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By Mark E. Gershon

The development of long term plans and schedules for strip mines now faces many companies, especially those developing large properties in the West. The rule of mining the lowest strip ratios first, while delaying equipment acquisitions and recouping investment the fastest, creates the situation where stripping ratios are too high in the latter years of mining operations. A program concept taking life of mine return on investment into account is developed in this paper to optimize mine scheduling and equipment acquisition. In addition, quality considerations (heat content, ash, sulfur, washability) can be considered by including the appropriate blending constraints to meet contract requirements.

Jan 1, 1983

By Seth Pollak, Jon Hurt, Mark Havekost, David Vardiman, James Schick

"INTRODUCTION The Long Baseline Neutrino Facility (LBNF) Far Site Conventional Facilities are proposed to be sited at the Sanford Underground Research Facility (SURF) located within the former Homestake Gold Mine in Lead, South Dakota. The project involves excavation and support of three large caverns which will house four 10 kT fiducial volume liquid argon (LAr) neutrino detectors and cryogenic equipment, as well as numerous ancillary connecting drifts and chambers. This paper describes the geological setting of the project, the geotechnical investigation undertaken nearly a mile underground and the challenges associated with collection of reliable data in a high stress and geologically complex environment. The layout for the new facility will be presented, along with a description of some of the constraints that will impact construction, including shaft access and working within an operating research facility. THE LBNF PROJECT The global neutrino physics community is coming together to develop a leading-edge, dual-site experiment for neutrino science and proton decay studies, the Deep Underground Neutrino Experiment (DUNE). The facility required for this experiment, the Long-Baseline Neutrino Facility (LBNF), will be an internationally designed, coordinated and funded program, comprising the world's highest-intensity neutrino beam at the Fermi National Accelerator Laboratory (Fermilab) in Batavia, IL and the infrastructure necessary to support massive deep underground cryogenic detectors 800 miles (1,300 km) downstream at the LBNF Far Site at the Sanford Underground Research Facility (SURF), in Lead, South Dakota. The Deep Underground Neutrino Experiment is expected to achieve transformative discoveries, making definitive determinations of neutrino properties, the dynamics of the supernovae that produced the heavy elements necessary for life, and the possibility of proton decay. Neutrinos created by the LBNF beamline will travel on the 1,300 km (800 mi) path shown in Figure 1 leading straight through the earth's crust to intercept DUNE's massive, cutting-edge neutrino detector at the Sanford Lab. No tunnel is needed as neutrinos pass easily through soil and rock rarely interacting with the matter. The DUNE far detector will consist of four modules, each of which will be housed in a cryostat containing 17,000 metric tons of liquid argon target material, providing a 10kT fiducial volume. The LBNF Far Site Conventional Facilities project will excavate and fit out a set of four caverns 4850 ft underground in which to place them."

Jan 1, 2016

By Brian S. Prosser, Ian J. Duckworth

With the trend in the coal mining industry pushing towards improved productivity and greater production, the number and size of longwall panels is increasing rapidly. The development and mining of large longwall panels causes unique problems in the provision of adequate ventilation at the working faces. Because of the transient nature of the longwall panel, and the difficult field conditions for ventilation measurements, detailed pressure and volume surveys are often not conducted around the longwall circuit. This is unforlunate because the highest resistance airway in longwall mines is typically the longwall tailgate, which frequently represents the only unregulated split in the ventilation network. This paper examines data collected from ventilation studies of longwall panels at nine mines. The variation in airway resistance, ventilating pressure and airflow is examined and compared with specific factors such as airway dimensions, ground conditions and support type used.

Jan 1, 1997

By Felicia F. Peng

Flotation process is particle hydrophobic surface-based separation technique. To improve the essential flotation steps of collision and attachment, and reduce detachment probabilities between air bubbles and hydrophobic particles, a selectively designed cavitaion venture-tube can be used to generate very high numbers of pico-nano bubbles to flotation column. Fully embraced by those high numbers of tiny bubbles, hydrophobic particles are readily attracting those tiny bubbles to their surfaces. The results of column flotation of Pittsburgh No.8 seam coal are obtained in a 50 cm ID and 162cm height flotation column equipped with static-mixer and cavitation-venture tube, using kerosene as collector and MIBC as frother. Design of experiment procedure combined with statistical two-stepwise analysis method are applied and attempted to made the optimizing the grade and recovery. The effect of independent variables on response has been explained. Combustible material recovery of 85-90% at clean coal product of 10-11 % ash are obtained from feed of 29.6% ash, with reduced amount of frother and collector than that used in conventional column flotation. The column flotation process utilizing the pico-nanobubbles can also be extended to the lower limit and upper limit of particle size ranges for better recovery minus 75 µm and 300-600 µm, respectively.

Jan 1, 2013

By David J. Kruse

Accurate field measurements are essential when validating a conveyor design. They are fundamental in determining a conveyor's behavior, its long-term maintenance requirements, and the life expectancy/ condition of the installed equipment. Field measurements are also invaluable in forensic engineering, particularly when vital equipment has failed This paper will discuss a wide variety of data acquisition equipment, field measurement techniques and accuracies achieved State-of-the-art, custom designed monitoring equipment, as well as, ''08-the-shely instruments and sensors, will be discussed.

Jan 1, 2004

By Daniel R. Hack

Spatial relationships among physical 'and chemical properties pertinent to economic development of sand and gravel deposits have been little studied. Models need to address trends or zonation of material properties applicable to mine evaluation and planning or as a guide among deposits for use in regional assessment Models can then be utilized to design sampling programs to optimize additional data acquisition. Development of a preliminary methodology in the lower Boise River Valley, western Idaho, will utilize historical and recent data from a terrace-gravel deposit. Classical statistics and techniques of spatial data analysis will be evaluated as a precursor to formal geostatistical evaluation.

Jan 1, 2002

By Richard Minnitt, Philippe Renard, Christina Dohm, Winfred Assibey-Bonsu, Matthew Aboagye, Julien Straubhaar, Mahlomola I. Mabala

The application of multiple point statistics (MPS) in oil studies has gained traction over the years; however, the use of MPS in mineral resource estimation and classification is still limited. This is despite MPS’ ability to deal with complex and heterogeneous geology better than the commonly applied two-point based methods. The availability and choice of a representative training image (TI) are often cited as the main challenge holding back MPS’ application in mining geostatistical studies. On the other hand, the general approach used in mining whereby early focus is on higher grade areas and lower grades are planned to be mined later presents a massive opportunity for the development of representative TIs. Mined-out areas provide large amounts of historical data that can be used to develop training images or training datasets that can be used to estimate in mining extension areas (often lower in grade), provided low grade areas are underpinned by similar geology analogue. This approach will enable more robust estimates in mine/pit extension areas for both high- and low-grade extensions than with traditional two-point geostatistical methods.

Jun 25, 2023

By Robert J. Timko, Edward D. Thimons, Robert L. Derick

In early June, 1986, a fire of unknown origin erupted in one of several main entries of a coal mine located in southwestern Colorado. The fire was aggressively fought with high- expansion foam. As a result of several strategic decisions, the fire appeared to be held in check. Unfortunately, sufficient quantities of foam were unavailable and as soon as the foam was depleted, control of the fire was lost. To prevent further damage and the possibility of an explosion, all entries to the mine were sealed. This paper recounts activities from the discovery of the fire to the initial reentry of the sealed mine including location of the fire, the decisions made to best combat it, and the steps taken to rapidly and securely seal the mine when this became necessary. The mine operator requested the Bureau's assistance in obtaining and analyzing mine fire gases taken from sampling ports placed through the mine seals. This report describes how samples were taken and what gases were analyzed. In addition, this work describes the initial exploration of the sealed mine by personnel using oxygen breathing apparatus.

Jan 1, 1987

By Robert R. Brandom

The Boss-Bixby deposit is one of several iron deposits that occur in the Precambrian igneous rocks of southeastern Missouri. It differs, however, from all of those deposits by its significant contents of copper, cobalt, and titanium, and its close relationship with a basic igneous intrusion. Ore microscopic study of selected drill core samples has shown that the hypogene ore minerals are magnetite, hematite, chalcopyrite, bornite, covellite, ilmenite, rutile, sphalerite, cobaltian pyrite, carrollite, scheelite, and wolframite. Subsequent partial oxidation has formed martite, pseudobrookite, and anatase. Textural evidence indicates that two stages of iron and iron-titanium oxide formation were followed by the deposition of the copper-iron sulfide minerals and carrollite.

Jan 1, 1985

By Steven L. Webb

In 1965, Monsanto started planning of a new dike (No. 15) for use in disposing of ore tailings at its Columbia, Tennessee phosphorus plant. Generally, in the phosphorus industry only clay tailings are produced making it necessary to borrow fill for construction of a retaining dike. Borrow area investigations indicated that weathered shales and limestones adjacent to the dam site would provide adequate construction materials. It was proposed that the more clayey weathered shales would be used for the impervious core and the more granular weathered limestones would be placed in the outer shell of the dike. A dike section is shown in Figure 1 with gradation curves for core and shell materials in Figure 2. Figure 3 shows an aerial view of the tailings pond and dike during first-stage construction. Although the borrow area explorations indicated that the weathering of the sedimen-tary deposits was highly irregular, it was not considered necessary, at the time, to specify special excavation techniques that would ensure a thorough blending of the materials in the borrow pit. Instead, because of the short haul distance, a scraper operation for both clay core and granular shell materials was adopted as the most economical construction method. Using this materials-handling technique, variations in permeability could be expected in the compacted layers inthe embankment. Where continuous layers of less clayey limestones were placed in the core of the dam, extending from the upstream to downstream shells, seepage losses would be expected to increase substantially. Upon completion of the damn 1966, and shortly after reservoir filling, it was apparent that the construction technique used had resulted in the formation of pervious layers through the clay core. Excessive seepage on the downstream face of the dike was noticeable within a very short time. A monitoring program was established, using piezometric observations and flow measurements. These data indicated that seepage should be reduced and the application of an asphaltic emulsion

Jan 1, 1971

By R. I. Pennington, J. L. Vanderbeek

Investigations have been conducted at Chino Mines Co. into the effect that SAG mill recycle material (critical size) exerts on SAG mill throughput and specific energy requirements. Tests were conducted on laboratory, pilot, and plant scales to evaluate the merits of alternative treatment options. Removing critical size material from the SAG mill circuit has been shown to improve new feed rates by 84% with a reduction in specific energy (kWh./t) of 88%. Test results obtained to date are presented.

Jan 1, 1987

By W. DR. Fritz

Technical progress depends on strategic objectives and a concept showing how to benefit from the effects of novel techniques in an innovation process and how to implement them creatively in harmony with manpower capabilities. With the invention of prime movers, it was initially power engineering which dominated the development of industrial history before it was replaced by production techniques resulting from the more widespread use of machines. With the advances in the field of data processing and with the introduction of novel communication techniques, it is information technology- which today is having an ever increasing impact on technological progress. The main objectives of information technology in this context are a positive influence on the ?time? factor as well as the provision of tools to handle the complexity governing many operational processes through a concentration of information for the decision-making process. The German hardcoal industry became aware of the chances inherent in these new technological possibilities for the optimization of operational sequences and of decision-making and planning processes as a potential for success at an early stage and it has worked out a purposeful concept for their implementation.

Jan 1, 1992

By Duluth Engineers' Club, Engineers' Club of Northern Minnesota

"There are three distinct producing iron ranges in Minnesota, the Vermilion, Mesabi and Cuyuna. In trend the Vermilion and Mesabi are approximately parallel (E.N.E. and W.S.W.) and about fifteen to twenty miles apart. The Vermilion lies farthest north, near the. Canadian boundary. It is from seventy-five to eighty miles due north of Duluth. The length of its productive part is about twenty miles.The Mesabi Range is from fifty to seventy-five miles north and northwest of Duluth. Its length along the strike is about 110 miles, and the length of its present productive area about eighty miles. The Cuyuna range lies southwest of Duluth nearly ninety miles, and is the last of the Lake Superior iron ranges to be developed. The relative positions of the ranges are shown on an accompanying map. The Mesabi Range is by far the largest producer and contains the largest ore reserves of the three. The Cuyuna is next in quantity of proven ore, and in production since 1916, while the Vermilion is first in average quality of ore.On the west, both Vermilion and Mesabi ranges disappear beneath heavy glacial drift; and on the east, extend into Canada, the so-called Gunflint range near the international boundary being an eastward continuation of the Mesabi formation. This latter range is of no economic importance, however, at present. The exploration and development of the Cuyuna range has proved up a considerable tonnage of manganiferous iron ore, besides ordinary merchantable iron ore."

Jan 1, 1920

By R. G. Reddy

Chemical and structural changes occurring during the roasting of refractory gold ores were investigated. Effect of temperature on oxidation behavior of ores was analyzed using TGA, DTA and X-ray diffraction methods. The experimental results showed that the carbon in the ore has to be oxidized to a minimum value before any appreciable oxidation of sulfur occurs. Oxidation rates as a function of temperature were calculated. Optimum conditions under which a successful roasting of the refractory gold ores can be obtained are discussed.

Jan 1, 1990

By X. Shi, F. -Y. Wang

Automation and robotics are the keys to new intelligent autonomous mining systems that can remove operators from hazardous and stressful mining environments and provide the tools for greater productivity. This paper presents the components necessary for an Intelligent Task Control System (ITCS) for machine control in dynamic unstructured mining environments. In particular, the design details of a controller for an automated excavator are developed. The excavator controller uses fuzzy logic to interpret forces and torques gathered from a wrist mounted force/ torque sensor during the excavation process. This approach enables the transfer of human heuristics and expert knowledge to the controller. Several excavation tests using the fuzzy logic controller are described. These experimental results represent the first step toward an integrated approach that uses force/torque, vision and other sensor data to perform generic tasks in uncertain mining environments.

Jan 1, 1995

By B. Basim

Novel chemicals that can be used for increasing the efficiency of fine coal dewatering were developed at Virginia Tech. Reagent A was tested on three different coal samples in laboratory vacuum filtration tests. These included flotation products from Middle Fork plant, Elkview Mining Company, and CONSOL, Inc. The tests conducted with the Middle Fork coal sample (100 mesh x 0) showed that cake moisture can be reduced by more than 10% beyond what can be achieved without using dewatering aid. This improvement was achieved at 1 lb/ton of Reagent A and 0.1 inch cake thickness. At 0.5 inches of cake thickness, the improvement was limited to 8% at the same reagent dosage. The results obtained with the Elkview coal (28 mesh x 0) showed similar advantages in using the novel dewatering aid. Depending on the reagent dosage, cake thickness, drying cycle time and temperature, it was possible to reduce the cake moisture to 12 to 14% range. In addition to achieving lower cake moisture, the use of Reagent A substantially decreased the cake formation time, indicating that the reagent improves the kinetics of dewatering. The test results obtained with CON SOL coal were not as good as with the other coals tested in the present work, which may be attributed to possible oxidation and/or contamination.

Jan 1, 1998

By Joe W. Siefke

The world-class Kramer sodium borate deposit is being developed by modern open pit operations near Boron, California. The deposit is a bedded, lenticular sedimentary sequence of borax and kernite crystals together with claystone. The borates dip south into a structural basin-bounding fault and were formed in the bottom muds of a permanent shallow lake. The lake was fed boron and sodium-rich solutions from a thermal spring source of volcanic origin. In addition to deposit geology, present day geotechnical concerns such as groundwater and slope stability will be discussed.

Jan 1, 1995

By B. K. Mishra, R. K. Rajamani, R. Venugopal, P. Songfack

Millsoft is a computer-simulation software that predicts the performance of large industrial grinding mills. This software surpasses all other tumbling-mill analysis techniques available today because it is based on fundamental laws of physics instead of empirical correlations. Graphical user interface (GUI) forms simplify the specification of the following design and operating parameters: mill diameter, length, speed, charge density and size distribution, lifter material and geometry. All of these parameters are taken into account in the discrete element numerical technique that constitutes the essence of the simulation software. In turn, the software produces a visual animation of grinding-charge motion, predicts mill power and gives the distribution of impact energy. In this paper, a case study of an 8.5-m-(28 ft-) diam SAG mill is used to illustrate the application of Millsoft for mill design and trouble shooting.

Jan 1, 2000

By H. Walqui, A. Buendía

The Toquepala concentrator expansion project incremented the capacity of the existing concentrator by 15,000 Metric tons per day (t/d), from 45,000 to 60,000 t/d. The plant is located in southern Peru,1,200 km southeast of Lima. The implementation plan for the expansion project was based upon an engineering and procurement contract, and a construction contract. The overall Project Management was by Southern Peru Copper Corporation (SPCC). The expansion followed a very aggressive schedule that considered a construction period of only ten months, with minimum interference to the existing facilities. Major equipment was purchased during basic engineering. This paper details the design, construction, and commissioning of the 6.4 m diameter by 10.2 m long ball mill, and the performance of the milling circuit during the first two months of operation.

Jan 1, 2003

By J. P. Ramsey

This is a description of the efforts of a research project intended to demonstrate methods of alleviating pollution from coal mine refuse piles and slurry lagoons. These are mainly derelict barren sites. Some are burning and some are vulnerable to wind erosion which causes air pollution. Some occupy valuable land near metropolitan areas. They are an integral part of the landscape of the Appalachian and Midwestern Coal Fields. They are important in the light of growing civic awareness of the great general problem of waste disposal and environmental improvement. In the V-shaped valleys of the Pocahontas Region, they continue to be piled higher and higher. In flatter topography, they tend to form broad, flat ridges. Some contain more metal forms than others and some have a minimum of metal, but weather to a fine talc, which chokes streams with a fine particle suspension. Most are burning or have burned, but burning or weathering, most all are sources of pollution to the atmosphere and to adjacent waterways. This demonstration project is being carried out at an abandoned mine near the town of Du Quoin in southern Illinois. It is jointly sponsored by the Truax-Traer Division of Consolidation Coal Company and by the Federal Water Pollution Control Administration of the Department of the Interior. The site area is a refuse pile and slurry lagoon, each of fifty acres. It is hoped that basic data from this study will be generally applicable to other sites and will provide a basis for rational and efficient engineering design of future reclamation projects. Most refuse piles have extremely long term capabilities to produce highly potent acidogenic oxidation products typifying the more serious aspects of acid mine drainage contamination. Numerous sites remain where the abandoned mine no longer discharges acid waters, but its associated refuse pile continues to generate significant quantities of acid and other oxidation products even after many years.

Jan 1, 1969