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By Christopher D. Henry

Environmental geologic maps of the Wilcox and Jackson-Yegua lignite belts of the Texas Coastal Plain delineate land areas on the basis of their natural characteristics. Criteria used to define map units include substrate, soil, topography, geologic process, vegetation, and land use. The maps are useful in planning and reclamation of lignite mines and in meeting the requirements of State and Federal surface mining laws. Specific applications include identification of land capability, recharge areas and geometry of aquifers, flood-prone areas, areas that may qualify for prime farmland status, and other areas sensitive to lignite mining.

Jan 1, 1982

By John W. Lane

Climax Molybdenum Company, a Division of American Metals Climax, Inc., operated a hydrometallurgical plant* at Climax, Colorado from August 1966 through August 1968 to recover molybdenum from a mixed oxide and sulfide ore. The ore treated for this addition to the existing plant contained sufficient Molybdenite values to be mined for Molybdenite recovery alone, so that the oxidized molybdenum recovery could be regarded as a byproduct operation. Climax is located at an elevation of 11,300 feet. All process equipment, except thickeners, was enclosed in buildings. Annual snowfall is approximately 250 inches per year. Paved highways and rail service to the plant are maintained and kept open all year. Most of the employees live in the town of Leadville, which is approximately twelve miles from the plant site. The sulfide flotation plant handles 40,000 to 45,000 tons per day of ore. The mine is one of the world's largest underground mines.

Jan 1, 1971

By Roland W. Rammler

In recent years, the crude oil reserves of the world have increased at the same rate as the consumption. A Consideration of the global figures suggests that adequate supplies of petroleum will be available during the next decades. On the other hand, it in a fast of economic and political significance that the reserves in the industrialized countries increase much more slowly than in the developing countries. In Western Europe the reserves have even decreased. At the present time, about 70 % of the petroleum reserves of the world are in the Middle East and in Africa in regions in which political arises are prevalent or impending. For the industrialized countries, the discrepancies between the consumption and reserves in various regions of the world are a strong urge to investigate whether oil can be recovered from other sources. The situation will probably not be changed to a large extent by the discovery of oil in the north of Alaska. The main starting materials for the production of synthetic crude oil are coal, oil shale and tar sand. In North America, where the consumption of petroleum increases more rapidly than the reserves, there are enormous deposits of each of the three materials. This fact is another incentive toward the utilization of these unconventional oil reserves, which provide a reliable basis for a supple of energy for a long time to come.

Jan 1, 1970

By John P. Hunt

Early disseminated copper mineralization at Quebrada Blanca, Chile, accompanied 38 million year old quartz monzonite stocks and dikes. Early mineralization was followed by hydrothermal mineralization, mineralized breccias, and post-mineral faulting. After supergene leaching and enrichment, Quebrada Blanca was buried under late Tertiary gravels, and then partially re- exposed in Quaternary time. Based on work to date the orebody appears to contain more than one hundred million tons of plus one percent secondarily enriched copper ore, overlying several hundred million tons of protore averaging more than 0.5% copper. A source of industrial water appears to have been located. Pilot scale metallurgical tests, mine planning, and feasibility studies are in progress.

Jan 1, 1981

By Harry Elkin

Control of coal dust has long been an important aspect in the conventional mining of coal; the main reasons being from a health and disaster standpoint. With the advent, of mechanized longwall mining, the control of dust has required more attention due to the high extraction rate common to most longwall systems. The purpose of this paper will be to describe the dust abatement activities of the longwall operation at Sunnyside. Kaiser-Steel Corporation has three mires located at Sunnyside, Utah, with a total production averaging 6,800 tons of clean coal per day. Of this 6,800 tons, 71 % is mined with continuous miners, the remaining 29% coming from one longwall unit located in No. 3 Mine. Our first longwall panel was started in November, 1961. In October, 1966, we started mining our seventh panel. The present panel is located in the Upper Sunnyside Seam which averages five feet in thickness, but does get as low as 51 inches. The seam pitches 5.5% in this vicinity. The roof is generally good and is comprised of 10 inches of shale cap rocs overlain with sandy shale and sandstone. The floor is sandy shale and is quite undulating in nature. The present panel is 3,800 feet in length with a face of 670 feet. The major equipment employed on our longwall unit is a 125 H.F. Anderton Shearer-Loader, British Jeffrey Diamond armored conveyors and a Dowty self-advancing-roof support system. The Anderton Shearer in use on our longwall unit has a 60" diameter x 27" cutting drum. During the shearing cycle, it traverses the face at 20 feet per minute with a cutting rate of 7.5 tons/minute.

Jan 1, 1967

By Dale E. Hirschfeld

The clays in Eastern Washington occur in a variety of forms and are extracted for uses in Face Brick, paper coatings, and aggregates. Not in large volumes in comparison to other areas, not even from impressive large mines. However, mans utilization of these clays has progressed from historical clay tablets to the present technically oriented manufactured products of today. White Face Brick, perhaps the whitest produced anywhere is the unique product produced by INTERPACE CORPORATION's Mica Plant from these unusual clays. It is this basic characteristic feature of the clay's in the Mica area that differentiate them from the other clay's in this belt. ORIGIN The significant properties of clay's used in Face Brick are plasticity, fired color, fired strength, dry and fired shrinkage, the PCE or Pyrometeric Cone Equivalent, and extrudability. Testing clay's for these properties is standard laboratory procedure. No two clays are alike, and seldom can one clay be substituted for another. Mica White Clays respond favorable to all these properties, but more especially, the Mica Clays fire to a brilliant white color, from almost the natural state. The geologic history of Eastern Washington is largely conjectural because of the absence of rocks representing segments of geologic time. The oldest rocks in this area are the argillaceous and arenaceous sedimentary rocks which have been slightly metamorphosed. These rocks have been correlated with the Belt Series of the Pre-Cambrian age, although some may be older. These rocks were subsequently intruded by granadiorites and related rocks that are considered to

Jan 1, 1971

By R. Sandrik

Northwestern Resources Co. (NWR) was established in 1972 as a wholly-owned subsidiary of Western Energy Company of Butte, Montana, to acquire, explore, develop, and produce energy resources outside the state of Montana. Western Energy is a coal mining company with successful operations in Montana and Wyoming. In 1974, NWR acquired its first lignite lease in Texas. NWR eventually acquired a large leasehold in central Texas, which was identified as having a high potential for future production. In 1979. NWR contracted to supply lignite to Utility Fuels, Inc. (UFI), a fuel affiliate of Houston Lighting and Power Company (HL&P). This project, together with leases held by UFI, became the Jewett Mine. Lignite from the Jewett Mine is used as fuel at the adjacent HL&P Limestone Electric Generating Station, at an annual rate of approximately 7.3 Gkg (eight (8) million tons) per year.

Jan 1, 1991

By T. W. Camm

"As engineers, we are trained to use logical, rational problem solving to insure our mines operate at maximum efficiency. We tend to use the same technical approach to design safety into all mining systems. This works well for machines, but not so much for the human component. Recent insights in the field of behavioral economics provide useful ideas for addressing the fact that we are driven by emotions more often than by rational thought. Understanding the nonrational aspect of human behavior is an important piece of any safety system design. INTRODUCTION The most common economic model is based on humans making rational decisions; that given the proper information, we will make a logical, rational decision based on what is best for ourselves (Ariely, 2009, p. xviii). In many cases this is an accurate description of how we make decisions. As an engineer, I was trained to apply the precision of mathematics and logic to solve problems. As an engineering professor, I now teach this approach to bright young minds preparing them for a life of professional effectiveness as practicing engineers. That said, we are not only rational. Daniel Kahneman, winner of the Nobel Prize in Economics, describes a model for how we think (Kahneman, 2011). System 1 is the part of our mind that is fast, intuitive, and emotional; while our logical, slower, and deliberative mind is System 2. According to Kahneman’s model, System 1 runs automatically, most of what you think and do originates in System 1. System 2 takes over when things get difficult, including the application of math and logic, and the resolution (or avoidance) of conflict. As engineers, we would typically assume that we operate in System 2 mode most of the time. This is where the model becomes useful, for Kahneman points out two important aspects of the dynamic between the two systems in our mind. First, System 1 has biases, systematic errors that lead to answering questions with an easier answer (rather than a right answer) before System 2 is engaged. Second, we can be blind to the obvious, and also be blind to our blindness. Complicating things further, System 1 cannot be turned off (Kahneman, pp. 24-25)."

Jan 1, 2015

"INTRODUCTION While the United States coal mining uses prescriptive regulation under the Title 30 Code of Federal Regulation enforced by the Mine Safety and Health Administration (MSHA), Australia uses a risk based approach. Australian regulation is individual to each state. In Queensland, Australia this risk based approach to address principal hazards is underwritten by the Queensland Coal Mining Safety and Health Act of 1999 and the Coal Mining Safety and Health Regulation of 2001. Each Queensland Mine is required to have an overarching Health Safety and Environment Management System, of which Safety Management Plans are an element. “Safety Management plans (SMP’s) are intended to formalise the process by which mines address principal hazards and other related matters to ensure the safety of mine personnel.”7 THE QUEENSLAND CONTEXT In Queensland, the basic elements of a coal mine’s safety and health management system must provide for risk identification and assessment, hazard analysis, hazard management and control, and the reporting and recording of relevant safety and health information and data.5 (Part 2 Division 1 Section 6(a-d)) The initial guidance for writing Safety Management Plans comes from the Approved Standard for Mine Safety Management Plans and Guidance Note QGN09- Reviewing the Effectiveness of Safety and Health Management Systems. The Guidance Note and Approved Standard are supplemental to the Act and Regulation, and put in place to provide more clarity around the topic. The definitions in this section come from the Approved Standard and are included to provide context for those who may not be familiar with Australian or Queensland law and regulation. A hazard is defined as a source of potential harm or a situation with a potential to cause loss, while a principal hazard is a hazard with a potential to cause multiple fatalities. A risk is the chance of something happening that will have an impact upon objectives which is measured in terms of consequences and likelihoods. It is important to be able to make the distinction between a hazard and a risk. For instance, a lion is a hazard, while the risk associated with a lion is getting eaten. As defined by the Queensland Approved Standard for Mine Safety Management Plans, a Safety Management Plan (SMP) requires a systematic definition of all the actions necessary to ensure that mining operations are carried out safely. A SMP includes, but is not limited to organisational structures, planning, activities, responsibilities, practices, risk identification, audits and reviews.7 The goal of a SMP management plans is to mitigate the risks to bring them to an As Low As Reasonably Achievable (ALARA) level."

Jan 1, 2016

By Michael Fellows

Epidote is a common hydrothermal alteration product in many copper deposits of the southwestern United States. In many of these deposits epidote, along with calcite and chlorite, generally characterize a distal or halo propylitic alteration assemblage, but the mineral can occur within the central potassic alteration zone as well. Epidote is also a common alteration mineral in deposits formed in calcareous host rocks -- the skarn or pyrometasomatic ore bodies. Within the past 15 years, studies of the major and trace element composition of other alteration phases, principally biotite, associated with base metal ore deposits have demonstrated that some hydrothermal alteration minerals are compositional distinct from their igneous or metamorphic counterparts: However, the use of major and minor element content to identify and zero in on mineral¬ized areas does not appear to be very promising. Little work has been published upon the geochemistry of epidote from this standpoint and the results of my work suggest that a similar conclusion can be applied to epidote. My work (Fellows, 1976) suggests that epidote minerals in hydrothermal alteration suites from porphyry copper deposits in the southwestern United States are generally iron-rich rather than aluminum-rich. As a group, these alteration minerals differ compositionally from epidotes of regional metamorphic terrains. I ascribe these differences to the variations in the oxidation character of the respective environments. However, it appears as though the use of major element compositional variations of epidotes as an exploration tool is severely limited. Epidote is a complex calcium-aluminum silicate. Replacement of aluminum by ferric iron establishes a solid solution series between

Jan 1, 1977

By A. Juganda, Jr. Bogin, J. Brune, J. Grubb, S. Lolon

"Face ignitions at the longwall face are a serious hazard in underground coal operation that can lead to a major mine explosion. Despite having methane monitoring system mounted on the shearer and at various locations on the longwall face, undetected accumulations of methane can still occur and result in face ignitions. With the use of Computational Fluid Dynamics (CFD), the interaction between the air flow at the longwall face and factors that contribute to the accumulation of methane around the longwall face can be modeled and visualized in great detail. The results confirm that the tailgate corner of longwall face is a critical area that is prone to face ignitions and needs to be properly monitored. The occurrence of roof falls on the tailgate entry inby the face and/or poor caving conditions behind the shields can pose a safety risk in the longwall operation. Poor gob caving can lead to insufficient face air quantity to dilute methane at the tailgate corner, while blocking of tailgate by a roof fall can carry methane contaminated air from behind the shields back into the face near the tailgate corner and pull the explosive gas zones (EGZs) inside the gob closer to the face. INTRODUCTION Ignitions of accumulated methane gas at longwall faces are well known to be among the major causes of methane explosion in underground coal longwall mining operations. Some of these ignitions can lead to major mine explosions, such as the Upper Big Branch mine disaster in 2010, in which methane migrated from the gob to the shearer cutting drum where it was ignited, resulting in a major mine disaster (Phillips, 2012). History has shown that, despite having methane monitoring systems mounted on the shearer and various locations at the longwall face and alarms set to 1% CH4 (Mine Safety & Health Administration, 2012), undetected accumulations of explosive methane-air-mixtures can still occur and result in face ignitions. Recent study by Verma and Brune (2016) state that frictional ignitions on longwall faces contributed to 379 incidents or 23% of the total 1,637 cases of face ignitions recorded from 1983 to 2014. The common cause of mine explosions usually involves poorly designed ventilation systems, insufficient ventilation, and inadequate monitoring in critical areas that are prone to methane accumulations. In longwall operation, the tailgate corner of the longwall face can be considered as one such critical area. On-site studies by Krog et al (2006) and Thakur (2008) show that increasing the longwall panel width may also increase cumulative methane emissions at the tailgate. There are also indications that increasing longwall face lengths can result in an increase of the void space behind the face under certain roof conditions (Schatzel et al, 2006). This may cause higher leakage rates from the face to the gob, thus reducing the amount of fresh air available at the tailgate."

Jan 1, 2017

By Gerry Norton

The purpose of this paper is to make the most complete assessment of coal cleaning methods, both process and equipment related to modern-day production and environmental requirements. In order to achieve this primary objective, a number of interdependent aspects of coal cleaning technology require evaluation and analysis. 1.0 CLASSIFICATION OF SEPARATION PROCESSES Processes and cleaning equipment can be categorized according to the important parameters of 1) mechanics of separation, 2) size range application, 3) range or variance in accuracy of separation related to 2) above, and 4) feed-size ratio affecting 3) above.

Jan 1, 1977

By Milton E. Wadsworth

The evolution of engineering education and research has been profoundly influenced by computer technology and has concomitantly followed changes in this technology. Today, virtually all faculty have access to at least two hierarchies of computers: desk personal computers and at least one echelon higher (workstations or a variety of mid-sized computers). Most faculty have access to three or even four hierarchies: the two listed, plus super-mini and super computers. The ready availability of computers at a low cost has increased dedicated and site-specific computer technology. This has permitted universities to move into the field of macro-engineering, to address increasingly complex problems in resource recovery, manufacturing and many other areas, including important societal problems, like the environment. The creation of university research centers indicates the growing importance of macro-engineering involving large systems of interactive components. Funding agencies have increasingly favored such centers since they cross disciplines, generate inter-university consortia and foster university-industry programs.

Jan 1, 1992

By David A. Collins

Red Dome Gold Mine classifies ore types within the pit by gold and copper grades. Copper grades are further distinguished by total copper and cyanide soluble copper levels. At present, Cyanide Soluble Copper samples take six hours of agitating before they can be assayed. This agitation time produces results which are a proportion of the total cyanide amenable copper. This relates to our plant's performance. Frequently the total copper result is needed before we can begin the cyanide soluble copper analysis. This caused a protracted tum around time. Mennetech Pty. Ltd has produced a catalyst proven by David Martin Menne to accelerate the cyanidation of gold. David said that the information at hand indicated that Leach WELL TM also accelerates the leaching of cyanidable copper substantially. Test work was undertaken on-site at Red Dome Gold Mine to investigate the potential of Leach WELL TM to reduce the leaching period and therefore, the overall tum around time required for cyanide soluble copper determinations.

Jan 1, 1995

By P. Whincup, T. Showell, B. Marchant, R. Dunne

An oversupply of copper on world markets in the early 90' s, coupled with a decrease in demand, resulted in a "tight" market for the sale of copper concentrate. In these conditions small producers of low grade copper concentrates found it difficult to sell their products. The situation was exacerbated for those producers also having reasonable quantities of penalty elements (e.g. As, Bi). The Telfer Gold Mine bulk copper gold concentrate, produced from treating underground sulphide ore, fell into this category (i.e. 16% to 20% copper, 30% to 35% sulphur and 3500ppm to 4500ppm arsenic). The concentrate sulphide minerals are predominately chalcocite and pyrite. Although a higher grade copper concentrate was attainable a substantial decrease in gold recovery ensued. Under the prevailing market conditions a decision was made to stockpile concentrates pending either an easing of market conditions or alternatively finding an on site method for treating the concentrate to recover both the contained gold and copper.

Jan 1, 1995

By A. D. Davis

The historic Homestake Gold Mine at Lead, SD, was closed in December of 2001, after 125 years of operation. Since closure, the mine has been selected by the National Science Foundation as the proposed host site for the Deep Underground Science and Engineering Laboratory. Pumps in the 8000-ft deep mine were shut off on June 10, 2003. Post-closure flooding of the mine has resulted in rising water levels that reached the 5000-ft level in July of 2007. The rate of water inflow into the mine is about 750 gal/min. A plot of water level vs. time shows that the rise has not followed an exponential decay curve. When the pumps are turned on for dewatering, the rate of water-level decline will be monitored. Water in the Homestake mine contains arsenic derived from arsenopyrite. In samples of mine water, the median concentration of arsenic was below the surface-water aquatic life standard for beneficial use.

Jan 1, 2008

By R. D. Miller, L. Schulte, J. Davenport, D. W. Steeples

Shallow seismic reflection methods were successfully used to delineate the subsurface extent of roof failure associated with the dissolution mining of a 120-m (400 ft) deep and 60-m (200ft) thick salt bed in central Kansas. Surface subsidence at North American Salt's Hutchinson, KS, salt-dissolution well field represents a potential risk to surface structures and transportation facilities. Three intersecting common depth point (CDP) seismic reflection profiles, targeting the subsurface around an actively subsiding sinkhole, possess sufficient resolution to delineate the horizontal and vertical extent of subsurface rock failure associated with the subsidence. The three seismic profiles showed a disturbed subsurface area 90 to 105 m-diam (300 to 350 ft-diam) at a depth of between 60 to 75 m (200 ft and 250 ft). Confirmation drilling verified the interpretation of the seismic data. The seismic reflection method has the potential to resolve disturbed subsurface areas greater than 23 m-diam (75 ft-diam) at this site.

Jan 1, 1994

By Johanna I. Wong, R. John Caulfield, Victor S. Romero

The existing Hetch Hetchy water system, owned and operated by the San Francisco Public Utilities Commission (SFPUC), serves 2.4 million people within the San Francisco Bay Area. The system has existing 1920s-era pipelines crossing under the Bay that are vulnerable to seismic damage from the nearby San Andreas and Hayward fault zones. The SFPUC plans to replace the pipelines with the first TBM-driven tunnel underneath the San Francisco Bay. The tunnel will be constructed using an Earth Pressure Balance machine. The new tunnel will pass under environmentally sensitive habitats and will be approximately eight kilometers (five miles) long with no intermediate shafts. The project challenges will include tunneling through a prominent buried bedrock ridge that transects the alignment and through soft soils under the Bay. Seismic performance criteria include maintaining service flows after a large earthquake on one of the active faults in close proximity to the project site.

Jan 1, 2007

By R. F. Hüttl

World-wide Germany is the leading lignite mining nation. Most of the lignite is produced in opencast operations. However, opencast mining causes enormous impacts on natural ecosystems and even on entire landscapes. The extensive production of lignite particularly in eastern Germany results in large devastated areas, which so far have been reclaimed only to some part. For the restoration of the post-mining area of more than 80,000 ha the major land use option is the reestablishment of forest ecosystems. However, adverse site conditions of the post-mining landscape such as extreme soil acidification and salt concentrations call for specific recultivation practices. Therefore, after the German reunification new reclamation and reforestation concepts have been developed for these brown coal areas of eastern Germany by the Collaborative Research Center (SFB 565) at the Brandenburg University of Technology at Cottbus (Germany). As a case study our comprehensive investigations into forest ecosystem development on terra nova in the Lusatian lignite mining district, south-east of Berlin, will be presented.

Jan 1, 2003

By Michael P. Foose

In 1994, more than 41 of the approximately 160 coal-fired, electrical- power plants within the six-state Ohio River Valley region used flue-gas desulfurization (FGD) units to desulfurize their emissions, an approximately 100% increase over the number of plants using FGD units in 1989. This increase represents a trend that may continue with greater efforts to meet Federal Clean Air Act standards. Abundant limestone resources exist in the Ohio River Valley and are accessed by approximately 975 quarries. However, only 35 of these are believed to have supplied limestone for FGD electrical generating facilities. The locations of these limestone suppliers do not show a simple spatial correlation with FGD facilities, and the closest quarries are not being used in most cases. Thus, reduction in transportation costs may be possible in some cases. Most waste generated by FGD electrical-generating plants is not recycled. However, many FGD sites are relatively close to gypsum wallboard producers that may be able to process some of their waste.

Jan 1, 1999