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By William J. Orlandi

The intent and scope of this paper is to present to you, as concisely as possible, the problems and requirements -- and what we consider advantages -- of all-belt haulage in a modern underground coal mine. Mine No, 10, at Pawnee, Illinois, was opened in 1951; consequently, all the planning and consideration given to haulage selection was based on information then available and on Peabody Coal Company? s experience to that date,

Jan 1, 1961

By R. H. King

The Deserado Mine of Western Fuels- Utah Inc. installed a micro-computer based mine wide monitoring and control system for mine environment, beltway fire protection, belt operating parameters, and equipment power utilization. The Colorado School of Mines was funded by the U.S. Bureau of Mines to document, evaluate, and report on the system design, procurement, installation, tests, and operation. This paper results from that project. The paper compares planned activities such as installation and start up, procurement contract specifications and system layout with actual performance to develop recommendations for future installations by mine operators.

Jan 1, 1987

By Yasushi Arai

"Among Tokyo Metro’s approximately 200km of subway lines, the Tozai Line that connects Chiba Prefecture and mid-Tokyo experiences congestion of up to 199% at worst and relief of this has become urgent. Therefore, as it is imperative to increase the number of trains operating in the exceptionally congested area from mid-Tokyo going east, a large-scale renovation work is planned between Iidabashi Station and Kudanshita Station that will facilitate turn-back via 3 tracks. While ensuring the safe and stable operation responsible for about 1.35 million passengers daily, this highly difficult work of inner wall demolition and reinforcement of the side walls and floor slabs will only be implemented for 3 hours during late night. This paper discusses large-scale plans to improve turn-back facilities, and the methods of construction therein as an example of operational improvement of a subway network. 1) INTRODUCTION The Tokyo Metro Tozai Line (“Tozai Line”) opened over the entire 30.8 km distance from Nakano to Nishi-funabashi on March 29, 1969. It has the longest operating length of the nine Tokyo Metro lines, and was the first subway line to extend past the borders of the Tokyo Metropolis. Through train services with two other railway companies are available from the Tozai Line. Tozai Line trains join the Sobu Line of the East Japan Railway Company (“JR East”) and the Toyo Rapid Railway Line of Toyo Rapid Railway (“TR”) from Nishi-funabashi Station, and the JR Chuo Line from Nakano Station. The line is structurally distinctive in that 51% of it was built using the open-cut method, 43% of it is elevated and the remaining 6% was built when we used the shield method for the first time 1)2)3)."

Jan 1, 2016

By Lewis L. Oriard

INTRODUCTION In recent years, there has been a trend in the direction of larger drilling equipment and larger diameter blastholes. Although this change has improved the efficiencies and reduced the costs in many operations, it has increased the potential for damage to underground openings. In addition, in many instances one now finds more sophisticated delicate instruments, automated control facilities, and a large variety of structures in proximity to blasting activity. The combined effect of larger-scale blasting activity and its proximity to various features of interest is such that there is an increased need for a more refined analysis of blasting effects and their control. BLASTING EFFECTS ON ROCK SURFACES The Breakage Mechanism In order to develop techniques for controlled blasting, one must first understand the features of the mechanisms by which blasting causes rock breakage to occur. These features have not been easy to demonstrate, mostly due to the difficulty in making tests and observations at the high stress levels and short time durations involved. When an explosive charge is detonated, the material surrounding the charge is subjected to a nearly instantaneous, very high pressure [on the order of 1.4 to 13.8 GPa (0.2 to 2.0 X 106 psi), depending on the explosive]. If the charge is coupled to "average" rock, this pressure will pulverize the surrounding rock for a distance on the order of 1 to 3 charge radii in hard rock, and to a greater distance in softer rock (this is also dependent on the type of explosive). As the pressure wave passes into the rock, high tangential stresses cause radial cracks to appear, and the nearly discontinuous radial stress zones gen¬erated by the shock front may cause tangential cracks to appear. The extent of these cracks depends on the energy available in the explosive, how quickly the energy is transmitted to the rock, and the strength properties of the rock. The discontinuous shock front is quickly dis¬sipated, but the expanding gases generate a longer-acting pressure. A compressive pulse travels to the nearest face or internal rock boundary where it is reflected in tension. The tensile strengths of most rocks are roughly 40 to %o of their compressive strengths, so the rock may now fail in tension whereas it may have been able to support the diminished compressive phase without failure. The ten¬sile deflection typically produces a failure described as tensile slabbing or scabbing. Laboratory experiments and field experience have pretty well established that several mechanisms are involved. These include (1) the classical case of tensile parallel slabbing when the pressure pulse is reflected at a free surface; (2) failure under quasi-static compressive loading (the shape is normally irregular due to discontinuities in the rock); (3) radial cracking under the action of tangential stresses at the periphery of the expanding pressure pulse; (4) peripheral cracking at the discontinuous shock front which is quickly dissipated; and (5) additional mass shifting due to the venting of the explosive gases. The first three items have received much attention in the laboratory and the literature. The complex effects of gas venting are difficult to test in the laboratory because of the difficulty in reproducing the many weak planes and discontinuities typical of most field conditions, which play such a prominent role in determining the behavior of the rock mass subjected to blasting. Unfortunately, gas venting effects can be pro¬jected to significant distances under certain field conditions, and are sometimes difficult to control. It is not unusual for gas venting to be the overriding factor in determining the final geometric shape and physical condition of the finished excavation. Sources of Damage For the purposes of this discussion, damage includes not only the breaking and rupturing of rock beyond the desired limits of excavation but also an unwanted loosening, dislocation, and disturbance of the rock mass the integrity of which one wishes to preserve (such as mine pillars, underground openings, etc.). The sources of damage include, of course, all those physical features of the rock breakage mechanism. Each of these effects must be limited to the desired zone of breakage and excavation if the integrity of the remaining rock mass is to remain undiminished. The primary zone of rock breakage usually can be controlled in the normal process of field experimentation to determine proper charge sizes and location for primary excavation. However, it frequently happens that there is damage from sources which are more difficult to account for in the design process, which are often overlooked. These are (1) the overbreak due to poor drilling control, (2) dislocation of rock (mass shifting) due to venting of explosive gases, and (3) loosening or dislocation due to the influence of seismic waves (ground vibrations). CONTROL OF ROCK BREAKAGE Importance of Geometry In studying the rock mass and blasting design con¬siderations, it is important to keep in mind the geometric relationships among charge size, shape, and position, and the physical features of the rock mass to be preserved. The features of principal interest are the external shape and position of the rock mass relative to blasting, and the position and attitude of any weak planes in the rock mass. The Sequence of Blasting and Excavation Events Unfortunately, there are too many times when the task of preserving delicate rock is considered hopeless, and because of this attitude, no further effort is ex¬pended towards caution or control. In such cases there is often a failure to recognize the importance of the se¬quence of the procedures. Attention to this can greatly reduce unwanted effects at minimum cost. Perimeter Control The requirements for perimeter control are highly dependent on the special needs of each particular proj¬ect. The desirable degree of control is a highly variable

Jan 1, 1982

By R. Musu, J. A. E. Bell

P.T. Inco has constructed a smelter to produce 45 000 tonnes (49 500 tons) of nickel per year as a nickel matte from the lateritic ores of Sulawesi, Indonesia. The facilities include mines, five screening stations, two dryers, three novel reduction kilns, three electric furnaces, three top blown rotary converters, and associated infrastructure of port, towns and a hydroelectric generating station. The screening stations and converters are unique in the industry. The problems encountered in the construction and operation of this complex facility in remote Indonesia are described.

Jan 1, 1979

The effects of additives, sodium hydroxide, sodium carbonate, sodium oleate, oleic acid and polyacrylic acid, on stirred media milling of limestone have been investigated. The results are evaluated in terms of specific surface area, specific energy and energy efficiency as a function of additive dosage, polymer molecular weight, solids concentration and relevant operating variables. Use of additives generally results in changes in specific surface area and energy efficiency, while under certain conditions a more than 100% increase in these parameters can occur. Relevant interfacial properties have been measured and milling mechanisms involved are explored particularly in terms of the effect of additives on the flow patterns at higher solids concentration.

Jan 1, 1996

By H. L. Monroe

Meramec Mining Company, owned 50% by St. Joseph Lead Company and 50% by Bethlehem Steel Corporation,- is engaged in the mining, concentrating and pelletizing of iron ore from the Pea Ridge Mine which is located in the rugged, wooded Missouri Ozarks about 15 miles from the town of Sullivan or 75 miles southwest of St. Louis. The orebody was delineated in the middle 1950's by the St. Joseph Lead Company during the Company's intensive exploration program to discover new lead orebodies to replace the declining reserves of the famous Southeast Missouri Lead Belt. An airborne magnetometer survey was run by the U.S. Geological Survey, the Missouri Survey and several mining companies, (of which St. Joseph Lead Company was the principal supporter). The survey was published in 1950 and disclosed an anomaly in the vicinity of Pea Ridge. In 1950 test drill holes disclosed that under some 1300 feet of sediments there did exist an iron deposit of probable commercial significance. No further action was taken until 1956 when additional drill holes confirmed beyond reasonable-doubt-that this was a major iron ore discovery.

Jan 1, 1965

By Thomas P. Oxford

The impact of recent legislation on Florida phosphate industry operations has been dramatic. The most significant influences are described: the National Environmental Policy Act of 1969; the Federal Water Pollution Control Act Amendments of 1972; and implementation of the Florida Environmental Land and Water Management Act of 1972. Further discussion includes: critical examination of the recently completed EPA Areawide EIS; potential effects of the Resource Conservation and Recovery Act of 1976; the Surface Mining Control and Reclamation Act of 1977; current local and state laws; and summary of studies on radiochemical effects of mining, seepage from gypsum ponds, and dewatering of waste clays.

Jan 1, 1979

By Mark A. Krall, Robert L. Geddes, James C. Frost

Introduction The Conda Partnership's Dry Valley phosphate mine is a thinly bedded, multiple seam open-pit mining operation where selective mining techniques are used to recover phosphatic shales. The mining methods used are truck/shovel and scraper/dozer operations. Ore is shipped 32 km (20 miles) by rail to a beneficiation facility. The ore is upgraded by washing and calcining. The mine and beneficiation complexes are owned by the Conda partnership. It is a joint venture between Beker Industries Corp., of Greenwich, CT, and Western Co-Operative Fertilizers (US) Inc., of Alberta, Canada. The Partnership operates as a separate entity of the two partners. The Dry Valley mine is located 48 km (30 miles) northeast of Soda Springs in Caribou County in southeastern Idaho. The mine is situated on the Caribou National Forest. Mining operations take place between 2 and 2.4 km (6400 and 7900 ft) in elevation. It is accessible partly by 32 km (20 miles) of paved roads and 16 km (10 miles) of dirt roads. The winters are long and severe, and the summers are short and mild. This article describes the history, geology, exploration, mining, and reclamation that makes this mine Idaho's largest producing mine and the western US' leading phosphate producer. History and production In the mid-1950s, Western Fertilizers of Salt Lake City, UT, drove an exploratory drift in Maybe Canyon. A large bulk sample of phosphatic shales was analyzed for phosphate content and processing characteristics. No large scale mining or processing operations were undertaken. In the late 1950s, the Dry Valley property was sold to Central Farmers of Chicago, IL. No major operations took place. In 1964, Central Farmers sold the property to El Paso Products Co. of Odessa, TX. El Paso Products supervised the mining operations of Wells Cargo Mining Co. from 1965 through 1967. During this time, El Paso Products built a beneficiation facility and a fertilizer complex in Conda. A 32-km (20-mile) railroad was also constructed from the mine to this facility. From 1968 through 1972, the mine was shut down due to a depressed fertilizer market. In 1972, El Paso products sold its ore reserves, beneficiation plant, and fertilizer complex to Beker Industries Corp. In 1979, Beker Industries sold 50% of its ore reserves and 50% of its beneficiation plant to Western Co-Operative Fertilizers (US) Inc., of Alberta Canada, forming the Conda Partnership. It has operated the mine and beneficiation plant since January 1979. From the mid-1950s to the mid-1960s, no substantial production took place. From 1965 to 1967, El Paso Products stripped 3 Mm3 (4 million cu yd) and mined 2.3 Mt (2.5 million st). From 1972 through 1983, 50 Mm3 (66 million cu yd) were stripped and 18 Mt (20 mil¬lion st) were mined. Geology The Wells Formation forms high ridges and hillsides in the Dry Valley area. It is best exposed along the west face of Dry Ridge. It forms the imposing wall on the east side of Dry Valley. The formation is divided into two members. The lower member, about 213 m (700 ft) thick, is dominantly thin to medium-bedded limestone and silty limestone. It contains nodules and stringers of chert and minor sandstone. The upper member is composed principally of thick-bedded to massive cross-bedded, light-gray to orange-yellow, fine grained sandstone. There is some interbedded brown to light-gray limestone. This member varies from 369 to 457 m (1300 to 1500 ft). Recent investigations indicate that the upper Wells is of Permian age. Under some conditions, the Wells may be water-bearing. Otherwise, it has no apparent economic significance. Grandeur Member (Park City Formation) Overlying the Wells Formation is a distinctive light-gray to white dolomitic fossiliferous limestone. This unit has been identified by the US Geological Survey (USGS) as the Grandeur Tongue Member of the Park City Formation. This member is sometimes absent due to its contact with the Meade Peak Member of the Phosphoria Formation. It is easily detectable by its color, hardness, and fetid odor. Phosphoria Formation The Phosphoria Formation of Permian age was named from Phosphoria Gulch, Bear Lake County. The formation has been studied extensively and developed for its economically valuable phosphate reserves.

Jan 11, 1985

By V. C. Lo

The major cost in comminution is energy consumption, which can be as high as 50 percent of the operating cost. Improvements in plant operations have resulted in up to a 15-percent reduction in energy usage (kwh/t). These improvements have been made through optimization of grinding efficiency and use of expert model-based control systems. Optimization involves the determination of the levels of the critical operating conditions that result in the most efficient breakage of ore in the mill. These optimal levels are identified through plant/laboratory testwork and computer simulation using advanced process models. Model-based expert control achieves the maximum performance from the grinding circuit by identifying the characteristics of the ore in the mill with an optimal on-line estimator. Using this information, the control system dynamically determines the operating point that will yield the optimal performance. Two industrial applications of grinding circuit optimization and model-based control are presented to demonstrate the power of this new technology.

Jan 1, 1995

By W. J. Roberds

A formal and explicit yet cost-effective approach is proposed to ensure that decisions made during mine development are optimum (with respect to their ultimate consequences) as well as defensible. This risk management approach is based on probabilistic risk assessment and established decision analysis techniques, and appropriately considers the relationships among various mine development decisions, tradeoffs among consequences, the uncertainty in predicting consequences, and the benefits of flexibility to respond to changed conditions.

Jan 1, 1992

By C. R. Nailler

Two recently published papers describing the use of psychological tests for selection and placement of coal mine personnel have created considerable interest within the Coal Industry, one paper, published in the April 1957 "Mining Congress Journal," entitled "Personnel Evaluation and Training," discusses the use of tests by the Christopher Coal Company, The second paper, published in the "West -Virginia Coal Mining Institute's 1957 Report" and in the September 1957 "Coal Age," entitled "Testing to Select Better Personnel for Coal Mining Today," outlines Hanna Coal Company's test and selection procedures. Since these rather detailed sources are readily available, and to avoid repetition of the material in them, we will confine this paper to a very brief review of the essential steps already taken by these companies and a more extensive look at newer material. Briefly, the Personnel Managers, Mr. Harold L, Durrett and Mr. Albert M,. Rowe, of the Hanna Coal Company and Christopher Coal Company, in conjunction with Dr. Quin F, Curtis, Head of the Psychology Department of West Virginia University, developed two different groups oftests for coal mine personnel, The first group oftests was designed to assist in the selection of supervisors. These tests of the supervisory group were "The California Short Form Test of Mental Maturity - Advanced Series," which gave an I.Q. rating, and the second test is known as "The Minnesota Multiphasic Personality Inventory," which measures several personality characteristics, These tests must be given, grade, and interpreted by a person trained in psychological testing. As a result of testing all of Christopher's supervisory employees (seventy in number) by this method, and then comparing the individual results with the individual ratings of the foremen on the job, a so-called foremen's scale was developed. If this resulting foremen's scale had been used to select the foremen who were rated as, the best men in on-the-job performance, it would have correctly identified seventy-four percent of that group.

Jan 1, 1958

By Peter Joralemon

I want to limit my remarks to epigenetic ore deposits, but do not necessarily subscribe to the classic theories of hydrothermal ore deposition. I will consider an epigenetic deposit as a primary deposit in which the economic minerals have been introduced subsequent to the formation of the enclosing rock, regardless of the source. Past ore discoveries have been made to a great extent by prospecting techniques that have remained relatively constant over the last many decades. In many cases the discoveries have been enlarged or enhanced with the use of technical tools such as geophysics, but theoretical geology, which should serve as a foundation for exploration, has shown little progress of practical importance since the turn of the century.

Jan 1, 1967

By C. Wayne Burnham

Much has been written about hydrothermal alteration and the compositional changes induced by it in the wallrocks of mineral deposits, especially in alummino-silicate wallrocks. So much has been written and the descriptions so varied, in fact, that the casual reader frequently is bewildered by the extreme complexities and lack of uniformity, real or apparent. Certainly the mineralogy and chemistry of altered rocks are not as simple as most of us would like, but neither are they as complex in their principal aspects as pa of what has been written would lead us to believe. The trend until recently seems to have been toward greater complexity and hence greater confusion, but the straightforward presentation of Creasey (1959), it is hoped, marks a reversal in this trend.

Jan 1, 1962

By E Marambio, R Brändle, G Fischer, G von Rickenbach, L Burgos, R Luis Fonseca

Ground support systems must provide safe and effective designs for underground excavations under high stress conditions. These systems must be capable to resist dynamic impacts and yielding during the loading process. In this context dynamic testing of the reinforcement and retaining elements that compose the ground support system are required to study and improve the behaviour of these elements under dynamic load events. During the last years, Geobrugg has been working on the improvement of retaining products by testing them in a large-scale impact test facility located at Walenstadt, Switzerland. The test facility is composed of a double level platform with a square-shaped pyramidal trunk geometry, in the upper level housing a loading mass that drop from a height up to 5m. The loading mass is guided by one central steel pipe, and the impact occurs in the sample to be tested located at the lower level in a slab with an area of 3.6m × 3.6m where the ground support system is installed. During the last years, this innovative facility has been used to test several configurations of ground support systems. The results of these tests have enabled to improve the understating of the behaviour of ground support systems under dynamic loads. In this manuscript, the arrangement, measurement, results, and the preliminary analysis of a single impact dynamic test performed during 2021 of a ground support system with a high-tensile steel wire mesh MINAX 80-4.6 is presented.

Apr 26, 2022

By Yashar Pourrahimian, Roberto Noriega

Truck fleet dispatching plays a crucial role in reducing operational costs and fulfilling operational targets in open-pit mining operations and is subject to large uncertainty arising from the operating cycles of trucks and loading equipment. This paper proposes a reinforcement learning-based truck dispatching system. Reinforcement learning is a machine learning area that deals with learning an optimal sequential decision-making strategy in an uncertain environment. An open-pit load-and-haul simulation is developed that also captures the truck movements and interactions in the shared road network, and a Neural Network is successfully trained to suggest truck dispatching decisions in a real-time manner.

Jun 25, 2023

By M. J. Shulman

The exploration geologist is frequently confronted with the problem of allocating his resources, i.e., exploration effort, among various areas. Although geologic, financial and logistic considerations influence the allocations, no objective criterion is usually given which determines the optimal allocation. Maximizing the gain in information, subject to the constraint of a limited exploration budget, is used as the objective criterion to allocate reconnaissance effort. The information function, I(x), quantifies the expected gain in information, where x is the scale of exploration. To calculate the information function the following data are necessary: 1. The probability that an area contains a target must be estimated. 2. For each scale of exploration, four probabilities must be estimated: the probability that an anomaly is produced by the target; the probability that an anomaly is not produced by the target; the probability that an anomaly is produced by a barren area (false signal); and the probability that an anomaly is not produced by a barren area. Alternatively, the barren area can be replaced by other targets. To illustrate the allocation model, the optimal number of line kilometers/line spacing per area is determined for an aeromagnetic survey for iron in Egypt.

Jan 1, 1985

By R. Hogg

Sedimentation in highly flocculated suspensions of fine particles such as clays occurs through individual settling units (flocs) which have very open structures and correspondingly low density -typically less than 5% solids by volume. It follows that such settling processes rapidly lead to the build-up of a bed of flocs which are essentially close-packed, with inter-floc porosity of perhaps 50%, but with an overall solids content of no more than about 2-3 percent by volume. An important consequence is that the thickening process is dominated by the consolidation of this bed rather than by simple settling of the individual flocs. Experimental measurements of sediment consolidation in flocculated clay suspensions indicate that for a given system, consolidation rates are essentially determined by solids concentration and can be evaluated using the classical Kynch treatment. However, these rates are strongly dependent on the physical as well as chemical conditions of the flocculation process. Furthermore the extent to which gravity consolidation proceeds depends on the total weight of sediment (i.e. on both height and solids concentration). The implications with respect to thickener operation and the requirements for laboratory testing for thickener design are discussed.

Jan 1, 1992

By John F. Slonaker

This report is a review of current research being conducted in the United States which is intended to increase the utilization of coal ash. In order that this report be as timely as possible, the majority of information was obtained by direct comunication with the people listed in the references. Due to the magnitude of the flyash research program, some projects may be inadvertently omitted. Field research on flyash for use as an agricultural fertilizer is being monitored at Virginia Polytechnic Institute and State University.1 This research is directed at determining the plant nutrients that are available in flyash as well as the quantities of flyash that can be applied to agricultural soil without adversely affecting plant growth, Coal mine spoil and refuse bank reclamation with power plant flyash is being demonstrated by United States Bureau of Mines, Morgantown, West Virginia.2 Numerous highly visible coal refuse piles and strip mine spoil banks contribute to air, water, and land environmental problems. Revegetation of several experimental sites with flyash from bituminous coal-fired power plants was undertaken in West Virginia and Pennsylvania. Conventional farm equipment was used at some of the sites while large earthmovers were required at others. The flyash served as a neutralizing agent, dilutent, and soil amendment to provide some nutrients which enhanced vegetation of the barren areas, Estimated cost of reclamation by this method is $300.00 per acre of previously leveled area. This figure can vary considerably depending upon the topography of the site, haul distance, quality of the soil and quality of flyash.

Jan 1, 1974

Large variations of coal seam thickness and roof conditions are associated with the occurrence of mine floor undulation at Shoal Creek Mine, operated by Drummond Company, Inc.. Ground control problems, such as roof falls and face failures along with extremely high shield pressure and rapid face convergence, are often reported at the longwall face when these undulations exist. This greatly increases equipment downtime and causes production delays. As a result. a comprehensive study of mine geology including roof conditions and longwall performance were conducted in the mine. With the help of continuous full-face shield pressure monitoring using the Longwall Strata Control and Maintenance System (LoSCoMS), a large data base of shield pressure with various roof conditions has been established. This enables the mine operators to accurately evaluate the roof behavior and shield performance and to take the appropriate operational steps at the face to reduce the number of downtime and face failures. This paper summarizes all works and findings from the study including detailed roof geology and its effect on longwall performance.

Jan 1, 1998