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By Osvaldo A. Bascur

Standards and technology for bringing information to the desktop have greatly evolved in recent years. The benefits to be realized depend on how these new tools are embraced at the performer level. A key operating challenge is to ensure cooperative effort is geared towards the most efficient achievement of identified operating and corporate objectives. Presentation, application and database layers are emerging in successful client/server applications, the three-tier architecture.

Jan 1, 1996

By T. Gupta, T. Ghosh

"Rare Earth Elements (REEs) and their compounds are essential for numerous modern high tech applications such as renewable energy technologies, catalysts and defense applications. The destabilization of REE pricing owing to the global demand and supply deficit has forced many countries to re-evaluate the possibility of indigenous production of REEs. Cost effective and eco-friendly opportunities are being widely explored for extraction of REEs from non-conventional mineral sources such as coal and coal byproducts to stabilize the supply chain. Coal from Central Alaska (Healy Coal Mine) and Southern Alaska-Cook Inlet (Wishbone Hill) province have been found to possess elevated REE concentrations as compared to average world coal estimates. The objective of the study is to enrich the REEs in the fine size fraction (-75 Microns) from Healy and Wishbone Hill by froth flotation technique. A Box-Behnken design was applied for modeling and optimization of some operating variables on the flotation to maximize REE enrichment. The variables studies were frother dosage, pulp density (% Solids) and collector dosage. Experiments were carried out using a statistical design and the main and interaction effects on response variable was evaluated by analyzing 3D response surfaces. Based on the experimental results the optimum flotation conditions for maximum REE enrichment in the froth fraction was obtained at 4.2% Solids and 32.7 ppm of frother dosage for Healy coal sample and 10% Solids and 37.9 ppm of frother dosage for Wishbone Hill coal sample. The quadratic equation for modelling and optimizing the response variable is found to be independent of collector dosage for both the coal samples. INTRODUCTION Alaskan coal deposits are distributed in three major coal provinces and are in Cretaceous and Tertiary rocks. The climate, vegetation type and sedimentation process has attributed to low sulfur content (averaging 0.3 percent) in Alaskan coals compared to other coal deposits found across the globe. In Central Alaska-Nenana and Southern Alaska-Cook Inlet coal province coal resources are contained in Tertiary rocks while bulk of the Coal resource in North Slope coal province is contained in Cretaceous and Tertiary coal bearing rocks [1]. Coals from Central Alaska- Nenana (Healy) and Southern Alaska-Cook Inlet province (Wishbone Hill) have been found to possess elevated concentrations of critical REEs as compared to the amounts present in world coals (Figure 1). The Wishbone Hill deposit is considered a relatively small deposit, with about 14 million tons of identified reserves, compared to Healy which has over 500 million tons identified [2]. The REE concentrations up to 286 ppm and 524 ppm on ash basis have been reported by Gupta et al. in 2016 with elevated concentrations Ce, La, Y and Nd which are expressed to be of critical importance by US Department of Energy. Accordingly, the two coal samples possess the potential to be used as a REE resource in the near future under favorable socio-economic and geo-political scenarios. [3, 4]"

Jan 1, 2017

By A. Khoshnevisan

Molybdenum resources around the world are mainly associated with porphyry copper ores. Molybdenite (MoS2) is the main Mo mineral that has rhenium in its crystal lattice. This paper investigates the recovery of rhenium and molybdenum from a molybdenite concentrate using a hydrometallurgical treatment method. The molybdenite concentrate is leached with nitric acid and subjected to solvent extraction to recover and separate rhenium and molybdenum from the leached liquor. The effects of pH and the chemicals? concentration on extraction characteristics of Mo and Re are investigated to define the best condition for selective extraction of these metals. The tested leached liquor contained of 8.2 g/L Mo, 1.5 g/L Fe, 0.5 g/L Cu and 60 ppm Re. A good extraction efficiency, up to 94%, was achieved for Re from the leached liquor, where the extraction of other metals, such as Fe and Cu, was negligible. In particular, at very low pH, rhenium is extracted selectively from solution, while the extraction of molybdenum is less than 10%. After removing rhenium, molybdenum was extracted with LIX984N. The selectivity of molybdenum extraction over other metals in solution was significant. Nearly 94% of molybdenum can be extracted from the solution at a pH value of -0.12, without any interference from other metal ions such as copper and iron.

By J. A. Restrepo, K. D. Luxbacher

"The U.S. underground coal mining industry has recently seen the occurrences of several multifatality events that have interrupted an otherwise steadily improving safety record. These events transpired even with an unprecedented level of government regulations and safety technologies. These events may indicate that current safety practices have reached a level of diminishing returns. Risk management, a safety approach that has been successfully applied in numerous industries including mining, may provide a means to overcome this plateau. Riskgate is an Australian mining risk management program that may be successfully applied in the United States. However, fundamental differences between the Australian and U.S. coal mining industries prevent direct implementation. This paper discusses aspects of the Riskgate body of knowledge that require adaptation for its application in the United States. IntroductionThe underground coal mining industry in the United States has recently seen the occurrences of several high profile, multifatality events. These events transpired in the midst of an unprecedented level of government regulations and modern safety technologies. The recent increase in fatal events in conjunction with minimal declines in fatal and nonfatal injuries over the past decade may signify that current safety practices have reached a level of diminishing returns. In order to surpass this plateau, a modification to the manner in which the mining industry approaches worker safety may be warranted.The implementation of a risk-management- based approach may potentially provide a means for not only surmounting the current safety stagnation but also for achieving the long-desired objective of zero harm.Riskgate is an Australian risk-management- based body of knowledge that shows great potential for application in the United States. This paper discusses aspects of the Riskgate body of knowledge that require adaptation for the U.S. mining industry. The proposed adaptations are based on differences in operating practices and government regulations. This discussion will focus on the three major U.S. risk areas of explosion prevention, ground control and moving equipment."

Jan 1, 2015

By J. J. Reilly

The Vesta Mines of the Jones & Laughlin Steel Corporation operate in the Pittsburgh Seam in Washington County, Pennsylvania. This seam is overlain with a drawslate, 12" to 16" in thickness, which slimes readily when wet. Because of the need for a uniformly good quality metallurgical coal, the amount of reject, together with the top and particle sizes of the raw coal feed, is a serious problem at the Vesta Preparation Plant. The Preparation Plant operates two, seven and one-quarter hour shifts per day and processes 2,100 tons per hour of raw coal feed. The third shift is, used for planned maintenance of equipment. Since the water clarification equipment is so vital in insuring a uniform product, there is no alternative but that it be in operation at all times. To insure this continuous operation,. well-planned maintenance is a necessity. For years, Plant Management has kept performance records of the various units to determine the renewal dates of vital component parts, the length of wear, the various materials used in the manufacture of the equipment, and the labor cost for renewal. These records have been of inestimable help in planning an effective maintenance program to insure continuous operation of the various units.

Jan 1, 1959

By Frank E. Chase

Retreat mining is one of the most hazardous operations conducted underground. One of the keys to miner safety and an efficient recovery of the reserves is to design adequately sized production pillars to prevent pillar squeezes, excessive pillar spalling, severe floor heave, roof falls, and pillar bumps. Currently, few pillar design approaches are available which consider the abutment pressures generated by the gob. The Bureau of Mines is developing a method called Analysis of Retreat Mining Pillar Stability (ARMPS) to aid in the design of retreating sections. Back analysis of 42 case studies indicates that ARMPS can be helpful in predicting stability during retreat mining operations.

Jan 1, 1993

By A. Nieto

Rare earth elements (REEs) are crucial to green technology such as hybrid-electric vehicles, wind turbines and fluorescent light bulbs. As of 2011, China dominates the global production of REEs and is reducing its export quotas. To predict the supply of rare earths in the United States based on future supply scenarios, a web-based database and geographic visualization tool was built. Five case scenarios with varying levels of REE demand were created by varying several economic conditions including (1) international trade policy, (2) greenhouse gas regulations, (3) environmental mining regulations and (4) tech applicability ratio of REEs. The most likely scenario, which is based on current international demand levels, indicates the importance of expediting the development of extractive operations of current REE resources within the United States. The results of the different case scenarios are supported by using dynamic geographic maps indicating the location of rare earth ore (REO) resources.

Jan 1, 2012

By E. C. Westman, W. R. Thomas, W. J. Conrad, A. J. R. Russell

"Understanding ground control problems continues to remain a focus of the mining engineering community. To aid mine operators and engineers in identifying and responding to ground control issues, the Ground Observation System (GOS) is being developed. The GOS is an integrated, web-based graphical user interface that displays ground response data collected wirelessly from an underground mine. It presents data in an intuitive manner to assist mine personnel, who are on- or off-site, in quickly identifying hazardous areas. Geotechnical instrumentation will be connected to wireless transmitters that will relay data in real-time to a surface computer that stores the information in a database. The GOS website will then display the geotechnical data in graphical and tabular forms, as well as in conditionally formatted mine maps. Data from each measurement device will be able to be viewed in its entirety or within a time interval, and can be downloaded for further analysis. The ability of the GOS to quickly interpret and communicate mine hazards to personnel of varying technical ability should prove to be a useful tool in understanding ground control and thus improving mine safety.INTRODUCTION Computer-based data information centers that convey operating parameters and conditions are prevalent in modern underground mines. Today’s systems are popular in showing ventilation controls and monitoring equipment performance (Jyothi & Meena 2013). In ground control monitoring, Conover, Ross, and Bigby, 2010 have installed a wired telltale roof monitoring system that sends roof displacement data every ten minutes to a computer on the surface. The computer receives, stores, and displays the data in real time. Data can also be viewed remotely through a password protected internet connection. Additionally, an internet connection allowed for remote updates to the system which streamlined software development and maintenance by eliminating travel (Conover et al., 2010). Currently, no such system beyond Conover et al.’s design has been accomplished. The Ground Observation System (GOS) is being developed to fill the void of real-time geotechnical monitoring in underground mines. A wide array of data will be transmitted wirelessly and broadcasted to on- and off-site mine personnel through the internet. The GOS will incorporate geotechnical data from roof deformation, borehole scratch testing, photogrammetry, and seismic monitoring into one interface, all while achieving permissibility for the use in gaseous mines. As a result, a comprehensive view of rock movement due to mining will be available. The overall purpose of the GOS is to deliver warnings; to ensure reliable data is relayed to personnel for the identification of potential ground failures, provide mine engineers information to design more stable mines, and assist with further geotechnical research."

Jan 1, 2015

"Iron ore is the source of primary iron for the world’s iron and steel industries. Its production can be reported as crude ore, usable ore or iron content of ore. Historically, the U.S. Geological Survey (USGS) used reported crude ore production from China in tabulations of world iron ore production while other countries have typically reported their production in terms of usable iron ore. When China’s crude ore production was tabulated with usable ore production from other countries, world iron ore production totals have been overestimated by 10 percent to a high of content and may include products such as concentrates, direct-shipping ore, pellets, and sinter.• Iron content, also referred to as metal content or grade, denotes the amount of elemental iron in the crude or usable ore.BackgroundIron ores consumed in the steel industry typically require an iron content greater than 58 percent before being considered commercially usable. Iron ores that are not commercially usable must undergo beneficiation to raise the iron content. Approximately 98 percent of the world’s usable iron ore production is consumed in blast furnaces to make pig iron, which is further processed to make steel.High-grade iron ore mines can supply usable iron ore, known as direct-shipping ore, to blast furnaces, with minimal physical processing and no beneficiation. With direct-shipping ore, the reported production for crude ore and usable ore are the same. Ore from low-grade deposits must undergo beneficiation to increase the iron content before it can be used by the steel industry. In this instance, the mined material is called crude ore and post-beneficiation concentrates are called usable ore; the amount produced will be less than the crude ore amount. With the notable exceptions of countries such as Australia and Brazil, most of the world’s iron ore deposits are low-grade and require beneficiation."

Feb 1, 2017

By A. Lashgari, V. Kecojevic

This paper presents research on the environmental impact of digging and loading equipment used in surface coal mining. Environmental impact was assessed through the measurement of equipment exhaust and dust emissions, and sound level. In this study, exhaust emission refers to carbon dioxide (CO2), carbon monoxide (CO), nitrogen oxides (NOx), sulfur oxides (SOx) and volatile organic compounds (VOCs). Dust generation refers to fine particles (PM2.5), inhalable particles (PM10) and total suspended particulate matter (TSP). Sound level refers to the sound pressure level at different distances from the equipment. Modeling of the environmental impact of digging and loading equipment was conducted using the Microsoft Visual Studio.NET software package. This research was a part of a broader project involving the development of a software system for the selection of productive, cost-efficient and ecofriendly mining systems, sponsored by the Appalachian Research Initiatives for Environmental Sciences (ARIES). This research may assist mining professionals in quantifying the environmental impact of digging and loading equipment, and developing strategies for reducing the overall impact of such equipment in surface mining.

Jan 1, 2013

By P. Bissert, M. Klein, L. Yan, D. Yantek, R. Matetic

"U.S. Mine Safety and Health Administration (MSHA) regulations require underground coal mines to use refuge alternatives (RAs) to provide a breathable air environment for 96 hours. One of the main concerns with the use of mobile RAs is heat and humidity buildup inside the RA. The accumulation of heat and humidity can result in miners suffering heat stress or even death. MSHA regulations require that the apparent temperature in an occupied RA not exceed 95 °F. To investigate this, the U.S. National Institute for Occupational Safety and Health (NIOSH) conducted testing on a 23-person tent-type RA in its Experimental Mine in a test area that was isolated from the mine ventilation system. The test results showed that the average measured air temperature within the RA increased by 9.4 °C (17 °F) and the relative humidity approached 94 percent at the end of a 96-hour test. The test results were used to benchmark a thermal simulation model of the tested RA. The validated thermal simulation model predicted the volume-weighted average air temperature inside the RA tent at the end of 96 hours to within 0.06 °C (0.1 °F) of the average measured air temperature. IntroductionIf an accident occurs in an underground coal mine, miners who fail to escape from the mine can enter a refuge alternative (RA) for protection from adverse conditions, such as high carbon monoxide levels. One of the main concerns with the use of mobile RAs is the potentially adverse thermal environment inside an RA from the metabolic heat of the occupants and the heat released by the carbon dioxide (CO2) scrubbing system. Moreover, the humidity within the RA will increase through occupants’ respiration and perspiration, and from the chemical reaction within the CO2 scrubbing system. The accumulation of heat and humidity can result in miners suffering heat stress, heat stroke or even death."

Sep 1, 2016

By Jerry C. Tien

The rare earth elements (REEs) are a group of 17 chemical (metallic) elements. REEs are used widely in high-technology, clean-energy products as well as weapon systems. China's dominant position as a producer of over 95% of the world REEs output and the world's increasing reliance on REE products have highlighted concerns about the future availability of rare earths in recent years. This paper briefly reviews the REEs world reserves, production, consumption, the impact of our heavy reliance on REEs products and China's changing policies on REE export on world supply chain.

Jan 1, 2013

By W. D. G. Hunter

Since 1945 the world's iron ore industry has experienced radical change. This transformation is reflected in new levels of production, consumption and trade, in shits in the location and size of markets, in the tapping of far distant sources of iron ore, and in the emergence of new export centres catering on an increasing scale to ore deficient, importing countries. Within the broad framework of shifting supply/demand relationships, certain operationally meaningful adjustments can be singled out for special mention: 1. The iron and steel industry has undergone vigorous and aggressive expansion, during the post-war period, not only in the capitalist world and among the socialist bloc, but in backward regions as well. New countries have been added to the list of steel producers, while new facilities have been relocated by established steel makers. 2. Overall demand for iron ore has risen rapidly, arid has flowed different channels.

Jan 1, 1964

After the war that was nearing an end In early 1945, regular consulting work for Bralorne, the Bradleys, Pennsalt Chemical Co., and a directorship and occasional consulting for Homestake Mining Co. made it almost certain that in spite of my 61 years I would have enough work to feed my family. But this routine work would not provide enough income to lay up funds for the inevitable future when I could no longer do arduous work. And it would not give me the adventure that had first lured me into mining. Therefore I was greatly relieved as well as pleased when, in the 18 months from April 1945 to November 1946, I was asked to make three of the most adventurous as well as profitable examinations that ever came my way. Pati[n]o Mines, Bolivia The first of the exciting jobs was an examination of the Pati[n]o tin mines in Bolivia. After I had unsuccessfully tried to induce Anaconda to purchase these mines In 1915, the World War I crisis that had forced the half-Indian accountant to try to sell the mines had come to an end. The European market for tin improved dramatically, and "Don Simon" was able to borrow money for expenses while the concentrates were still In Bolivia. He took advantage of the favorable conditions by buying adjacent properties and increasing development work until his Bolivian tin mines were the greatest in the world. And his daughter had marled the French Count de Boisrouvain and was cutting a swath In high International society. Pati[n]o wanted to get rid of the drudgery of running a complicated mining Industry in a remote area In Bolivia when the fleshpots of Paris were much more seductive. An added incentive was the fact that his miners had become unruly and had even threatened his 11fe.

Jan 1, 1976

By K. A. Perry, R. Q. Eades

The University of Kentucky conducted inerting tests and angle of ejection tests on three types of rock dust. A newly developed hydrophobic dust was compared against typical dry and wet dust applications. This new product is designed to alleviate respirable dust concerns for dry dusting and caking issues with wet dusting. Samples for both test types were prepared in a laboratory and subjected to temperature and humidity cycles that are typical of an underground coal mine. Inerting tests were conducted in a 38-L chamber with a 5-kJ Sobbe igniter. Angle of ejection testing was conducted at the University of Kentucky Explosives Research Team’s laboratory in Georgetown, KY. The results of these tests indicate that the newly developed dust has improved results for flame suppression and ejection compared with typical wet dust applications. The significance of these results is discussed with regard to existing respirable dust regulations and the issues associated with caking.

Jan 1, 2016

By M. R. Shahan, C. E. Seaman, Mischler S. E., T. W. Beck

"Float dust deposits in coal mine return airways pose a risk in the event of a methane ignition. Controlling airborne dust prior to deposition in the return would make current rock dusting practices more effective and reduce the risk of coal-dust-fueled explosions. The goal of this U.S. National Institute for Occupational Safety and Health study is to determine the potential of open-air water sprays to reduce concentrations of airborne float coal dust, smaller than 75 µm in diameter, in longwall face airstreams. This study evaluated unconfined water sprays in a featureless tunnel ventilated at a typical longwall face velocity of 3.6 m/s (700 fpm). Experiments were conducted for two nozzle orientations and two water pressures for hollow cone, full cone, flat fan, air atomizing and hydraulic atomizing spray nozzles. Gravimetric samples show that airborne float dust removal efficiencies averaged 19.6 percent for all sprays under all conditions. The results indicate that the preferred spray nozzle should be operated at high fluid pressures to produce smaller droplets and move more air. These findings agree with past respirable dust control research, providing guidance on spray selection and spray array design in ongoing efforts to control airborne float dust over the entire longwall ventilated opening. IntroductionCoal mining processes produce airborne dust that naturally deposits on the floor, roof and ribs of mine airways. These fine dust particles, termed float coal dust when smaller than 75 µm in diameter, are deposited in the return entries of coal mines and can be reentrained by pressure waves induced by methane-air explosions (Rice et al., 1911; Nagy, 1981; U.S. National Institute for Occupational Safety and Health (NIOSH), 2006). These particles are also those most likely to participate in coal-dust-fueled explosions, which can potentiate and propagate explosions resulting in extensive damage. In order to meet compliance requirements of at least 80 percent incombustible content in the composition of material deposited in mine entries (U.S. Mine Safety and Health Administration (MSHA), 2016), coal mines apply an inerting agent, specifically, rock dust (Harris et al., 2009). Should methane be present in the mine atmosphere, the required fraction of incombustible content is further increased by 0.4 percent for each 0.1 percent methane. The removal of airborne float coal dust (AFCD) prior to deposition is an approach intended to make current rock dusting practices more effective by increasing the proportion of inert material to combustible material, resulting in a lower risk of coal-dust-fueled explosions."

Jan 1, 2018

By K. A. Larsen, J. L. Ariail, C. M. LaRosa

This article discusses the evolution of U.S. laws and policies towards environmental remediation at mine lands over the last 20years, the opportunities that these changes present for reuse, and the remaining challenges associated with community capacity for effective reuse planning and implementation. Emerging initiatives by the U.S. Environmental Protection Agency and Department of Interior for addressing these challenges are discussed.

Jan 1, 2004

By V. Kecojevic

Environmental and economic costs related to equipment fuel consumption and carbon dioxide (CO2) emission present a substantial challenge to the mining industry. Haul trucks are an integral part of the overall surface mining system and they consume a significant quantity of fuel. Consequently, they produce a significant amount of CO2. The objective of this research is to (i) establish a mathematical relationship among a truck?s fuel consumption, power and engine load factors and (ii) determine the amount of a truck?s CO2 emission and the associated cost that may arise from potential CO2 legislation. In order to achieve these objectives, the authors have considered original equipment manufacturer (OEM) haul trucks, which are commonly used in surface mining operations. The research presented here may be used by mining professionals to help determine the cost and environmental burden of the trucks? application and efficiently manage energy consumption.

Jan 1, 2010

By Laura Suarez, Jörgen Kajberg, Pär Jonsén

How does an investigation into the breakage characterization of electric arc furnace (EAF) manganese slags contribute to a more responsible usage of resources throughout the life cycle of steel products and reduction of carbon emissions? The main goal of this study is to increase the knowledge on the mechanical response of manganese slag to open the potential of pyrometallurgical residues to become secondary material in industrial applications such as infrastructure construction, fillers, binders and soil stabilization, among others.

Mar 1, 2024

By Jason Clarke, Glen Trainor

As the mining industry faces increased challenges with declining ore grades and harder to access deposits, operating mine sites in an environmentally responsible and economically viable manner will require innovations that improve efficiency in energy logistics, and automation. Technological advancements in mining have been successful primarily because of the willingness and capability of these solutions to share information with one another, for example OEM payload systems sending information to Fleet Management Systems, and in turn Fleet Management Systems interfacing to ERP systems. To promote and facilitate the sharing of data, there has been a push towards open standards with initiatives led by organizations like ISO, ISA, EMESRT, and GMG. These efforts are aimed at creating a more collaborative and interoperable environment within the sector. However, when it comes to implementing autonomous solutions, a different trend dominates— closed-stack solutions. These closed stack solutions not only prohibit a mine site from selecting best-of-breed solutions, by blocking the competition from entering the market, they also risk slowing innovation that could help overcome the challenges the mining industry faces. Open Autonomy, an internationally published standard that allows any FMS to work with any Autonomous solution, breaks this closed-stack approach and invites competition from other industries. This competition comprises of autonomous suppliers from other industries and manufacturers of smaller, civil-sized haul trucks. The availability and capabilities of these smaller-sized autonomous haul trucks will help tackle the challenges of responsibly and economically mining lower quality ore grades and mining harder to access deposits.

Feb 1, 2024