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By Kang-Hyun Lee, In-Mo Lee, Byung-Kyu Kim, Parkm Jinho, Seoung-Won Lee

"In this study, the TBM Resistivity Prediction (TRP) system is developed for predicting the location, thickness, permittivity ratio and electrical conductivity of anomalous zones ahead of tunnel face using the measured resistivity of the ground. The applicability of the developed system was verified by performing field tests at a construction site in which an EPB-shield TBM is used for tunnelling work. In the first field test, it was found that the rock around the tunnel face had the same resistivity and permittivity with the rock ahead of the tunnel face indicating no anomaly ahead of the tunnel face. In the second test, a stronger zone 5-m thick was predicted ahead of the tunnel face based on lower permittivity than that of the rock around the tunnel face. The ground condition assessed by the newly developed TRP system matched well with that either predicted from geophysical exploration or directly obtained from drilling boreholes or from daily observed muck conditions. INTRODUCTION During tunneling work, the emergence of unpredicted zones of relatively weaker or stronger ground can lead to delays in construction work or an increase of construction cost. Predicting anomalous zones ahead of tunnel face in advance can thus prevent time and economic loss. For these reasons, various methods to predict the ground condition ahead of the tunnel face have been studied and developed. Prediction methods using various kinds of equipment include tunnel seismic prediction, ground penetrating radar, electromagnetic surveys based on electronic antennas, and electrical resistivity surveys conducted by analyzing electric currents in the ground ahead of the tunnel face (Ryu et al. 2008). However, most of the prediction methods are only applicable to conventional tunneling job sites, which feature free access to the tunnel face. In mechanized tunneling projects, accessibility to the tunnel face is very limited because the tunnel face is occupied by the TBM."

Jan 1, 2016

By K. Lagnese, C. Robinson, S. Muddasani

"Mine water generated from underground coal mining operations contains both dissolved and particulate solids. Dissolved solids primarily consist of sodium, calcium, magnesium, potassium, chlorides and sulfates. When discharged to a receiving stream without treatment, these constituents create a potentially toxic environment for aquatic life. A case study is presented to discuss how a centralized treatment plant treats mine water from six locations to meet discharge limitations for chlorides. Located in West Virginia, this facility consistently achieves less than the NPDES permit limitation of 218 mg/L chlorides in the discharge while generating almost zero liquid waste. The dissolved solids concentration in the influent ranges between 5,000 and 10,000 mg/L, with chloride concentrations of 1,000 to 2,000 mg/L and sulfate concentrations of 2,000 to 6,000 mg/L. The mine water is treated using advanced treatment technology to produce clean water for discharge or reuse. The treatment process comprises aeration, softening, filtration, reverse osmosis, RO reject softening, evaporation, crystallization, final effluent remineralization and sludge dewatering. The solid waste generated in the treatment process is landfilled on site. The leachate is sent back to the facility’s thermal treatment process. Because no liquid waste leaves the property, this plant is termed a “Zero Liquid Waste” (ZLW) facility. INTRODUCTION The advanced water treatment system was built to meet a new 218 mg/l regulatory limitation imposed by the West Virginia Department of Environmental Protection for chlorides discharged to surface waters. The system is designed to treat a maximum flow of approximately 5 million gallons per day (795 m3/h) of mine water. The treatment process utilizes reverse osmosis (RO) membrane treatment to achieve the effluent criteria, and evaporation and crystallization technology to manage the RO concentrate from the water treatment process. As a result, the system produces clean water for discharge while generating zero liquid waste. The effluent water can be used for industrial purposes or discharged to a receiving stream. A Water Impact Index (WIIx) study indicated that discharge of this high-quality water into the Monongahela River watershed may improve the water quality for downstream water users. The waste produced in the treatment process, including softening sludge and salt, is disposed of in an on-site landfill."

Jan 1, 2015

The public relations problems of users of explosives have greatly increased within the past few years. One reason is that explosives and blasting agents are being consumed in increasing quantities. The principal reason, however, is that more people have become physically affected by blasting. Mines, quarries, and construction sites that were formerly in relatively remote locations now find themselves near congested areas. New express traffic ways being constructed to connect the suburbs with downtown areas are being built through the middle of long-established business and residential neighborhoods. The public becomes aware of blasting by two physical sensations-vibration and noise. Vibrations are usually so slight as to be negligible, and in most cases the only sensation noted is noise. The reduction of vibrations to this low level has been primarily achieved by the use of blasting practices and explosive products recommended by vibration engineers based on seismograph recordings. Unfortunately, very little scientific attention was given to the accompanying physical sensation-noise.

Jan 1, 1962

By K. F. Unrug

Fractures of sedimentary rocks in the vicinity of the outcrop are commonly encountered around the world. Mine highwalls and numerous highway cuts give excellent views for detailed study of surface fractures. This paper gives an explanation of the origin of fractures as well as characterization of the distribution and extent of joint system with reference to lithologic composition of the rocks. Practical implications of the joint system affecting mine operations are described. Among the subjects discussed are: discontinuous deformation as an effect of surface subsidence, stability of mine portals and near outcrop underground operations, and stability of highwalls, when using highwall miners and strip operations. Some design procedures are recommended that can minimize the problems encountered in mining areas with intense joint systems.

Jan 1, 1994

By W. W. Hartley

Following a Major underground coal mine incident there followed a review of the role of mines rescue ? the Queensland Mines Rescue Brigade. It wasn?t until 2002 that the real change started to happen. The issue of geographical distance was addressed by mines rescue sub stations being located on the mines sites with parent rescue stations in a central location. The funding was by means of a levy on the mining industry with legislative standards and performance included. The previous Rescue Brigades were not well organised (central districts) and the application of recognised quality management practices within local management was lacking. The structure was based on other nations models and miners managing miners was an issue for the organisation. The reform was some what painful and the QMRS organisation will still evolve with continuous improvement. Queensland has the National Champion mines rescue team for the eighth year. QMRS is participating at the level in the industry of influencing emergency systems and training senior mine management in ?Emergency Mine Management? coaching the industry in emergency response systems. We have come a long way. We have had some success and there is always the challenge of setting the standards, those we should aspire to and the courage to influence the industry to higher goals of a safer future.

Jan 1, 2010

By Rob Dorey

The disposal of mine waste continues to be one of the main controlling factors in the economics and feasibility of project development. Particular to gold and precious metal mining, waste disposal is further complicated by the environmental and political implications of the use of cyanide. Regulatory compliance criteria have partially dictated and can be anticipated to further dictate the approach and methods of tailings disposal. To develop practical, economic, and environmentally acceptable tailings disposal systems within these criteria requires the use of common sense approaches and the application of available technology. Waste disposal is typically considered during the pre-feasibility stages of project evaluation. At this time, the main emphasis is on the economics and practicality of extracting the metal values from the ore. Frequently, the result of this is that the nature of the tailings and the ability to dispose of the tailings is prejudged. It is also frequently the case, however, that during the feasibility stage and project permitting, the requirements for tailings disposal become paramount.

Jan 1, 1998

By J. E. Lees

Advanced remote sensing can be a powerful new information tool to help private and public entities make better environmental and resource management decisions. However, some regulated entities are reluctant to develop or use this tool because of their concerns that it will lead to increased risks and costs of environmental legal liability. They fear that new ways of monitoring the environment will increase liability, undermine existing enforcement agreements, reopen compliance agreements, and generally provide a competitive disadvantage to early adopters by accelerating environmental cleanup costs. Others counter that the increased risks are marginal, and that several advantages outweigh these risks, including the opportunity to more effectively manage environmental operations, target and set priorities, measure and track management and compliance effectiveness, provide more defensible environmental assessments and baseline conditions, make and defend optimal siting decisions, and avoid or resolve environmental disputes. This paper offers strategic advice on ways regulated entities can enjoy the benefits of these powerful new information tools while mitigating down-side legal and compliance risks as much as possible.

Jan 1, 1999

By D. E. Ranta

Orebodies with intricate three-dimensional shapes (such as porphyry molybdenum deposits) are difficult to model using geostatistics or other computer-assisted methods. The strong trends in their spatial grade distributions occur as mathematically complex shapes and prevent the customary assumption of local stationarity that is required for accurate ore reserve estimation. "Zoned Kriging", a new method developed by AMAX, solves this problem directly by using the geologist's interpretation of the ore zones as a parameter in the kriging equations. The geological basis and methods used in the Climax ore zoning technique are reviewed and discussed relative to their application in zoned geostatistical modeling. The Zoned Kriging technique is described and demonstrated using data typical of mineral deposits.

Jan 1, 1984

By T. J. Fronapfel

Impacts to ground water from mining are being comprehensively regulated in Nevada through specific requirements for design, construction, operation, permitting and closure. This program is the nation's most comprehensive for control of activities at mining operations which have the potential to cause groundwater degradation. It encompasses virtually all types of facilities, including placer, physical separation, flotation, testing, leaching and milling. Minimum design requirements are established by regulation, and must be met by each facility. Site-specific monitoring requirements are established for each facility, and are heavily emphasized. Regulatory and technical requirements and relevant permit conditions are presented and discussed.

Jan 1, 1992

By Dominc C. Torre

INTRODUCTION Rapidly increasing capacities of equipment used to load and handle material at the face require improved haulage equipment and better methods of transporting the mined materials or "muck" to the shaft or slope and out of the mine to the processing plant on the surface. Increasingly, those transportation demands are being satisfied with underground belt conveyors. Such con¬veyors provide the most readily available, most efficient, and most reliable method of carrying materials in a continuous and rapid flow from the face loading equip¬ment to the surface plant. Almost universally, belt con¬veyors are used in coal mines and those nonmetallic and metallic mines operating in relatively flat bedded deposits. Belt conveyors are available in a wide range of capacities, mainly limited by belt width, belt speed, and weight of the material to be transported. They can be used on the level, on grades, on the surface, or under¬ground. They provide a rapid and constant flow of material, transporting the material as quickly as it is mined. Length of belt conveyors is almost unlimited. Where the haulage distance exceeds the practical capacity of a single conveyor unit, two or more conveyors can be used in series. Single conveyors more than 1.6 km (1.0 mile) long are common; multiple-unit conveyors in series operation are transporting materials over distances exceeding 16.1 km (10 miles). Depending upon mate¬rials being transported, job conditions, cost of the terrain being spanned, and alternative haulage methods avail¬able, conveyors can be conceivably economical for even greater distances. Table 1 lists maximum belt speeds recommended for most materials, relating belt speeds to belt widths. Table 2 lists capacities of typical conveyors of various widths and speeds, transporting commonly mined mate¬rials of various weights. ADVANTAGES OF CONVEYOR SYSTEMS For several years after their initial introduction, belt conveyors were available only with rigid side frames or a supporting structure of steel and concrete. That con¬struction limited underground applications, due to the cost and relative inconvenience of extending or retract¬ing the belt conveyor in the confined underground environment. However, during the last 20 years, wire-¬rope side-frame belt conveyors, as shown in Fig. 1, have become widely used in underground applications. Even wider use can be anticipated with their application to the fast movement of materials in surface mining operations. Advantages of the wire-rope side-frame belt con¬veyors were realized first in panel or section belt haulage in coal mines. Soon afterward, use of those conveyors was extended to gathering and main-line haulage. The mobility of the wire-rope side-frame conveyor is the principal reason for its success. The conveyor can be extended, retracted, dismantled, moved, and reassembled easily, even in relatively confined under¬ground spaces. The intermediate structure consists of rope support stands, wire-rope side frames, wire-rope tie-off stands, and the necessary carrying idlers and return idlers. An important and very attractive feature is the ability to suspend the conveyor from the roof in an underground mine, as shown in Fig. 2, leaving more room for improved housekeeping and allowing passage of face-service equipment, haulage vehicles, and other mining equipment. The conveyor's open construction allows quick and easy visual inspection of its com¬ponents for failures or malfunctions; it also facilitates checking and correcting conveyor-belt alignment. Other advantages contributing to the attractiveness and widespread application of wire-rope side-frame conveyors in main-line, slope, and surface installations include: lower capital costs, lower installation costs, lower maintenance costs, reduced impact on idlers and belting, reduced spillage and minimal cleanup, improved conformation to undulating terrain or mine bottoms, and the ability to span most obstacles without heavy structural support. CONVEYOR CLASSIFICATIONS Underground belt conveyors are classified normally according to their function. Generally, conveyors are classified into one of four main categories: 1) Panel or section conveyors normally receive the material to be transported directly from the face-haulage equipment. 2) Gathering conveyors are secondary haulage units that usually receive material from two or more panel conveyors. 3) Main-line conveyors transport all the material mined in the underground operations to the slope or shaft. Normally, they receive the material from two or more gathering conveyors. 4) Slope conveyors generally operate in tandem with the main-line conveyor, providing continuous Table 1. Maximum Belt Speeds Recommended for General Use Run-of-Mine Hard Ores and Belt Width, Coal and Earth, Primary Crushed mm (in.) m/s (fpm) Stone, m/s (fpm) 356(14) 1.52 (300) 1.52 (300) 406(16) 1.52 (300) 1.52 (300) 457(18) 2.03 (400) 1.78 (350) 508(20) 2.03 (400) 1.78 (350) 610(24) 2.54 (500) 2.29 (450) 660(26) 2.54 (500) 2.29 (450) 762(30) 3.05 (600) 2.79 (550) 914(36) 3.30 (650) 3.05 (600) 1067 (42) 3.56 (700) 3.05 (600) 1219 (48) 3.56 (700) 3.30 (650) 1372 (54) 3.56 (700) 3.30 (650) 1524 (60) 3.56 (700) 3.30 (650) 1676 (66) 4.06 (800) 3.81 (750) 1829 (72) 4.06 (800) 3.

Jan 1, 1982

By Keat Chuan Chew, Qiao Yue Tung, Teoh Yaw Poh

"1 INTRODUCTION With a land area of 718 square kilometres housing a population of slightly over 5.4 million, as of 2014 (Department of Statistics Singapore 2015), Singapore is a highly urbanised city. Transport infrastructure is critical to keep the country and economy highly connected and functional as the population in Singapore continues to grow. The importance of a robust transport infrastructure is recognised by the Ministry of Transport in Singapore, which is working towards bringing 8 in 10 households within a 10-minute walk of a train station by 2030 (Ministry of Transport 2015). This gives rise to the rapid expansion of the rail network in highly urbanised Singapore, resulting in more tunnelling work having to be carried out in closer proximity to existing buildings. Such tunnelling work is expectedly more challenging and complex, and if not managed effectively, will impose higher risk to the adjacent buildings. Hence, the Building and Construction Authority (BCA) has implemented specific control measures to mitigate such tunnelling risks and to ensure safety of the public. 2 CHALLENGES FACED BY TUNNELLING WORK IN SINGAPORE 2.1 General Challenges of Tunnelling in Singapore With the increasing densification of the rail network in a highly urbanised setting, rail projects in Singapore are faced with several key challenges. One such construction challenge is constrained construction sites brought about by network intensification. Alongside the growth of the rail network, shown in Figure 1, other infrastructure networks in Singapore are also continuously growing. Underground interchange stations between networks become increasingly common, forcing each underground interchange station to be constructed deeper and in closer proximity to existing buildings (Figure 2). Singapore is not alone in facing this issue. The same can be observed in cities like London, in which its myriad network of subway lines pushes new lines and interchange stations to be constructed deeper."

Jan 1, 2016

By R. B. Elver

The St Lawrence Seaway, a deep-water canal system between Montreal and Lake Ontario, was opened for navigation on April 25, 1959. Prior to the opening of the new Seaway, small boats known as canalers and a few deep-sea carriers, primarily from Norway since World War II, were the only ships able to journey past Montreal into Lake Ontario through the old Canadian St. Lawrence canal system. Thus it was necessary for many tons of bulk and general cargo to be shipped all-rail to and from Atlantic ports or to be transhipped to and from canalers. With the opening of the new Seaway, large Great Lakes bulk carriers and a much larger percentage of the world's shipping fleet are now able to sail directly from the sea to the heart of industrial North America. In this paper, the historical events leading up to the construction of the Seaway and the physical nature of the Great Lakes transportation system are briefly reviewed. Following this, an attempt is made to evaluate the effects of the new Seaway on Canada's mineral industry. Because the Seaway has been in operation for only one season, this paper must be considered only an interim report. Because of the importance of the Seaway to iron ore, this commodity will be dealt with in detail, although the effect on other mineral commodities such as coal, petroleum, nonferrous ores, iron and steel will be mentioned. At this time the author wishes to thank the various company and government officials who provided both factual information and critical opinions.

Jan 1, 1960

By John A. Riddle

Some of the pitfalls and problems in selecting and applying corrosion-resistant materials in uranium plants are discussed, together with some suggested solutions. Includes some cost data.

Jan 1, 1979

By R. H. Lambeth

Disposal of mine tailings in "waters of the United States" is presently prohibited even though case studies indicate that the practice may be environmentally viable. To simulate disposal in the natural environment, nine containers of tailings and sediment were instrumented and placed on the ocean floor near Juneau, AK as were ninety-six biosample containers. Pore water concentrations of five metals were determined, and biota populations were characterized for both materials. After 500 days of exposure there were no statistical macro scale differences between tailings and sediment biota populations or Cu, Pb, and Zn pore water concentrations. Tailings released slightly more Fe than sediment, but sediment released significantly more Mn than tailings. Disposal of mine tailings in marine waters may be environmentally safe.

Jan 1, 1998

By Taghi Sherizadeh, Paul Brooks, Dogukan Guner, Samuel Nowak

Large excavations are well known to result in rock mass deformations which can present challenging situations for mine personnel. Most of the currently available ground movement monitoring devices fail to adequately provide mine operators with highly accurate and meaningful insights into rock mass deformation or displacement. The use of distributed fiber optic sensors (DFOS) in industries such as oil and gas and civil engineering has shown the potential of these sensors to deliver real-time, highly accurate, and long-range distributed strain measurements with great success. However, the use of these sensors in underground mining is limited to a few case studies.

By C. J. Webb

Abandoned uranium mines in the southern Black Hills of South Dakota were sampled for uranium, radium, and rare earth elements during 1992 and 1993. Analyses of water samples from several shallow ponds in the mine pits showed pH values between 3 and 4 with uranium concentrations between 1600 and 2600 ppb. Rare earth elements and their respective isotopes were analyzed with an inductively coupled plasma mass spectrometer and were referenced to a shale normalization pattern. All samples showed an enrichment in the middle rare earth elements. Rare earth levels often were greater than 0.2 ppm. At one site, the concentrations of lanthanides were 150,000 times above background levels. While the southern Black Hills have long been known for rich uranium ore deposits, these analyses show that significant levels of rare earth elements also are present, indicating that the potential exist for future development.

Jan 1, 1995

By W. E. Lytle

Environmental permitting is a critical component for joint-venture projects located in the Commonwealth of Independent States (CIS). This paper presents the basic CIS regulatory environmental requirements for permitting of a hypothetical mining source and emphasizes air permitting. Topics which will be covered include: the Expertiza process, air pollution quantification, data requirements, and air pollution modeling protocol. A comparison will be made between permitting requirements for air pollution sources in the United States and a CIS country, Kazakstan.

Jan 1, 1998

By T. M. Yegulalp

A numerical model is being developed to assess the enhancement of permeability by improved fracture connectivity by micro-hydrofracturing. A generic two-dimensional percolation model has been developed to test the impact of various field conditions on permeability. Field data from Cyprus Minerals' Mineral Park Mine has been used to establish statistical properties of the observed fracture systems. Results of statistical anlyses of the field data and examples of the use of percolation model are presented.

Jan 1, 1995

By Patricio Zarate

Due to the intrinsic variability in orebodies, similar metallurgical behaviour of all material sent to the concentrator is expected to have some variability. Still some specific ores have anomalous performance which can severely impact on the concentrator’s production of metal, in this case copper. The study first will show the mineralogical characteristics of “usual ore” and of this specific “abnormal ore” which will have to be processed by the concentrator in the future. After that base conditions on both ores and flotation test procedure will be explained. Later the different alternatives tested regarding collectors and modifiers results will be compared. Finally, after discussing the different results with different reagents and considering operational variables of the concentrator, Floticor PD 702 is recommended to obtain the best copper recovery without increase in excess mass recovery.

Feb 1, 2025

By Robert S. Hedin, David M. Hyman

Acid mine drainage (AMD) is a common water pollution problem on active and abandoned coal mine sites in the eastern United States. AMD forms when surface mining brings unweathered pyrite-containing rocks to the surface or when deep mining allows oxygen to contact buried pyritic strata. In the absence of neutralizing compounds, the drainage that results can be extremely acidic and contaminated with dissolved iron, manganese, and sulfate. Drainages with pH < 3.0 and concentrations of sulfate greater than 1,000 mg/L, iron greater than 50 mg/L, and manganese greater than 10 mg/L are common. Where water flows through alkaline materials (such as limestone) before surfacing, the drainage is less acidic and occasionally circumneutral, but it can still contain high concentrations of sulfate and metals. Current water quality standards in the United States require that mine discharges have a pH between 6 and 9, total iron concentration less than 3.0 mg/L, and manganese less than 2.0 mg/L. At thousands of active and inactive mine sites, drainage does not meet these standards and is being treated before discharge by the mining company. At thousands of other sites, which were abandoned prior to the enactment of water pollution laws or were operated by companies that have gone bankrupt, untreated AMD is polluting receiving water systems. The standard mine drainage treatment system involves the addition of a1 kal ine chemicals to the water, which raises the pH and cause metals to precipitate in a settling pond. These systems are expensive, often costing tens or hundreds of thousands of dollars per year for chemicals, operation, maintenance, and disposal of the metal- laden sludge. Because the drainage on many sites will likely be contaminated for decades, there is financial incentive to find alternative water treatment systems. In the last five years, many mining companies and engineering firms have experimented with the construction of wetland treatment systems. Very few of the several hundred wetland systems that have been built are performing well enough to justify total abandonment of chemical treatment. Nonetheless, systems continue to be built because the mining companies have found that wetlands can reduce their AMD treatment costs. It is also their hope that further research and development will eventually result in systems that will completely rep1 ace chemical treatment and offer long term performance at minimal cost. The Bureau of Mines has been actively involved, from a research perspective, with this approach to AMD treatment since its inception. In this paper, the status of constructed wetland technology is discussed with respect to the construction and performance of systems, chemical and biological processes that affect AMD chemistry within constructed wetlands, and the future of this technology as perceived by the Bureau of Mines. ORIGINAL OBSERVATIONS The constructed wetland concept has its roots in observations of natural Sphaqnum peat wetlands that received acid mine drainage and, instead of being adversely affected, appeared to cause an amelioration of the polluted water (Huntsman et al. 1978; Wieder and Lang 1982). These observations instigated the idea that wet1 and systems might be used for the intentional treatment of mine drainage. Because the discharge of AMD into a natural wetland is prohibited in the U.S. by several laws, it has been necessary to construct wetlands which act solely as water treatment systems. Initially, most wetland research and construction efforts mimicked the original observations by utilizing Sphaqnum moss and peat. Despite promising laboratory results (Kleinmann et al. 1983; Tarleton et al. 1984; Burris et al. 1984; Gerber et al. 1985), virtually all field tests of Sphasnum-dominated constructed wetlands failed to provide sufficient water treatment for more than several months. Sphasnum proved quite sensitive to the stresses associated with transplanting, abrupt changes in water chemistry, excessive or insufficient water depth, and

Jan 1, 1989