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By Nord L. Gale

The discovery of important new ore deposits of lead, zinc, copper and silver in 1955 in Southeastern Missouri has resulted in the development of a thriving mineral industry known as the "New Lead Belt" or "Viburnum Trend", to distinguish it from the older lead producing areas to the East. This region has recently become the world's largest lead producing district with production in 1970 reaching 432,576 tons or 74.4% of the entire United States lead mine production. The area is heavily forested with rolling hills dotted with numerous clear running streams in the Clark National Forest of the Missouri Ozarks. The location is within 70 miles of St. Louis, Missouri and has a natural abundance of water resources which provide an important recreational area for fishing, hunting, camping and other outdoor activities. Until this recent development, the area was sparsely populated and industrialization was almost unknown. The infusion of $150 million in mining capital has brought about a dramatic change in the economic structure of the area and will almost surely be accompanied by changes in its environmental picture. In an effort to maintain this bountiful national resource and to evaluate the changes occurring in surface water quality and aquatic life forms present, an inter- disciplinary research program at the University of Missouri has been undertaken with the support of the National Science Foundation. Research has been carried out to determine background values, establish natural baselines, and to evaluate the extent and causes of changes in streams effected by mine water discharges and wastewater from ore milling operations. The unique topography of the "New Lead Belt" area allows the channelization of milling and smelter wastes to separate stream systems (Figure No. 1) thus allowing measurements of the pollutional effects on an individual basis.

Jan 1, 1973

By P. A. Plunkert

Metallurgical-grade bauxite was imported into the United States from 11 countries in 2004. The principal suppliers of this 10 Mt (11 million st) of imported ore were Jamaica (33 percent), Brazil (25 percent), Guinea(23 percent) and Guyana (11 percent). The average value of imports, cost, insurance and freight (c.i.f.) U.S. ports, was $31/t ($28/st). Calcined refractory-grade bauxite imports were 165kt (182,000 st) with an average value of $146/t ($132/st), c.i.f. U.S. ports. China supplied 70 percent; Guyana, 22

Jan 1, 2005

By G. Xu, A. R. Kumar, N. A. Amoah

Prolonged exposure to high concentrations of respirable coal mine dust causes coal workers’ pneumoconiosis and silicosis. Underground coal mine roof bolter operators are more prone to elevated exposure to coal and silica dust. The canopy air curtain (CAC) was developed by NIOSH to protect roof bolter operators from the exposure. The CAC supplies filtered air over the breathing zone of the operator. This dilutes the high coal dust concentrations and provides for an impenetrable air curtain. Many studies have been carried out to improve CAC efficiency. However, field test has shown variable dust control efficiencies indicating rooms to further improve due to the nonuniform airflow distribution across the plenum and ineffective perimeter flow. This study therefore redesigns the CAC with optimized flow distribution that effectively protects roof bolters from coal dust exposures. Computational fluid dynamics (CFD) simulations are used to optimize the uniformity of airflow distribution across the plenum to achieve the best possible uniformity. A lab experiment validates the CFD model and confirms the ability of this design to reduce floor dust pickup, prevent external wind infiltration, and offer an improved protection efficiency

Mar 2, 2022

By David T. Kao

The energy situation the world faced during the decade of the Seventies resulted in actions throughout the free world to reduce its dependence on OPEC oil. Many nations heeded the indicators early in that decade and commenced efforts to reduce their oil requirements. Those nations which did not heed these warnings had the message brought to them more emphatically in the last portion of the decade with the further rapid and continuing rise in prices of OPEC oil. Furthermore, the demonstrated unstable nature of large oil-producing countries has made it clear to all free world nations that their energy demands of the future must be provided for by some more stable and assured supply. Now, early in the decade of the Eighties, we see the need for expanded use of coal as an energy supply to be essential. The result in 1980 and 1981 has been a great increase in demand for steam coal worldwide. In essence, a new business for the United States has developed in steam coal export. In the United States, the large growth in foreign demand for our steam coal is now well recognized and documented. A major impediment in meeting this growing demand became abundantly clear in 1980. This impediment is the congestion existing at U.S. coal export ports. With the recognition of this constraint, a plethora of activity has been observed in announcements for alleviating the problem by improving and expanding current export port facilities. In addition to improvement and expansion, an abundance of totally new facilities has been announced in an effort to find ways to meet this large demand in the new business of steam coal export. This is needed; and hopefully, many of these plans will be translated into action. While total implementation of all stated plans is not expected, much of the implementation depends upon large- scale dredging, large waterside ground storage sites, and improved handling equipments in the conventional type of export ports. The time and capital required for implementation is great, and environmental problems associated with dredging are substantial. Host significantly, and unfortunately, implementation that does include dredging our ports will still not permit use of the truly large colliers of 140,000 DWT and greater, which are evolving as the "state of the art" in long-distance sea transport.

Jan 1, 1981

By Edward Holloway

The basis for the selection of the ultimate pit for an open pit mining operation is generally opaque. Some form of value-based analysis will generally guide the final decision; however, the value will often gradually plateau whilst the ultimate pit size continues to increase. There is no established framework to guide specialists in the selection of the ultimate pit, with such decisions regularly made on a somewhat arbitrary basis. The key component that is missing from the analyses typically used to select the size of the ultimate pit is risk. Once risk is quantified within the analysis framework, the decision-making range is significantly reduced, and the process for selecting the ultimate pit becomes more consistent, replicable, and defensible. This paper provides an approach to including risk in the process used to select the ultimate pit.

Feb 21, 2024

By David Burgess

The paper describes experiments at the Somerset Mine, Colorado, under a cooperative agreement between U.S. Steel and the U.S. Bureau of Mines. A test was made of the tube bundle method of mine air sampling which was developed for European longwall mines; some 300,000 running feet of tubing provided continuous monitoring at 39 locations. Carbon monoxide concentrations were obtained with standard deviations of less than 1 ppm and oxygen concentrations with standard deviations of less than 0.20 percent. A base level of CO index (ppm CO evolved/pct 02 removed)) was determined to be 0-20 through most of the passageways of the mine. However, in one working section where the coal was initially hot (about 180°F within a pillar) the CO index was demonstrably higher, >20 trending upward to about 60 when smoke appeared and the section was sealed. The data are discussed in terms of laboratory experiments on CO evolution from coals.

Jan 1, 1975

By S. Chander, S. W. Musselman

The molecular structure of hydrophobic and hydrophilic groups in nonionic surfactants has been related to the wetting and dispersion of selected pigments. The nonionic surfactants included in this study are acetylenic diol based surfactants and ethoxylated alkyl phenols. The Langmuir model could be used to fit adsorption data. Further analysis of the data showed that the free energy of adsorption was a function of adsorption density of the surfactants at the interface. The change in free energy with adsorption density could be interpreted by considering a change in the orientation of the adsorbed molecules. Acetylenic diol based surfatants were found to have an area per molecule of 2-3 times that of similarly ethoxylated alkyl phenols. The wetting and dispersion properties of lamp black, a model hydrophobic surface, by these surfactants were investigated by contact angle measurements and particle size analysis. Acetylenic diol based surfactants with ethylene oxide contents between3.5 and 10 moles per molecule and alkyl phenol based surfactants with approximately 9 moles of ethylene oxide per molecule were found to provide superior wetting abilities. Longer ethylene oxide chains were required for superior dispersion capabilities within each family of surfactants. Complete wetting and dispersion was found to occur above the critical micelle concentration of the surfactants.

Jan 1, 2000

By Chelsea Woodward

The Spokane Research Laboratory of the National Institute for Occupational Safety and Health has demonstrated a prototype hydrogen-fueled mining vehicle as an alternative to diesel equipment in underground mines. Safety and control systems were added to allow a 70-kW rubber-tired hydrogen vehicle, originally developed by the U. S. Bureau of Mines and Hydrogen Consultants, Inc. (now Hydrogen Components, Inc., of Littleton, CO), to be tested. This work began in late 2000 and culminated with a Mine Safety and Health Administration fire safety review and field tests at the Stillwater Mine in Nye, MT, in 2004.

Jan 1, 2006

By Hugh Douglas

In the past two years recent increases in silver prices over levels that prevailed for many years have changed supply/demand patterns. On the supply side, a silver mining boom is in progress in the United States and elsewhere. On the demand side, traditional uses of silver by individuals are dropping while industry is conserving. These changes will alter the supply/demand balance and bring about more moderate rises in silver prices, which in turn will impact the mining industry.

Jan 1, 1981

By A. Yazadni-Chamzini

Considering the nature of open pit mines, harvest volume, it usually is required to remove a lot of waste to access to mineral planned grade. So, one of the most important part of open pit mines design, is waste dump site selection. Many factors are effective in waste dump site selection. These factors are sometimes in conflict with each other. So selecting the desired location for waste dump is a process complex and multi-criteria decision making. There are a variety of methods for decision making under complicated condition, such as fuzzy, Delphi, multi-criteria decision making and Expert system methods can be hinted. VIKOR method, which is one of the decision making multi criteria methods, is useful tool for decision-making. On the other hand with regard to uncertainty in decision-making, fuzzy approach is a useful tool for this purpose. This article has tried to select the best waste dump site in Sari Gunay Gold Mine by Fuzzy VIKOR. The results show that C position has a higher priority than other positions.

Jan 1, 2012

By Derek Brennan, Donald Brennan

"The existing Rondout West Branch Tunnel (RWBT) is part of the Delaware Aqueduct which has been in service since 1944 and accounts for more than 50 percent of New York City’s water supply. In early 2015, the New York City Department of Environmental Protection contracted Kiewit-Shea Constructors, AJV (KSC) to construct the Rondout West Branch Bypass Tunnel project (Rondout) in order to mitigate the leakage of 132 million L/ day (35 million gpd) of water from two areas of the existing tunnel; the Roseton and Wawarsing areas.The scope of the Bypass Tunnel 2 project is separated into two distinct phases. Phase 1 consists of completing the shaft sinking to a depth of approximately 274 m (900 ft) at shaft 5B, 213 m (700 ft) at shaft 6B and the excavation of approximately 3,850 m (12,500 linear ft) of tunnel at a diameter of 6.6 m (21 ft 7 in). This phase also includes the installation of 2,804 m (9,200 linear ft) of 4.8 m (16 ft) diameter steel interliner pipe through the new bypass tunnel with cast-in–place concrete liner for a finished diameter of 4.2 m (14 ft). Access chambers at the top of shafts 5B and 6B will be constructed for access and housing of the mechanical and electrical equipment for supporting pumps and valves.Included in phase 2 is the additional excavation from shafts 5B and 6B to the RWBT, and the drainage tunnel to remove ground water infiltration from RWBT. This work will be completed during a scheduled shutdown of the RWBT and will include approximately 31 m (100 ft) of excavation of the two connection tunnels. Additionally, construction of the permanent plugs within the RWBT will be undertaken. Figure 2 shows the layout of the work.Access to the work through the deep shaft at site 5B was critical to the success of the project. The hoisting system needed to be multi-functional to handle the different types of construction from drill and shoot of the shaft, starter and tail tunnel, the assembly of the tunnel boring machine (TBM), the excavation of the TBM tunnel including the supply of the precast segmental liner, the grouting operations, the installation of the steel interliner pipe and the cast-in-place concrete as well as ingress and egress of personnel. The production of the TBM operations was critical to the schedule of the project. This required a quick cycle for muck haulage and supply of the precast segmental liner in order to keep pace with the excavation time of the TBM. For TBM assembly, components were limited to a maximum weight of 104 t (115 st) for a single lift. Various cranes were analyzed for hoisting, however, none would meet all of the citeria. Therefore, the project team selected a specialized hoisting system designed in house in conjunction with Timberland Equipment Ltd. that consisted of a total of 14 separate hoists and winches with a total of more than 2,833 kW (3,800 hp)."

Mar 1, 2019

By J. L. Page, A. C. Marlowe

The Research and Development Services of South Africa has begun underground trials with a Robbins 52RE blindhole borer using a cutterhead fitted with high pressure water jets to assist mechanical cutting. The objectives of the work are to reduce cutter costs by increasing cutter life and to increase overall penetration rates. The paper reviews blindhole boring in South Africa and laboratory experiments in rock cutting assisted with high pressure water jets. The borer and its ancillary equipment are described. Initial results of underground boring experiments are presented. The paper concludes with the test programme for the future.

Jan 1, 1985

The National Institute for Occupational Safety and Health (NIOSH) has continued study of the Personal Dust Monitor (PDM) developed by Rupprecht & Patashnick Co. Inc. through a CDC contract and currently being commercialized by Thermo Fisher Scientific. This report examines the effect of oversize particles, cyclone inversion, and cleaning procedures. Clean and exposed filters were examined using light microscopy and particulates counted before and after various instrument manipulations. The data presented show that the dry cleaning procedures do not cause significant (greater than limit of detection) sample contamination by respirable or oversize particulates and that the cyclone is resistant to particulate carry over during inversion.

Jan 1, 2009

By Hyung-woo Kim, Sup Hong, Sung-Soo Kim, Chang-Ho Lee

A deep-seabed integrated mining system, which consists of four subsystems such as riser pipe, buffer, flexible riser, and tracked vehicles, is presented in Figure 1. In order to collect more manganese nodules, multiple tracked vehicle systems should be used in a deep-seabed integrated mining system.

Sep 1, 2014

By Andres Salazar, Carlos Delgado Robles, Richard K. Preece

The paper discusses the evolution of the geometallurgical model at the Escondida mine in northern Chile, the world’s largest copper producer. It highlights the transition from early metallurgical forecasting methods to a comprehensive model that includes spatial distribution of metallurgical forecasts. This model helps in planning and adapting to the variability in ore characteristics, such as hardness and mineralogy, which affect processing performance.

Dec 1, 2023

By T. Fernandez, V. Juchen, C. Petter, F. Cantini, V. Lenz, V. I. Araújo, R. Petter, R. Darrigo, A. Young, I. G. da Costa, J. Oppermann

There are many methods to estimate costs quickly. One of these is the Parametric Method, where costs are estimated from general algorithms (or curves). Derived from an original tool based on the O’Hara model, a software called MAFMINE was developed. MAFMINE is based on parametric models to estimate investment and operational costs in mining. The software itself is based on the use of a computer model known as client-server. However, the model needs new inputs from advances made by the mining industry, mainly in terms of electrification, automation, digital transformation and preconcentration to face Environmental, Social and Governance (ESG) concerns. Thus, this work was to prepare a new core module ready to incorporate the new technologies aiming to deliver operation and capital costs associated with environmental impact mitigation. The tool generates an order of magnitude estimate for CAPEX and OPEX to establish a very first Discounted Cash Flow (DCF) in a mining venture. For quick evaluations, at a preliminary level, the results are very promising.

Mar 2, 2022

By W. Choi

The present study revealed that the bioleachability of a chalcopyrite flotation concentrate is influenced by the semiconductor properties of CuFeS2. The overall reaction of biooxidation,

Jan 1, 1991

By Ray A. Rothrock

The in situ mining of uranium is the process whereby chemical lixiviant is injected by means of wells into, and flowed through, an ore body. The lixiviant reacts with uranium which has been previously oxidized making the uranium soluble. The solution is then brought to the surface by means of producing wells. In situ mining disturbs the ground-water quality in the immediate area. Since ground water is a natural resource used by man, care must be taken not to allow the lixiviant to escape the local mining area. Also, when the ore body is mined out, the area should be restored to as near its original state as is reasonably achievable. The return of ground-water quality to its original state can occur naturally over a long period of time or be enhanced using appropriate technological means.

Jan 1, 1981

By Faruk Oksuz, Clay Haynes, David Egger

The United States Army Corps of Engineers (USACE) has committed to solve a major drainage problem in the suburban Chicago community of Griffith, Indiana. The Cady Marsh Ditch is currently undersized and on occasion spills its banks causing flooding and economic setbacks to the community. Preliminary studies have identified both tunnel and surface solutions as being attractive and viable. The USACE has decided that this project is an opportunity to use the design-build contracting approach to maximize ingenuity in project approach and to allow the market to dictate whether a surface or subsurface solution is most attractive. The tunnel would be over one-mile in length through sands, gravels and clay. Water control will be an issue during tunneling. The paper will explore the contracting approach to the project and the adaptation of Underground Technology Research Council (UTRC) guidelines for underground contracting to a design build project. The roles of Owner, Owner’s consultant, and design-build contractor will be defined as interpreted by the USACE and key contract provisions will be described and contrasted with a traditional design-bid-build approach to tunnel construction.

Jan 1, 2003

By C. B. Manula

The Crushed Stone Industry plays an important role in Pennsylvania's mineral economy. During 1965, the total production of crushed and broken stone in the United States reached 780 million tons from which 57 million tons were produced in Pennsylvania (Mineral Industries Surveys, 1966). It is further significant that Pennsylvania is the nation's leading crushed stone producer. Future trends in stone production will quite likely parallel those in the construction industry. Stone and stone products are finding greater and more varied uses each year. Continued record expenditures for structures such as dams, highways and buildings are the prime reasons for this accelerated growth in demand. Completion of the interstate road system and the maintenance of Pennsylvania's already expanded highway system form the essentials for this expanding market.

Jan 1, 1968