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From a distance, the 0.75-km (0.5-mile) rail line that sits in the shadows of Vale-Inco?s Stobie Mine outside of Sudbury, Ontario could be mistaken for a standard conveyor belt hauling ore from the nearby mine. But with its large, yellow-painted loop and interconnected green rail cars that invert themselves on the loop before correcting with a smooth rollover further down the track, one might assume that this is some sort of test track for a new roller coaster. The fact of the matter is that it is the proving ground for Rail-Veyor technology, a technology that the company hopes will one day change the face of ore transportation in surface and underground mines around the world. With a line of linked, low-profile rail cars that are capable of carrying up to 1 t (1.1 st) per car of ore by way of simple, above ground, lightweight rail track, the technology is not groundbreaking. In fact, it was developed in the 1960s for the French State Railroad. A demonstration plant for the Florida Institute of Phosphate Research was installed in 2000 and the first commercial under-ground installation was in 2007 in South Africa at Harmony Gold?s Phakisa Mine. There, a 4.7-km- (2.9-mile-) long tram between two shafts operates three Rail-Veyor trains on a shared track. The difference is that the application that is being tested day-and-night in Sudbury is getting closer to wide production, thanks to the use of computer controlled automation that has helped turn an old idea into a cost-effective modern solution.

Jan 1, 2010

By Long An, Chao Wu, Yuanhui Li, Xing Sun, Shuai Xu, Changyu Jin

Stage open stope mining (SOSM) maintains the stability of excavation openings by leaving a large number of rib pillars. Affected by the strong unloading due to stage mining and the low width-to-height (w/h) ratio of the pillars remaining, large-scale destabilization disasters of rib pillars or excavation openings easily occur when the distribution of ground stress or the size of rib pillars is unreasonable. In view of these problems, a physical SOSM model test was carried out based on an underground metal mine in the city of Chifeng in China, revealing the deformation and failure characteristics of the SOSM pillar group by overloading.

Jul 1, 2023

By A. Mull, J. Weyer, J. Brune

"The “Reiche Zeche” mine in Freiberg, Germany, a 600-year-old lead-zinc-silver mine with extensive open mine workings, experiences severe ventilation losses due to leakage. Much air leaks into abandoned workings, decreasing the airflow available to active working areas. Usually, this leakage occurs in remote areas that lack transportation infrastructure like roadways or rail, making it difficult to haul construction materials to the sites to erect passive ventilation controls such as stoppings, regulators and seals. Transportation distances make it impractical to hand carry traditional construction materials, such as bricks and concrete. Alternative materials, such as brattice, foaming polymers, concrete canvas, and some innovative ventilation control designs have been investigated for this purpose. The suitability of the materials investigated depends on many factors including the pressure it can withstand, the ease of transportation, and workability. Impacts of mine water must be considered, as the Reiche Zeche is below drainage and experiences significant inflow of water. Researchers must consider the effects water inundation as well as how the stopping construction material reacts to being exposed to acidic mine water. INTRODUCTION Problem Statement Mining in the area around Freiberg, Germany began in the 12th century. The mine is used for research, mining engineering education, tourism and air conditioning for a local hospital. The first records of mining in the Reiche Zeche are from around 1384. Due to the strength and competency of the host rock, many of the oldest workings still stand and remain open today, although they may not be accessible. Reiche Zeche also connects to several other, closed mines in the area that are largely unmapped. This allows air to leak into neighboring mines, reducing the air available to ventilate to the working areas of Reiche Zeche. In order to improve ventilation efficiency, it is necessary to control the ventilation and reduce leakage by constructing seals, stoppings and regulators. A challenge with building traditional seals and stoppings in the Reiche Zeche is that the old workings lack transportation pathways or rails. Also, the lack of compressed air, water or electricity makes it difficult to operate power tools and drills. This means that construction materials must be hand carried – some over distances of several kilometers. Figure 1 shows a typical drift in the Reiche Zeche. Researchers investigated using lighter, more easily transportable materials including concrete canvas, expanding polyurethane and polyurea foams, and brattice. The applicability and utility of these materials depends on a variety of factors including the ventilation air pressure, chemical resistance to acidic and mineral-laden mine waters, ease of transport, and ease of construction. Stoppings and seals must be substantially constructed so that they remain tight and do not require maintenance. It is also important to consider the toxicity of the construction materials in case of a mine fire."

Jan 1, 2016

By James Withers, Dongbo An, Jinhong Zhang

A micro-scale investigation was carried out by applying an atomic force microscope (AFM) and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy to study in situ the adsorption of three different collectors — oleic acid, octanohydroxamic acid (HA) and salicylhydroxamic acid (SHA) — on bastnaesite in aqueous solutions. The results show that all three collectors adsorb on bastnaesite. The hydroxamic acid collectors — HA and SHA — adsorb on bastnaesite mainly in the form of insoluble metal hydroxamate. Their specific adsorption mechanism indicates that high selectivity will be achieved with a hydroxamic acid collector for the flotation of bastnaesite.

By James A. Finch, Xiang Zhou, Yue Hua Tan

Widely used as collectors for nonsulfides, amines also show some frothing properties. Evaluating frother functions of amines and their combination with conventional frothers addresses whether one reagent delivering both collector and frother functions compromises the efficacy of either. From the findings, whether blending with frother confers any benefit requires knowledge of the residual amine concentration. If it is below about 10 ppm, blending eliminated coalescence, but there appears to be no benefit if the concentration is above 15 ppm.

By Robert C. Freas, Donald D. Carr, Lawrence F. Rooney

Perhaps no other mineral commodities in this volume have as many uses as limestone and dolomite. These carbonate rocks are the basic building blocks of the construction industry, the material from which aggregate, cement, lime, and building stone are made. Carbonate rocks, and their derived products, are used as aggregates, fluxes, glass raw material, refractories, fillers, reactive agents in sulfur-oxide removal, abrasives, soil conditioners, ingredients in a host of chemical processes, and much more. Although the use of limestone and dolomite goes back before recorded history, new uses and products are continually being found. Carbonate rocks form about 15% of the earth's sedimentary crust and are widely available for exploitation. Found extensively on all continents, they are quarried and mined from formations that range in age from Precambrian to Holocene. Reserves of carbonate rock are large and will last indefinitely, although high-purity deposits may be absent or have limited availability in certain areas. Limestone and dolomite are so useful and so abundant that in 1989 about 798 Mt were produced in the United States. In fact, about 75% of all stone quarried or mined in the United States was carbonate rock. Sand and gravel was the only mineral commodity produced in greater quantity. In this chapter we have sought to provide the general reader an overview of carbonate rocks, their composition, distribution, production, and uses. The literature on the limestone and dolomite resources of the United States and Canada is so vast and diverse that one can easily become mired in print. We tried to list those references that are easily accessible and that provide the economic geologist with a starting point for more intensive study. The table listing selected references on limestone and dolomite resources in Canada and the United States reflects our attempt to be selective rather than exhaustive and to direct the reader to the best sources of detailed information.

Jan 1, 1994

By Thomas E. McNider, Robert C. Howell, J. W. Stevenson

As of the end of October, 1990, there have been eight spontaneous combustion heatings reported to the Mine Safety and Health Administration (MSHA) at the No. 5 Mine. A reportable heating is defined as one with elevated surface temperatures of the strata greater than ll°C (20°F) above the ambient. The first heatings occurred in November, 1986. The last three heatings were located near the start line of "K" Longwall Panel in the southwest where mining had begun on May 21, 1990. All of the heated areas had been at the time of detection, or were sometime areas of high ventilation pressure differentials or high air velocities. All of the heated areas are in an expanded seam with associated, extensive floor heave which is characteristic of all of the expanded seam thus far exposed by development mining in the No. 5 Mine. Jim Walter Resources, Inc. submitted a plan to MSHA which would reduce the potential for spontaneous combustion at the No. 5 Mine by reducing high air velocities and high pressure differentials in the gob. These two parameters are the dynamics which feed oxygen to the pyrite, thus initiating the oxidation process which can lead to spontaneous combustion. No. 5 Nine operated under this plan for 29 shifts before mining on the longwall was stopped by MSHA and the Spontaneous Combustion Control Plan revoked. This paper briefly details the geology of the expanded seam and history of the heatings. It also gives a retrospective view of the operation under the Spontaneous Combustion Control Plan and reasons why it was revoked by MSHA. Currently, knowledge of the reaction process of the footwall coal seams at No. 5 Mine and other potential spontaneous combustion seams in the United States is limited. There are techniques used in the United States and other countries to minimize the potential for heatings in spontaneous combustion prone areas. The No. 5 Mine has attempted to utilize this current technology. However, in deep, gassy mines the problem is complex.

Jan 1, 1991

By K. F. Hollberg, D. Graehl, L. Despain

OCI Wyoming's recent expansion of its surface Soda Ash production facilities outstripped the mine's ability to supply Trona ore necessitating infrastructure changes to the mine. A computer simulation of the mine's production systems along with the surface facilities was created to determine the most economic investment alternatives to increase mine production. This paper describes the development of the simulation model; the results obtained, and discusses the issues involved in using simulation modeling for mine production system design.

Jan 1, 2002

Maximising margins in competitive markets demands superior productivity. Unfortunately, management systems developed early this century for other industries often drive counterproductive behaviours choking mining productivity. Many executives and managers waste valuable time and effort relying on simply training and communicating to improve managerial practices and attitudes. In covering practical human behaviour, the paper explains why this fails - and explains how to use systems to successfully drive improved managerial practices and attitudes. It highlights use of modern performance Measurement, Analysis and Reporting systems to drive behaviours and improve margins - without capital investment - and make executive and managerial work easier and more effective.

Jan 1, 1999

By Nicholas T. Camicia

A career in the coal mining industry today offers students one of the most interesting and challenging opportunities available in the industrialized world. As reserves of other fossil fuels dwindle in face of the world's demand for energy, it has become apparent that coal, once the king of energy sources, must be relied upon again as the major fuel for powering industrial growth in developed and developing nations. Centuries of coal supplies lie beneath the earth's surface, assuring the world of a steady, plentiful supply of energy until science and technology can produce a way to harness and efficiently use renewable sources, such as solar. The need to increase our use of coal during the last two decades of the 20th century is reason enough to believe that the future growth of the coal industry is assured. A major impediment to that growth might be backward national public policies that could restrict the full utilization of our coal reserves. These policies could result from overregulation and a failure of the public to recognize that coal use, with proper techno- logical safeguards, is compatible with our society's environmental-quality objectives. Communication of this problem and its solution is a major undertaking of the coal industry in the 1980s. At the end of the 1970s, the American coal industry was producing approximately 635 Mt/a (700 million stpy) of coal. To meet the nation's projected energy needs by 1985, the annual tonnage must be doubled. A similar scenario is predicted for the rest of the world. Such growth in the modern international business world will require huge additional amounts of capital, equipment, and people who know how to wisely raise and apply the capital ; use the equipment productively; and deal with the many community, public, and governmental problems such expansion will create. Whether a student's interest is in actual mining operations, business administration, engineering, finance, law, industrial relations, marketing and sales, or public affairs, a career opportunity is available in the industry.

Jan 1, 1981

By M. P. Evans, Rainer Kahrger

During the last decade or so great advances were made in the solvent extraction, electro winning technologies. They, combined with heap leaching, made it viable to exploit large, relatively low grade oxide copper deposits. The El Abra mine is a good example for such a deposit. Situated in Northern Chile at an elevation of about 4000m (14000 feet), 70 krn north of Calama, the El Abra deposit has been known for many years. In the early 1990's Codelco decided to sell a major holding in the deposit to international mining companies. After lengthy negotiations Cyprus Minerals finalized in June 1994 the purchase of 51% of the deposit with Codelco retaining the balance. lance. Already in 1993 Cyprus and the engineer on the project, began discussions with international materials handling companies with regards to the materials handling system required for the project. These early discussions were considered critical for this fast track project. Immediately after the notice to proceed with the project, several companies were invited to submit competitive conceptual proposals for that portion of the material handling system which was to transport crushed and treated ore from the plant to the leach pad and build the leaching heaps at a rate of up to 150 000 tons per day. A supplier was selected. Additional studies were made for the conveyor system from the mine to the fine crushing plant. Due to the extremely rugged terrain and high altitude at the mine, a decision was made to locate the plant and the leaching operations 15 km east of the mine at an elevation of 3400m. In July 1994 the supplier started the conceptual engineering with a design team at the engineer's San Francisco office. The undertaking was unique in the sense that the supplier's engineering team was integrated into the project for the duration of the conceptual engineering. The open and continuous communication greatly contributed to the success of the design work.

Jan 1, 1996

By Patrick J. Ryan, Johann F. Kerl, Angelos N. Findikakis

Introduction Tailings disposal methods used by the mining industry include the use of on-land impoundments, surface and underground mine backfill and marine disposal. The latter method, where applicable and under certain circumstances, can be the most economical and best environmental option. The term marine disposal is used to describe deposition of tailings in the open ocean, coastal waters, fjords and inland lakes. A major element in planning and designing a marine outfall is the assessment of its potential environmental impacts. The nature of the disposed tailings, and the physical, chemical, and biological characteristics of the receiving water body must be carefully assessed prior to deciding whether marine disposal is an acceptable option for a particular project. During the last decade, the North American mining industry has demonstrated a commitment to studying potential adverse environmental impacts of marine tailings disposal and to continue monitoring of the receiving waters. Extensive monitoring programs have been undertaken by Canadian mines. Marine tailings disposal is not used in the United States today. One of the largest U.S. mines proposing to use this option is the Quartz Hill mine of U.S. Borax in Southeastern Alaska. To assure the regulatory agencies and the public of the viability and acceptability of this option, U.S. Borax undertook an extensive program of environmental studies aimed at assessing the impact of marine tailings disposal. This program was part of the feasibility and environmental permitting studies conducted by Bechtel Civil & Minerals, Inc, on behalf of U.S. Borax. Due to the unique nature of the proposed tailings disposal system, a Board of Consultants was established. The Board assisted in planning the modeling and field program and reviewed ongoing work. This paper outlines the basic elements of the marine tailings disposal study program which can be viewed as a prototype for similar studies elsewhere. Background The Quartz Hill molybdenum deposit is located on a knoll in an elevated valley in a mountainous region of southeast Alaska, about 45 miles east of Ketchikan (Figure 1).

Jan 1, 1986

By George M. Potter

During the late 1960s the mining industry became interested in USBM's efforts to develop the gold-silver heap leaching process. In the last 10 years, successful commercial heap leaching applications increased. The process provides a relatively low-capital means of processing treatable ores with reasonable operating costs. Present gold and silver prices compared to capital and operating costs favor the continued growth of the heap leaching method. The heap leaching process is defined as the percolation leaching of relatively coarse gold-silver ore piled on an impervious surface. To date, dilute alkaline cyanide solution is the lixiviant of choice. Other leaching reagents such as thiourea and hypo have been suggested, although they are not currently used in heap leaching practice. Ores may he run-of-mine in size or crushed as fine as about 10 mm. Gold and silver-bearing so¬lutions draining from the heaps may be processed in activated carbon columns to recover the metals, followed by stripping and metal recovery, or treated by the Merrill-Crowe zinc dust precipitation method. All solutions are generally recycled to the leaching step, and the heap leaching system is relatively easy to control from an environmental viewpoint. One advantage of the heap leaching process is its flexibility. Plants may be very simple, comprising leaching of uncrushed ore on a locally-obtained clay-lined pad and shipment of gold and silver recovered in the form of loaded carbon or zinc precipitates; such a plant would have a relatively low capital investment. More elaborate plants for larger ore bodies may be planned to include crushing, cyclic pad use, and done gold-silver recovery. General planning is similar in each case. This article outlines some key factors in designing heap leaching operations and discusses how these factors are applied to develop a working operation. Since individual design requirements and local costs vary so much, only a few general comments on costs are included.

Jan 3, 1981

Sweden is beginning to reap the rewards of a process that has transformed a country with a history of metal mining into one of Europe's most vibrant exploration regions. Exploration and mining companies from North America, Europe and Australia have joined local firms in the search of gold, base metals and diamonds. This has been due to changes in Sweden's mining laws in the early 1990s. These changes opened the way for unhindered private sector investment in the country's mineral industry. More than 20,000 km2 (4.9 million acres), mainly in northern Sweden, is now held under granted or applied exploration claims. Exploration permits diamonds, applied or granted covers more than half of Sweden's surface. This is a greater proportion of the country than ever before. Major mining companies and junior explorationists are evaluating a geological potential that bears favorable comparison to other major mining centers. Historically, Sweden's gold re- sources occur in greenstone belts in northernmost Sweden and in association with massive sulfide deposits in the Skellefte district. These are receiving particular attention by exploration companies. In addition, new areas in Sweden are also being explored for gold. This increases the probability that Swedish gold production - already the highest in Europe - will increase in the future (Table 1). Sweden's recorded mining history goes back for much of the last large pool of expertise in exploration, mining, equipment manufacturing and minerals industry research. In addition, the Geological Survey of Sweden provides sup- port for exploration in terms of data archives, processing and publications. Other benefits for exploration companies are Sweden's communications infrastructure, its member- ship in the European Union, bringing access to one of the world's major markets and the high level of educational, technical and language skills held by the country's work- force. And deregulation of the economy and the introduction of competitive corporate tax rates have made Sweden a favorable destination for investment in Europe.

Jan 1, 1997

By John F. M. Sims, Charles B. Green

Introduction The gold rush to the Canadian Klondike and then to the Alaskan gold camps is legend to Americans. The early years of the century also saw flourishing hard rock mining at the famous Treadwell and Alaska Juneau gold mines and the bonanza Kennecott copper mine. Over the last two decades, rich discoveries of copper, cobalt, zinc, lead, molybdenum, tin, and silver have furthered Alaska's reputation as a storehouse of US minerals. Alaska may also contain large commercial deposits of chromite, platinum, and nickel. Yet in 1984, with the exception of the Usibelli coal mine and several hundred small placer gold mines, Alaska's mineral potential remains largely undeveloped. Uncertain 70s The 1970s were years of uncertainty for the mining industry in Alaska. The discovery in 1968 of a huge reservoir of oil and natural gas in Prudhoe Bay brought the land claims of Alaska's natives to national attention and focused interest in Alaska's resource wealth. The Alaska Native Claims Settlement Act of 1971 (ANSCA) created the regional native corporations and granted them selection rights to some 178 000 km2 (44 million acres) of Alaska's 1.5 Gin' (375 million acres) - about 12% of the state's land area. The native land selection process would take years. During this time, the status of much of Alaska's land was in question. Additionally, section d(2) of ANSCA provided for the conversion of an undetermined amount of federal lands into conservation units. These consist of parks, scenic rivers, national monuments, and wildlife refuges. The debate over the d(2) lands was long and acrimonious. National conservation groups lobbied to include as much acreage as possible within restrictive classifications, regardless of its mineral or energy potential. The process was polarized into a preservation-versus-development struggle. To many Alaskans, what was at stake was the ability to develop a viable independent economy, rather than an ongoing role as economic wards of the federal government. The resulting compromise was the Alaska National Interest Lands Conservation Act of 1980 (ANILCA). ANILCA resulted in the placement of some

Jan 1, 1985

By K. E. Robinson, G. Re, L. Skoski

Introduction A new technology is evolving as a result of growing industry and government concerns over the potential impacts of possible airborne emissions from uranium tailings piles. A major component of the technology is the use of earth covers to stabilize the tailings after mill operations have ceased. While various analytical models have been used to predict the thickness of required covers, experimental validation of the models has been necessary. This paper presents the results of a field program to select and test cover material to determine its suitability for eventual reclamation of a currently active tailings pile. The two main criteria guiding the study were the U.S. Nuclear Regulatory Commission radon flux requirements (reduction to less than twice background pre-1979, and to 2 pCi/m2 -sec above background post-1979) and the desire to employ locally available material. The methodology chosen for this study consisted of three main elements: o Determination of the background radon flux. o Determination of the radon flux from the tailings pile. o Experimental determination of the cover material diffusion coefficient and and calculation of cover thickness. The first two elements of the study are relatively straightforward, the last phase is discussed in detail. Background Radon Flux Measurements of radon-222 emanation rates from the surface of the ground were taken at three sampling locations. Samples were collected by means of the accumulator can method described by Wilkening, 1977. Both morning and afternoon samples were collected at each site to obtain an average. The measured fluxes were fairly uniform and did not differ greatly among sites. The overall average flux for all sites was 0.63[+]0.28(o) pCi/m2 -sec. This value is equal to the average radium-226 concentration determined in the soil, thus yielding a one to one ratio of radon-222 emitted (in pCi/m2 -sec) to soil radium content (in pCi/g). Tailings Pile Radon Flux Two sites on the tailing pile

Jan 1, 1980

By James B. Meredith

The European Economic Community (The Common Market) is now shifting from I a coal oriented to an oil oriented economy. The proportion of energy supplied by oil has increased from only 13% in 1950 to 38% in 1962, and will approach 50% by 1970. In the past five years Common Market petroleum demand has in- creased 15% per year compared with only 3% per year in the United States. This rapid shift to oil can be explained by looking at oil's competition, First; there is simply not enough other energy - European coal, natural gas and hydro-electric power - to meet the demand, Secondly, oil?s primary competing energy in the Common Market is coal, and Community coal is high-priced - it costs more than two and a half times as much as U. S, coal at the pithead. The third reason for the shift to oil is consumer preference for the ease of handling, convenience and cleanliness of liquid fuels. As these reasons suggest, much of the shift to oil and the resulting growth in demand would have occurred whether or not the Common Market organization had existed. On the other hand, the Common Market has stimulated the use of oil by causing a higher rate of energy consumption, and oil has been the beneficiary of most of this growth.

Jan 1, 1963

By Susanne Pignolet-Brandom

This paper examines the viability of using the QEM*SEM automated scanning electron microscope for the determination iron sulfide and calcite volumetric percentages. The analytical reliability was verified by comparing elemental abundances calculated for fourteen samples using the QEM*SEM volumetric percentages and appropriate mineral compositions and elemental abundances determined by standard laboratory procedures. The abundances were comparable, thus demonstrating suitability of this technique for evaluation of the acid neutralization and generation potentials of mining wastes.

Jan 1, 1990

By B. K. Mishra

Power draw of the mill has been accepted as an indicator of the performance of the mill, yet the problem of predicting power under a given set of mill operating conditions still remains to be solved. In the literature, this problem of predicting power is attributed to a lack of knowledge with regard to the motion of the charge. Here a DEM based model is used to analyze the motion of the charge. The resulting information is used to predict the power draw of the mill. A 16-ft diameter mill is simulated. A factorial design study of the variables-mill speed, lifter configuration and ball size distribution-as independent variables is taken up. The power draw as a response variable is analyzed to establish the best operating condition of the mill.

Jan 1, 1993

By G. K. Roset, L. R. Woodland, J. A. Stevenson, G. J. Hodges

The Stillwater Mining Co. (SMC) is a partnership of Pittsburg & Midway Coal Mining Co. and Manville Corp. Since the summer of 1990, SMC has operated a precious metals smelter at Columbus, MT for further upgrading of concentrates from its platinum-palladium mine. The facility's gas-cleaning system utilizes "oxidation/dilute-mode," dual-alkali scrubbing technology to capture sulfur oxide gases from the process gas streams. This paper describes the rationale for selecting the dilute-mode, dual-alkali system and summarizes the design parameters. Also discussed are the startup problems encountered and their solutions.

Jan 1, 1993