurements in an industrial environment are also presented. Applications in the mining and mineral industry, for which this instrument was orginally developed, are outlined, with particular emphasis given to the areas of crushing and grinding control.

Jan 1, 1979

By A. MacG. Robertson

INTRODUCTION The tailings, or solid waste, remaining after uranium has been extracted from an ore and the liquid wastes associated with it contain both radioactive and other substances which, if released to the environment, may have a detrimental impact on man and his environment. Although the radioactivity of the waste is of natural origin, the mining and milling process results in bringing the radioactive ore to the surface, changing its chemical and physical form, increasing its mobility and, therefore, enhancing the potential radiological exposure to man. Exposure to radionuclides released from a tailings impoundment, while small as applied to any one generation, can be made large by counting far into the future, large enough to be the dominant source of exposure from the nuclear fuel cycle, Cunningham (1978). Increasingly it is being found that where the prime concern was initially the radionuclide releases, the release of other pollutants and contaminants may be of equal or greater concern. While there is a definite benefit, at least to present generations, resulting from the recovery of uranium, current and long-term concerns require that consequential present and future releases be kept as low as is reasonably achievable. Design practice, to minimize this release, is currently passing through a technical revolution; precipitated by public and institutional concerns. New techniques and methods are, therefore, being actively sought and continuously implemented. Because of the complexity of the pollutant release mechanisms and the sitespecific nature of each impoundment site and tailings product, a wide variety of site selection and design options have been implemented or considered. It is often possible to design a number of satisfactory tailings disposal schemes which differ widely in nature and cost. This paper outlines the principal areas in which options are available and discusses some of these options. Both operating and post-decommissioning conditions are consi-

Jan 1, 1980

By R. H. King, D. R. Schricker, R. E. Cameron

Mine managers rely on their experience, section foreman&apos;s daily reports and occasional time studies to make important production, maintenance and forecasting decisions. This information is often subjective and imprecise, consumes expensive engineers time, is often biased and is restricted to short time periods. Managers need better information. Furthermore, if a recently purchased machine is being evaluated, a large increase (>10%) in productivity may be obvious, but small increases are usually masked by other variables. In today&apos;s highly competitive markets, cumulative small changes are important, especially since managers have already exhausted most available, obvious avenues of improvement. A technique to separate these charges from effects of other variables and to quantify the target effect is necessary. CSM researchers are addressing this need by developing an intelligent decision support system (IDSS). It provides key production and maintenance information to support management decisions by recognizing patterns in mining machine sensor data and representing knowledge about mine management, operations, layout and equipment. A continuous miner section at Western Fuels-Utah Inc.&apos;s Deserado Mine in Rangely, CO is the test facility for the research. Power transducers located in the sections load center provide kilowatt versus time data from continuous section equipment. The IDSS pattern recognition algorithms classify the kilowatt versus time patterns into individual machine operating modes. It produces an output similar to a typical industrial engineering time study but continuously, automatically and without an engineer in the section. It is relatively easy for a time-study engineer to identify the stop and end points of a cycle element and classify it by looking at the machine and glancing at a stop watch. The problem is that monitoring system hardware and software do not have these unique capabilities. Consequently, IDSS algorithms must automatically define the begin and end points of machine tasks and identify the task by recognizing patterns in kilowatt versus time data. However, many mines have file drawers of time-study type data that are not very useful. So, IDSS contains the knowledge representation subsystem (IDSS/KRS) to produce short reports containing only key information. This is difficult because mine environments continually change and information requirements differ for each management level. Consequently, IDSS/KRS must learn and adapt to new conditions in a dynamic mining environment. Western Fuels-Utah owns and operates the Deserado Mine, located about 19 km (12 miles) northeast of Rangely, CO (Upadhyay, 1988; King and Eros, 1988). One longwall and two continuous miner sections produce about 900 kt (1 million st) of coal annually for the Deseret Generation and Transmission Cooperative&apos;s 4000 MW power plant located near Bonanza, UT. Three mine monitoring systems control the underground mine, the preparation plant and the unit train load out. Pattern recognition IDSS/PRS produces a listing of begin and end times for each machine operating event as shown is Table 1.

Jan 1, 1991

By A. W. Swanson

Iron carbide, containing 93.3% Fe and 6.7% C, is a tailor made feed for the electric arc furnace (EAF) and has recently gained worldwide attention as a possible replacement for premium quality scrap. With 38% of the steel in the United States being produced in EAFs, iron ore producers have an interest in becoming direct suppliers to the EAF industry. This paper explains the advantages of using iron carbide in an EAF and describes test work on the product and development work being per formed on engineering designs for a commercial plant.

Jan 1, 1994

By P. Christmann

The operational paradigm of mining industries is shifting from ?optimal profit for the financial stakeholders? to a new concept compatible with sustainable development ethics: ?maximize economic and social returns at the local, national and global levels, while avoiding negative environmental impacts?. The number of stakeholders concerned by mining companies has grown significantly over the last few decades, and the role of local communities and civil society is now acknowledged by the mining companies adhering to the sustainable development ethics. ?Involve me? is becoming a key to maximize the returns the mining industry can provide to sustainable development. As the world?s major importer of many mineral commodities, several coming from developing countries facing severe short-term problems, the European Union (EU) is an important stakeholder and has a responsibility in supporting actions to strengthen corporate and public governance capacities. The purpose of this paper is to highlight the drivers leading to the development of sustainability indicators and to propose, within the 6th European Framework Programme for Research, Technological Development and Demonstration Activities (FP6), an European-level initiative to develop sustainability indicators adapted to the mining industry and its population with relevant data.

Jan 1, 2003

By Joao B. Cardoso

This paper describes a two-stage reverse flotation method developed at the Mineral Resources Institute (MRII, University of Alabama, for Kerr-McGee Corporation (KMC), to separate the trona (Na2CO3 ? NaHCO3 ? 2H2O) from a saline deposit containing halite, borax, minor salts, and water insoluble materials. In the first stage, trona is depressed with Quebracho, and the insoluble gangue is floated with fatty acid. In the second stage, trona is floated with cresylic acid. The flotation concentrates contained better than 90% trona with insolubles ranging between 1 and 2%. Although the trona recoveries were low, optimization and middlings recycled in a continuous circuit could substantially increase the value.

Jan 1, 1989

By P. B. Queneau, J. E. Litz, T. P. McNulty

I. INTRODUCTION Modern hydrometallurgy has its roots in such notable successes as heap leaching for recovery of copper, cyanidation of gold ores, the Bayer process, the Oxland process for tungsten, electrorefining of copper, roast/ leach/electrowin process for zinc, and production of yellowcake from lowgrade uranium ores. Metallurgical testing techniques, sampling and analytical procedures, operating and maintenance practices, and improved methods and materials of construction which were pioneered in these processes have promoted the extension of hydrometallurgy into other applications. Periodically, new tools such as solvent extraction, resin ion exchange, and flocculants have opened new avenues to hydrometallurgists. Conversely, pursuit of more complex mineralization, the rising costs of energy and environmental quality preservation, and declining ore grades continue to create new challenges. For much of this century, it can be fairly said that practically any hydrometallurgical development moved the frontier of technology. The 1970&apos;s and 1980fs, however, have seen a significant maturing of hydrometallurgy&apos;s role in process metallurgy. Simplistically, this maturing seems to derive from a growing awareness of the strengths and weaknesses of hydrometallurgy and a determined effort to capitalize on the strengths. For example, many of us were among those revolutionaries of the 1960&apos;s and 1970&apos;s who taught that "chemical smelting" was the answer to the treatment of all sulfides. We now recognize, however, that only in very special cases can hydrometallurgy offer economic advantage over the generally less energy-intensive pyrometallurgical systems. The maturing of hydrometallurgy does not, however, signal stagnation. Important innovations are being studied and developed in most extractive areas, and a number are approaching or have achieved commercialization. From our company&apos;s perspective, that of an organization dealing with the development of the most economic solutions to metallurgical problems, innovation must be defined as the commercially successful reduction of an idea to practice. There appears to be no shortage of ideas, nor has there ever been a shortage. Many ideas now being implemented were conceived decades ago, but reduction to practice was foiled by the lack of such technology as responsive process control and economical materials of construction capable of withstanding highly corrosive or erosive environments. Commercialization of a new process is a particularly challenging undertaking. Even if technical risks are reduced to a minimum through careful and thoughtful process development, there are inevitable uncertainties in feed characteristics, variable costs, and product prices. Commercialization takes courage, both on the part of innovators who may be staking their careers or reputations and of investors who may face financial disaster in the event of project failure. This paper discusses innovative programs and recently commercialized processes which either have been discussed in the literature or disclosed to Hazen Research staff in private nonconfidential conversations with contacts in industry. Regarding this latter category of information, relative ease of communication has resulted in many of our observations being of North American origin.

Jan 1, 1985

By M. C. Rockwell, G. F. T. Lay

Promising placer gold exploration sites offshore Lunenburg County are drowned pre- and post-glacial river channels and auriferous glacial tills. Gold values up to 5.67 9/m3 have been encountered in the vicinity of the Ovens Peninsula offshore Lunenburg County. Moderate gold values associated with notable amounts of heavy minerals were reported from various other exploration sites in this area. This paper highlights the major geological and gemorphological features for placer gold depositions in southern Nova Scotia. The past to present gold exploration activities nearshore and offshore Lunenburg County are summarized and potential areas for placer gold identified.

Jan 1, 1988

By James P. Morris, William H. Hansmire

The U. S. Department of Energy&apos;s (DOE) Yucca Mountain Project (YMP) is a scientific endeavor to determine the suitability of Yucca Mountain for the first long term, high level nuclear waste repository in the United States. The status of this long-term project from the construction perspective is described. A key element is construction of the Exploratory Studies Facility (ESF), which is being excavated with a 7.6 m (25 ft) diameter tunnel boring machine (TBM). Development of the ESF may include the excavation of over 15 km (9.3 mi) of tunnel varying in size from 3 to 7.6 m (10 to 25 ft). Prior to construction, extensive constructibility reviews were an interactive part of the final design. The intent was to establish a constructible design that met the long-term stability requirements for radiological safety of a future repository while maintaining flexibility for the scientific investigations and acceptable tunneling productivity.

Jan 1, 1995

By YU. F. Vasyuchkov, K. Vasioutchkov, B. M. Vorobjev

Introduction It is now believed that, even with the environmental protection measures now being taken, the further application of traditional coal-mining and electric power-generation technologies will inevitably cause further irreversible damage to the global ecosystem. Further improvements in conventional coal-mining technologies, both surface and underground, are expected to have only limited impacts on the economical, ecological and social aspects of coal mining. In countries with a developed coal industry, coal reserves with favorable conditions at shallow depths are rapidly being depleted. Therefore, in the future, more coal will be mined from deeper levels, resulting in higher operational costs and lower labor productivity. The solution to this problem is to be found in developing, promoting and implementing unconventional coal-mining and advanced clean-coal technologies. This paper presents an unconventional concept that has been suggested by the authors. The basic goal is to achieve coal-methane energy resource conservation and to remove barriers to energy efficiency through the adoption of integrated, ecologically clean, innovative technology. The following principles form the foundation of this concept: Energy resource conservation: This principle concerns the exploitation of actual and potential coal-methane reserves in the most effective way with the lowest possible losses and with the application of the most energy-efficient electric power-generation technology. Energy conversion: Energy conversion means the conversion of solid coal to synthetic fuel gas (in situ or in-cycle), the conversion of methane bounded within the coal matrix to free-flowing drained meth¬ane, the conversion of solid coal in situ to a coal/water mixture (slurry), and the conversion of these gas fuels into electric power. Technological and managerial integration: This prin¬ciple means an integration of coal-gas methane min¬ing operations and electric power generation into one commercial mine-to-product enterprise with electric power as the final product. Thus, coalbed methane drainage and coal gasification (both in situ and in-cycle) integrated with a combined cycle of electric power generation constitutes a highly integrated coal-gas methane energy-generation system. The system can be materialized in the form of a local integrated coal-gas electric power complex (LICGEPC). General features of the new concept The coal-gas-methane electricity concept is actually a synthesis of the following four technological components: Coalbed methane drainage. This technique and its utilization attained recognition after commercial operations were proven successful in the San Juan and Black Worriers coalfields in the United States. Worldwide, extensive field experiments and research-and-development activities are being carried out in the area of coalbed methane exploitation and utilization. Recently, coalbed methane drainage for power generation has been undergoing intensive research and development. At the Harworth Colliery in the United Kingdom, a combinedcycle power plant has been built that uses coalbed methane. The plant has an installed capacity of 15 MW Also, Germany, Australia, the CIS and China have conducted various experiments and industrial tests on the use of coalbed methane power generation. Underground coal gasification. Another unconventional technological approach is underground coal gasification (UCG). A number of semi-commercial, demonstration and pilot projects have been undertaken in Russia, the Ukraine, Uzbekistan, the United States, the United Kingdom, Italy and Belgium to demonstrate the technical and economical viability of coal gasification in situ. In Uzbekistan, the Angren coal-gasification station has been in full-scale commercial operation for two decades. The operation supplies a power plant with synthetic coal gas. Under sponsorship of the US Department of Energy&apos;s Morgantown Energy Technology Center, large-scale laboratory tests simulating coal gasification in situ were successfully completed by the

Jan 1, 1999

By William F. Jenks

The possibility that a hypothesis explains almost all observed facts may be satisfying. Yet the almost gives a distinct sense of uncertainty. Moreover, overlooking the almost, reliance on the favored hypothesis may close our eyes to the discovery of new information and, in the field of mineral exploration, to the possibilities of finding new and hidden ores. A case in point is that of mines such as the Elizabeth and Ely, along the copper belt in eastern Vermont, principally in Orange County. The geology of the Strafford Quadrangle, where the Elizabeth Mine is located, has been described by Doll (1944). Two informative papers (McKinstry and Mikkola, 1954, Howard, 1959) present much valuable information about the geology of the Elizabeth Mine. Both reach the conclusion that the ores were emplaced after the peak of metamorphism, through the agency of metal-bearing hydrothermal solutions. Both, therefore, conclude that the source of the ores was somewhere below the outcrop area, presumably in some hidden intrusive mass. Neither yields a satisfactory guide for further exploration. Howard (1959) cites geophysical observations which show that there is a mass with a density similar to that of granite under the Strafford dome, adjacent to the Elizabeth Mine on the West. Yet examination of gneissic granite in the Chester dome, 25 miles to the South gives no suggestion of a young, near-surface intrusive capable of carrying or mobilizing large quantities of sulfur and metals. The Acadian intrusives in New Hampshire and in the Barre district

Jan 1, 1968