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By Guosheng Zhan

The Homestake Mine included the open cut and underground workings up to 2,484 m (8,150 ft) deep. The mine ceased mining activities in December 2001 after 125 years of operation. Pumping from the underground workings continued for 18 more months until June 10, 2003. Homestake had completed a comprehensive hydrologic evaluation on post-closure underground flooding prior to the shutdown of pumping. After closure, the mine was selected by the National Science Foundation as the site for the Deep Underground Science and Engineering Laboratory (DUSEL). An interim laboratory facility will be set at the 1478 m (4850 ft) Level. The final facility will be set at the 2256 m (7400 ft) Level or deeper. Pumping from the underground workings began on June 5, 2008 by the South Dakota Science and Technology Authority (SDSTA). During the period of June 2008 through March 2009, the pumping rate increased from 41 L/s (650 gpm) to 81 L/s (1,290 gpm) with an average rate of 60 L/s (950 gpm). As a result, the water level had been lowered more than 95 m (310 ft). It was found that the observed rebound and later decline to date is in close agreement with the model projections. Because of this, the authors of this paper reject claims of a lack of sufficient measurement devices in place and a lack of understanding of the hydrologic system at the Homestake Mine prior to shutdown of pumping in 2003 (Davis et al, 2009). Furthermore, it is believed that this validated model can serve as a useful tool for the SDSTA to manage future underground dewatering for the DUSEL operation. This paper evaluates the hydrologic conditions in the Homestake Mine area and projects the post-closure groundwater rebound and decline due to DUSEL pumping.

Jan 4, 2010

By Badiozamani Khosrow

Introduction The mining industry has been using computers since the late 1950s. Despite this early start, the use of mine planning software is not a common practice in many operations. But the trend might be changing because of the availability of relatively inexpensive personal computers (PC). The introduction of these machines has generated unprecedented interest by mine managers to computerize their planning operations. However, some managers have become disappointed with the PC's lack of adequate software and the inability to handle the massive amounts of information required for modeling. This paper is an attempt to shed some light on the future of computers in the mining industry. It will examine: • historical progress in the computer industry, • future advances in the computer industry, • historical usage of computers in mining, and • future alternatives available to mining. Historical Progress The computer industry has come a long way since the first full-fledged electronic digital computer Electronic Numerical Integrator And Calculator (ENIAC) was built in 1946. This machine weighed more than 27 t (30 st). It contained 19,000 vacuum tubes, occupied 139 m2 (1500 sq ft), and could perform 5000 additions per second. By contrast, today's fastest, commercially available computer is the CRAY-X. It weighs less than 5 t (6 st), has no vacuum tubes, occupies less than 9 m2 (100 sq ft), and performs over 100 million operations per second. This is an incredible advancement in less than 40 years. One person commented on the rate of advancement in the computer industry. He suggested that if the auto industry had advanced at the same rate as the electronics industry, we could buy a Rolls Royce for $2.75 and it would run

Jan 9, 1984

By M. M. Botz

There are currently more that 460 mines worldwide that utilize cyanide for gold and silver extraction. Despite this large number of cyanide-related mining operations, there have been no published accounts during the previous 25 years of the death of humans due to cyanide as a direct consequence of major mining-related environmental incidents. All published accounts of human deaths due to mining-related environmental incidents have been the result of physical inundation with tailings or waste rock materials. It appears that major mining-related environmental incidents have not been concentrated in any geographic location, are likely to occur regardless of the size of the mining company and do not occur more frequently with a specific type of mining activity. Several cyanide treatment and recovery technologies have been widely demonstrated to reliably control cyanide levels in mining solutions. With proper use of these technologies, tailings cyanide concentrations can be maintained at levels protective of wildlife while reducing the potential for adverse environmental incidents. The development of an international cyanide code of practice or management plan is recommended and should take into consideration the adoption of a weak-acid-dissociable (WAD) cyanide standard that maintains the levels entering a tailings impoundment below 50 mg/L.

Jan 1, 2001

By Ray Brainard

Charleston Water System?s Daniel Island Extension Tunnel, initially thought to be the simplest of the four replacement tunnels to design and build, became the most challenging after the discovery of an unexpected 30-ft thick lens of sand in the normally consistent Cooper Marl while sinking a shaft on Daniel Island. This paper will explore the challenges involved with determining the extent of the unforeseen lens of sand, the accelerated boring program, and the redesign of the vertical alignment?keeping the alignment between the sand layer and the bottom of the Cooper River. It will describe how the challenges were overcome, and how the Owner, Engineer, and Contractor were able to team together to achieve the desired results.

By Jeffrey D. Thatcher, Debra W. Struhsacker

With the burgeoning development of precious metals heap leach mining projects throughout the country regulatory agencies are beginning to take a closer look at the short-and long-term environmental consequences of heap leach mining. This increase in regulatory review is occurring on federal, state and local levels, and is affecting both large- and small-scale mining developments. Small-scale mining developments are receiving especially critical regulatory scrutiny because in the eyes of some regulatory agencies, small developers lack the credibility automatically accorded to major mining companies. This is due in part to a bad image of small miners based upon past environmental problems and permit violations caused by a few, small operators. The proponent of a small mining development thus faces special problems during the project permitting process, and must convince the regulatory authorities of his company's ability and commitment to plan, develop, and decommission a mining operation in compliance with environmental regulations. Not only must the small developer have a thorough understanding of the regulatory requirements affecting his project, he must also devote considerable effort to careful internal planning in order to produce a well organized approach to project permitting. The importance of proper planning cannot be overstated. Project planning is key to convincing the regulatory agencies that the small miner is capable of developing a viable project. More- over, the economics of a small mining project demand permit acquisition at modest cost and in a timely fashion. A well planned permitting effort will thus ensure that permits are received within budget and on schedule. This paper will review the federal, state, and local permitting requirements for heap leach projects, and the variability of these requirements from state to state. The environmental assessment process for projects developed on public lands, and the acquisition of zero- discharge water quality permits, air quality permits, and local special use permits as they apply to small mining developments will be discussed. The paper will conclude with a review of project decommissioning and cyanide neutralization requirements and their implications for small-scale heap leach projects.

Jan 1, 1987

The design/optimization of the pump and cyclones to maximize grinding circuit efficiency first requires a concise understanding of, and clearly defined specifications for, desired grinding circuit performance. Subsequently, the pump and cyclone performances that provide the desired grinding circuit performance can be defined. Once the performance requirements of each process unit are determined, selection of physical equipment parameters that will deliver those performances can be carried out. The Functional Performance Equation shows that there are two distinct efficiencies in closed circuit ball milling. One of these, ?Circuit Classification System Efficiency? (CSE), is the fraction of ?coarse? material inside the ball mill upon which grinding energy is deliberately expended, versus the remaining fraction of ?fines? or finished size material inside the mill, upon which grinding energy is wasted (on over-grinding). The role of the pump and cyclones is to maximize CSE, which is the desired grinding circuit performance. The obtainable, target CSE for any given circuit can be estimated, for example by referring to a plant data base of CSE?s. Design/optimization guidelines then allow us to specify the pump and cyclone performances that will achieve the target CSE. This paper outlines the step-by-step, systematic method of pump and cyclone selection which maximizes CSE. Numerous examples of its successful application are provided.

Jan 1, 2011

Several industrial-scale HydroFloat separators have recently been installed at Mosaic?s South Fort Meade beneficiation plant for the purpose of improving phosphate recovery and throughput capacity. This technology was implemented after numerous laboratory, bench-scale and on-site, pilot-scale test campaigns. The results from this detailed test work provided sufficient justification for the complete retrofit of the existing coarse and ultra-coarse flotation cells. Data indicate that the metallurgical results obtained with the full-scale separators are consistent with that obtained during both the bench- and pilot-scale evaluations. The benefits, theory of operation and commissioning of the equipment are also discussed.

Jan 1, 2007

By Ryan C. Stephan, Christopher Mark

"Some of the weakest roof in United States coal mines is found in the Illinois Basin. Historically, the Illinois Basin has also suffered from high rates of unplanned roof falls and rock fall injuries. During the past decade, however, roof fall and rock fall injury rates have fallen dramatically, and are now lower than the national average. Several technologies are responsible for the improvement. Roof screen was rarely used ten years ago, but a number of mines now use it on a regular basis to prevent rock falls and rock fall injuries. Other roof skin control fixtures and work practices have contributed as well.The reduction in roof falls is also directly attributed to enhanced intrinsic roof support. Stiffer primary bolting patterns have reduced the magnitude of roof spalling and roof sag. They have also helped create a more intact beam that is able to be suspended from longer cable bolts. Cable bolt design methodology has also contributed to this reduction in roof falls. Some early cable bolt applications were unsuccessful because they employed as few as two cable bolts per intersection. This paper describes a methodology for estimating rock loads for support design.ROOF FALL TRENDS IN THE ILLINOIS BASINAlthough the Illinois Basin has a long history of poor roof conditions and high rates of unplanned roof falls and rock fall injuries, recent data indicates a change in the trend. Roof fall rates are determined by dividing the total number of non-injury roof falls by the total number of hours worked underground. The data is considered for 200,000-man hours. While the Illinois Basin was once a coalfield experiencing roof falls at nearly twice the national average, it is now at or below the national rate. Figure 1 indicates the trend over the past 20 years. In 2008, the Illinois Basin mines experienced 5.06 roof falls every 200,000-man-hours, compared to only 0.75 in 2018.There has also been a significant reduction in the rate of rock fall injuries in the Illinois Basin coal mines, as shown in Figure 2. In 2008 there were 1.48 rock fall injuries every 200,000-man-hours, compared to only 0.43 in 2018.ILLINOIS BASIN COAL ROOF GEOLOGYThe roof rock in the Illinois Basin has been studied in the past to understand the primary causes of roof failures (Molinda et al., 2008; Thompson, 2010; Molinda and Mark, 2010). Rusnak and Mark (2000) evaluated 10,000 laboratory strength tests from 800 rock units and concluded that for shale, siltstone, and sandstone, the strength of the Illinois Basin variety was less than half that of the same rock types in Central Appalachia (Figure 3). A study of Coal Mine Roof Rating (CMRR) measurements in more than 200 US coal mines also found that weak roof was predominant in the Illinois Basin (Mark and Molinda, 2005)."

Jan 1, 2019

By G. Récoché, A. Chamaret, M. O’Connor

Building indicators that respond to all stakeholders' needs is a time-consuming and complex exercise, with certain questions still unsolved. The aim of the current three-year research project, carried out in partnership between BRGM’s Mineral Resources Division and C3ED, is to propose a top-down / bottom-up indicators building methodology that combines conception and coordination methods and a participative approach. The tool-design phase is based partly on a comparative analysis of existing international initiatives according to different criteria (objective, observation scale, framework, etc.). The study of two African mining projects will provide the opportunity to confront the conceptual aspects with reality in the field. Careful consideration of the participants’ suggestions will result in a set of indicators that can be easily understood and adopted by all stakeholders. The final objective is to measure the impact of a mining site on a local, regional and national sustainable development frame, throughout the full life cycle of a mine.

Jan 1, 2005

By A. Duerksen

Surface coal mining in West Virginia has supplied energy to the eastern coast of the United States for over a century. The coal mining industry has been forced to adapt as societal demands regarding health, safety, and environmental impacts have changed with time. More recent pressure has called for another iteration of change: long-term post-mining sustainability. The research presented in this paper investigates one potential solution?or component of a solution?to improve mining sustainability in Appalachia: post-mining wind power. This paper intends to demonstrate and explain the feasibility of synergistic mine closure and wind development. Wind conditions at three reclaimed mine sites in West Virginia were monitored in order to develop representative case studies for post-mining wind power. This paper contains a summary of the literature consulted to plan the site assessments, the methodology employed to execute them, the analysis steps undertaken to derive conclusions, and a discussion of all findings. This research has found that significant cost savings can be yielded from synergistic mine closure and wind development, as compared to greenfield wind development. Though wind conditions themselves remain the primary driver for site feasibility, post-mining wind power is a practice with significant promise for improving project economics, contributing to renewable energy development, enhancing company-community relations, providing local employment opportunities, and exemplifying sustainable business practices in Appalachia.

Jan 1, 2012

By Moussa Wone

The Washington, DC Water and Sewer Authority (WASA) has implemented facility planning for the Anacostia River Projects portion of a program to bring its Combined Sewer System (CSO) into compliance with federal water quality regulations by 2025. The program includes approximately 19 kilometers (12 miles) of deep CSO storage/conveyance and flood relief soft ground tunnels, construction, vortex drop, overflow, maintenance and air release shafts, as well as near surface diversion structures and conveyances. The Project encompasses major technical and non-technical challenges including completion under a federal consent decree schedule, construction within the confines of heavily developed urban areas, difficult ground conditions, major infrastructure crossings, and close coordination with several major public agencies. This paper discusses the planning stage considerations related to the geotechnical investigation program, discusses obstructions that influenced alignment selection, and provides two examples of preliminary estimates of settlement induced ground movement due to the tunnel and shaft construction.

Jan 1, 2008

By Thomas G. Goonan

Copper production through smelting generates large volumes of material flows. As copper contained in ore becomes copper contained in concentrate to be fed into the smelting process, it leaves behind an altered landscape, sometimes mine waste, and always mill tailings. Copper concentrate, fluxing materials, fuels, oxygen, recyclables, scrap and water are in-puts to the process. Dust (recycled),gases — containing carbon dioxide(CO2) (dissipated) and sulfur dioxide (SO2) (mostly collected, transformed and sold) and slag (discarded or sold) — are among the significant process outputs. This article reports estimates of the flows of these input/output materials for a particular set of smelters studied in some countries. They include Chile (Altonorte, Caletones, Chagres, Chuquicamata, LasVentanas and Potrerillos), Japan(Naoshima, Onahama, Saganoseki,Tamano and Toyo), the United States(Garfield — Fig. 1 — Miami and Hayden) and Europe (Glogow I, Glogow II, Huelva, Norddeutscheand Ronnskar).

Jan 1, 2005

By Christos Roumpos, Philip‑Mark Spanidis, Francis Pavloudakis

Coal mining operations are large-scale, long-term frameworks of high complexity. Mining organizations accumulate, develop, and leverage knowledge from diverse scientific and technological fields as a result of these operations. Both practical experience and existing literature indicate that knowledge management (KM) methods within the mining industry primarily target solving immediate technical challenges and operational requirements. However, they are not commonly regarded as strategic tools to enhance the performance and competitiveness of mining companies. Empirical evidence from the Greek mining industry suggests that the management of available knowledge is intricate, less effective, and dysfunctional. This paper presents a methodology based on the principles of quantitative research (QNR), collaboratively conducted with a group of mining experts, to assess the KM landscape in the Greek mining industry. The methodology involves a structured data collection framework using questionnaires, subsequent statistical analysis, a discussion on critical methodological aspects, and an interpretation of results focusing on key aspects useful for planners and designers of KM systems in the mining industry. Finally, the paper concludes by summarizing the methodology’s outcomes and proposing further perspectives for research.

Mar 16, 2024

By Steve Kral

Invensys is a London-based supplier of automation and control systems to a variety of manufacturing and processing industries. Through its global subsidiaries, Invensys provides customized, advanced process control systems and networks for automating industrial plants, including mineral processing plants. The company employs more than 80,000 people worldwide in its four divisions. They include Automation, Control, Powerware and Software Systems. These four divisions work together to design the complete package for their customer’s automation and process-control needs.

Jan 1, 2002

Using a series-model of an automotive short range radar sensor (SRR) and a recently completed experimental radar system, field tests have been performed in a surface mine. It was examined, to what extent low-cost electronically scanning radar sensors can provide useful data for assistance systems on large scale mining machines. Simple sensors are useful for anti-collision safety zones or hopper car automation. The more complex and sophisticated experimental radar system using digital beam-forming can clearly detect and map the contours of trenches and slopes. The overall promising results refer to many more potential applications for electronically scanning radar in surface and underground mining as a reliable alternative to mechanical laser scanners.

Jan 1, 2007

By R. W. Carn, D. Vincent

Environmental Considerations With significant increases in bulk coal movements through terminals, operators are under constant social and political pressure to reduce or remove environmental pollution problems incidental to their operations. To meet these requirements, both equipment manufacturers and terminal designers are endeavoring to design equipment and systems with stringent environmental controls. The most challenging environmental problems facing coal terminal designers and developers are terminal siting restrictions, dust control, and noise abatement. Terminal Siting Finding a suitable site can be a difficult problem because of public concern over coal dust or the impact of a terminal on the surrounding community or natural habitat of the area. Often the only suitable flat land available for terminal development is on a tidal estuary or salt water marsh with great environmental value. In many cases a period of four to six years of full environmental and social assessment has been needed. A recent example of such difficulties is the expansion at Roberts Bank, British Columbia, where environmental impact assessment studies and their public review took almost six years from initial expansion applications until the time of approval. Dust Control Modern coal terminal dust control techniques usually consist of water sprays at strategic locations to suppress dust. The application points include rail car or barge dumper, main conveyor transfers, perimeter sprays around stockpiles, stacker/reclaimer, ship-loader transfers, and loading spout. The water sprays may include a chemical wetting agent or surfactant to reduce the water requirement and increase effectiveness. Recently there have been advances with development of effective micro foam agglomerating agents. In these systems, a micro foam with very small bubble sizes is sprayed into the coal stream. The foam fills the interstices between coal particles and wets the coal fines. These systems have proven to be very effective and usually one application before stockpiling and one upon reclaiming will markedly reduce the coal dusting. Stockpile perimeter sprays can be operated either manually or at the sophisticated terminal, actuated by a computerized control system that senses key environmental conditions such as humidity, precipitation, and wind velocity. Most modern terminals collect the drainage from the stockpile area, remove the solids in settling basins, then recirculate the water to reduce water requirements and effluents from the site. Dusting of long-term storage stockpiles can be reduced by spraying the piles with chemical resin or latex binding compounds to seal the surface. These compounds also can minimize erosion of the pile by rainfall. Dust collection with air evacuation systems and cyclone or wet scrubbers can be used at key areas such as rail car dumpers, main conveyor transfers, and ship-loader spouts. The trend in dust control is away from dust collection since most dust collectors are high maintenance items requiring good operator supervision and servicing. Coal handling conveyors are usually open and uncovered. However, in areas requiring special attention they may be covered or even completely enclosed. Dust generation from terminal roads is often a significant amount of the total dust emitted from a terminal. To reduce this dusting, roadways where traffic is heavy can be paved or sprayed by water trucks. Speed limits can be enforced and use of tracked mobile equipment for stockpile handling rather than rubber-tired loaders is encouraged by authorities. Noise Abatement Terminals located close to residential areas are often faced with noise control problems. Noise can be one of the most difficult environmental problems to solve. Usually, use of electrically-powered equipment is encouraged to reduce noise levels. Rail car dumper houses can be totally enclosed to reduce both dust and noise emissions. Diesel locomotives can be fitted with special muffling devices. Green belts of trees surrounding a terminal or the ap-

Jan 7, 1983

By M. J. Farrell

Mining is a significant emitter of greenhouse gases and is the focus of increasing attention from green groups and regulators. Miners need to know their own carbon emissions and how they compare with the rest of the industry. Miners and mining companies need to know where they fit in the emissions curve. Who is in the bottom quartile? This article is based on research report data from minecost.com and Metalytics Pty Ltd which detail the specific carbon dioxide emissions for 208mines producing 90% or more of western world copper, zinc, lead and nickel in 2007. The copper and nickel mines also include Norilsk in Russia, KGHM in Poland and Kazakhmys in Kazakhstan. This is the first time that such information has become available.

Jan 1, 2009

By Luzheng Chen

Pulsating high-gradient magnetic separation (PHGMS) of fine hematite from tailings was studied using a pilot PHGMS separator to investigate the possibility of its application in industry. The results of this investigation indicate that PHGMS is effective for recovering fine hematite from the tailings and greatly improved the separation performance compared with the conventional high-gradient magnetic separation at the same conditions. By applying the pilot separator with a 1-mm rod matrix to a tailings containing 28.76% Fe, a concentrate assaying 54.35% Fe with 35.89% recovery was achieved. It was found that the separation performance of the pilot separator closely correlates with the main pulsating parameters, i.e., pulsating stroke and frequency. It was also found that a change in the wire diameter of the rod matrix from 2 to 1 mm causes a weak drop in concentrate grade but results in a considerable rise in recovery. This finding proves that the improved performance achieved by the pilot separator is attributed to the pulsating of slurry and to the use of a 1-mm rod matrix. When the first commercial SLon-2500 PHGMS separator with a 1-mm rod matrix was applied to recover fine hematite from the tailings, the results duplicated those achieved with the pilot PHGMS separator.

Jan 1, 2009

By James L. Weeks

Introduction This paper attempts to summarize some of the major criticisms of drug testing. Eight problems with drug testing are discussed. These are: • It does not measure something employers have a reasonable need to know, • It is a distortion of priorities, • Drug use is not known to be associated with increased risk of occupational injuries, • Drug testing is proposed as a dangerously simplistic solution to poorly conceived problems, • In the absence of safeguards, it is unacceptably inaccurate, • In the absence of treatment commitments and confidentiality protection for persons dependent on drugs, it is an unethical practice of medicine, • Drug testing is an invasion of privacy, and • It will have a negative effect on treatment of persons with drug or alcohol dependencies. Employers' need to know It does not measure something employers have a reasonable need to know. It is reasonable for employers and fellow workers to want to know if workers are functionally impaired (intoxicated) while on the job. Drug testing does not measure impairment. It measures the concentration of drug metabolities in urine or blood. Unlike measurements of blood alcohol concentration (BAC), drug metabolites are not correlated with impairment or intoxication. They indicate only drug use in the one to two weeks before a urine sample. And, in some instances, they indicate chronic use. Impairment caused by drug use, on the other hand, occurs immediately and declines rapidly within hours. Drug metabolites may linger for days afterwards. Drug metabolite concentrations in urine are a function of (Morgan, 1984; Schartz and Hawks, 1985; MMWR, 1983): • the amount and purity of drug consumed before taking the test, • when the drug was consumed, • whether the person was a chronic user, in which case a certain amount of drug metabolites would be stored in body fat and slowly released, • the person's metabolic rate, and • for metabolites in urine, any dilution effects of urine. Only the first two factors has

Jan 11, 1987

By A. Yazadni-Chamzini

Maintenance strategy selection plays a significant role in mining design. The nature of maintenance strategy selection is a complex multi-criteria decision making (MCDM) problem including both tangible and intangible parameters which are often in conflicting with each other. Moreover, when decision makers are uncertain in determining and defining the ratings and the weights of alternatives and criteria respectively, fuzzy theory provides an appropriate tool to handle the existing uncertainties. In this paper, a new fuzzy MCDM method based on the concepts of TOPSIS and AHP was proposed to evaluate the feasible maintenance strategy. The linguistic terms are employed to assess the ratings and weights. Fuzzy AHP is utilized to calculate the weights of the evaluation criteria; then, the rankings of alternatives are computed based on fuzzy sets theory and TOPSIS. A real world case study is presented to illustrate a potential application of the proposed model.

Jan 1, 2012