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By G. R. Goldak

All of Canada's older uranium mining areas have been intensively prospected and known outcrops have been repeatedly examined. The only ground in these areas which has not been explored is that which is covered by water or other overburden. The discovery of new mines in these areas will, in the author's opinion, depend on the development of new geophysical or geochemical tools capable of locating uranium deposits which are-buried beneath tens to hundred of feet of overburden. Such tools would be extremely useful in Saskatchewan's Cluff Lake and Wollaston Lake areas. Uranium has recently been discovered in significant quantities in these regions but exploration is made extremely difficult and expensive by an almost uniform overburden cover. The author's experience has been confined to Canada but apparently a subsurface uranium prospecting method could be widely exployed in the western United States and Australia as well. Radon-222 measurements have been used for more than a decade on practically a worldwide basis in an attempt to obtain a useful method for subsurface uranium prospecting. It is well known that ha-222 produced by buried uranium deposits can diffuse through an overburden cover so that it can sometimes be detected at surface. An advantage of this method of prospecting is that Rn-222 can be detected with a simple scintillation, ionization or semiconductor detector. One of the essential weaknesses of the method is that the mean diffusion path length of Rn-222 is limited by its very short (3.8 days) half life. For a deeply buried deposit, vitually all of the Rn-222 atoms will decay before reaching surface and, therefore, such deposits cannot be expected to produce a detectable radon anomaly. Thus, except in unusual cases where groundwater or ground air flow assists the movement of radon towards surface, the depth of exploration is probably limited to ten or twenty feet of overburden cover. The high solubility of Rn-222 in water is also a source of difficulty. In an area where overburden covers bedrock with water saturation of the lower overburden levels, the radon will simply dissolve in the groundwater, and soil gas readings at surface will indicate falsely low

Jan 1, 1974

By R. J. Hamilton

Considerable success has been achieved in recent years in reducing concentrations of respirable dust in UK coalmines; thankfully this has been reflected in significant improvements in pneumoconiosis statistics. However, continuous increases in mechanisation and in rates of working, accompanied by more stringent dust regulations, necessitate the introduction of improved and often more sophisticated methods of dust control. The increased application of exhaust ventilation and air cleaning techniques seems likely to be the most important step forward in dust control in coalmining during the next few years. A typical drivage in a UK mine is not more than 16 ft (5 m) wide and is supported by steel arches. In the past the majority of such roadways were driven by the conventional means of blasting and loading. Since the main purpose of ventilation was to clear blasting fumes and to provide adequate scouring of firedamp, not surprisingly it was usual to have 'forcing' ventilation. Present systems of operation are making increasing use of heading machines and it is not surprising that well over half of all drivages are now ventilated by exhausting methods. (1) The great majority of coal getting in the UK is from longwall faces, usually in seams of less than 6 ft (1.8 m) thickness. Although this method of min¬ing has many advantages in terms of safety and productivity, dust control is made more difficult because of the need for men and machines to work in the same ventilation stream. Much emphasis has been placed on improving the design and methods of opera¬tion of longwall machines to reduce dust production, and improved ventilation has provided greater dilution, and in consequence, reductions in dust concentration. On all machines water is now fed through internal galleries to the cutting elements. Unfortunately, one of the difficulties associated with mining thin seams is that there is some unavoidable cutting in the roof or floor and in many seams there are faults to be traversed and dirt bands which must be removed with the coal. Under these conditions it appears that the use of exhaust ventilation and air cleaning offers the most promising way of achieving satisfactory dust conditions.

Jan 1, 1980

By Joe D. Mitzel

The Indian Head fine has been in existence since 1922. For over 56 years there have been North Dakota people mining coal at this same location. The area affected will fit inside a circle 5 km in diameter, and the coal is lignite. The seam thickness has varied from 2.4 m to 3.65m, and the overburden from 6 m to 30 m in depth. me Lignite coal which is being mined at the Indian Head Mine is from 15.8 x l0 6 to 16.7 x 10 6 J per kg; it has a moisture content of 33 to 38%; an ash content of 5 to 10%; and a sulfur content of from 0.5 to 0.7%. The moisture content and the fact that we crush the coal co a top size of 14 cm x 0, are two of the characteristics or the product which cause it to freeze and remain inside of the railroad cars on the slope sheets. The market for the coal initially was almost entirely local coal sales. That is, coal was sold to people in the area who used the lignite to heat their homes, stores, offices, schools, and churches. Back in the early 1920's, there were no stoker-fed boilers, or pulverized fuel boilers, as we have in today?s marketplace. Basically, all of the coal was sold as lump coal, pieces about 30 to 35 cm square, to be used in furnaces: and nut coal with a top size of about 7.5 cm to 10 cm to be used in the old kitchen cookstove. All of the coal fines, less than 5 cm, were screened out and layed onto a pile. There was no market for the smaller sizes of the lignite coal. It has been our experience that when the coal is in lumps or chunks larger than 7.5 cm to 10 cm, there is a very slight possibility of freezing. That is the chunks themselves freeze, but by their nature, they do not cling to one another or form large masses of frozen material which are difficult to remove from the slope sheers of the railroad cars.

Jan 1, 1980

By L. Yuan, A. C. Smith

MFIRE, the mine-fire simulation program of the U.S. National Institute for Occupational Safety and Health (NIOSH), is widely accepted as a standard for assessing and predicting the impact of a fire on the mine ventilation system and the spread of fire contaminants in coal and metal/nonmetal mines. MFIRE has been used by U.S. and international companies to simulate fires for planning and response purposes. It is a dynamic, transient-state, mine ventilation network simulation program that performs normal planning calculations. It can also be used to analyze ventilation networks under thermal and mechanical influence, such as changes in ventilation parameters; external influences, such as changes in temperature; and internal influences, such as a fire. The program output can be used to analyze the effects of these influences on the ventilation system. Since its original development by Michigan Technological University for the former U.S. Bureau of Mines in the 1970s, several updates have been released. In 2012, NIOSH completed a major redesign and restructuring of the program with the release of MFIRE 3.0. MFIRE’s outdated Fortran programming language was replaced with an object-oriented C++ language and packaged into a dynamic-link library. However, the MFIRE 3.0 release included no change or improvement to the fire-modeling algorithms inherited from its previous version, MFIRE 2.20. This paper reports on improvements that have been made to the fire-modeling capabilities of MFIRE 3.0 since its release. These improvements include the addition of the t-squared fire as a new fire-source model and the ability to include available heat-release-rate versus time data, the addition of a moving fire source for conveyor-belt fire simulations, improvement of the fire location algorithm, and the identification and prediction of smoke-rollback phenomena. All of the improvements discussed in this paper will be included in MFIRE 3.1 and released by NIOSH in the near future.

Jun 1, 2016

By Daniel A. Wasson

A review of the history of boosters is given with examples of the prominent types that have been made commercially. The performance and design features of protected core boosters are discussed in detail. A new gel booster is discussed with its advantages to the mining industry. Booster size, hole configuration, performance and safety aspects are reviewed. Important features of boostering in above ground and underground blasting are related to an economic analysis. This presentation will cover different types of boosters commonly used in mining. However, for the purpose of this paper a few terms need to be defined to clarify the action of different parts of a priming system. Booster* - "Any unit of explosive or blasting agent to be used in a charged hole for the purpose of perpetuating or intensifying the initial detonation". Primer* - "A unit, package or cartridge' of explosives containing a detonator or detonating cord which is used to transmit detonation to other explosives or blasting agents". Detonator - A device for initiating a detonation from a flame or a small electric current, the former being represented by a fuse cap and the latter an electric blasting cap.

Jan 1, 1981

By Stuart Lister

"When MacLean Engineering chairman and founder Don MacLean got the first question from a minesite about the possibility of addressing ventilation limits through incremental fleet electrification, he was intrigued. It was back in 2015, and the MacLean scissor bolter was already diesel-electric (jumbo trailing cable), so it made sense to him that if they could engineer a battery drive system for the unit’s tramming cycle, they would have the inaugural electric vehicle (EV) MacLean unit.At that time, there were not any entirely diesel-free hard rock mines in existence on the planet, and that remains the case to this day — although the Borden project in northern Ontario is progressing toward that goal (see page 33). This meant there was essentially zero market demand for battery electric vehicles as well as a complete lack of battery technology to address the battery electrification of heavy haulage. Heavy haulage is the part of a typical mine’s mobile fleet with the largest footprint when it comes to diesel particulate emissions, greenhouse gases and wasted energy in the form of heat.Three years later — the wave of battery electrification that is currently picking up speed across the mining industry promises to hit full swing by the early 2020s when a slew of new build, diesel-free mines will start construction. But this movement toward emissions-free mobile fleets is not a completely new phenomenon. Instead, it is an updating of mining technology from a previous generation. What is going on now is the re-electrification of mining. Up until the 1960s, early generations of battery technology (lead acid) and electric locomotive systems were the norm for material and ore haulage in Canada and elsewhere.The thought of a coming paradigm change in mining was particularly pertinent to Don MacLean back in 2015, as he had been part of the era that ushered in the first generation of rubber-tire diesel equipment, when he was a divisional foreman with Inco in Sudbury in the 1970s. He was part of the operating team that was tasked to build a rail loop on one extraction level of the mine. At that time, events on the ground overtook the project, as diesel-powered mobile equipment became a viable option. Once the first diesel scoop was introduced at Creighton #3 shaft, it was clear what the power, haulage capacity and mobility could do for operations and that era of electric rail haulage underground was effectively over."

Jan 10, 2018

By R. C. Emmett

Waste treatment in the mining industry is by no means a new problem to this field. In a sense, the entire process from ore to finished product is one of waste treatment - the separation of a relatively minor quantity of desired component from valueless material. Where it has been necess-ary or economical to practice conventional waste treatment or pollution control methods, such as dust collection, water recovery from tailings, or impounding of residues for future treatment, this has been done. Generally the containment of hazardous pollutants such as arsenic and cyanide also has been followed in modern times. But it is only recently, with the public outcry for the elimination of all forms of pollution, "that the industry has been forced to solve what often appears to be a myriad of difficult and costly waste treatment problems, or be faced with the alternative of closing down the operation. It is the objective of this paper to describe new as well as conventional approaches to these problems, specifically as might be applicable to liquid-solids separation methods. Host wastes in the industry are present either as solutions or slurries, or can be most advantageously handled by conversion to this form, such as in scrubbing noxious gases and dusts with water. Separation of the solids and purification of the aqueous effluents are, therefore, often the principle problems.

Jan 1, 1971

By John MacDonald

An unstable economy has shown businesses what the mining industry has known for decades ? a successful business location today may not succeed in the future. Unexpected expenses, natural events and workforce changes have a big impact on the costs of production. To help focus production and maintenance budgets, mining executives are increasingly turning to production metrics to make key decisions. Role of mine and mill data Companies employ a variety of information systems to allow employees to accomplish their operational tasks, and each worker is focused on the metrics, or key performance indicators (KPI), for his or her individual function. For example, machine operators monitor throughput and cycle time to keep the machines running continuously and to meet daily production quotas. Meanwhile, the maintenance teams monitor machine performance, overall equipment effectiveness (OEE) and meantime between failure to predict and help prevent downtime.

Jan 1, 2013

"A commercially available through-the-earth (TTE) communications system was evaluated at an underground coal mine in eastern Kentucky. This field study was conducted as part of a larger multisite evaluation of available TTE systems. The mine detailed in this paper was idled at the time of the study, which provided the nearest practical representation of a postevent mine shutdown environment. For this study, surface-to-underground and undergroundto- surface communications were tested. Standard deployments of the TTE system using the manufacturer’s recommended procedures were able to achieve clear communications between underground and surface locations. Other arrangements of the units yielded mixed results. Future experimentation is planned to further examine the phenomena observed at this mine IntroductionThe ability to establish effective communication between surface and underground personnel after a mine event is essential for both evacuation and rescue efforts. Current wireless underground communication technologies are reliant on intermediary physical infrastructure, such as antennas and repeaters, to enable underground communications. As such, communications are easily disabled during a mine event because of the inherent vulnerabilities to physical damage (Damiano, 2012; National Academy of Engineers, 1970; Yenchek et al., 2011). A true emergency communications system would function regardless of a mine’s physical state. Through-the-earth (TTE) wireless communication technology only requires the use of a single transmitter and a single receiver to achieve point-to-point communication through solid strata. With this capability, TTE systems have the potential to serve as a true emergency communications platform."

Apr 1, 2016

By Bradley S. Van Gosen, Anjana K. Shah, George M. Bedinger, Donald I. Bleiwas, Karl J. Ellefsen

"Ancient and modern coastal deposits of heavy mineral sands (HMS) are the principal source of several heavy industrial minerals, with mining and processing operations on every continent except Antarctica. For example, HMS deposits are the main source of titanium feedstock for the titanium dioxide (TiO2) pigments industry, obtained from the minerals ilmenite (Fe2+TiO3), rutile (TiO2) and leucoxene (an alteration product of ilmenite). HMS deposits are also the principal source of zircon (ZrSiO4), from which zirconium dioxide (ZrO2) is obtained for uses mostly in refractory products. Sometimes monazite [(Ce,La,Nd,Th) PO4] is recovered as a byproduct mineral, sought for its rare earth elements, and thorium (Ault and others, 2016; Sengupta and Van Gosen, 2016; Van Gosen and Tulsidas, 2016).HMS are sediments containing dense (heavy) minerals that accumulate with sand, silt and clay in coastal environments, locally forming economic concentrations of the heavy minerals (Fig. 1). Economic (mined) HMS deposits include Holocene sediments on modern coasts, such as examples in India and Brazil, as well as coastal deposits formed by transgressions and regressions of the seas during intervals in the Quaternary, Tertiary and Cretaceous, such as in Australia and the southeastern United States. Economic deposits typically contain heavy-mineral concentrations of at least two percent. Individual heavy minerals are commonly defined as minerals with a specific gravity greater than approximately 2.9 g/cm3. These minerals are generally resistant to chemical weathering and physical degradation and thus survive well in fluvial and coastal environments. Heavy minerals in coastal HMS deposits may include, in order of general abundance, ilmenite, leucoxene, rutile, magnetite, zircon, staurolite, kyanite, sillimanite, tourmaline, garnet, epidote, hornblende, spinel, iron oxides, sulfides, anatase, monazite, cassiterite and xenotime. Of these, ilmenite, leucoxene, rutile and zircon are the primary economic minerals. Garnet, monazite, cassiterite and xenotime are occasionally recovered as byproducts. The heavy minerals as a suite typically make up no more than 15 weight percent of a deposit and usually much less. Quartz and clay minerals form the bulk of the sediment. The geology of HMS deposits and examples of significant districts are summarized in Van Gosen and others (2014) and Hou and Keeling (2016)."

Oct 1, 2016

By W. F. Visser

The growing availability of information and data analysis capabilities provides new opportunities for improving the performance of operations. By using real-time measurements and artificial intelligence, it is possible to respond faster to changing conditions, while accurate and timely information permits the rapid evaluation of changes and fast business improvement decisions. This paper presents a blueprint for system alignment, organizational design and management practices to leverage these developments in performance-driven operations management in mining and mineral processing.

By D. S. McAllister, P. M. Rice, M. E. Fowler

The Westside Light Rail Project, a major 19.3-km (12-mile) extension of Portland, Oregon's light rail system, includes 4.6 km (2.8 miles) of twin 5.8-m (19-ft) diameter running tunnels, a binocular type station which, at 80 m (260 ft) below the ground surface, will be the deepest mass transit station in North America, two 9.4-m (31-ft) diameter station access shafts, and a 5.2-m (17¬ft) diameter ventilation shaft. The tunnels are being excavated by TBM and conventional rock, soft ground, and mixed-face methods. Geologic conditions, alignment, underground opening design, excavation method selection, and payment provisions for excavation and initial ground support are discussed.

Jan 1, 1995

By Albert F. Duzy

Recently there have been some problems associated with hot coal in shipments from the USA to overseas markets. This paper will serve several functions. First, a brief review is presented, together with a selective bibliography. Second, a thorough discussion of coal oxidation is covered. Third, potential effects of storage are presented and, lastly, methods are suggested for the safe storage and bulk transfer of coal. The scope includes coal storage for power plants.

Jan 1, 1983

By E. Allen Hendt

It is a pleasure to be invited to speak before a gathering of executives representing America's leading mineral companies, I welcome this opportunity, particularly because it comes at an important period in the development of U.S. commodity policy. This morning, I discussed our general commodity policy primarily in the. Context of the north-south dialogue between developed and developing countries. This afternoon, I would like to focus more specifically on potential cartel activity and U.S. mineral import dependence.

Jan 1, 1978

By Lee W. Saperstein

In surface mining for coal, common practice for the disposal of preparation plant refuse is to bury it. As with surface refuse piles, these buried wastes can ignite and can also lead to ground and surface water pollution. Steps to ameliorate these problems have been devised over the years. C and K Coal Company, of Clarion, Pa., the largest Pennsylvania surface mining company, has incorporated all of these steps and added of few, of their own in their latest disposal practice. In addition to layering and compacting, C and K practices selective placement and dilution to minimize longterm problems.

Jan 1, 1977

Mining steeply dipping coal seams is a difficult task. Prior to 1996, fully mechanized longwall mining methods along the seam strike direction were tried in China and other countries. Due to its larger coal reserve in steep seams, China made more, but still limited, progress on mining such seams than other major coal-mining countries. In the last two decades, accelerated research efforts have tried to improve the mining technology in steeply dipping coal seams. Based on this work, a dynamic model of a roof-support-floor (R-S-F) system under asymmetrical constraints in mining steep seams is established here, and a theory of strata control and hazard prevention is formed. The key technologies for mining steep coal seams include global and regional strata control methods in the longwall face; methods for the longwall face machines to sustain static and dynamic loads; and flexible protection technology. These theories and technologies have been successfully applied in China to the mining of steep coal seams of varying thickness and hardness, with hard and soft roof and floor, and with a high potential for spontaneous combustion. In recent years, the technology has been introduced to Russia, India, Uzbekistan and other countries where steep coal seams are mined.

Jan 1, 2013

By Yi Luo

Simulation of the multi-entry and multi-crosscut (MEMC) ventilation systems commonly employed in U .S. underground coal mines can be very tedious, due to the large number of crosscuts with stoppings to be represented in the network models. In order to reduce the amount of work needed to build the models, a common practice is to represent a number of crosscuts with one equivalent airway. However, this introduces certain errors into the simulation results. In this paper, algorithms have been proposed to simplify the ventilation networks of common MEMC systems encountered in panel development operations. The algorithms can be used to reduce a MEMC system into one airway with an equivalent resistance and to determine the airflow distributions in the system and the leakages through the stoppings.

Jan 1, 2011

By D. Tepavac, S. Simmonds

"The high virgin horizontal in situ stress field in the Sydney Basin and its impact on civil engineering projects is a well-known and accepted phenomenon found in significant literature (e.g., Pells, 2013). The prevailing high-stress effects depend on many factors — rock quality, tunnel orientation, proximity of geological features to tunnel crown, size and shape of opening, depth of excavation and stress magnitude. The behavior of the rock mass under high in situ stress conditions can cause stress fracturing and consequent dilation of the tunnel periphery, resulting in rock spalling at the tunnel crown/ invert or raveling of rock blocks on the tunnel sidewall. This type of failure is of a brittle nature and may create construction and safety risks during tunnel excavation, if it occurs behind the excavation face where ground support has already been installed. Therefore, the associated risks need to be managed during construction. This paper presents the design strategy adopted to mitigate these adverse tunneling conditions for the WestConnex Project to-date. Overview of the WestConnex M4 East and new M5 tunnel projectsWestConnex is one of the New South Wales government’s key infrastructure projects. This 33 km (20.5 mile) project aims to ease congestion and connect communities and is the largest integrated transport and urban revitalization project in Australia. It was a key recommendation of the State Infrastructure Strategy released in October 2012. It brings together a number of important road projects, which, together, form a vital link in Sydney’s Orbital Network. These road projects include a widening of the M4 east of Parramatta, a duplication of the M5 East, and new sections of motorway to provide a connection between these two key corridors. The WestConnex project includes a number of stages: Stage 1a: M4 Widening; Stage 1b: M4 East; Stage 2: New M5; and Stage 3: M4–M5 Link. The tunnel design referenced in this paper relates to Stage 1b and Stage 2 of the WestConnex Project (Fig. 1)."

Dec 1, 2018

By Kirk Carlton

The Athabasca tar sands of Alberta are an increasingly important source of crude oil for the North American continent. Published figures indicate estimates of recoverable resources in the tar sands at some 300 billion barrels of synthetic crude of which some 86 billion barrels can be recovered by surface mining techniques. At the present time, two commercial plants are in operation, Great Canadian Oil Sands Limited and Syncrude Canada Ltd. Their present combined capacity is approximately 150,000 barrels per day. Some of the factors which will make this oil expensive will be noted here. The location of the present producing plants is 500 kilometres north of Edmonton at an elevation of approximately 320 metres. Recorded temperatures range from +38 to -55 degrees Celsius. Wind velocities are not high but the chill factor with even a slight breeze and minus 40 degrees is very uncomfortable.

Jan 1, 1979

By Kyle Amoroso, Aaron K. McCain

Frozen soil shoring has been used for decades in the tunneling industry to provide temporary support of excavation for shafts and cross-passage excavations. However, horizontal penetrations through the frozen soil can prove to be challenging. The key to creating a stable portal through frozen ground is managing and mitigating groundwater flow into the excavation through the annular space surrounding the drill stem or casing. This paper will review different approaches that have been successfully used to penetrate frozen soil shoring on multiple projects.

Jun 13, 2023