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By J. Ke

Traditional geostatistical methods have been used in ore reserve estimation for decades. Neural Networks (NNs) have provided an alternative approach to data analysis and ore reserve estimation. Unlike the traditional geostatistical methods, neural network uses a highly non-linear complex algorithm to do the estimation. Although Neural Networks have been demonstrated to be attractive alternatives as with every new techniques, there are questions which remain unanswered. This paper presents a comparative analysis with different types of metamodeling approaches -- Triangular, Kriging, Spline, and Neural Network. The neural-network is organized in a multiple-layers and Back-propagation model is used to handle the non-linearity and hidden slabs for smoothing the predicted results. With multiple dimensional and very noisy drill hole sample data, the ore grade is predicted and the overall performance is validated by the analysis of R-squared (R2), Root-Mean-Squared (RMS), and contours of ore grade spatial variability. The ore grade and tonnage of estimated outputs are also compared with various cut-off grades.

Jan 1, 2003

At the 25th Peruvian Mining Convention, the start-up of Antamina was called ?the mining event of the year.? Antamina, one of the largestcopper-zinc mines in the world, began operations in May 2001.Augusto Baertl is Executive Chairman of Compañía Minera Antamina, the operating company. He said in a convention address that Antamina would be in full production in 2002. ?I would like to stress that Antamina is, in every respect, a highly stringent operation, as it intends to be the Peruvianmine of the future,? Baertl said. ?Antamina has set the target of being, and remaining throughout time, a model mine as to technology, environmental practices and social responsibility.? [ ] In the areas of technology and operations, Baertl noted that ?we have incorporated the best engineering design available and state-of-the art technology for mining, grinding and transportation processes, among others.? In the environmental area, he said that ?we have carried out careful environ-mental impact studies and have incorporated modern technologies and methods to control and minimize any environmental impact.? In the social field, Baertl noted that ?our relationship with neighboring communities is being developed under the premises of the social responsibility philosophy.? These include popular consultation processes, environmental committees and conciliation discussion committees. The purpose, he said, is to encourage communities located within the area of influence of the project to find and lead by themselves their path toward sustainable development, beyond the life of the operation itself.?

Jan 1, 2001

By Mingfei He, Jianhua Chen, Yingchao Liu, Yuqiong Li

Pyrite is one of the most common sulfide minerals on earth, which is usually grown with chalcopyrite and other sulfide minerals. In flotation practice, pyrite from different mines or different sections in a same mine may have different flotation behaviors. This is because the pyrite crystal contains lattice defect, including ionic vacancy and lattice impurity. The present work investigates the effects of three typical 3d transition metal (Co, Ni, and Fe) on the adsorption of CH3OCS2 −, OH−, and CN− on pyrite surface by density functional theory (DFT) calculations. Calculated results show that Co impurity reduces the adsorption energies of CH3OCS2 − and CN− on the surface of pyrite, while Ni and Cu impurities significantly increase the adsorption energies of CH3OCS2 − and CN− on the surface of pyrite. Co impurity has small influence on the adsorption of OH−, but Ni and Cu impurities significantly increase the adsorption energies. Calculations on Mulliken charge population of Co2+, Ni2+, and Cu2+ indicate that the Mulliken charges of Co2+, Ni2+, and Cu2+ after OH− adsorption are more than those after CN− adsorption. This suggests that the ionic property of the M-OH- coordination bond is greater than that of M-CN- coordination bond, while covalent bonding of M-CN- coordination bond is greater than that of M-OH- coordination bond. The adsorption results are discussed based on coordination field theory (CFT).

Oct 6, 2020

By Sunny Schoone, Maximilian Getz, Felix Leaman, ELISABETH CLAUSEN

Jan 5, 2023

By Richard L. Gordon, William A. Vogely

ENERGY POI.ICY-PRINCIPLES AND THEIR PRACTICE Persistently, at least since the end of World War 11, governments have intervened broadly, deeply, and incoherently in major energy markets. If we take a broad definition of energy that encompasses gas distribution and electric power, we can observe regulations of even older vintage. This trend, of course, is not unique to energy. Expansion of government controls has occurred in many areas. The relevant basic question about energy regulation, therefore, is not why is energy special, but whether any general principles exist to explain the wisdom of existing regulations. This review takes place at a time, the middle 1980s, in which a massive onslaught is being undertaken against government regulation. However, the present chapter is influenced primarily by my observations of the failures of energy regulations and not by any inspiration from those ideologically opposed to government intervention. Several subquestions arise in policy appraisal. A primary need is to establish clear objectives and determine the consistency between these goals and the policies imposed. Thus, the first step is to set objectives. The next is to outline ways to attain these goals. However, it should be recognized that many apparently distinct options are economically equivalent. When the goal is to charge producers or consumers for something, it is possible to attain the same result through either government ownership or taxing private transactions. The tax can raise the price to the level the government would have charged if it were the owner. Creation of a Department of Energy is not necessarily any different from having separate energy agencies well coordinated by some small supervisory body. Thus, a distinction should be made between substance and form in policymaking. The critical substance concerns such matters as whether the government imposes financial penalties, incentives, or rules to attain a goal. Then, there can be many equivalent ways to implement the basic policy form. The second prior illustration suggests that one favorite question is how to attain proper integration of policy. At various times, voices on either (or even both) sides of the Atlantic have called for a coordinated energy policy. The U.S. Paley Commission made this a primary goal for future policy. The western European governments that were the founding members of the Coal and Steel, Economic, and Atomic Energy Communities spent much time in the middle fifties and much of the sixties trying futilely to agree on an energy policy. (See Gordon, 1970 for an annotated review). The energy price rises of the 1970s rekindled United States interest in coordination. However, astute observers of the problem such as O. C. Herfindahl of the United States and Maurice Allais (1 962) in France warned the discussions confused form with substance. The crucial issues were what were the goals and what were the best types of policies to attain such goals. Policy suffered, not from poor organization, but from discord about the goals and how to attain them. All this suggests that we need principles to guide policy appraisal. The branch of economic theory known as welfare economics concentrates on providing guidance about the problems of policymaking. The theory examines both what

Jan 1, 1985

By Niles E. Grosvenor

One of the most important considerations in the efficient operation of an under¬ground mine is the haulage system. Often the determining factor between profit or loss is the quick removal of ore and waste from the working places to secondary and main-line haulage areas, and so on to the outside. Important, too, is moving supplies from the surface to the working faces so that the loading process can continue with little interruption. Men must he transported in a rapid but safe manner. It has been through the efficient use and generally the combination of mine cars, track, belt conveyors and rubber-tired haulage equipment that underground operations have been able to compete with the more popular strip or surface mining. As near-surface ore bodies are exhausted, underground haulage will play an expanding part in economically furnishing the world's needs for all types of minerals. The choice of underground haulage equipment, wherever possible, should be one that will give the smallest overall cost of ore removal during the life of the mine while meeting necessary safety requirements. The reader is referred to Sec. 12 for equipment such as scrapers and load-dump-¬haul units that perform loading as well as haulage duties. 14.1-MINE CARS AND TRACK NILES E. GROSVENOR Main-Line and Secondary Haulage-Many mines today use a combination of belt and rail haulage. Even if a- belt system is used to carry the product from the face to the surface, track is used to transport workmen and supplies. A track system, when properly installed, will provide interruption-free and safe haulage. Schrecengost 2 lists the following as major advantages of track haulage: 1. Safety in transporting men in and out of the mine in personnel cars. 2. Easy and rapid transportation of supervisory personnel. 3. A temporary shutdown occasioned by a roof fall or power failure along the haulage system will not shut down the production areas. 4. Quick availability of repair parts and supplies. 5. Large pieces of coal or rock can be handled without damage to the haulage equipment. 6. In areas where quality fluctuates noticeably, different cars may be separated out for special preparation. 7. Rock or equipment may be loaded and moved out of the mine without interference with the production or preparation of the coal. 14.1.1-MINE CARS Mine cars with steel bodies are used in all types of present-day mining. Wooden cars usually are more bulky and less resistant to wear and damage, but are more easily repaired. Regardless of the type of mine car selected, it is most practical to standardize on one type or make to simplify repairs and limit the amount of spare parts necessary to stock. Rigid-body flat-bottomed cars are simpler and usually lower than others of equal capacity. Advantages are: ease of loading because of the low sides, simplicity, cheapness and high ratio of capacity to weight. The disadvantages include the

Jan 1, 1973

By Nasri Munfah

Long Island Rail Road’s (LIRR) service to New York City is limited to Penn Station on the West Side of Manhattan, which is operating at its practical capacity for the commuter railroad. This situation imposes serious considerations for future growth and limits the destination of many Long Island commuters. The East Side Access Project will provide a connection of the LIRR to the landmark Grand Central Terminal (GCT)on the East Side of Manhattan. The construction of the connection will require significant tunneling and underground work utilizing a variety of construction techniques. In Queens, the connection will require five soft ground tunnels using pressurized face tunnel boring machine. In Manhattan, the connection will require a series of rock tunnels and caverns connecting to two deep large station caverns under GCT to accommodate eight tracks with four platforms in a stacked configuration. The caverns housing train rooms are connected to the lower level of GCT where a large concourse will be provided. With a budget of $4.3 Billion, The East Side Access Project is the largest transportation project ever undertaken in New York City. This paper provides an overview of the project, discusses its environmental and the engineering challenges, and provides an insight into the design development to date.

Jan 1, 2001

By J. H. Wilhelm

Continuous thickeners can be sized either from previous experience, continuous pilot-scale test results, or from batch settling tests. Although it is a relatively simple process to size full-scale thickeners when previous experience or pilot-scale operating data are available, batch testing is often the only realistic method for sizing thickeners due to time restrictions, budget limitations and availability of sample material. Many authors have, therefore, suggested means of running batch tests and analyzing the resulting data. Fundamental thickening theory had its beginning with the work o£ Coe and Clevenger(1). In order to determine the size of the thickener settling area, they proposed that a series of batch settling tests be run at various initial concentrations. The solids handling capacity at each concentration can then be determined and the lowest capacity (maximum area requirements) used to size the thickener. Kynch(2) developed a mathematical analysis in which the relationship between solids concentration and settling rate can be obtained from a single batch settling curve. Talmage and Fitch(3), Yoshioka(4)(5) and Dick(6), have enlarged upon these works to give a basis for methods of sizing thickeners.

Jan 1, 1979

By John C. Draper

The principal object of an underground coal mine transportation sys- tem is to move coal from the face where it is produced to the outside of the mine where it is prepared for market. In addition to the movement of coal, a transportation system must also move supply materials to the inside; it must move men in and out of the mine; and it must move rock and other debris out of the mine for disposal. Usually, mine haulage is divided into three categories named for the various areas of the mine served : 1) Pace Haulage. This is used at face from the mining machine to the intermediate transport system. 2) Intermediate or Secondary Haulage. Generally this is used between face haulage and main haulage. Sometimes this is merely an extension of the main haulage. 3) Main Haulage. This extends from the secondary haulage to the outside and is usually either a track or conveyor system, sometimes a combination of both. Transportation modes of coal in the various areas pose different problems, but the whole system must be synchronized. For instance, at the face the coal should be removed quickly from the various places to facilitate the movement of machines, whereas the intermediate system just passes the same coal on to the main transportation system. Selection of the transportation system must be based on the seam height, mining methods used to extract the coal, capacity required, ease of coal handling, and haulage efficiency. When driving rooms, mine cars can be used. They often simplify supply haulage and rock handling because they can also handle these items. Conveyors could be used and would have a greater haulage capacity but they cannot handle supplies easily or segregate the rock. When using a different mining method, such as longwall, mine cars cannot be used because there is not sufficient space to move the cars at the face nor can the cars haul the coal without delays which would cause excessive losses in production. As for ease of handling at a longwall face, conveyors are convenient because of their low height, ruggedness, and ability to operate while being advanced. Similarly, in low seam heights, conveyor systems are easier and more economic to operate than the regular track haulage because roof has to be taken down for handling mine cars of adequate size.

Jan 1, 1981

By Edoardo Misano, Magali Schivre, Martino Semeraro, Alain Bochon

"INTRODUCTIONThe Laboratoire Souterrain de Modane (LSM) is an underground research laboratory located in the Western Alps on the French – Italian border. It is located in the middle of the 13km long Fréjus highway tunnel that links Modane (France) to Bardonecchia (Italy) in correspondence of the highest overburden of 1800m. The LSM current activity is mainly based on the investigations about the dark matter and requires very sensitive instrumentation which shall be protected from cosmic rays. To comply with the new legislation about safety in tunnels, the highway tunnels owners agreed in 2007 the construction of a parallel safety tunnel, at an average distance of 50m from the existing tunnel and the laboratory owner CNRS (Centre National de recherche scientifique) also decided to extend the existing laboratory with the construction of a new 17000 m3 cavern allowing the installation of wider and more powerful instruments that could increase chances of success of research. Preliminary studies stated that, considering both geological and functional issues, the most appropriate location for the new laboratory shall be in between the two tunnels and parallel to the existing laboratory (see Figure 1).Hence, the CNRS asked Systra, already in charge of the works supervision of the safety tunnel, to realize the design of the new cavern. The laboratory extension includes the construction of a 40 m long cavern with 300 m² cross section and two smaller tunnels connecting the safety tunnel and the existing laboratory to the new cavern. The minimum distance between the front face of the new LSM and the highway tunnel is about 25 m.The French and the Italian authorities, responsible of the exploitation of the Fréjus highway tunnel, asked the CNRS to develop an accurate study indicating that the construction of the laboratory extension would not have any negative impact on the existing structures of the highway tunnel. The main results of the developed study by Systra are summarized hereafter. The construction works should begin prior to the end of the construction works of the Fréjus safety tunnel in 2018."

Jan 1, 2016

By Charles G. Frush

The function of the mine surveyor is to (a) provide a network of points of accurately known position, covering the entire mine property, (b) obtain the required data for the preparation of useful maps and sections! (c) provide position and directional control for the guidance of the operations, (d) measure the progress of the work, (e) measure the movement of rock masses, and (f) make miscellaneous surveys as needed. Mining properties range from the very small to the extremely large, and from those which involve only surface operations to those involving extensive underground workings. Active mines undergo constant change, necessitating continual updating of the surveys. The differences in the character of the deposits, the scale of mining and the mining methods result in large differences in the surveyor's activities and techniques, but many of the problems involved are common to most mines. The surface work of the mine surveyor is very similar to that, of the plane surveyor in that control points are established by triangulation, trilateration and traversing. Detail is taken by direct measurement, by stadia and by aerial photography. The equipment used, the techniques and the methods of processing the resulting data are likewise very similar. However, the underground work is quite different : A. The lines of sight frequently must be carried through constricted openings, often involving short lines of sight and awkward setups. B. The lighting often is poor, requiring illumination of the backsights and foresights, and the crosshairs. C. The ambient conditions often are difficult, involving falling water, high tem- peratures, poor visibi 'kv and heavy traffic through the area being suneyed. D. The surrounding rock map be unstable, resulting in movement or loss of the surveying stations, as well as hazard to the surveyors. E. The points to be measured often are difficult or impossible to reach. F. Steep vertical sights often are necessary, requiring the use of special equipment. G. Many working levels commonly are involved, requiring the transfer of position and orientation to each with a high level of precision. This section therefore will concentrate on surveying problems peculiar to the mine surveyor, chiefly underground work. 22.1-THE MINE COORDINATE SYSTEM A system of coordinates is essential for all permanent mining operations It is very desirable that all mining operations in a ,given area b~ tied into the same system, as this minimizes problems of boundaries and connections Whenever possible this system should be tied into and made part of the state or regional grid system. It is desirable to orient the coordinate grid on a true-north line and to position the origin of the coordinates so that all of the work will be in the "northeast" quadrant, making the north and east coordinates always positive. This can be done by subtracting suitable constant values from the north and east coordinates of the regional system The residual values are of more convenient magnitude and can be used as the local mine coordinates. If the long axis of the mineralization is not generally north-south or east-west.

Jan 1, 1973

By Robert M. Stevens, Arnoldo Acuña

INTRODUCTION In the early 1950s, underground miners and tunnel¬ing contractors were experimenting with ways to supple¬ment or eliminate track-bound loading and hauling equipment. Diesel-powered crawler and rubber-tire mounted front-end loaders and trucks designed for use on the surface were being modified and tried with limited but encouraging success. Miners began working with interested manufacturers to explore the develop¬ment of vehicles specifically designed to meet the de¬mands and constraints of underground material han¬dling. By the mid 1960s, load-haul-dump (LHD) vehicles were firmly established as a fundamental part of what has become known as the "trackless" mining concept, used in many mines and many countries around the world. The flexibility, mobility, and versatility of these units have given the industry a useful tool and have added new dimensions to mine development and produc¬tion. Many old mines have been redesigned to accom¬modate these trackless vehicles, and few new mining plans have failed to find some use for the concept during some phase of development and production. By 1977, several manufacturers in several different countries were producing a variety of LHD vehicles to meet the growing worldwide demand. GENERAL DESCRIPTION LHD vehicles combine certain characteristics of conventional front-end loaders and dump trucks, spe¬cifically designed for materials handling in underground mining and tunneling. The design intent is to provide one vehicle with one man, with the vehicle loading itself, hauling the load over level or inclined haulageways, and dumping the load. A typical production cycle of the most popular units has the operator driving the vehicle forward, forcing the bucket into the muck at or near floor level, and using the tractive effort of the vehicle and the prying action of the bucket to roll out and tilt back the load as shown in Fig. 1. With the bucket rolled back into the carrying position on the boom and the boom resting on the main frame of the vehicle, the load is hauled (trammed) to the dump point as shown in Fig. 2. At the dump point, the boom is raised, the bucket is rolled forward, and the load slides out as shown in Fig. 3. After dumping, the bucket is rolled back to the carrying position, the boom is returned to rest on the main frame, and the unit is driven back to the loading point for another load. There are two other types of LHD units that are slightly different in the cycles that they perform. One uses a hopper arrangement carried on the front of the machine, with a small bucket mounted ahead of the hopper. Several passes with the small bucket load the hopper, which is dumped by opening its floor. Al¬though this concept is several years old, it has gained less than 0.5% of the total market. The most recent LHD concept differs in that it has one bucket nesting inside another. The smaller inner bucket is loaded first, and it is then tilted back and above the larger bucket. When the larger bucket has been loaded, it is rolled back, and the total load is trammed to the dumping point. The dumping operation tilts the buckets in the reverse order from that of the loading operation. The impact of this new concept on the mining industry has not been measured yet. This chapter concentrates on the LHD vehicles employing the cycle described by Figs. 1 through 3, since these LHD units constitute an estimated 99% of the units in current use. MAIN VEHICLE FEATURES In general, the LHD vehicles available from most manufacturers share the same basic features.

Jan 1, 1982

By A. Hoath, V. Paul, F. Haslam McKenzie

This paper considers mining ventures occurring in rural communities in Galicia, Spain and Western Australia, Australia. It compares and contrasts the communities where mining is taking precedence over other industries, examining the potential land use conflicts and the future of both the communities and the mines currently operating there. The Galician case study, Trevinca, is located 200 km inland and was once a primary producing area, notable for its scenic alpine landscapes, which have since been developed for small scale tourism purposes. The Australian case study, Boddington is located 100 km inland in what has been a highly productive farming area. Mining was a marginal industry in the case study areas but due to the comparative devaluing of agriculture and tourism and the increased value of mining outputs, mining has increased in scale and economic importance. This paper will consider the environmental, social and economic impacts that have occurred in both the case study localities. Where there have been land use conflicts, strategies for minimising the adverse outcomes will be considered.

Jan 1, 2011

By Dell H. Adams

Coal exploration may be defined as the acquisition of data necessary to define and acquire a block of coal which can be mined at a profit. Unlike ore minerals, coal resources are widespread and relatively abundant with supply exceeding demand in almost every case. Thus simple discovery of coal is generally not enough. The chemical and physical variability of individual coal seams, the capital intensive nature of coal mine development, and the changing patterns of utilization require that a multiphase, three-dimensional evaluation be made of each potential reserve. Factors which must be investigated include not only the quantity and quality of the coal but also the geologic, hydrologic, and engineering characteristics of the seam and its surrounding strata. Acquisition of property to provide a secure base for exploration and mine development is equal in importance to the geologic and engineering programs. The successful development of a coal reserve requires that control of coal and, in the case of a strip mine, the surface be in the form of contiguous blocks of sufficient size to support mining.

Jan 1, 1981

By R. L. Grayson, R. C. Althouse, M. J. Klishis

The health and safety of employees, efficiency of the operating system, and production are paramount goals in underground coal mining. The section foreman assumes responsibility for making his part of the total system function to meet these goals. However, section foremen often have not been prepared to assume the full range of their responsibilities upon becoming a supervisor. This paper addresses the full range of section foreman responsibilities and concomitant authority. Management principles that must be mastered by him are presented, and performance expectations as well as criteria for their evaluation are examined. The benefits realized from effective foreman training are discussed.

Jan 1, 1987

By J. W. Merks

Spreadsheet software is an effective tool for simulating dynamic stochastic systems such as mineral processing plants. The two-product formula is used to show how to set up a Monte Carlo simulation in a spreadsheet template and how to calculate variances of dependent variables. The key to a reliable and realistic simulation model is to obtain unbiased estimates for all independent variables and variances in the set that defines the stochastic system. Monte Carlo simulation is also a powerful tool for optimizing sampling procedures, for applying sensitivity analysis and for designing and evaluating experiments.

Jan 1, 2000

By Thomas H. Koenning

The number of spontaneous combustion incidents in the U.S. is expected to increase as the consumption of lower rank coals and the use of longwall mining becomes more prevalent. A spontaneous combustion incident holds the potential for substantial loss of life from a mine fire or explosion if not prevented or controlled at an early stage. Laboratory tests have been developed which are useful in ranking the susceptibility of various coals to spontaneous combustion. Ventilation circuits and mining methods can be designed to minimize the risk of spontaneous combustion. Early detection of spontaneous combustion is possible with the combined use of continuous monitoring, periodic gas sampling, and inspection.

Jan 1, 1989

By V. Rajaram

A mine fire or roof collapse may necessitate the reversal of main fans to isolate the fire or provide an escapeway. Hence, to assist the mine operator in estimating the flow and pressure during reversal, Engineers International, Inc. conducted a laboratory and field study of the reverse performance characteristics of main mine fans. Laboratory tests were performed using a 96-inch (2.4 m) diameter vane axial fan to establish the forward and reverse performance characteristics under controlled conditions. Subsequently, a field test was conducted in a Colorado oil shale mine during which two 79-inch (2 m) diameter fans were reversed. The data obtained indicate that reverse performance characteristics are dependent upon the blade angle and the hub to tip ratio. The quantity in the reverse mode ranged from 30 to 65% less than in the forward mode, and the static pressure was directly proportional to the square of the quantity.

Jan 1, 1985

By Georgios Kafantaris, Carsten Bonde, Nataša Katic

Within the investigation works for the Copenhagen Cityring metro, Geo/CMT have carried out 90 geotechnical boreholes. Together with the previously available investigation, this resulted in more than 15 km of vertical drillings and several thousands of laboratory tests. The design is made for 17 stations, four shafts and two parallel 16 km long tunnels. The geotechnical investigation and design have been carried out in several stages comprising appropriate refinement of structural design and design of excavation operations, including TBM break-in and launching operations at each station shaft. Acceptance of the solution and / or refinement of the investigation and design schedule in the next stage were based on the geological conditions, area availability at surface level, planning and cost-control criteria. The applied recursive design refinement is presented herein with an example of the Østersøgade shaft location.

Jan 1, 2016

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

Jan 1, 2010