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By R. H. King

The Deserado Mine of Western Fuels- Utah Inc. installed a micro-computer based mine wide monitoring and control system for mine environment, beltway fire protection, belt operating parameters, and equipment power utilization. The Colorado School of Mines was funded by the U.S. Bureau of Mines to document, evaluate, and report on the system design, procurement, installation, tests, and operation. This paper results from that project. The paper compares planned activities such as installation and start up, procurement contract specifications and system layout with actual performance to develop recommendations for future installations by mine operators.

Jan 1, 1987

By M. R. Rosen

CARBINDER Polymer 498 is a liquid organic taconite binder which significantly improves fired compression in both fluxed and acid pellets. It has been used commercially in both shaft and straight grate furnaces. This new binder produces an unusual wicking phenomenon during balling wherein the rate of movement of interstitial water is accelerated to the surface of the balls. The phenomenon is proposed to be responsible for the significant improvement seen in fired compression. This paper presents information as to the effect of CARBINDER Polymer 498 on green ball and fired pellet properties. It also describes the wicking phenomenon and discusses a reversal in the normal balling operation procedures required for successful agglomeration.

Jan 1, 1988

By Roy M. Fleming

During the decade of the 1970's, a new emphasis was placed on assuring a safe and healthful workplace for all American workers. Much of the basis for this national effort was federal legislation: the Occupational Safety and Health Act of 1970 and the Federal Mine Safety and Health Act of 1977 (amended from the 1969 Coal Mine Act). One of the agencies involved in this protection effort is the National Institute for Occupational Safety and Health (NIOSH) of the Centers for Disease Control (CDC) in the Department of Health and Human Services (DHHS). In fulfilling its mandates under the 1970 and 1977 Acts, NIOSH conducts research, experiments, and demonstrations to support and stimulate advancements in health and safety practices. Priorities for NIOSH research are established primarily through congressional mandates, requests from the Department of Labor, needs as defined by NIOSH researchers, and surveillance information. Emphasis is placed on research in the areas of toxicology, industrial hygiene, physical and chemical sciences, physiology, ergonomics, engineering, psychology (behavior and motivation), and epidemiology (industry-wide studies). The framework of the current Institute program to identify, evaluate, and control occupational hazards includes activities in surveillance, research, evaluation, and training. These activities are planned and evaluated through a system that coordinates the efforts of eight research and scientific divisions. Each division develops projects to address program areas that have been identified by NIOSH management as having highest priority. In surveillance programs, the objectives are to identify substances and agents found in a representative sample of workplaces and to collect and evaluate information on rates of disease and injury in occupational groups. Information is also collected on occupational safety and health programs implemented by industry. Estimates of worker exposures and the potential for adverse health effects are considered in setting priorities for further investigations. A related activity, which also serves to provide technical assistance to industry, is NIOSH's Health Hazard Evaluation program. On-site investigations of workplaces are made in response to worker, employer, or government agency requests. Both industrial hygiene and medical examinations are conducted, and the results contribute to identifying new problems and evaluating their significance which may have public health implications beyond the particular worksites that are investigated. Field and laboratory research projects are performed to meet several objectives: - Characterize the working environment by evaluating current and past exposure levels for workers who are included in epidemiological or medical investigations. - Develop epidemiological information to define the association between the substance or agent under investigation and the acute and chronic health effects on workers. - Determine through animal studies the parameters of an association between exposure and effect. - Investigate the etiology of disease. - Develop sampling and analytical instruments and techniques and demonstrate their application for measuring toxic materials in the workplace. - Formulate sampling strategies that will accurately and precisely indicate exposure levels. - Develop medical procedures to prevent disease and to detect the presence of disease and early indicators of disease. - Assess the technology for control of exposures, including engineering and administrative techniques, personal protective equipment, and work practices. Presently, the research program is focused on reproductive effects, neurotoxic effects, injury/trauma, lung disorders, cutaneous disorders, cardiovascular disorders, cancer, stress-related disorders, effects of physical agents, digestive disorders, and renal and other organic disorders. In studying these issues, priorities are determined by the seriousness of possible adverse health effects resulting from occupational exposures, the feasibility of studying existing records or obtaining new data, and the size of the population which is potentially affected. Where there is low level of suspicion concerning adverse health effects or where an occupational disease occurs in a variety of industrial environments, investigations are limited to gross analyses of health effects such as review of mortality patterns. In such studies, the industrial populations selected are those for which existing data resources can be utilized. Such data consists of records of occupational exposures or health status which have been maintained by the employer, the union, or Government agencies. Where a review of the available information suggests that serious health hazards exist and the existing data resources are inadequate for quantifying the relationship between the specific biological response and type and degree of exposure, prospective studies are initiated. Information derived from such research is essential for the development of sound criteria for control of industrial exposures to noxious agents. Other input to the criteria documentation process comes from searching and evaluating the literature. Criteria documents contain the recommendation of an environmental limit where information is available to support it, as well as the recommendation of work practice controls, medical evaluation, information for workers to recognize and avoid the hazard, and identification of specific research gaps. In some cases, during the criteria document preparation, gaps in knowledge are found which necessitate further research before an occupational standard can be recommended.

Jan 1, 1981

By F. Mauviel, J. Bernard, G. Herrouin, J. P. Lenoble, C. Charles, B. Taine

Manganese nodule projects were quite fashionable during the 1970s. At the beginning of the 1980s, low metal prices led to an almost complete reduction of such activities; however, the Law of the Sea incited the countries that signed it to build a strategy for this ocean resource. Gemonod was created in France in 1984 with a four-year mission. This paper presents the results of its program devoted to the technical and economic studies of nodule exploitation. A commercial mining system is presented. The nodules would be collected by a self-propelled miner and lifted hydraulically through a rigid pipestring. A complete optimized scenario has been built taking into account offshore mining, ore transfer at sea, transportation and processing to analyze the profitability of the project. Considering an average conservative basis for metal prices, after a deep analysis of the market, the return rate of investment of the project appears fairly interesting. These results are new and are explained in comparison with previous foreign studies. These results must not hide the innovative nature of the project nor the associated risks. This is why a mining pilot is required and has been specified by Gemonod.

Jan 1, 1991

By J. P. De Carvalho, R. Dimitrakopoulos

An actor-critic reinforcement learning approach is presented to improve the production of an industrial mining complex by defining shovel allocation and adapting the short-term plan given grade-control decisions. Blasthole data updates the simulated orebody models, which are input into a stochastic grade-control method based on a spatially constrained clustering approach that minimizes the profit-loss function. These aspects are embedded in a discrete-event simulator that defines the material flow from faces to processors. A case study at a copper mining complex shows the methods’ ability to adapt to new information, improving the quality of the material feed and increasing cash flow by 23% compared to a baseline case.

Jun 25, 2023

By Alexandra P. Wright

A vital aspect of environmental impact assessment for surface mining operations is the determination of potential effects on water resources. This topic has been the subject of much recent concern, controversy and legislation. As increasing data become available regarding the types of hydrologic effects that may be anticipated, methods for safe guarding our water resources can be refined. In view of our current energy situation, the need to develop coal re- sources in a timely and economic manner is apparent. The challenge to the mining industry is to develop these resources in a manner that is also compatible with the beneficial use of water resources in mining regions. For this reason, thorough evaluation of the hydrology of potential mining areas in consideration of proposed mining processes and relevant legal criteria is essential. While pre-mining hydrologic investigations often suggest generalized potential effects, a more reliable method for evaluating specific potential effects is to establish and maintain a hydrologic monitoring program. Such a program must be carefully designed to suit the specific project and its location. This paper describes an approach for selection of criteria for designing a monitoring program for a proposed coal surface mining operation and gasification plant in southwest North Dakota. Woodward-Clyde Consultants (WCC), recently prepared an environ- mental impact report for the ANG Coal Gasification Company (ANG), a subsidiary of the American Natural Gas Company. The mining will be carried out by The North American Coal Corporation (NACCO). Preparation of the report provided the opportunity for the development of a sensitive and economical monitoring program which would function as a baseline hydrological data gathering network as well as act an an early detection system for hydrologic effects of the proposed mining.

Jan 1, 1975

By Monica Pavlik, Thomas Wildeman

Water from the Forest Queen mine adit near Silverton, Colorado drains into a natural wetland. Because the pH of the water averages 5 and the iron concentration averages 18 mg/L, it was thought that the wetland might naturally treat the water. Of most concern with respect to the aquatic environment is zinc whose concentration averages 0.60 mg/L. Starting in October 1997, the surface waters, ground waters in the peat substrate, and the sediments in the wetland were sampled and analyzed four times over the course of four months. The adit water primarily remains as surface water where Fe, minor amounts of Al, and no Zn are removed. After the adit water enters the peat, then it is found that the pH rises to 5.8-6.5 and sulfate is reduced. The removal of Zn and A1 is caused by these two changes. However, Fe in its reduced state is quite soluble and may be remobilized in the reduced environment of the peat.

Jan 1, 2000

By Jozef Descour, Kazunori Nishioka, David M. Neil

Designers, engineers, and contractors are using three-dimensional seismic tomography for geotechnical site investigations and during tunnel excavation for hard rock and soft ground applications. Utilizing multiple types of seismic signals produced by a TBM, drill, or impact breaker, the reflection of different velocity features are processed into a holographic image of the actual structure to be encountered. The Mill Creek Phase 3 alignment in Cleveland, Ohio, was imaged to define existing conditions along a 1,200-ft section of a proposed 6.1-m (20-ft) diameter CSO tunnel and, specifically, a zone of expected anomalous conditions where drilling was inconclusive. In Japan, Kajima Corporation used TRT™ to image a number of tunnels including the Fujikawa and Kanaya tunnels in a combination of methods to map structural features along the alignment.

Jan 1, 2001

By Peter H. Grimley

It is important to realize that lending institutions have a very different risk-profile from that of an equity investor. For bank financing, a feasibility study must address the concerns of the lender and these can be summarized under the four 'PI Is: Project, Performance, Product and People. Generally, feasibility studies focus on the measurable project risks associated with a new venture, but frequently insufficient emphasis is placed on key risk areas such as ore grade and metallurgical recovery. Before accepting full or even partial non-recourse risk, financial institutions will demand evidence that the project was constructed according to specifications and within budget and that its Performance within agreed limits has been demonstrated. Product risk should be discussed in detail in any feasibility study. For industrial minerals, penetration of the market can be critical to success and for commodities with volatile prices, the sensitivity of the cash flow to a range of prices should be carried out. Methods of reducing price risk such as long term contracts or, in the case of gold, forward selling should be carefully evaluated. The People risk is rarely discussed in feasibility studies, but can be a key element. Few projects turn out to be faithful copies of the study and the ability of the operator to identify

Jan 1, 1988

By Donald M. Keagy

How many times have you said or heard someone say, 'What are you doing right now?" And how many times have you heard the reply, "Breathing air!" Probably never, or at most only a few times in a facetious vein. Breathing air is absolutely necessary to sustain human life, and yet most of us take it completely for granted. Beginning ten to fifteen years ago there was growing concern on the part of the general public that pollution of the air is a threat to man's health and welfare. Concurrently much thought and effort was devoted to the task of defining and resolving the problem of air pollution. In the course of this effort it has become quite clear that our National policy in this regard should be founded upon three basic axioms: (1) Action should not be postponed until emergency conditions make it compulsory; (2) The air cannot be purified after it is polluted, and (3) Air pollution control cannot be accomplished without close cooperation among all levels of government, industry, and the public.

Jan 1, 1967

By George E. Peacock

Campbell Red Lake Mine is situated at Balmertown, in the Red Lake District of Northwestern Ontario, Canada. This area is some 120 miles north of the Trans Canada Highway and is some 160 miles Northeast of Winnipeg, Manitoba. The majority of our 300 employees live in Balmertown, which is a community of some 1,200 people, situated adjacent to the mine proper. The mine is serviced by a single shaft 4,300 feet deep. There are 27 levels at 150 ft. intervals. Stoping is being carried out down to the 20th level with only preliminary development having been done on the bottom 6 levels. The majority of our mill feed of 825 tons per calendar day comes from above the 10th level. Gold occurs as specks and streaks in bluish-grey to white quartz carbonate veins. It is extremely fine grained and most is invisible to the unaided eye. In addition to Gold the veins carry varying amounts of sulphides such as, Arsenopyrite, Stibnite, Pyrite, Pyrrhotite and Sphalerite. A minor amount of silver occurs as an impurity in the gold. Arsenopyrite is a marker for the gold ore at Campbell. The average grade of the mill feed is 0.7 oz. of gold per ton. The ore is dumped into an underground ore pass that feeds to a jaw crusher on the 20th level that reduces the rock to a maximum size of 4". This material is hoisted by skips to an ore bin in the head frame.

Jan 1, 1975

By Bernard J. Scheiner, R. J. Wesely, Cy E. Jordan, A. D. Zunkel, Gary M. Wilemon

The U.S. Bureau of Mines has investigated leaching of off-grade western United States phosphate deposits using sulfuric acid (H2SO4) in the presence of methanol. A combination of ore grinding followed by sulfuric acid in methanol leaching extracted over 80 pct of the phosphate. This leaching technique significantly limited the dissolution of iron, aluminum, and magnesium impurities and produced a phosphoric acid that was well within the desired limits for these impurities. The dissolution rate of phosphate rock in the sulfuric acid methanol system was significantly slower than the conventional aqueous sulfuric acid dissolution. Initially dissolution of the phosphate particle was controlled by the amount of surface area available to the sulfuric acid reactant. After about an hour of leaching, phosphate dissolution was slowed almost to a stop, limited by the rate of ion diffusion through the calcium sulfate barrier layer surrounding the unreacted phosphate particle. Consequently, the ore was ground below 38-pm to increase the particle surface area available and improve the overall dissolution kinetics and extraction. In addition, the sulfuric acid was slowly metered into the reactor to prevent any excess heat from the mixing of acid with the methanol from simulating the formation of methyl sulfates. The formation of methyl sulfate ultimately lowered the overall phosphate extraction by exhausting the supply of available sulfate ions for the dissolution reaction. Subsequent evaporation of the methanol from the product acid decomposed the methyl sulfates leaving undesirable sulfate ions in the product acid. Slow acid addition to the reactor provided high phosphate extraction and limited the amount of sulfate in the final product acid.

Jan 1, 1993

By Rodrigo Estay Huidobro, Andrés Martinoli, Claudia Pavez-Orrego

The effects of induced seismicity caused by mining activities are one of the main problems that the mining industry faces. Although it has been documented by countries with a great mining tradition (United States, Canada, Australia and Chile) for over a century, the problem has been intensified throughout the years due to the greater depths that mineral extraction reaches, where the stress levels and environmental conditions increase the possibility of a rockburst occurrence. Seismic events inside the mine cause important losses of human lives and infrastructure damage. To deal with this problem it is necessary to implement several kinds of safety protocols. For example, seismic indicators allow to identify, through the analysis of a set of seismic parameters -magnitude, energy, time, decay rate, among others-, periods of time when a seismic event of considerable magnitude is most likely to occur. The objective of this work is to use the frictional energy generated by a microearthquake inside the mine as a seismic indicator, linking it with the occurrence of large magnitude seismic events which are outer the background activity. Thus, we seek to determine the set of seismic parameters which allow the best performance of the frictional energy/heat indicator. In the present study, we considered magnitude, frictional energy, and time as seismic parameters to study the efficiency of the proposed indicator. The optimal set of parameters was determined using two different methodologies: accumulated thermal energy and alert bands. The Piece Skill Score and the Accuracy indexes were used to evaluate each set of parameters. Both approaches show a high rate of true positive and true negative hits. Furthermore, it was concluded that both methods show complementary results in terms of the detection of critical events (Mw > 3.0).

Apr 26, 2022

By L. Yan, T. Lutz, J. Noll

"Mine disasters, such as fires and explosions, can create a hazardous atmosphere due to the generation of carbon monoxide (CO). After a mine disaster, contaminated mine air can enter the refuge alternative (RA) as miners enter. Most built-in-place (BIP) RAs use an air delivery system to provide an unlimited supply of breathable air through a borehole which also serves to purge contaminants. In order to determine what levels of contaminants enter the RA, researchers from the National Institute for Occupational Safety and Health (NIOSH) conducted testing in NIOSH’s Pittsburgh Experimental Mine using groups of 5, 15, and 30 subjects entering the RA. The experiment used sulfur hexafluoride (SF6) as a tracer gas that was released into the air outside of the BIP RA to establish a uniform concentration. After the human subjects entered the BIP RA, the SF6 levels inside the RA were measured to quantify how much of the tracer gas entered the BIP RA. In tests conducted while the borehole air supply was left off as test subjects entered, interior contaminant levels were less than 3% of the exterior concentration. In tests conducted with the borehole air supply activated as test subjects entered, the interior contaminant levels were measured at less than 2% of the exterior concentration. Considering a mine disaster can result in 10,000 ppm of CO in the mine atmosphere, these percentages indicate that unhealthy CO concentrations that may lead to headaches, dizziness, and loss of judgement can occur in a BIP RA. This information will help mines make decisions concerning air locks, air delivery systems and a determination if purging mechanisms are necessary. INTRODUCTION The Mine Improvement and New Emergency Response Act of 2006 (MINER Act) was enacted in the wake of three mine explosions/fires that claimed 19 lives that year. Intended to help improve underground coal mine accident preparedness, the MINER Act includes provisions that target mine safety issues in areas such as emergency response planning, adoption of new technology, training and education, and enforcement of mine safety standards (MSHA, 2006). Section 13 of the MINER Act specifically directs the National Institute for Occupational Safety and Health (NIOSH) to provide for research into the effectiveness and viability of RAs for underground coal mines. This mandate culminated in the 2009 adoption of changes to the 30 CFR mining health and safety regulations, requiring underground coal mines to provide RAs capable of maintaining a life-sustaining environment for persons trapped underground. Such RAs can be either pre-fabricated or BIP shelters. The regulatory changes also include provisions establishing requirements for Mine Safety and Health Administration (MSHA) approval of RAs and their components, and among these provisions are numerous criteria for providing a safe, breathable atmosphere within RAs."

Jan 1, 2018

By L. M. Turner

Perlite is a unique mineral that upon heating expands to about twenty times its original volume. Mining is by open pit method. The processing cycle involves crushing, screening and sizing the ore. An on-site quality control facility at the Manville Products No Agua mine exerts a high degree of control over every phase of the operation from blasting to finished product.

Jan 1, 1985

By J. Fuchs

This paper describes the mechanized narrow vein cut-and-fill approach used for the Deep Copper orebody at Falconbridge Limited's Strathcona Mine. Strategies for achieving high productivity while maintaining ground stability at depth and controlling dilution are discussed, including the use of mini-electrohydraulic drilling equipment, containerized truck haulage, consolidated rockfill placement techniques, and a miners' incentive system.

Jan 1, 1992

By Greg Beckstrom

Minnesota is a major mining state. This statement is not a dream or stretch goal but is a fact. As reported in a recent edition of Mining Engineering magazine, Minnesota ranks as the third largest state in terms revenues generated from nonfuels mineral production. The vibrancy of the mining sector in Minnesota can be attributed to several factors. The northeastern corner of the state is home to Minnesota?s iron range, one of North America?s largest deposits of iron ore. Iron ore from Minnesota is a strategic resource that has been [ ] instrumental to the nation?s development ? 90 percent of the iron used to build ships and planes during World War II came from Minnesota. Taconite pellets now produced from openpit mines on the iron range are shipped to steel mills worldwide. The growing appetite for steel in China and India has reignited once moribund mining operations throughout the iron range.

Jan 1, 2012

By V. Enns, E. Soprovich, J. H. G. Laflamme

A mineralogical and geochemical characterization study was carried out on arsenic-bearing Ketza mine tailings to complement a column extraction test program with the purpose of assessing the potential of arsenic mobilization from the tailings. Two types of tailings samples (i.e., exposed tailings from the impoundment area and water covered tailings samples) were subjected to column tests under standing water cover and with no water cover but weekly flow-through flushing. The tailings have a uniform size distribution. The samples are characterized by high Fe2O3 (44.0 to 68.2 %) and As (3.7 to 4.4w%) concentrations. Ferric hydroxides are the dominant species that are mostly amorphous or cryptocrystalline. Arsenopyrite, scorodite, an Fe-Ca arsenate hydrate phase, an Fe-Bi-As phase and ferric hydroxides are the arsenic-bearing minerals. Arsenic is essentially contained in Ca-As goethite, Fe-Ca arsenate hydrate phase and scorodite. Goethite, although containing low levels of arsenic, could be a significant arsenic-bearing phase because of its high abundance. There does not appear to be any significant chemical or mineralogical difference between the original exposed tailings and the material left underwater with no flow-through for over a year. There are differences in terms of CaO, Fe2O3, SiO,, As, goethite, scorodite, calcite and dolomite concentrations between the exposed tailings and the column material after undergoing approximately two-year flow-through and aggressive leach tests. These differences are likely to be resulting from a combination of different column test conditions and sampling or heterogeneity of the material.

Jan 1, 1998

By S. C. Termes

This paper discusses recent Federal Bureau of Mines research on the selective flocculation of various minerals with insoluble crosslinked starch xanthate (ISX). ISX is insoluble, has a shelf life of over a year when kept cold, and has a higher molecular weight due to cross linking than the soluble noncrosslinked starch xanthate used in previous flocculation studies on nonsulfide minerals. ISX readily flocculates a number of sulfide mineral fines but not silicious gangue. Floc formation, floc size, and settling rate are strongly dependent on pH, with the pH dependence differing for each mineral. Bornite has been selectively flocculated from bornite-quartz mixtures, and the bornite-containing flocs were separated from the unflocculated quartz using decantation and washing procedures.

Jan 1, 1982

One of the most challenging and ambitious dump rehabilitation projects in South Africa’s mining industry is being carried out at Greenside Colliery’s smoldering coal dump, which lies adjacent to the N 12 Johannesburg-Witbank highway. Greenside Colliery is the largest coal mine in the Gold Fields Group. It began operation in 1946, the year in which the burning dump had its origins. Today, Gold Fields plans to spend R16 million (about $USS8 million) to encapsulate the dump, bringing it into compliance with South Africa’s Mining Environmental Management Programme, according to Martin Hamer, engineering manager of the Greenside Colliery. The improved environmental management approach will result in reduced sulfur dioxide gas, smoke and dust emisson into the air and an enhanced aesthetic appearance of the dump from the N 12 highway. The objectives of the project are to place and compact coal discard to within the National Institute of Coal Research specifications in order to prevent spontaneous combustion, and to preserve as an asset the coal portion of the discard.

Jan 1, 1994