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By J. A. Cremeens, D. D. Overton, J. C. Varnier

"Slope failures that occurred in 2008 and 2009 at the Pikeview Quarry in El Paso County, Colorado, USA were investigated using three-dimensional discrete element modeling methods. Large scale block sliding failures occurred along weak bedding planes that dip steeply into an excavation located at the toe of the slope. Several mining sequences at the toe of the slope were simulated to evaluate the effects of various degrees of extraction and backfill on slope stability. Slope stability back analysis was conducted using pre-failure and post-failure conditions to determine the joint shear strength properties. Laboratory testing was also conducted to determine intact rock properties. Three-dimensional discrete element analysis was uniquely applicable to this evaluation because it allowed representation of shear stress of the basal sliding surface and it afforded evaluation of several scenarios of extraction and backfill at the toe of the slope. INTRODUCTION The Pikeview Quarry is an aggregate quarry located approximately five miles northwest of Colorado Springs in El Paso County, Colorado, USA. The quarry has been operated by several owners since the early 1900s. The Pikeview Quarry has been a major source of construction aggregate for the Colorado Springs area for many years (MSHA 1986). In the 1950s, the site was mined by Peter Kiewit and Sons to provide limestone for the construction of the nearby Air Force Academy. A large scale slope failure occurred on December 2, 2008, which stopped mining activity at the Pikeview Quarry. A second, related slope failure occurred on September 13, 2009. The second slope failure was located immediately adjacent to the initial December 2008 failure. The objective of this publication is to discuss the three-dimensional slope stability evaluation. The causal relationships of slope instability are not within the scope of this publication. However, omitting the precursors to slope failure would limit understanding of the nature of the slope stability evaluation. The regional and local geology and the history of slope instability at the Pikeview Quarry aid in understanding these precursors. Two main failure mechanisms were hypothesized during the failure investigation to explain the triggering of the 2008 and 2009 large slope failures at the Pikeview Quarry. Both mechanisms are given equal credence in this publication. Quarry excavation was a key factor in the slope instability for both failure mechanisms. The objective of the three-dimensional model was to evaluate the effects of extraction and backfill at the toe of the slope with respect to slope stability. GEOLOGY Regional and local geology are both important factors in slope instability at the Pikeview Quarry. Geologic structure at the quarry is related to regional mountain building and basin development associated with the Laramide Orogeny and the Rocky Mountains. Lithologies at the Pikeview Quarry are also related to regional trends. Localized geologic features, primarily related to weathering and erosion, have also been major contributing factors to slope instability at the Pikeview Quarry."

Jan 1, 2017

By Ross A. Scarano

It wasn't until late 1976 that the U. S. Nuclear Regulatory Commission (NRC) set about to address the uranium tailings issue in earnest. It was decided that a generic environmental impact statement related to uranium milling operations would be prepared to support formal tailings regulation. We recognized, however, that this was a task that would take many years to complete and we could not take a "business as usual" approach to tailings management in the interim; the issue was too sensitive. To facilitate licensing during the interim period, the NRC developed guidelines in May 1977, for the industry in the form of the following performance objectives for tailings management: Siting and Design 1. Locate the tailings isolation area remote from people such that population exposures would be reduced to the maximum extent reasonably achievable. 2. Locate the tailings isolation area such that disruption and dispersion by natural forces is eliminated or reduced to the maximum extent reasonably achievable. 3. Design the isolation area such that seepage of toxic materials into the groundwater system would be eliminated or reduced to the maximum extent reasonably achievable. During Operations 4. Eliminate the blowing of tailings to unrestricted areas during normal operating conditions. Post Reclamation 5. Reduce direct gamma radiation from the impoundment area to essentially background. 6. Reduce the radon emanation rate from the impoundment area to about twice the emanation rate in the surrounding environs. 7. Eliminate the need for an ongoing monitoring and maintenance program following successful reclamation plan. 8. Provide surety arrangements to assure that sufficient funds are available to complete the full reclamation plan.

Jan 1, 1980

By Rolando V. Cuaño

For geostatistical applications, heterogeneous spatial phenomena are better modeled as mixtures of populations. However, the modeling of the constituent populations can become complex. The alternative mixture model offers a simplified approach to the w modeling problem. The model is applied and tested on the Walker Lake data set. Compared to the univariate ordinary kriging model, the alternative model generates less biased block estimates.

Jan 1, 1996

By L. Bernoth, I. Firth, S. Rhodes, P. McAllister

As biotechnologies emerge from laboratories into main-stream application, the benefits they offer are judged against competing technologies and business criteria. Bioremediation technologies have passed this test and are now widely used for the remediation of contaminated soils and groundwaters. Bioremediation includes several distinct techniques that are used for the treatment of excavated soil and includes other techniques that are used for in situ applications. They play an important and growing role in the mining industry, for cost-effective waste management and site remediation. Most applications have been for petroleum contaminants, but advances continue to be made in the treatment of more difficult organic and inorganic species. This paper discusses the role of biotechnologies in remediation and pollution control from a mining-industry perspective. Several case studies are presented, including the land application of oily wastewater from maintenance workshops, the composting of hydrocarbon-contaminated soils and sludges, the bioventing of hydrocarbon solvents, the intrinsic bioremediation of diesel hydrocarbons, the biotreatment of cyanide in water from a gold mine, and the removal of manganese from acidic mine drainage.

Jan 1, 2000

By NICHOLAS BELLUSCI, D. Erik Spiller, Patrick R. Taylor, VICTOR BRAMAN

Approximately 30% of the world’s production of soda ash comes from mining and processing of naturally occurring deposits of sodium carbonate containing species. Of these deposits, the largest and most profitable have been the trona beds found near Green River, Wyoming. Processing of trona ores is water-energy intensive, particularly due to unit operations of calcination, dissolution, and evaporative crystallization to wield a high-quality dense soda ash product and reject the insoluble gangue species, primarily in the form of oil shale. However, it is speculated that the glass-manufacturing industry, the largest consumer of soda ash, may be able to use a product of a lower grade and consistent level of the insoluble constituents. Thus, pre-concentration of trona ore was investigated using sensor-based sorting, to produce a beneficiated trona stream that would be fed to calcination. The study encompassed preparation of a run-of-mine (ROM) Green River ore sample, selection of 25–75-mm-sized specimens, imaging of the specimens by x-ray transmission (XRT), color, and laser-induced fluorescence (LIF)-based sensors, insoluble analysis of the specimens, and a bench-scale sorting test. Results of the study established that a correlation between the color of the individual ore particles and their insoluble content existed and that a surface detection-based sensor, particularly LIF, was apparently more suitable than XRT to produce a beneficiated trona stream. The bench-scale sorting test demonstrated that a 65% separation efficiency and a 70% recovery of trona could be achieved.

Aug 9, 2022

By Marcus M. Key

Silicosis among metal miners is an ancient disease, probably as old as mining itself.' However, the primitive forms of mining were not productive of much silica dust, and the short life span of slaves used in mining probably precluded the development of more than a few sporadic cases of silicosis. Early diagnostic terms of miners' asthma and miners' phthisis suggested an occupational relationship and a tubercular component, but little attention was given to silicbsis until the turn of this century when epidemics of silico-tuberculosis arose due to the great expansion of the mining industry in the United States, especially silver and gold mining. The expansion was accompanied by mechanization and the introduction of pneumatic tools, which generated increasing amounts of fine silica dust. Mining communities were crowded and hygiene was poor.' The tubercle bacillus would probably have flourished even without the predisposition of silicosis.' As is so often the case in occupational health, biostatistical analyses first called attention to the problem, and environmental-medical studies later confirmed its existence. The bio-statistical analyses were occupational mortality statistics compiled by the Prudential Life Insurance Company in 1907, showing evidence of excessive mortality from tuberculosis and relationship to dust exposure. I The

Jan 1, 1971

By W. Irwin

As a consequence of the oil crisis of the 70?s, the commercial value of coal increased very sharply and an upward trend in coal prices although now less pronounced, continues today. The graph shown in figure 1 illustrates the trend in the F.O.B. price of U.S. metallurgical coal. This trend occurs during a time when mechanized mining is firmly established as a means of production throughout the coal mining world. With modem methods of mining, mechanical cleaning is a necessity and quality control is no longer entirely dependant upon coal face practice. The efficiency of fine coal recovery is of vital economic importance to present day operations and good practice in this field contributes significantly to improving profitability. Numerous processes are available for the duty and this paper discusses one such system, namely the practice of froth flotation.

Jan 1, 1980

By Gerald L. Dollinger, Joseph A. Roby, David Krauter, Kenneth Deering

Three high performance TBM's equipped with large diameter (483mm) disc cutters are currently operating in Norway. This paper summarizes the design philosophy, field performance and ongoing technical development of these cutters. Included are discussions of the early problems encountered with their usage and the solutions to these problems that have been developed. Also included are discussions of the penetration rates and cutter usages observed. From this data it is concluded that high performance TBM's with large diameter cutters can produce significant improvements in both overall performance and in cutter costs under hard rock conditions.

Jan 1, 1991

By G. Chancellor

"INTRODUCTION The paste plant is located at the Barrick Goldstrike mine in Northern Nevada on the Carlin Trend. The Goldstrike property consists of an open pit and an underground mine; along with two processing facilities: a roaster and an autoclave. The underground portion of the mine produces approximately 1,800,000 ore tons per year and approximately 400,000 ounces. The mine is broken up into four distinct zones: Banshee, Meikle, Rodeo and Northpost. The current paste plant services both the Rodeo and Northpost zones. Development of the conceptual designs and permit approval for this plant was an extensive process that took over a decade to complete. A testing program was developed in conjunction with this process and implemented throughout to ensure the following metrics were achieved: ensure no environmental impact, material available onsite would be able to flow through the pipe to all required locations, and that this material could achieve the appropriate final strength. PLANT AND UNDERGROUND CONSTRUCTION This is the first paste plant to be built in Nevada. The paste plant at Goldstrike began construction in January 2012 and was completed in March of 2013. This plant was constructed to service the Rodeo side of the underground mine which previously utilized a cemented rock fill (CFR) plant to meet their backfill needs. However, in March of 2013, the same month the plant was commissioned, the raise that fed this CRF plant was mined out in a planned phase of the adjacent open pit. This made the switch to paste all the more difficult as it was being relied on for as the sole source of backfill production even though the system yet to be fully tested and optimized. The plant was designed to be fed with onsite Roaster tailing which would be thickened and then mixed with cement and fly ash. The plant was designed to pump 177 tons of paste per hour with a utilization of 65%. The original design specifications for the paste were 77% solids with varying binder contents depending on where the paste was being placed"

Jan 1, 2015

By W. M. Haffner, S. L. Borek, H. M. Edenborn, R. W. Hammack, D. H. Dvorak

The conceptual designs of three new applications for the biogenic &S treatment of metal- containing waters are presented. These include: 1. the treatment of a circumneutral-pH ground water containing Zn and Cd using limestone as an alkalinity source, 2. a two-step treatment process where toxic heavy metals in contaminated ground water are recovered separately from nontoxic metals to lessen disposal costs, and 3. a copper recovery process that may be a low-cost alternative to solvent extraction/electrowinning or cementation for dilute copper leach liquors. Preliminary results of initial field testing are discussed

Jan 1, 1995

By D. Mudd, G. Robertson

"Ask an average non-industry person on the street “What is coal? What is coal mining? What is a coal miner?” The most common answers are coal is something Santa puts in your stocking for being naughty, coal mining is destroying the earth causing global warming, and a coal miner is a person that uses a pick and shovel to dig coal out of the earth. As farfetched as these answers seem, unfortunately this is the opinion of many Americans. Realizing the lack of educational opportunity regarding coal and coal mining, a first-of-its-kind grassroots coal education program known as CEDAR (Coal Education Development and Resource) was created. What started from a general conversation at the December 1992 North Carolina Coal Institute (NCCI) Winter Meeting at the Mid Pines Club in Southern Pines, North Carolina led to the creation, and later expansion of, CEDAR. NCCI President, Gene McBurney, challenged John Justice, NCCI Board Member from east Kentucky, to come up with an idea of how to improve the image of the coal industry, pledging $5,000 from the NCCI as seed money to assist in the development of any such program. John then met with the leaders of Coal Operators and Associates, Inc., (COA) in Pikeville, KY where they agreed to match the NCCI commitment, as well as to assist in the program’s development. After further meetings with representatives from industry, business, and the local school system, CEDAR, Inc. (of east KY) was born. The first year of implementation, the program offered coal education programs to public and private schools in one county in east Kentucky. Although it started in the coalfields of eastern Kentucky, it certainly did not end there. After an amazingly successful first year of the program, it didn’t take long for industry leaders in the western Kentucky coal-fields to learn about, and take note of this new, unique, and exciting program that provided opportunities for teachers and students to learn, “the rest of the story” about the coal industry. Through the joint efforts of Costain Coal, and the Western Kentucky Coal Association, CEDAR of West Kentucky, Inc. was formed in 1994, and has operated since that time, except for the two year period from 2004-2006. The program restarted in 2006 under the name of CEDAR West, Inc. and continues to be offered in six western Kentucky counties."

Jan 1, 2015

By Neal P. Cochran

My talk today is an effort to project our thinking forward a few years to that point in the future when we will be producing gas and liquid fuels from coal. To those of you that are concerned with meeting today's production quota--my remarks may sound like a Buck Rogers projection. Not so. Although I'm talking about the future, please understand that my thoughts are focused on the near term future. The coal plant of the future will be an energy plant producing energy products to meet the needs of our modern society. This plant is an outgrowth of Government- industry cooperation. Much of the research work that makes such a plant possible was jointly funded, other work was a continuation into development of private research expenditures, other work was performed by private research organizations with Government funding, other work was performed in Government laboratories, both State and Federal. As indicated above, and in the title of my talk, I expect to describe the coal plant of the future. I will describe a plant producing Carbon, Oil, Pipeline gas, and Electricity--Project COPE. This plant copes with the Atomic-Nuclear Group. As stated above, this plant is an energy plant. Energy plants today are large-scale operations. Power plants of 5,000 megawatts are projected, refineries of 500,000 daily barrels are near term probabilities, 48" transcontinental gas pipelines are with us today and 25,000 daily ton mines are here as well. The COPE plant will be of the same general size and require 50,000 - 100,000 tons of coal per day.

Jan 1, 1969

By J. F. T. Agapito

Energy West Mining operates the Deer Creek and Cottonwood/Trail Mountain coal mines in the Wasatch Plateau about 40 km (25 miles) southwest of Price, UT. The Deer Creek Mine extracts the Upper Blind Canyon seam and the Cottonwood/Trail Mountain Mine extracts the Hiawatha seam 12 to 36 m (40 to 120 ft) below. Both seams average about 2.8 m (9 ft) in thickness. Cover depths exceed 550 m (1,800 ft) in a large portion of the unmined reserve. Stability problems at Deer Creek are mostly due to coal bursts caused by high stresses associated with deep cover and sandstone channels. Most of the bursts have occurred in gate pillars and, to a lesser extent, at the longwall face and during development. The introduction of a two-entry gateroad system with 9-m- (30-ft-) wide yield pillars has been a major factor in controlling and minimizing gate pillar [ ] bursts (Agapito et al., 1988). However, some bursting began to occur in the 9-m- (30-ft-) wide pillars as cover depths reached 550 to 610 m (1,800 to 2,000 ft). This was due to more rapid and higher abutment loading in areas with very strong roof and stiff floor.

Jan 1, 1997

By David J. Akers

In past years, water drainage control in coal mines has been primarily directed on the basis of water quantity rather than quality. Due to the recent intense interest in total ecology and environment, emphasis has shifted to the point where the water exiting from a mining operation may be of better quality than when it enters. In most operations this has meant the use of treatment methods (neutralization) while the technology for the prevention of acid drainage is being developed or refined. To date, underground abatement of acid formation has generally been less expensive but also less effective than surface treatment of the mine water. It seems probable that total mine water pollution control will have to include both underground abatement and surface treatment methods. The general acid producing reaction involving the oxidation of pyrite - 2FeS2 (pyrite) + 702 + 2H20 ? 2Fe2S04 + 2H2SO4 - is well known, even though the individual steps are not clearly understood. The major implication of this reaction, that acid production can be eliminated by not allowing the contact of pyrite with free oxygen or water, has been well substantiated both in the laboratory (1,2) and in practice. (3) Underground abatement or control processes can be generally classified into two types: (1) the effective control or elimination of acid causing reactions within the mine, and/or (2) the reduction or prevention of water flow into and out of the mine. Recognizing the fact that these two types may be directly inter-related, this paper will, for the purposes of clarity and simplification, discuss each separately.

Jan 1, 1973

By Hassan El-Shall, El-Sayed A. Abdel Aal

The major goal of this study is to decrease iron content in wet-process phosphoric acid. Reducing the amount of post-precipitated sludge in the acid is another important objective in this investigation. In order to achieve these goals, research efforts have focused on bench scale testing of an iron-chelating reagent to remove iron from phosphoric acid produced from South Florida high-iron and -magnesium phosphate concentrate, and plant testing using freshly produced concentrated acids for reducing the post- precipitated sludge. The data obtained in the above studies suggest that the addition point of the precipitating reagent is very important, as the precipitated iron compound has higher solubility at higher P2O5 concentrations. Up to 60% Fe2O3 removal efficiency is achieved depending on the amount of the reagent, concentration of acid used, and operating conditions. The addition of precipitating reagents to freshly concentrated phosphoric acid leads to a decrease of up to 84% in sludge volume percentage depending on acid type and clarification conditions. Decreasing the volume percentage of the sludge facilitates acid handling as well as decreases the adherent water- soluble P205 leading to lower total P2O losses.

Jan 1, 2002

By James E. Lonergan

To determine the best materials handling system for surface mined materials, one must develop a mine plan for each candidate system based on the most efficient use of that system. This is essential for a fair, unbiased economic compari¬son of the candidate systems. This paper will present two case studies where an integrated mine planning /systems engineering approach has been utilized at different levels of detail in the analysis of an in-pit crushing/conveying system vs. total truck haulage at 2 open-pit copper mines.

Jan 1, 1985

By C. C. Harvey

Asia is experiencing a growth market for industrial kaolins for use in ceramics, paper, plastics and other market sectors. Export and import data for the Asian countries reflects this growth with the Peoples Republic of China as the major exporter of clays and Japan the major importer. The growth in tonnage and product sophistication of kaolins produced on Belitung in Indonesia is typical of developments that are taking place in many locations in Asia. This region therefore presents opportunities for mineral processors and a challenge for the exploration geologist, the mineral processing engineer, the mineral economist and the marketing specialist.

Jan 1, 1996

By ETHAN FUSTER, STEPHEN LEE, Richard Ray

By offering savings in space and capital cost compared to ducted axial and centrifugal fan systems, horizontally mounted jet fans are commonly used worldwide to ventilate vehicular tunnels. They discharge high-velocity jets to transfer momentum to the surrounding airstream to induce longitudinal flow in the same direction as the jet. Vertically mounted jet fans installed in exhaust shafts have been successfully used to ventilate a large passenger rail overbuild in New York City. A comparison of shaft dimensions, vertical placement of the jet fans and measured shaft airflows is presented to evaluate optimum jet fan configurations. Measured shaft airflows are compared to airflows predicted by computational fluid dynamics (CFD) simulations of a three-dimensional model of the overbuild.

Sep 1, 2022

By C. Fuellenbach, J. Brune

"INTRODUCTION Mining activities must be safe and profitable. These two requirements influence each other. The purchase and implementation of safety improvements costs money. Injuries and illnesses at mines stop or delay production and may result in additional costs or a loss of profit. Other effects of injuries and illnesses include the negative influence on employee morale, corporate reputation and conflicts with contract partners. Based on this researchers asked the question: are mines with lower rates of injuries and illnesses more profitable than mines with a higher frequencies? One aspect of this research is the evaluation of the safety situation and the measurement of benefits of safety improvements in the German mining industry. In the following paper, this part of the research will be examined. The main aim is the evaluation of injury rates in different German mining sectors and regions in Germany. SELECTION OF GERMAN MINING OPERATIONS The research team decided to focus the study on the salt and potash and the aggregate and industrial minerals mining industries in Germany. These two mining industries are different in the number and size of operators, structure of the industry, pricing and markets. The selection of two different industries adds to the clarity of the evaluation. Salt and potash mining industry The German salt and potash industry is primarily located central Germany. All salt and potash mines in Germany are underground operations. In 2015, the German potash industry employed 8,100 employees and generated a total revenue of 2 billion Euros. German potash reserves include magnesium compounds like kieserite (MgSO4·H2O), in addition to sylvite (KCl) and carnallite (KMgCl3·6(H2O)). The German salt industry employed 2,300 people in 2015 and generated revenue of 800 million Euros (Krueger, 2015) There are seven mining companies with salt and potash operations: esco-european salt company GmbH & Co. KG, K + S Kali GmbH, Saline Luisenhall GmbH, GSES Glückauf Sondershausen Entwicklungs- und Sicherungs-gesellschaft GmbH, Südwestdeutsche Salzwerke AG, Wacker Chemie AG and Südsalz GmbH. In this way, esco – european salt company GmbH & Co. KG is an affiliated company. Esco was founded as a joint venture of K + S and Solvay in 2002, since 2004 K + S is the sole holder (esco - european salt company GmbH & Co. KG, 2016). Likewise, the Südwestdeutsche Salzwerke AG has a controlling interest in Südsalz GmbH (Südsalz GmbH, 2016). Aggregate and industrial minerals mining industry The aggregate mining industry in Germany is comprised of many small mining operations and relevant companies. According to the German Department of Economics (BMWi, 2015), the following industrial materials are classified as aggregates: fluorite, barite, kaolin, quartz and quartz sand, quartzite, silica, loamy and foundry sand, pegmatite sand, shale, clay, bentonite, schistose, limestone and dolomite, gypsum and anhydrite, basaltic lava and lava sand, gravel and split, pebble and silicic sand and peat."

Jan 1, 2017

By Ravi Shah, Augusto Lucarelli, Daniele Peila

"In mechanized tunneling the annular gap between the segmental lining and the surrounding soil caused by tunnel driving, must be backfilled almost instantaneously with an adequate grouting mortar. The objective of this research is to perform a fully three dimensional modeled parametric study using FLAC 3D and evaluate the effects of backfill grouting on the tunneling performance. The research focuses on comparisons between different injection materials and state-of-the-art Bi-Component grout and their effects on the settlements on the surface. The research consists of testing a regular situation of tunnel excavation using a shielded machine with face under pressure. The tunnel dimensions and the soil properties are selected as close as possible to the reality and based on Turin Metro case. 1 INTRODUCTION Excavation of tunnels in urban areas can induce ground movements, which have negative effects on existing structures. In such scenarios, shield tunneling has become a well-accepted construction method in various ground conditions. It is characterized by relatively complex interactions between the soil, the tunnel boring machine (TBM) itself, the tunnel lining and the tail void grout. The problem to control the settlement depends on the face pressure, ground properties and back filling procedure and material of the tail void. The face pressure acts against the front to guarantee the face stability. In case of EPB TBMs the stability of the tunnel face is ensured through the excavated soil itself, which is conditioned and is maintained in compressed state within the excavation chamber. When excavating with TBMs a tail void is created between ground and the lining (Fig.1) after the TBM excavation and ring assembly that must be backfilled instantaneously by injecting the backfill material through the TBM’s tail shield. The process is of primary importance as it reduces the surface settlements and creates an immediate link between the ground and lining, sealing against ground water and leakage, reducing the differential movements between segments and providing long-term stability. The most used backfilling materials are: Inert mixtures that do not contain cement instead sometimes they are replaced by fly ash or other substitutes. A typical design of an inert mortar consists of sand, fly ash, bentonite and water. Pea gravel, which is constituted of granular materials with grain size ranging from 8 to 12 mm. This mixture is highly recommended for tunnels being constructed in rock mass with little deformation rates.Cement mortar is composed of cement, water, aggregates and sometimes bentonite. Cement controls the principle mechanical property of the mix, which can reach high values of 15-20 MPa in 28 days. The aggregates contribute towards the shear strength and reduce the pumpablity of the mix (Thewes and Budach, 2009). The reduced active systems have a cement content of 50-100 kg/m3, whereas the active system the binder component derives full hydration with cement content of over 200 kg/m3 ."

Jan 1, 2016