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Planning for a surface coal mine includes selecting the best means and equipment for uncovering the coal, loading it, and transporting it to the preparation plant. The machines and methods that will ensure optimum production will depend upon the location and characteristics of the seam to be mined. Stripping Techniques The choice of stripping units is influenced primarily by the system of mining, such as contour or out-crop mining as contrasted to mining in a region of rolling terrain with relatively flat upland surfaces. Factors such as the life of the mining operations production requirements, types of overburden, local and regional dip of coal, and land reclamation are other important considerations.

Jan 10, 1967

By K. Hartman

Certain external forces affect the manner in which business is conducted. and in recent years changes in the business environment have altered how some of these external forces affect the management of a business. These changes must be understood and considered in definition of the strategy of the business. Implementation of the strategy must assure commitment from all departments within a company, and this commitment sometimes involves compromises to assure that a department's goals mesh with the overall business objective such compromises must be externally motivated. i.e. for benefit of the customer. Complete implementation transcends internal departments to all aspects of managing the efforts in the marketplace.

Jan 1, 1989

By Walter Ccallo, Dante Soberon

El área de estudio está ubicada entre los 15° - 16° 30’ Latitud Sur, comprende los departamentos de Arequipa e Ica. En esta área fueron definidas las nuevas unidades intrusivas del Batolito de la Costa (Segmento Arequipa), en el marco de la actualización de la carta geológica a escala 1:50,000. En base al mapeo detallado de rocas intrusivas, estudio petrográfico, geoquímica de rocas e isotopos U/Pb, se logró determinar hasta doce nuevas unidades intrusivas, distribuidas en un tiempo geológico continuo desde el Jurásico medio (168 Ma) al Cretácico superior (92 Ma). Se evidenciaron además nuevas estructuras relacionadas a mineralizaciones de yacimientos tipo pórfido, IOCG (Iron Oxide Copper Gold), vetas mesotermales auríferas y cupríferas.

May 1, 2008

By T. Rockley, J. Brune

"The mining of tabular deposits accounts for a significant portion of modern production in both underground hard rock and especially, soft rock mining. There is a large discrepancy between the availability of tabular reserves and the amount of development of these deposits, particularly when the deposit has a dip of around 25-50 degrees. This project studied the technical and practical barriers to the mining of these deposits through modern and historical case studies. The primary technical barriers to the development of these deposits are material movement and roof support. The study of historical attempts overcome these barriers and why they failed allowed us to research the possibility of implementing modern technology on previously unsuccessful methods. By modifying some common mining methods, some of these deposits can be mined at only a marginal increase in cost and using readily available equipment. These modified mining methods could make previously underdeveloped deposits to become viable. INTRODUCTION Tabular deposits are defined as orebodies that extend at least hundreds of meters along two dimensions, and a substantially smaller amount along another [1]. Moderately bedded tabular deposits are mined less often than their more horizontal counterparts due to the technical issues they present. These issues often cause lower productivity, higher cost, and more frequent accidents. Moderate dip is a less well defined term; but in this case, it will refer to any deposit which has a dip of at least 20°. This paper will focus on deposits that dip around 25°-50° and are deep enough to require underground excavation methods. These deposits are too steep for most conventional methods yet not steep enough for gravity fed methods to work efficiently. In some cases, this dip range is also referred to as intermediate or steeply dipping. The types of deposits most likely to fall into this category are sedimentary bedded deposits such as coal, trona, evaporates, placers, and other alluvial deposits. Some other types of deposits can fall into this category as well. These include some of the metal reefs such as the Bushveld Complex in South Africa, which was deposited by lava flows, but is tabular. Some areas have dips that fall into the moderately inclined category. There are also some metamorphic deposits such as slate or marble that can have dips of more than 20°. The dip angle of these deposits can cause several challenges. Ore movement becomes more difficult as the exceeds the limits of conventional conveyors, rubber-tired, or tracked vehicles. At the same time the dip is below the angle of repose of the material. This prevents gravity assisted haulage, as the ore and waste will not run downhill by itself. Another common problem in moderately inclined underground mines is roof support. The dip angle can increase the risk of pillar and support failure. This is due to slippage between rock layers, non-perpendicular support of the vertical stresses, and slippage of standing supports. The inclination leads to stresses that are not usually found in typical horizontally bedded deposits. These stresses may require larger pillars that may reduce ore recovery below profitable levels."

Jan 1, 2017

The N3500 orebody is the northern continuation of the 3500 orebody at Xstrata Copper's Enterprise Mine and occurs at a depth of 1.3 to 1.8 km. At the nearby S3500 orebody, extreme deformation was observed in access drives where there was a high number of bedding planes per metre combined with either graphite or talc infill. The observed failure mechanism was largely controlled by the geometry of the inclined bedding submitted to high horizontal stresses. Due to the anisotropic strength and deformation behaviour of the shale rock mass, traditional isotropic methods of geomechanical property estimation based upon GSI are not appropriate. A numerical modelling approach, based upon the distinct element codes UDEC (2D) and 3DEC (3D), has been developed to accurately simulate the failure mechanisms and deformation observed in the initial infrastructure surrounding the N3500 orebody.

Nov 25, 2010

Seattle offered sunny, dry weather to about 2500 mining men who assembled September 10 to 14 for the 1961 American Mining Congress. The impact of snappy sessions on national mineral policy, state of the industry and foreign competition (to name only a few) was somewhat overshadowed by enthusiasm of conventioners for salmon fishing. This lordly fish, which mysteriously runs to its hatching place to spawn and die at this time of year, was not cooperating with the anglers in Puget Sound. However, this did not prevent consuming ample amounts of the deliciously prepared Quinault salmon at the "Potlatch" celebration.

Jan 10, 1961

By P. D. Hanson, H. Colijin

"New procedures and techniques are now available for the design of bulk storage bins. These new methods have essentially eliminated guesswork in the gravity flow of bulk solids, and have provided a sound basis for the quantitative analysis of alternate designs of hoppers and bins. This paper will discuss the practical application of the Solids Flow Theory (Jenike & Johanson) and illustrate the required design procedure with a few examples of actual bin operations."

Jan 1, 1970

By W. Swidzinski

"Zelazny Most" post-flotation copper mine tailings pond is the only place to of storeing wastes for KGHM POLSKA MI EDZ S.A. The flotation tailings is are the main waste stream in copper mining in Poland. Sufficient storage capacity for tailings is crucial for , thus uninterrupted production of copper is crucially related to the possibility of storing wastes in the pond. The pond covers a Its over 14 km2 arca, almost 50 m high dams making this dame this construction one of the largest in the world. The risk assessment of potential damage due to un stable ility loss of dams or environmental contamination, as well as safely constructing damsincrease of dams within the design criteriaprocess, require quick access to a large amount of the monitoring data , which in vast amount have to be monitored, that needs to be analyzed and processed and reported, every day. This In the paper describes the numerical information system "SyZeM" , used for designated to the "Zelazny Most" pond, baseding on the Oracle database and Geographical Information System , to manage the graphical and descriptive data in coherent way., is presented. The main structure of the system, as well as the methodology of storing, processing and reporting the geological, geotechnical, hydrogeological, geophysical, chemical and survey data are shown. The aspects of Optimizing optimal and risk mitigation and safe management of copper wastes and risk mitigation with the help of "SyZeM" are discussed.

Jan 1, 2007

By Waddah Akili

At an offshore site along the Red Sea coast of Saudi Arabia, marine structures were supported on tubular steel piles driven into coral and coral contaminated sands and silts. Surprises and disappointments faced during the installation of the piled foundation were, to a large measure, due to inappropriate design methodology and absence of proper soil information. The paper describes the design evolution process, highlights the static pile test program conducted to verify design parameters, and amplifies the need to prepare for worst possible scenario when coral deposits are encountered. Despite corrections made to the design, based on site-specific insitu parameters (skin friction, end bearing) perceived from load tests conducted on site; the final design adopted overestimated capacities in over 50 percent of total piles driven. The paper describes the changes introduced to the design during the execution of the project, highlights the pile test program conducted to verify the design, and compares pile design penetration with actual penetration depth. The unpredictable and erratic pile behavior observed, ascertains the need for more appropriate pile design and installation guidelines for driven piles in coral and coral contaminated formations.

By E. H. Ahrens

This paper deals with the daily work of operating geologists and should be of interest to recent graduates. Working with development and production is quite different from exploration and many of the required skills and techniques must be learned on the job. Try to obtain your first position at a mine where good geological work is being done because it is important that you establish a solid foundation by learning valid techniques. Many do not! Those who desire to work in exploration are well advised to spend the initial two or three years at an operating mine where they will deal daily with an orebody during development and mining. Attempt to understand the controls of ore deposition and be interested in all phases of the operation. Learn something about factors which can adversely affect profitability and you will be a better explorationist.

Jan 1, 1983

By W J. Rankin

A study was carried out to compare the environmental impacts of a number of process routes for lead and zinc metal production from sulphide ores using Life Cycle Assessment methodology and based on average industry data derived from the literature. The processes investigated were:blast furnace production of lead; Imperial Smelting Process for lead and zinc production; and electrowinning of zinc with the mining and mineral processing stages common to all three routes. The effect of a number of process variables, namely ore grade, fuel source for electricity generation and efficiency of generation, on the environmental impacts was also examined. The environmental impact categories considered in the study were:total (or full cycle) energy consumption; Global Warming Potential (GWP); and Acidification Potential (AP). The results of the study show that when produced separately, zinc production is more than twice as energy intensive as lead production (viz 48 and 20 MJ/kg respectively), however when produced jointly by the Imperial Smelting process, the energy intensity of the two metals is not all that dissimilar (viz 36 and 32 MJ/kg respectively). The metal production and refining stage was found to make the greatest contribution to the overall environmental impacts for all three processes. The study also highlighted the importance of taking a life cycle approach when comparing the environmental impacts of different processes.

Jan 1, 2002

By Behdeen Oraee

Constructing tunnels underground is generally described as a high-risk activity because conditions in the surrounding area tend to be unpredictable. This would and can create unique dangers in every situation. It is important to gain a deep understanding of the risks associated with tunneling in order to reduce the likelihood of their occurrence and severity of their consequences should they occur. For this to be achieved, different risks should first be evaluated and ranked according to their relative importance and criticality. The Amir Kabir tunnel is considered one of the most dangerous tunnels in Tehran, Iran, in terms of the risks involved in its excavation and their potential consequences. In particular, part T4 of the tunnel passes through a zone of different strata and also a compound of various soils. This paper studies part T4 of the Amir Kabir tunnel from a risk analysis and risk management point of view. In doing so, factors increasing total cost, causing delay in the project completion time, decreasing the operation rate and downgrading project quality were identified and ranked according to their importance using the aggregate primary index risk method. For this purpose, a comprehensive questionnaire was designed and completed by tunneling experts. By responding to the questionnaires, the experts determined the relative likelihood of occurrence of the studied factors and their potential consequences. As a result, the experts suggested several alternatives to reduce the risks involved in this particular study. Moreover, the experts completed new questionnaires whilst taking into account different alternatives. In the next step, the risks before and after applying the alternatives were compared. As a result of performing the said analyses, it was concluded first that the aggregate primary index risk is an effective tool in identifying the risks involved in such projects. Second, it was concluded that, by taking into account different alternatives when analyzing and ranking the risks, severity of the said risks can potentially be reduced. Also, by considering such matters when analyzing tunneling risks, the projects? efficiency can greatly increase as a result of reducing risks that threaten financial and human resources. The approach introduced in this paper, together with the methodology described, can be adopted by the mining design engineer in all similar situations. They will be of particular advantage in such methods as room and pillar mining, where the number of similar tunnels required is high.

Jan 1, 2014

By Walter K. Utt

The vibration levels of the heavy machines used in surface mining are much greater than for vehicles used on highways. In order to assure the proper functioning of electronic equipment placed on the surface mining vehicles, the U.S. Bureau of Mines has conducted a program of field measurements to define their vibration environment. The information in this report is for a class of vehicle that has a blade for scraping and wheels with rubber tires. The statistical information derived from these measurements can be used as a basis for laboratory testing to qualify equipment for a surface mining vehicle of this class. The envelope that would encompass 99 pct of the vibrations encountered in normal operations is presented for each location on the vehicle. The five locations for which data were recorded are the floor of the cab, the engine, the frame, the drive train (gear, differential, and torque converter), and the axle. Tabulated data are provided for those who wish to use a different probability level. The appropriate test profile for the laboratory testing can be determined from the information presented in this report.

Jan 1, 1993

By N. Brown

From the theories of flow and fracture it is shown that the difference in reciprocals of the transition temperatures (OK) is a quantitative measure of temper ernbrittlement. Experimental data are given which support this conclusion. STUDIES of temper embrittlement have been made with various viewpoints; some involved a study of the kinetics of the reaction,',2'" others were concerned with changes in the mechanical properties," . and still others investigated the structural differences between the embrittled and unembrittled states by means of the microscope," -ray ,' measurements of electrode potential," and electrical resistivity." In all these studies, the difference in impact properties was the criterion for distinguishing between the embrittled and unembrittled states. By common agreement the difference in transition temperatures is now taken as a measure of the degree of embrittlement, and this measure is used as the quantitative measure upon which studies of the phenomenon are based. Vidal and Jolivet"' suggested that the degree of embrittlement was the same whether measured by impact or by a slow bend test. Their conclusion was based on tests at constant temperature. Jaffe and Buffum" using the impact and slow bend test showed that, for a given degree of embrittlement, the difference in transition temperatures varied with the method of testing. Hultgren and Chang" showed that the difference in transition temperature produced by the V-notched Charpy impact test was not the same as the value produced by the keyhole-notched impact test. This is a very fundamental point because there can be no true measure of temper embrittlement unless it is invariant with respect to the test method. Theory The purpose of this analysis is to show how the transition temperature depends on the stress distribution and the state of the material. The criterion for fracture may be stated as follws: where iF is some function of the principle stresses and F is a critical condition depending on the state of the metal. Similarly yielding occurs when Where is another function of the prin-ciple stresses and Y is a critical value depending on the state of the material. There is some controversy as to the exact form of the function f,.(u,, u,, us) but most experimental data give the following criterion:= where 8, and 6, = 21 or 0. Combinations of 6, and 8, give the various criteria such as the normal stress, the hydrostatic tension, and the maximum shear stress laws. Agreement is general that the octahedral shear stress law adequately describes the yield condition. where the bracketed factor will be called the design factor and depends on the stress distribution. Whether the metal decides to yield or fracture is given by the condition that The effect of temperature and strain rate upon Y has been studied by various investigators, It has been shown by MacGregor and Fisher" that

Jan 1, 1955

By I. A. Tinto

"Labrador City is located in the southwestern portion of Newfoundland-Labrador, approximately 965 kilometers north-east of Montreal. The mine and beneficiation complex of the Iron Ore Company of Canada, known as the Carol Project, is situated 535 metres above sea level in a climatic region characterized by cold winters and short, cool summers.HistoryThe Iron Ore Company of Canada commenced work in the area in 19 4 9' however, it was not until 1958 that the decision was made to proceed with mining operations. The ore body consists of Specular Hematite (Fe203) and Magnetite (Fe304) with small quantities of Limonite and Geothite. The average grade of the ore bodies is 39% iron.The mining facilities, crushing plant, and concentrator were in operation by the early part of 1962. In the summer of 1961, a decision was made to build a pelletizing plant adjacent to the concentrator. This plant was designed, erected and placed in operation during 1962 and the first half of 1963. Since the completion of the pelletizing plant, additional expansions to both the pellet plant and concentrator have taken place in 1967 and 1973. Today, the Carol Project has the capacity to produce 20 million tonnes of concentrate from which 10.5 million tonnes of pellets can be produced.The period 1980-85 spans a period of energy crisis, world-wide recession, and a consequent re-structuring of the North American steel industry as it struggles to survive in an arena of excess world steel making capacity, government subsidized industries, and the increasing competition from overseas and from developing countries.The media headlines over the past few years echo the woes of the industry and the strategy plans for survival of the fittest. Today's buzz words are foreign competition, steel import quotas, joint ventures, employee participation, work rules, quality, productivity, and state of the art technology."

Jan 1, 1986

By Luis Felipe Morán G.

El objeto del presente texto busca difundir una manera de standarización en la formación técnica de los carbones peruanos, basándose en la standarización y desarrollo del mercado para antracita en Pensylvania. Asimismo se sugiere la introducción del sistema ASTM para de esa forma tener datos comparativos, con otros carbones en un sistema de difusión y aceptación. Para la utilización del carbón en el Perú y el extranjero, se requiere de un estudio que describa sus características físicas y químicas según el usuario y mercado, y siguiendo las pautas en que otros carbones fueron estudiados en las naciones industriales. En este sentido, los carbones más usados por los usuarios son las antracitas, cuya composición (volatibilidad, lustre, fiabilidad, facilidad de molienda), es similar a las de Pensylvania. De otro lado, no se encontraron estudios anteriores sobre las propiedades de carbón en aquellos yacimientos en exploración y reserva potenciales, excepto en las minas de actual explotación. Entre las propiedades del carbón está la volatiblidad, humedad, poder calorífico y ablandamiento de cenizas, mientras que la clasificación americana de la andracita debe basarse en el contenido de materia combustible y no por tamaños. En consecuencia, es necesario elaborar las pautas de conocimiento(características) sobre el carbón peruano, de forma que sirva de guía futura para el comprador y diseñador a nivel nacional.

Jul 20, 1959

By D. B. Taliaferro

Information regarding the pores or voids in reservoir rocks is vitally important in the scientific extraction of petroleum from natural underground reservoirs, and petroleum technologists concerned, with subsurface, conditions have devised various methods that give reasonably accurate information as to the porosities of oil and gas-bearing sands.5/ In this, work, several investigators have made use of the experience of the ceramic and other industries. The method of determining the effective porosity of oil sands described in this report falls within the general classification of gas-expansion methods. It was devised and developed at the United States Bureau of Mines Petroleum Experiment Station, Bartlesville, Okla., as a part of the research dealing with fluid and energy relations in reservoirs and improved oil-recovery methods. The apparatus and procedure are well adapted to the requirements of the Bureau, and the following detailed description has been prepared so that others may make use of the information. A tabulation at the end of the report gives the results of several hundred porosity determinations for oil sands in fields of 11 States.

Jan 1, 1937

By D. B. Taliaferro

Information regarding the pores or voids in reservoir rocks is vitally important in the scientific extraction of petroleum from natural underground reservoirs, and petroleum technologists concerned. with subsurface conditions have devised various methods that give reasonably accurate information as to the porosities of oil and gas-bearing sands.5/ In this work, several investigators have made use of the experience of the ceramic and other industries. The method of determining the effective porosity of oil sands described in this report falls within the general classification of gas-expansion methods. It was devised and developed at the United States Bureau of Mines Petroleum Experiment Station, Bartlesville, Okla., as a part of the research dealing with fluid and energy relations in reservoirs and improved oil-recovery methods. The apparatus and procedure are well adapted to the requirements of the Bureau, and the following detailed description has been prepared so that others may make use of the information. A tabulation at the end of the report gives the results of several hundred porosity determinations for oil sands in fields of 11 States.

Jan 1, 1937

By F. J. Radd, R. L. McGlasson

The mechanisms of corrosion and corrosion fatigue damages to sucker rods are examined from a fundamental electrochemical viewpoint, and the relationships of sucker rod microstructures to these damaging effects are defined. The common corrosive agents in crude oil production and storage are discussed as to types of attacks that they cause. The variations of fatigue strength with alloy content, surface preparation, and stress ranges are analyzed. Finally, conclusions are drawn as to how microstructures largely influence and control sucker rod performance. INTRODUCTION Greater than 90 per cent of the crude oil produced by artificial lift methods is produced through sucker rod pumping systems. In the USA each year more than $14 million is spent for sucker rods in new and old pumping installations. It is important to make this investment a wise one. Essentially, the sucker rod system is a long series of steel rods, operating under alternating stress loadings and under mechanical vibrations, which connect the surface power source with the subsurface pump. These rods often operate in a variety of corrosive media, including water, brines, carbon dioxide, hydrogen sul-fide, and air. Basically, this paper is concerned with the problem of the behavior of certain steels in various corrosive media under high and dynamic stress patterns. The main objective of this paper is to show how, once the stress effects and the corrosive environments are defined, one can still realize structural control and beneficial influence upon corrosion and corrosion fatigue. FUNDAMENTAL DEFINITIONS AND ANALYSIS In the corrosion and stress behavior of this solid state mixture of iron and iron carbide called steel, one must analyze upon what major factors does its service life depend and of what, exactly, is steel composed. The former question can be referred to two external factors and two internal factors. The two major external factors are: 1. the nature of the stress patterns — size and range of stresses present 2. the nature of the corrosion — erosion environment — the corrodent and/or wear involved The two fundamental internal factors that govern the strength and useful life of a steel both in normal duty and in heavy-duty corrosion service are: 1. the nature of the steel volume properties 2. the nature of the steel surface properties For the latter question normal steel is defined as a solid mixture of iron and iron carbide particles, generally with certain accidental and intentional elements present. (The amount of iron carbide present is determined by the carbon content of the steel.) These additional elements generally dissolve into either the iron (ferrite) or the iron carbide (cementite) components.

Jan 1, 1955

By L. Wolofsky

"The Candego property is in Boisbuisson and Christie Townships, Quebec, about 13 miles south of Marsoui, a village on the north coast of the Gaspe peninsula, 80 miles east of the railhead at Matane. It was the first producing mine in the peninsula. Production to October 1954, when operations were suspended, totalled 68,497 tons of ore, which yielded concentrates containing 8,706,535 lb. lead, 5,870,272 lb. zinc, 355,526 oz. silver, and about 1,000 oz. gold. The property was acquired by the present company in the summer of 1955.The mine has been developed by seven adits, driven into the west slope of the valley of the Marsoui River. The river here is at an elevation of about 1,600 feet, and is roughly 1,500 feet below the level of the adjacent upland. Adit elevations range from 1,760 to 2,330 feet. Five of them are in one vertical zone, on what was originally believed to be a single vein. Past production has come from Nos. l to 5; the chief present high-grade ore reserves are in No. 7.The author's observations were made in adits Nos. 3 to 6, in several of the old pits, in the surface trenches, and on drill core, at various times between December 1952 and September 1953. Much of the surrounding area has been mapped by Jones (I) and McGerrigle (2) for the Quebec Department of Mines. H. M. Kingsbury served as consulting geologist to the mining company for several years.General GeologyThe Candego veins occur in Lower ( ?) Ordovician sedimentary rocks which form a strip about 15 miles wide along the north coast of the Gaspé peninsula. The series includes limestones, shales, and sandstones, mildly metamorphosed in places. Three miles south of the mine is the north contact of the granitic intrusive, regarded as Lower or Middle Devonian, which underlies the Tabletop Mountains area. This batholith is about 10 miles long, in a north-south direction, and about 4 miles wide. At Mount Albert, about 5 miles west of the Tabletop intrusion, is a group of basic rocks, amphibolites and serpentinized peridotites, thought to have been intruded at the close of the Ordovician."

Jan 1, 1949