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By R. Strandahl

As one of the largest private utilities globally, E.ON currently operates hard coal fired power stations in with a total installed capacity of some 20.000 MW: These thermal power plants consume domestic coals but are increasingly dependent on imported seaborne traded coal (in 2009 approx. 17 million t). Knowing that the company’s reputation and credibility depends in part on how E.ON lives up to the responsibilities along the entire energy value chain, E.ON takes a collaborative approach with the various suppliers. Hence, E.ON’s responsible policy also applies to the procurement of coal; the utility launched in 2009 a comprehensive Corporate Responsibility program with special focus on supply-chain audits. One of the first coal audits focussed on the Cerrejón coal mine in North Eastern Colombia. The authors will share the key learning’s and experience from the Colombian audit jointly conducted with an independent auditor and E.ON experts from the Corporate CR and E.ON Energy Trading.

Jan 1, 2011

By M. Javier

"The impact of mine closure is perceived through a veil of compliance to human laws and regulations rather than the laws and equilibrium of nature. This perception motivates present research. Understanding the causes and effects of mine closure defines levels of responsibility. This understanding evolves from mine closure's legacy. Mine closure is characterized in perpetuity by three aspects: Future liabilities; level of technologies for extraction and, usage of mineral resources. These aspects must be updated to a rationally appropriate level. This paper will address the following questions: Will the minerals remaining in the process of mine closure ever be recovered? Will the mine closure inhibit the availability of minerals for the next generation? How many mines are designed to perform a successful mine closure? Do we close the mines or do we close nature? Is it responsible to continue mine closures as we do them today? Is mine closure a complement of mine operations or a contradiction of mining? Do we need to perform mine closures, yet? This paper reviews mine closure practices and principles with the level of responsibility to nature and for the next generation.PREFACE The planet has irreversible issues to deal with regarding the depletion of mineral resources and contamination occurring from human activities. The population increased exponentially to more than seven billion, this high population with its lifestyles, demands a higher supply of minerals. In spite of these conditions, mining is a vital industry to keep ""civilization"" in society. This is evidenced by what we see around us, in that everything ""made"" in society is directly or indirectly due to mining. Hence, mining cannot be avoided or ignored. Society misunderstands the importance of mining in relation to other activities. At this time, mining is fragmented and economically oriented to supply cheap minerals to a market with peculiar characteristics regarding products that could be designed for recycling and stimulate nature’s equilibrium. These issues add important “variable factors” to the equation, when they are considered as parameters for the next generation. It also raises many questions regarding principles and attitudes about morals and ethics exercised in all anthropogenic activities. The industry's practices have many flourishing paradigms which are subject to a variety of criticisms and observations. Some of these observations will be described in this paper. It is important to clarify in advance a ""normal disclaimer"" about the ""apparent contradiction"" that could take place in the writer's comprehension when we abruptly ""jump to conclusions"". We must remember that we are profiling the future in an arena that demands a better understanding of solutions to problems created by actual mining."

Jan 1, 2015

By William Paul Robinson

I would like to first summarize the relevant health information relating to the workers and general populations around uranium mining as a basis for understanding the hazards associated with these operations and their available remedies. This discussion will summarize the literature on Radon and its daughters, among the most toxic uranium decay products. Second, I will discuss waste handling in the uranium industry: past, present and future, discussing exploration, mining, and milling and the volumes of water and solid and gaseous wastes which are associated with these various phases of uranium operations. This paper will also include a discussion of the various past and present materials handling technologies and their responsiveness to the concern for uranium waste isolation. I will then conclude with a summary of recent modifications in the relevant standards as applied to uranium mining and milling. Joseph Wagoner, a research epidemiologist with the U.S. Public Health Service has summarized the literature on uranium mining and its health effects in his written testimony as a commissioned witness in British Columbia Royal Commission of Inquiry into Uranium Mining in January of 1980, entitled Uranium, The U.S. Experience: A Lesson in History.1 Briefly summarizinq his report, as early as 1546, miners of uranium bearing ores in Central Europe were reported to have unusually hiqh frequencies of fatal lung disease2. As early as 1879, the real nature of pulmonary disorders among these miners was first diagnosed to be malignant neoplasia or lung cancers. Of 655 miners dying between 1875 and 1912, 40% or 276 of these Central Europe miners died of lung cancer.4 By 1939, it was reported that lung cancer mortality rate for miners in these Central European mining districts was several times (9.7 per 1000) higher than that for similar populations in Vienna, Austria (0.34 per 1000). Thus, before uranium mining began in the U.S., there was a considerable body of information linking uranium mining to lung cancers. The U.S. experience can be summarized in Table 1 also from Wagoner's B.C. Testimony.1 This table shows that through 1978, 205 respiratory cancer deaths have been observed among white underground uranium miners in the

Jan 1, 1980

By A. Habibi

A study has been undertaken on two 1.12 m diameter industrial booster fans operating under different blade settings powered by a 1200 rpm motor at the Missouri University of Science and Technology. The fans total pressure varies up to 1kPa forcingup to 25 m3/s through the workings. A pressure-quantity survey has been conducted inby and outby the booster fans with different blade settings. The study uses a variable speed drive (VFD) to determine the effect of rotational frequency on the system. The pressure drop across the bulkheads has been monitored during the experiments. The fans were operated with various blade settings to determine the optimal scenario that maintains the maximum airflow quantity and the lowest power demand at a particular ventilation station. Five scenarios were conducted with different blade setting and mostly with two different speeds. The experimental results show that alteration of fans? speeds by use of a VFD unit can reduce power consumption while maintaining airflow requirements. With the flow rate forced through the mine by the surface fan the blade settings 4 and 5 were determined as possible alternative for the mine ventilation system. In scenario 4, the airflow at the particular ventilation station for a number of speeds is over 20m3/s. The power consumption at 1080 rpm was measured to be 20.1 kW compared to 25.5 kW at 1200 rpm. The operating cost would be significantly less at lower speeds. Scenario 5 is the alternative making use of both booster fans and the main fan in series that meets the minimum airflow requirement at the particular ventilation station along with minimum power consumption. Reducing both booster fans speeds to 1054 rpm results in power consumption of both together dropping to 11.8 kW. Therefore blade setting 5 using two booster fans was determined to be the optimal setting. Separately it was determined that the combination with use of only one booster fan, the West booster fan, running in series with the main fan is the overall optimal scenario. The power consumption of the West booster fan was calculated to be 8.8 kW at 860 rpm with the minimum airflow requirement being met. Computational fluid dynamics is used for analyzing three dimensional flow structures in time domain and calculating the corresponding unsteady pressure fluctuations. The sliding and dynamic mesh techniques were used to study the unsteady flow interaction arising due to the rotation of the fan blades. The numerical predictions of the variables in the form of velocity vectors and contour plots detailing the flow characteristics are then analyzed according to the known physical situation and existing experimental data.

Feb 27, 2013

By D. Symonds, A. J. Richins, M. G. Nelson

Mining activities at Kennecott and Park City are similar in that both districts began operation in the last half of the 18th century, and both operated on a large scale for many years. However, they are different for two important reasons. First, the mines in the Park City district were always underground. The city of Park City was above many of those mine workings. It remained in place after mining activity stopped, and as the town became an up-scale ski resort, property values increased and the tailings dumps became desirable building sites. In contrast, Kennecott eventually became an open pit mine, and the growing pit effectively consumed many of the small towns that had grown up around the underground workings. Even towns on the periphery of the open pit were razed to allow for the disposal of mine overburden. Second, almost all mining activity stopped in Park City in the early 1970s, just as the first rigorous environmental legislation in the United States was enacted. (The Ontario mine operated sporadically until 1982.) Many mine structures, waste dumps, tailings ponds and piles, and tunnels were simply abandoned as the mining companies ceased business or were bought out. Kennecott, on the other hand, has been in continuous operation for more than 120 years, so a closure plan hasn’t been finalized. Nonetheless, environmental and social problems have arisen, and the company has had to address them.

Mar 2, 2022

By A. Kyriazopoulos

Quarrying is an important activity as it significantly contributes to the economy of a country. This activity presupposes the destruction of the natural vegetation, the removal of the surface soil and deposition of inactive materials. The lack of fertile soil in these disturbed areas is usually a problem for the plant cover establishment. The purpose of this study was to investigate the potential of the establishment of ten herbaceous plant species to inactive quarries with the use of limited amount of fertile soil. The research was conducted in the area of the quarries of the cement manufacture company ?TITAN?, Thessaloniki, Greece. On a terrace of one of the quarries, a 2 cm layer of fertile soil was placed. In early October 2007, the herbaceous species, Lolium rigidum, Festuca arundinacea, Bromus inermis, Agropyrum desertorum, Phalaris aquatica, Dactylis glomerata, Medicago sativa, Medicago lupulina, Sanguisorba minor and Phacelia tanacetifolia, were seeded separately. The first results indicated that among the tested species Dactylis glomerata, Festuca arundinacea and Phacelia tanacetifolia had the highest establishment capability.

Jan 1, 2008

By F. D. Fox

Abandoned mill tailings deposits can be found scattered throughout the Northern Black Hills of South Dakota, indicative of past mining activities that originated during the great gold [ERRATA SHEET RESTORATION OF GOLD MILL TAILINGS, BLACK HILL, SOUTH DAKOTA 84-119 F. D. Fox Under subtitle Prospects Related to Present and Future Tailings Disposal Practices, include reference No. 12 in paragraph seven after "construction of the Grizzly Gulch tailings disposal project,"12 Reference 12 should read: Jeffries, Lawrence F. and Tczap, Andrew, "Homestake's Grizzly Gulch Tailings Disposal Project," paper presented at 1978 International Mining Show, October 11, 1978.]

Jan 1, 1984

By C. Tsatsanifos

Following closure of an old asbestos mine in Zidani, Kozani Prefecture, Greece, the geotechnical and environmental restoration of the tailings slopes was required. The geotechnical aspects of the restoration included the formation of gentler slopes to increase stability, in combination with drainage works for the same purpose. The environmental aspects of the restoration included covering the slopes with successive layers of soil in order to minimize infiltration of rainwater, and hence the potential for further transport of asbestos fibers, and to provide a suitable layer for revegetation of the slope. The paper presents results of slope stability evaluation using both limit equilibrium and finite element analyses and raises some issues related to reducing impacts to the geoenvironment when designing such restoration projects.

Jan 1, 2006

By C. Menidiatis

The first cement plant of TITAN Cement Co was founded in Elefsis in 1902. It was the first cement industrial facility to operate in the Balkans and in the Eastern Mediterranean region. Currently have four cement plants in Greece producing 5.4 million tons per annum, and 25 ready-mixed concrete sites producing 1.4 million m3 annually. It has a total of 20 quarries, 14 of which are producing materials used in the making of cement while the remaining six produce aggregates used in the production of ready-mixed concrete. All plants in Greece are accredited for ISO 14001. The restoration of quarries began in 1976 at the company?s limestone quarry of the Patras plant, and was soon extended to all quarries. At that time, a department responsible for all environmental issues was established. To date, over 700.000 shrubs and trees have been planted and maintained at quarries, plants and ready-mixed concrete facilities, while over 100,000 trees have been donated to municipalities, communities, customers and to the Greek state.

Jan 1, 2002

By J. `. Spitzinger

In situ recovery (ISR) of uranium alters the baseline groundwater geochemistry in order to mobilize and complex uranium to extract and concentrate it. ISR wellfield restoration is often challenging, and primarily relies on groundwater sweep, reinjection of treated permeate, and/or injection of reductants. Greater focus should be placed on injection-based approaches (using existing infrastructure) based on established engineering concepts used for in situ remediation of groundwater plumes. Such injection-based approaches could shorten restoration timeframes consequently reducing long-term operational costs. This paper addresses various types of injection-based approaches to wellfield restoration based on in-situ remediation success with other constituents that require similar treatment. This paper describes necessary design practices for injecting reactive chemicals (e.g., reductants or biostimulants), operations and maintenance (O&M) strategies to prevent fouling of the chemical delivery system and well network, and natural constraints to restoration. Best practices for successful biostimulation strategies that minimize residual uranium, radium, oxoanions, and other trace elements are as described. Advantages of such injection-based approaches could include significant reductions in restoration times, and consequently, lower restoration costs.

Feb 23, 2014

By James E. Gingrich

The new Track Etch* technique for uranium exploration has been utilized in several survey programs conducted during the last few years. The results from these programs have been very encouraging, and new uranium ore bodies have been discovered by using this new technique. The Track Etch method is being used in several exploration programs in various locations around the world. The Track Etch exploration technique utilizes small pieces of special radiation-sensitive plastic film to detect the presence of radon gas which is released by uranium ore bodies. Because of the selectivity and sensitivity of the technique, ore bodies not normally detected with other surface or airborne monitoring methods are found. Since no large equipment or special training of personnel is needed, the Track Etch technique is easily used in field operations. The basis for the Track Etch method, its application in field exploration programs, and the results obtained to date in locating uranium ore bodies is discussed.

Jan 1, 1974

By M. A. Trevits, G. L. Finfinger

Various methods have been developed through US Bureau of Mines research to remove gas in advance of, during, and subsequent to mining. These include drilling horizontal or cross-measure boreholes from a mine opening, and vertical boreholes stimulated for drainage in advance of mining or for gob gas drainage. Techniques and equipment now exist that allow drilling a borehole at any angle to the vertical, and even along an arc. Stimulation treatments have also been developed that provide for increased gas production capability. This paper describes the long-term production history of five select gas drainage installations. The Bureau of Mines conducted or participated in four studies. The remaining study was conducted by the Equitable Gas Co. Principles of storage, release, and migration of coal bed gases The amount of gas contained within any given area of a coalbed depends on the coal's inherent storage capacity and the physical conditions of the coalbed. The gas storage capacity of coal is primarily a function of rank. As such, it cannot be affected by the presence of drainage holes (Kim, 1977). Certain physical conditions of the coalbed can, however, be changed that will affect the release and migration of gas. By pumping water out of the coalbed through the vertical boreholes, two important changes occur - pressure is reduced and water saturation is lowered. Reducing reservoir pressure releases gas as the coalbed adjusts and equilibrates gas to the change. Increasingly large amounts of gas are released for each incremental decrease in pressure. Lowering the water saturation level raises the permeability of the coalbed to gas and allows the gas to more readily migrate to the wellbore (Kisse and Edwards, 1975). For horizontal boreholes completed near mine openings, the coalbed has already undergone a pressure or water saturation reduction phase. This condition thus allows such boreholes to be highly productive with minimal water production. Case studies of coalbed gas production Pittsburgh Coalbed - Marianna mine 58 A methane drainage study was begun in July 1978 at Bethlehem Mines Corp.'s Marianna mine 58, Marianna, PA (Fig. 1). The work was conducted in a section of the mine that was advanced 1.5 km

Jan 8, 1986

By Mark J. Schultz, William J. Francart, Michael P. Snyder

The Pittsburgh Safety and Health Technology Center surveyed MSHA Coal Mine Safety and Health Districts to monitor the implementation of computer based atmospheric monitoring systems (AMS) in underground coal mines. This survey was first completed in 1984, and has been periodically updated with the latest update completed in 1995. The utilization of computer based monitoring systems has steadily increased over the past 12 years, with over 16 percent of all producing underground coal mines using this technology in 1995. This paper discusses the results of the MSHA 1995 AMS Survey.

Jan 1, 1997

By Frederick B. Brien

For many years tin mining in Bolivia has been very important to the economy of the country. In recent years the tin content of the ore reserves has been steadily declining. An improvement in concentration efficiency is highly desirable in order to increase productivity from the present-low-grade mine ores and to allow retreatment of the many millions of tons of tailings from past operations, some of which equal the present ores in tin content. A number of investigators have been or at present are working on various phases or approaches to the problem. Gravity concentration is used in Bolivia today as it has been in the past to recover tin minerals from the mine ores. An objective of the work reported in this paper was to examine the possibility of treating present low-grade ores and sink-float tailings products, at a relatively coarse grind, in order to produce a higher grade feed material to the present gravity concentration plants. The possibility of using heavy liquids in cyclones to treat large tonnages with a minimum of outlay presented itself and is of particular interest since appropriate heavy liquids are available and with physical properties which lend themselves to simple recovery methods. Tests were carried out using a closed circuit laboratory cyclone assembly. It was desirable to determine the value of using the SG50 concept and Tromp curves for analyzing the cyclone concentration test results. The effects of entrained water on the behavior of ore particles in the cyclone were examined.

Jan 1, 1964

By CORA ROELOFS

In the USA, miners are at higher risk for work-related disorders that could precipitate an opioid prescription, injury-related opioid prescriptions, and opioid overdose. We aimed to support prevention of these outcomes with an “opioid hazard awareness” miner safety training module. In January and February 2020, the training module was embedded within required mining safety and health training for stone, sand, and gravel miners in Massachusetts (USA). Training impact and reception were assessed with a pre- and post-training survey of trainee characteristics, training content knowledge, and attitudes. Over 800 miners were trained and over 600 responded to surveys. We found statistically significant improvements in opioid risk factor knowledge and knowledge of resources to help a coworker. Nonstigmatizing attitudes were high both at baseline and following the training. The training was perceived as relevant and useful by trainees. Improving opioid hazard awareness in high-risk worker populations has potential to reduce opioid dependence and downstream impacts including overdose death. Employer injury-prevention efforts should be reinforced while worker health and safety training enhances awareness of opioid-related harms and prevention strategies for miners and other high-risk worker populations.

Nov 19, 2021

By CORA ROELOFS

While the COVID-19 pandemic has dominated the headlines, another epidemic in the United States has continued apace — the opioid epidemic. Half a million opioid overdose deaths have occurred in the United States since 1999, when the opioid epidemic began. The causes of the epidemic include the rise in prescriptions for opioid pain medications, including for work-related pain. Miners and other occupations identified as physically demanding and at higher injury risk have been found to be at increased risk for opioid overdose [1]. However, awareness of the risk factors that might lead to opioid use, the potential hazards associated with their use, and resources to prevent addiction and death can allow miners to make choices that can reduce these risks.

By S. R. Dindarloo

"Truck-shovel systems are the dominant material loading and haulage machinery in open pit mining operations. Optimal selection, sizing, and allocation of this capital intensive equipment is highly desirable for both achieving production targets and improving the mine’s economics. In this study, discrete event simulation technique was applied for modeling material transportation in Golegohar open pit iron ore mine in Iran. Direct observation of the material loading and haulage for duration of three months resulted in statistical modeling of the operation in the form of probability distribution functions. These probability models were used as the inputs of a stochastic simulation model constructed in GPSS/H simulation language. The model was validated through comparison with the actual operation and was used to test different what-if scenarios and sensitivity analysis of the current system. Some modifications in the number of trucks, shovels, and dispatching strategies were proposed. Simulation resulted in considerable improvements in the mine’s production and economics.INTRODUCTION There are three different mechanisms of discrete, continues, and hybrid material transportation in open mines, including but not limited to: i) in-pit crusher and conveyor belts (hybrid), ii) slurry piping (continues) and iii) truck-shovel system (discrete). Although, each mechanism has its advantages, the truck-shovel system is the dominant method of material loading and handling in open pit mines owing to its high production rate, excellent flexibility, relatively low operating and capital costs, and good maintainability. General objectives of optimal equipment selection include: i) meeting the long and short term requirements of production rates, ii) human & equipment safety, iii) environmental protection, and iv) economic operations (Figure 1).The two most important decision factors on a truck-shovel system selection and sizing are the equipment geometry and size. Geometry (equipment width, weight, turning radius, swing angle, etc.) is mostly controlled by mine’s designs and layouts, as well, as operational constraints. After selection of a favorable geometry based on the constraints; the next step is to select the equipment manufacturer. Once the geometry and manufacturers are selected; the next step is to decide on models (e.g. Bucket size) and required number of each unit"

Jan 1, 2015

By S. R. Dindarloo

"Truck-shovel systems are the dominant material loading and haulage machinery in open pit mining operations. Optimal selection, sizing, and allocation of this capital intensive equipment is highly desirable for both achieving production targets and improving the mine’s economics. In this study, discrete event simulation technique was applied for modeling material transportation in Golegohar open pit iron ore mine in Iran. Direct observation of the material loading and haulage for duration of three months resulted in statistical modeling of the operation in the form of probability distribution functions. These probability models were used as the inputs of a stochastic simulation model constructed in GPSS/H simulation language. The model was validated through comparison with the actual operation and was used to test different what-if scenarios and sensitivity analysis of the current system. Some modifications in the number of trucks, shovels, and dispatching strategies were proposed. Simulation resulted in considerable improvements in the mine’s production and economics.INTRODUCTION There are three different mechanisms of discrete, continues, and hybrid material transportation in open mines, including but not limited to: i) in-pit crusher and conveyor belts (hybrid), ii) slurry piping (continues) and iii) truck-shovel system (discrete). Although, each mechanism has its advantages, the truck-shovel system is the dominant method of material loading and handling in open pit mines owing to its high production rate, excellent flexibility, relatively low operating and capital costs, and good maintainability. General objectives of optimal equipment selection include: i) meeting the long and short term requirements of production rates, ii) human & equipment safety, iii) environmental protection, and iv) economic operations (Figure 1).The two most important decision factors on a truck-shovel system selection and sizing are the equipment geometry and size. Geometry (equipment width, weight, turning radius, swing angle, etc.) is mostly controlled by mine’s designs and layouts, as well, as operational constraints. After selection of a favorable geometry based on the constraints; the next step is to select the equipment manufacturer. Once the geometry and manufacturers are selected; the next step is to decide on models (e.g. Bucket size) and required number of each unit"

Jan 1, 2015

By Wenhua Wan, Jan M. Mutmansky

Many concerns have been expressed worldwide regarding the use of diesel equipment in underground mines due to the potential health risks associated with diesel particulate matter (DPM). In assessing the risk to the health of miners and designing control strategies for DPM, it is important to know the concentration of DPM in the working areas of a mine. In some mines, significant stratification occurs due to the characteristics of the diesel exhaust, affecting exposure and the ability to measure DPM concentrations accurately. This study outlines some of the concentration profile data obtained during sampling at three mines where diesels were employed. Mine #1 (a gold mine) employed large openings in which a diesel-powered roof bolter was used. Mines #2 and #3 are both room-and-pillar operations with varying conditions. Mine #2 is an experimental mine where two stationary diesels were utilized for sampling purposes, while Mine #3 is a traditional evaporite operation using two mobile diesel vehicles for section haulage. These field studies indicated that some level of stratification occurred in all the mines, but the stratification was not as pronounced in the case of Mine #2 due to the complex pattern of exhaust emissions generated by the vehicles. The stratification seemed to depend on the distance from the vehicle, the mine air velocity, whether the vehicles were moving or stationary, and whether the exhaust was diluted by equipment design features. The concentration of DPM was generally higher at samplers located near the roof and lower at samplers located near the floor. However, this was not found in all cases. This paper provides conclusions on how knowledge of stratification patterns can be utilized in sampling and control of DPM in mine atmospheres.

Jan 1, 1997

By John D. Morton, J. H. LaVerne Palmer, Douglas J. Belshaw

An extensive programme of ground instrumentation and observation was carried out for the West Duff in Outfall Sewer tunnel project prior to and during construction, to establish the performance characteristics of the rock through which the tunnel and appurtenant openings were dug and to examine the nature of the lining-to-ground interaction. The existence of high horizontal residual ground stresses was confirmed, and values established by overcoring. Rock deformations and stress changes were monitored during tunnelling. Permanent stress and strain monitoring devices were set into the final lining and these are continuing to operate. INTRODUCTION The site is located on the north shore of Lake Ontario at Pickering, some 20 miles (32 kilometres) east of Toronto, Canada where a variable thickness of glacial or interglacial sediments overlies bituminous shale bedrock of. the Collingwood Formation which is lower Ordovician age. Approximately 50 feet (15 metres) of glacial cover exists at the shaft, though this thins abruptly at the regressing cliffed shoreline such that several small areas of exposed bedrock exist in the lakebed. The general location, overall geological section and detailed site plan and profile are illustrated in Figs.1,2 and 3 respectively. General properties of the rock as established during an extensive test drilling and site investigation programme are listed in Table 1, while stress determination by USER overcoring stress meter device are given in Table ll. These data formed the basis of analyses which were done to examine the intended outfall design, and to detail the construction procedure and the observational instrumentation programme.

Jan 1, 1979