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By Ralph E. Magnuson

The quality of our environment is of great importance to all of us. Today, there is a great public concern about the degradation of our air, land, and water and the resultant slow death of our planet Earth. The miner has always been concerned with his environment. Historically, mining has been a part of the frontier. As a result, the miner has pioneered and developed many parts of the world. In the beginning, he had to hack out a place for his mine, himself, and his family. He was given accolades and praise for his accomplishments. Now, however, he is attacked as a ravager of the landscape. It was and is no different on the Marquette Iron Range in Marquette County, located in the Upper Peninsula of Michigan. Iron ore was discovered in 1845 and mining was begun by 1848. Over nearly 1 ¼ centuries, a total of 379,197,000 tons have been shipped to market. Ports, docks, railroads, and towns all had to be built in order to get that tonnage out to iron and steel makers. In those early days the environment had to be mastered, not pampered.

Jan 1, 1970

By E. B. Kroeger

Spoil instability has been a problem at a coal mine in interior Alaska. Parameters such as original site topography, groundwater conditions, material properties, spoil-pile geometry, geology, permafrost, natural slope instability, changing weather conditions, and dense, near-surface vegetation have interacted to produce unstable slopes. Several failure modes have been identified including deep seated earth block slides, bimodal earth flows, and solifluction. Thawing of permafrost also created conditions where sliding of spoil along the interface separating the spoil and the natural ground surface occurred when the cohesion and the friction angle of that zone was reduced to zero and below 15?respectively.

Jan 1, 1992

By A. Bhagavatula, M. Rezaee, M. J. Kiser, R. Q. Honaker

"A field study of the coal preparation plant fleet in the eastern United States was undertaken to determine if quantify of rare earth elements (REEs) present in the product streams are large enough to justify further concentration. Representative composite samples were taken from the clean product, coarse refuse, and fine refuse streams from 20 coal preparation plants. Each stream was then separated into various size and density classes and analyzed for ash and REE contents. The large database showed that coarse refuse contained the largest amount of REEs, although the ratio of heavy to light REEs was greater for the clean coal products. The concentration of REEs was also compared to that typically seen in the earth’s crust. This enrichment ratio ranged from approximately 1.5 to more than 4.0 as the ash content varied. The database also showed that a linear correlation existed between La and Ce for many REEs of interest, although there were several notable exceptions for some of the high-value REEs. INTRODUCTION Worldwide energy demand is expected to grow by as much as 37% by 2040 according to the International Energy Agency (2014). This growth, coupled with a decrease of the reliance on coal to generate energy, means that it is more important than ever for countries to secure the materials necessary to meet its energy projections. For the United States, the U.S. Energy Information Administration (EIA) predicts that total domestic electricity use will increase roughly 25%, from 3,836x109 kWh in 2013 to 4,797x109 kWh in 2040 (EIA, 2015). In the EIA’s reference case, coal’s contribution to electricity generation drops from 39% in 2013 to 34% in 2040. On the other hand, renewables share of electricity generation grows from 13% to 18% for the reference case. Compared to its current state, renewable energy electricity production is predicted to grow as little as 50% to as much as 121% over this time period, depending on the economic case being examined. This growth will largely be seen in the wind and solar sectors (EIA, 2015). The focus on viable renewable energy resources will be crucial to the future of fueling American growth. Many of the renewable energy technologies, such as wind turbines and photovoltaic films, rely on materials and supply chains outside of the United States. The lack of a reliable and low-cost domestic supply could pose a threat to the growth of the renewable energy markets in the United States. This potential vulnerability recently led the United States Department of Energy (DOE) to create a Critical Materials Strategy Report. In this report, 15 elements were identified as critical for the continued growth of the renewable energy market. Eight of these elements were rare earth elements (REEs). Five REEs (dysprosium, neodymium, terbium, yttrium and europium) were identified as highly critical and vulnerable to shortages (Bauer et al., 2012)."

Jan 1, 2016

By P. L. Dunn, G. T. Adel, E. B. Cruz

Automatic control of fine-coal cleaning circuits has traditionally been limited by a lack of adequate sensors. Although several nuclear-based analyzers are available, none have seen widespread acceptance. In this investigation, image analysis is used for the on-line determination of ash contents in fine-coal slurries. The ash content of a flotation tailings stream is correlated to the mean gray level of the slurry. Based on a 90% prediction interval, an analysis of sensor performance indicates an accuracy of 73[±] 4% ash over a range of from 65% to 90% ash. While the results are comparable, the video-based system costs only a fraction of what a nuclear-based analyzer costs. The sensor is now installed at the Middle Fork preparation plant, which is owned by Pittston Coal Co.

Jan 1, 1999

By Ivano Andreis, Georgios Kalamaras, Mario Liti, Sebastiano Pelizza, Filippo Avesani

"THE SS640 AGRIGENTO-CALTANISSETTA PROJECT The Caltanissetta tunnel is part of the works for the construction of the second 28km-long maxi section of the SS 640 motorway of Porto Empedocle, from km 44 to the junction of Imera in Sicilian hinterland. Amongst other major infrastructure works, the €740 million ANAS (Italian national roads and highway administration agency) project consists of four twin tube tunnels three of which are being excavated by conventional means. The longest tunnel, underpasses the Caltanissetta city and has a length of 3.9km under a maximum overburden of 120m. The JV consisting of CMC of Ravenna and TECNIS SpA won the design & built tender in 2010. Construction started in early spring 2012 following the approval of detailed design and later on the approval of design for construction. THE CALTANISSETTA TUNNEL The Design Phase Tender design and detailed design foresaw the construction of 13.4m excavation diameter tunnels that were to be enlarged in a second phase to create, every 600m, 50m-long tunnel sections for emergency parking. During the design for construction project phase the JV proposed to replace the 13.4m tunnel with a 15.08 excavation diameter that incorporated apart from the two 3.75m wide lanes a 3.25m wide continuous emergency lane. This significant tunnel section modification was associated with better road safety conditions, simpler and safer construction procedures, better statics for the tunnel section while in terms of overall cost the solutions were equivalent.Geologic context The tunnel is located in the middle of the geologically known Caltanissetta basin that is intersected by various tectonic structures. The geologic context for the tunnel scale, was defined in collaboration with the University of Catania in early project phases. For almost its entire length the tunnel is excavated in the Terravecchia formation that represents the lower part of the stratigraphic sequence that was formed in the Tortoniano period of Miocene. The quite complex geological model is also characterized by the presence of the so-called Trubi formation that consists of clay and marl clay. Almost 90% of the tunnel traverses formations that are quite similar in terms of excavation behavior. Exception to this are thrust zones and a calcareous stretch of the alignment. This last segment has a length of 200m and was identified since the very beginning as a tunneling challenge due to the combination of very poor geotechnical properties and an important water load."

Jan 1, 2016

By Clifford R. Porter

A 200 pound per hour Magnex Pilot Plant was designed and constructed. A non-compliance Eastern Coal which would generate more than 2.0 lb of SOZ per million Btu upon burning was brought into compliance (less than 1.2 lb of S02 per million Btu) during continuous operation of the pilot plant. Approximately 85 percent of the pyritic sulfur was removed while recovering 86 percent of the Btu of the feed coal. Pilot plant operation is summarized and preliminary economics presented. Present status of the Magnex Program is reviewed.

Jan 1, 1977

By Evan Dressel, Mark S. Diederichs, Kathy Kalenchuk

As hard rock mining develops deeper over time, there is an increasing need to predict the spatial and temporal distribution of adverse seismogenic rockmass reaction to mining. Real-time monitoring and feedback of mine data are used to tactically manage risk associated with induced-seismicity; however, strategic risk management requires reliable tools for forward predictions of seismic hazard. The forward prediction of seismic hazard is strengthened by understanding of potential seismic intensity, which often relies on well calibrated mine-wide numerical models. This paper uses a case study to explore how future seismogenic potential and the nature of future seismicity can be domained according to numerically predicted stress-strain paths at past seismic event locations. Delineation of high confinement seismogenic volumes vs. lower-confinement, high-strain seismogenic volumes at the mine-scale can be achieved, based on a loading and unloading stress path analogue, to refine understanding of seismic intensity. Practical qualitative and quantitative methods to achieve this delineation will be demonstrated. Once seismogenic mode (high-stress vs. high-strain) is identified, detailed analyses of seismic source parameters demonstrates change in seismic hazard between the domained volumes.

Apr 26, 2022

By J. C. Heter

The P.W. Gillibrand Company has been processing and stockpiling a suite of heavy minerals at its Soledad Canyon Mine as co-products with construction aggregates since 1984. The heavy minerals are composed of ilmenite, magnetitie, apatite and zircon. The source of the heavy minerals is the Precambrian San Gabriel Anorthosite Complex of the western San Gabriel Mountains. The valuable minerals are readily amenable to standard ore dressing techniques, such as, gravity, magnetic, flotation and electrostatic separation with good recovery and product quality. More than 20,000 short tons of coarse ilmenite were sold in 1990 to the export market for titanium pigment production.

Jan 1, 1992

By Alfredo Valdivia, Hamed Nejad, Vincent Monaco, William Cao

"The East Side Access (ESA) CM005 Contract - Manhattan South Structures - consists of the installation of the waterproofing and final concrete lining for railroad tunnels, 3-Level Wye track turnout structures, segments of the Main Cavern Station, and a series of Ventilation Structures excavated beneath the existing Metro North Railroad (MNR) Grand Central Terminal. Several key team decisions made collectively by the Construction Manager (CM), Designer, and the Contractor has allowed the scheduled construction duration of 29 months to be maintained. These strategies include the use of alternate design and construction methods, including the use of pneumatically applied concrete lining and precast lining. This paper discusses these strategies, and illustrates how successful teamwork and cooperation during the execution of a large-scale construction project can lead to lowering costs, improving quality, and maintaining the overall project schedule. INTRODUCTION The East Side Access Project The Long Island Railroad (LIRR) currently transports commuters from Long Island into Manhattan, terminating at the already over congested Penn Station on the west side of Manhattan. Once completed, the ESA Project will provide LIRR commuters direct access to the east side of Manhattan underneath Grand Central Terminal. The ESA Project will help alleviate the congestion at Penn Station, which currently accommodate the NJ Transit, Amtrak, and LIRR lines; reduce travel time for LIRR passengers traveling to the east side of Manhattan and facilitate connections to the NYCT Subway System and Metro North Rail Road. The ESA Project includes building new tunnels and facilities under Manhattan and Queens. (See Figure 1).The Manhattan Alignment In the Manhattan segment of the ESA Project the excavation in hard rock of tunnels, cross passages, caverns and shafts has been completed by tunnel boring machines, drill and blast, and road header. The construction of the structural concrete final lining, interior structures and fit-out of the previously excavated caverns and tunnels are currently being performed under Contract CM005 Manhattan South Structures awarded to Michels Corporation and Contract CM006 Manhattan North Structures awarded to Frontier Kemper Constructors Inc. This paper focuses on the design and construction aspects of Contract CM005 which is the first ESA Contract in Manhattan to successfully construct concrete final linings in pre-existing excavated areas."

Jan 1, 2016

By Ronald R. Hartman

I can recall a time 10 or 12 years ago when I spent a pleasant Sunday afternoon driving to Jim Thorpe, Pennsylvania to see a carnotite deposit that had recently been discovered. The announcement of the discovery stated that it was in the Pottsville conglomerate in a road cut along the highway. To my surprise, the highway was lined with cars and every weekend prospector for 100 miles had come to see the ?big uranium deposit of the east?. I literally had to stand in line to make a measurement with the scintillation counter I had with me. The thought at first occurred to me that this is evidence of how thoroughly the surface of the United States must have been prospected, more likely, perhaps it points out quite the opposite. A lot of time and energy was being spent in tracing the footsteps of others and a lot of time was spent looking for the obvious occurrences. The point is, that in the early days a tremendous amount of uranium exploration was carried out but few systematic surveys were made. Thorium anomalies were usually discounted after cursory surface field checks. Conversely, in airborne surveys - anomalies due to elevation changes or thin over- burden on hilltops were often investigated more thoroughly than smaller indications on hillsides and valleys. An adequate supply of uranium was nevertheless found due to the ingenuity and persistence of the geological profession and the public in general. This ?adequate? supply, like so many estimates for raw materials turned out to be far too low.

Jan 1, 1967

By A. Wright

Gold Fields Mining Corporation is presently evaluating gold mineralization beneath thick, wet alluvium at the Chimney Creek Project, Nevada. Contamination of reverse circulation samples has been visually apparent since drilling began in the area. Tests have shown that, while contamination can affect assays, reverse circulation holes appear to define mineralized zones almost as well as the diamond drill holes. To improve reverse circulation sample integrity several techniques were tried including a stiff-mud injection system but with limited success. Diamond core drilling continues to be used in conjunction with reverse circulation drilling to further delineate the mineralization.

Jan 1, 1991

By P. Eng. Daniel Kelly

INTRODUCTION The Astoria property is located in the prolifically mineralized Abitibi greenstone belt and is one of the most advanced projects presently under development by Yorbeau Resources Inc. This property, which hosts the Astoria gold deposit, is located in the southern part of Rouyn township, Abitibi area, Quebec, 4 km south of the city of Rouyn-Noranda (Figure 1). The Astoria deposit has been the subject of underground development for over a half century, beginning with Granada Rouyn Mining Co. in the 1930's and followed by Astoria Rouyn Mines Ltd. in the 1940's. Yorbeau Resources Inc. acquired the property in 1984 and has, since then, conducted numerous exploration programs on this gold deposit. The diluted reserves of the Astoria deposit are estimated at 1,3 million metric tons grading 6,14 grams of gold per metric ton (1.4 million st at 0.18 oz/st). This reserve figure is based on the results of surface and underground exploration carried out from January 1986 to June 1987 and includes ore in the proven, probable and possible categories. This paper is divided into two sections. The first part includes a summary of the geological environment including a description of the gold bearing zones and a short discussion on wall rock alteration. The second part of this paper reviews the underground work and the objective of the ongoing exploration program.

Jan 1, 1988

By C. Strachan

This paper presents an evaluation of tailings dam incidents from the 1994 USCOLD Tailings Dam Committee report. Comparisons are also made with water storage dam incidents from USCOLD reports and recent tailings dam incidents. The evaluation results show that tailings dam incidents are due to a number of factors including overtopping, static and seismic instability, seepage and internal erosion, and foundation conditions, and that no particular type of tailings dam or operational condition is more susceptible to incidents. In addition, the results confirm that tailings dams should be located, designed, operated, and reclaimed with a thorough knowledge of site conditions, mill operation, site monitoring, and tailings characteristics.

Jan 1, 1999

By L. E. Garner

Aggregate resources should be considered primary factors in urban development. Resource planning is essential because land values, previous construction, or zoning restrictions often preempt exploitation of aggregate deposits within an urban area. Sequential land use practices allow development of areas prior to urban development. Population and aggregate consumption trends in Austin, Texas, indicate that substantial quantities of reserves will be lost to future development. Aggregate materials are present in nearby seas. However, a comparison of transportation and reclamation costs indicates that reclaiming land after mineral extraction can be significantly cheaper than transporting materials longer distances.

Jan 1, 1979

By J. Rostami, P. P. Nelson, A. Khetwaln

Tunnel boring machines (TBMs) can be considered as the method of choice for tunneling in many projects due to the high level of efficiency and high potential productivity, safety, and applicability in a variety of subsurface conditions. The muck transportation system in a TBM tunneling operation plays a significant role in the process and impacts the overall performance of the machine. This paper introduces a recently developed method of simulating TBM operation through discrete event simulation (DES), which allows for tracking of the various activities, incurred downtimes in the operations, and overall machine utilization. The study presented here compares two different muck transportation systems, conveyor and rail, under similar geological conditions to quantify the impacts of the choice of muck transportation systems on machine utilization. The results show the applicability and extent of redundancy in the use of the two systems relative to machine capabilities and their sensitivity to geological conditions.

Jun 13, 2021

By Francesco Chiappalone, Miriam Piemontese, Lance Waddel, Paolo Perazzelli, Emidio Tamburri, Roberto Schuerch

The Three Rivers Protection & Overflow Reduction Tunnel is part of the Long-Term Control Plan of the City of Fort Wayne, Indiana (USA). The 4.9 m internal diameter tunnel, of length approximately 7.5 km, is excavated at a depth of approximately 40–60 m through carbonate rocks using a slurry TBM. Due to the high hydraulic conductivity of the rock mass and the high in-situ ground water pressure (up to 6.5 bar), the management of the water inflow during the TBM advance and standstills, represents the major challenge for the project. This paper outlines the geotechnical conditions and the hazards related to the large water inflows expected in the pre-excavation phase and discusses the experience gained during the construction of the first 8,224 feet (2,507 m), (first third of the total length of the tunnel).

Jun 13, 2021

By Erik Vlot

"The mining industry has recognized the advantages of high density backfill or ‘paste’, which is typically pumped with a hydraulically driven piston pump. Due to the discontinuous flow of this type of pump, pressure pulsations can occur in the discharge line. Pressure pulsations are an undesired phenomenon in pumping installations for a number of reasons that include: damage to the pumping system; piping and supports; disturbing noise levels; and even safety risks for operators and maintenance personnel.This paper describes an advanced system on the GEHO® piston pumps, which will prevent virtually no pressure pulsations from occurring, rather than merely reducing the already existing pulsations.INTRODUCTIONThe first GEHO® hydraulically driven piston pump was developed in the mid-1970s. It was an industrial design pump designed to operate in the high-standard industrial environment with regards to operating hours per day, duties, maintenance and lifetime of the pump and spare parts. This type of pump has a proven track record and has been further developed for the type of applications that we are describing today. The special feature of this pump type is its ability to pump extremely viscous slurry with solids content of up to 90% by weight, at high pressures. Typically, in the mining industry, this pump is used for tailings transportation, with a focus on mine backfill and is often referred to as a paste pump.In the 1980’s the hydraulically driven piston pump made its entry into the application of mine backfill, thanks to the high discharge pressure capabilities enabling the mines to pump higher density (i.e. higher solids concentration) slurries and pastes over longer distances.Part of the ongoing development was (and still is) the increase in discharge pressure and flow capacity to comply with the ever growing demands for high power piston pumps. In line with the technological developments and increase in performance duties, the popularity of this pump type increased significantly and many other industrial applications have discovered the benefits of this pump type.Together with the increase in pump discharge pressures and flow capacities the effect of an undesired phenomenon also increased: the phenomenon of pressure pulsations. Before we explore this subject in more detail it is important to first understand the design and the characteristics of a hydraulically driven piston pump."

Jan 1, 2017

By Adrian C. Dorenfeld

The lesser developed countries (LDC's) may be classified into two categories: 1) oil producers, and 2) non-oil producers. The non-oil producing LDC's, as a class, are at present in very difficult financial straits. (1) Since the quadrupling of world market crude oil prices in 1972, an ever greater share of the LDC's export earnings have gone to pay for oil imports, in-stead of national reinvestment. The LDC's inter-national debts--much of it to pay for oil--have soared to record levels, with consequent limits for future credits. (1) Again, this inhibits future national investments, and there does not seem to be an end to the future increase of Organization of Petroleum Exporting Countries (OPEC) prices. Indeed, some of the economic difficulties in some metal markets--particularly the imbalance of production vs. markets for copper, can be traced indirectly to the OPEC cartels' heavy-handed impact on copper producing LDC's which must produce copper at any price to meet their oil bills. (2) Among the major oil importing LDC's are the Philippines and South Korea. 50th nations have substantial cement industries. The South Korean industry is geared for major export markets in the Far East. Both nations have ambitious plans for economic growth in order to accommodate burgeoning populations with ever increasing expectations for high standards of living. These plans had some success, more or less, until the high OPEC oil cartel charges had to be borne. Now, in common with all oil-deficit areas, the Philippines and South Korea are seeking lower cost sources of energy. Both countries have coal deposits. In the case of the Philippines, the reserves are in scattered, relatively small deposits. Most of the coal deposits are faulted, folded and, in general present formidable production problems for limited reserves. Nonetheless production has been on the order of about 70,000 to 150,000 tons per year in the last 30 years. Prior productions (1920-1941) varied between 9,000 Co 150,000 tons per year. (13)

Jan 1, 1978

By Frank M. Howell

Creede, one of the younger major mining camps in Colorado, grew spectacularly to a town of eight or ten thousand people in the early 1890's following discovery of rich ore in the Amethyst and Last Chance mines. Gross metal production in gold, silver, lead, copper and zinc rose to a maximum of four million dollars a year in 1893. Annual production dropped to much lower figures and ranged between one hundred and five hundred thousand dollars per year during the period from 1914 to 1940. Production reached a gross of eight hundred thousand to one million dollars per year by the mid-1950's. In the years 1953 to 1957, Steven and Ratté conducted geologic investigations which were carried on as part of a cooperative program of the U. S. Geological Survey and the Colorado Metal Mining Fund Board. In a preliminary report on the Creede District, Steven and Ratté suggested that the Bulldog Mountain Fault Zone appeared to be a favorable structure to prospect. On the basis of that recommendation, augmented by independent work done by Manning W. Cox, the property was acquired, transferred to Bulldog Mountain, Inc. and financed by an O. M. E. loan. Late in 1963 Homestake Mining Company, under a Lease and Option Agreement, backed the venture by furnishing additional funds plus management.

Jan 1, 1969

SOLUTION MINING Solution mining techniques present a means of extracting soluble ores, particularly such materials as salt and potash, from horizons which are not accessible by conventional mining. In the process of dissolving materials, it is evident that solution may be complete or partial. In general, the solution mining operations described in the following section relate to complete solution of the desired compound. Even though the solution of material is complete, there may be instances in which insoluble material is present to a large extent either as granular separated particles or as insoluble layers. The process required for obtaining the desired product involves access wells to reach the deposits, sufficient water supply to yield the production goals, and the development of an underground cavity. The process of solution mining, therefore, depends to a great extent on three factors: availability of a relatively pure strata or formation of salt or potash to be mined, access well or wells, and adequate control of the solutioning process so that enlargement of underground cavities can be fairly well delineated. Since halites represent the most general ores mined by this procedure, the considerations which follow are based primarily on the production of sodium or potassium chloride. The producing formations may be in the form of bedded evc~porites wherein the salt member may be some 30 to 500 ft thick or from salt domes in which great depths of salt occur. Solution mining has been carried out to depths of nearly 10,000 ft. The recovery of saturated brine from wells drilled to effect the solution-mining process leads to further processing. In many instances, the procedures are relatively simple and involve simple recrystallieation or fractional crystallieation, while in others more complex flow systems are required before a final product is obtained. The intent of this section is to provide information relative to the basic procedures for obtaining materials which are soluble in water and to acquaint the engineer with the various aspects of the overall problem which in many instances, may become quite complex and present numerous difficulties. The storage of fluids, particularly hydrocarbons, underground has proven to be a very important part of industry operations. Cavities formed in salt provide excellent storage facilities. The formation of well-defined controlled configurations of such cavities has been possible because of better understanding of the solution process, wide experience gained over nearly 30 yr, and improved technology in drilling and completing wells, surveying caverns, and the operation of numerous types of systems. Solution mining techniques will improve in the future. Many facets of the simple operation of pumping solvents and extracting valuable minerals require further study. Developments undoubtedly will occur to further the processes of mining by solution. In addition to those whose names appear in connection with the individual subjections which follow, a major role in assembling and processing the material in this section was played by Dr. D. A. Shock, Central Research, Continental Oil Co., Ponca City, Okla.

Jan 1, 1973