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This paper presents the development of a knowledge based integrated decision support system (E.X.I.S) for the extractive industries to provide information concerning the environmental impact of extractive operations on land quality, surface and ground waters, and the best solutions for the rehabilitation/revegetation of the waste disposal areas to the relevant target groups (extractive industries, regional authorities, national authorities, research institutes, public). GIS was integrated with the decision-making models for the rehabilitation and revegetation of mine spoil. The system design involves several steps including site selection ? mine type identification ? waste identification ? selection of rehabilitation (revegetation or other methods). The knowledge based model consists of two integral parts: the model base, in which the input data are processed and classified using special fuzzy algorithms and criteria and the knowledge model, which hosts the various decision algorithms concerning evaluation of vegetation covers, selection of trees and plant species, selection of rehabilitation and revegetation schemes and also economic analysis for each option. The system input will include parameters on site characteristics (climate, topography, geology, hydrology etc), waste type and properties (physical-geotechnical and geochemical data) as well as environmental parameters of the existing waste disposal area. Based on the values of the above parameters and the characteristics of the rehabilitation technologies developed worldwide, the system, using IF-THEN rules will define a list of appropriate techniques for the rehabilitation of the examined waste. Then, the model will involve the application of multi-criteria analysis (MCA), i.e. a structured system for ranking alternatives and making selections and decisions. Each technique shall be judged based on its behavior into four fields, i.e. financial, social, technical and environmental criteria. In turn these fields will be analyzed into a lower level of evaluation criteria.

Jan 1, 2006

By L. A. Romo, J. A. Ferrer

INTRODUCTION The principle line of the Caracas Metro is located generally along the most important east-west traffic corridor of the city from the yards and shops in Propatria at the western extremity to Petare, and eventually beyond to Palo Verde at the eastern end, a route distance of 21 kilometers. There will be 23 stations along the alignment, underground, at grade and elevated, and the line is forecast to handle 1,209,100 passengers daily by the year 2000 with a travel time of 29 minutes between Propatria and Petare. This principle line was divided into three sections for design purposes: Propatria-Fuerzas Armadas, Section I, Fuerzas Armadas-Chacaito, Section II and Chacaito-Petare, Section III. These sections were further subdivided into subsections for construction purposes. The Venezuelan Government, through its Caracas Metro Office in the Ministry of Public Works, awarded design contracts in sections to PARSONS BRINCKERHOFF-TUDOR-BECHTEL for Propatria-Fuerzas Armadas, Section I, OCOIDESA-GRID-APM for Fuerzas Armadas-Chacaito, Section II and OCOIDESA GRID-APM for Chacaito-Petare, Section III. Construction contracts were awarded by international bidding and work is now underway, by joint venture organizations of Venezuelan and foreign firms. The first two sections are under the administration of a company of Engineer/Inspectors in each section. The construction supervision of contracts in the first section is under the administration of the Venezuelan firm, Gómez-Celis-Herrera, (GCH) Engineers, acting under contract to the new C.A. Metro de Caracas that replaced ' the former Office of the Metro. The Propatria-Fuerzas Armadas section, approximately seven kilometers long, consists in part of the 2,951 linear meters of twin-bore

Jan 1, 1979

By E. D. Gardner, William O. Vandenburg

This chapter on the square-set system of mining em¬bodies the results of a special study of the subject made as a part of the US Bureau of Mines (USBM) general investigation of mining methods and costs. Data for the chapter were gathered by the authors during visits to mines using square-set mining, from information circu¬lars prepared by consulting engineers to the USBM on mining methods at individual mines, and from articles in the technical press and the Transactions of the American Institute of Mining and Metallurgical Engineers. Al¬though some of the properties discussed are no longer in operation, the methods described are still valid. The square-set system of mining has been very widely applied and is one of the oldest methods in use in the US. It is mainly employed for extracting rela¬tively high-grade ore in heavy ground. It is also useful in taking out pillars left in mining by other methods. It is used to some extent as an auxiliary method with many underground systems and as an alternate with cut-and¬fill, shrinkage, and open-stope methods when heavy ground is encountered. In some cases as much as 50% of the ore may be extracted by square setting at mines listed as using some other method of mining. A large tonnage has been mined yearly by square setting, prin¬cipally in the western states. Due to the high cost of timber and the relatively low average production per manshift, this system generally is not used when the ore can be mined by some other method; it usually is adopted as a last resort. Square setting, however, has a special field in that ore bodies not minable by other methods can be stoped by this system. As square-set mining was widely known, there was a tendency for years to use the method regardless of its suitability. With the increasing need for economy and the development of other methods, square setting has been superseded in many mines by cut-and-fill, top slic¬ing, or sublevel caving methods. The term square-set mining as used in this chapter includes all stoping methods in which the space made by the removal of the ore is timbered with framed sets. The sets usually are square in horizontal section. The stope may or may not be filled with waste rock as stoping progresses. HISTORY OF THE SQUARE-SET SYSTEM Prior to 1860, open-stope methods with stulls for casual support accounted for most of the mineral pro¬duction from underground mines. Attempts to mine large ore bodies that required artificial support resulted in disastrous cave-ins and loss of life. The art of mining received a tremendous impetus following the introduc¬tion of methods for mining the bonanza ore body which was discovered in 1860 in the Ophir mine on the Comstock lode, Virginia City, NV. This ore body was phe¬nomenally rich and eventually proved to be 122 m (400 ft) high, 27 m (90 ft) wide, and 98 m (320 ft) long. The mining of this large high-grade ore body taxed the best engineering talent of the time; the problem was finally solved by Philip Deidesheimer. According to Eliot Lord (1882): "At the 50-foot level the vein of black sulphurets was only 3 or 4 feet thick, and could be readily extracted through a drift along its line, propping up the walls and roof when necessary by simple uprights and cap-posts. As the ledge descended the sulphuret vein grew broader until, at the depth of 175 feet, it was 65 feet in width, and the miners were at a loss how to proceed, for the ore was so soft and crumbling that pillars could not be used to support the roof as in coal mines. They spliced timbers together to hold up the caving ground; but these jointed props were too weak and ill-supported to with¬stand the pressure upon them, and were constantly broken and thrown out of place. The dilemma was a curious one. Surrounded by riches, they were yet un¬able to carry them off and their mass of black sulphurets bade fair to become a white elephant on their hands. The Ophir Company began to wish themselves less for¬tunate, as their miners narrowly escaped burial day after day in their attempts to stope out the ore. "A young mining engineer, Philip Deidesheimer, was in charge of a quartz mine in Georgetown, El Dorado County, Calif., in the autumn of 1860, when this serious check to the development of the lode occurred. At the request of William F. Babcock, a trustee of the Ophir Company, Mr. Deidesheimer left his California mine and crossed the mountains with a letter from the direc¬tors of the Ophir Company, authorizing him to inspect the workings of their mines and make such changes in the method of timbering as should seem to him expe¬dient. After examining the vein he designed, in the course of a few weeks, a system of timbering which proved to be exactly adapted to the requirements of the work. Experiments which he had previously made in California gravel and quartz mines furnished the out¬line of his plan. This was to frame timbers together in rectangular sets, each set being composed of a square base, placed horizontally, formed of four timbers, sills, and crosspieces from 4 to 6 feet long, surmounted at the corners by four posts from 6 to 7 feet high, and capped by a framework similar to the base. The cap pieces forming the top of any set were at the same time the sills or base of the next set above. These sets could readily be extended to any required height and over any given area, forming a series of horizontal floors, built up from the bottom sets like the successive stories of a house. The spaces between the timbers were filled with waste rock or with wooden braces, forming a solid cube when¬ever the maximum degree of firmness was desired. By adjustments of these sets the ore bodies along the line of the lode were extracted with comparative ease and security." Most mining methods are evolved slowly and are the result of the combined efforts of a number of minds; Deidesheimer's feat was remarkable in that his system was immediately successful. He died in 1916 at the age

Jan 1, 1982

By R. Fedel-Moen, R. W. L. Kimber, B. D. Williams, S. R. Ragusa

The use o f cyanide to extract gold from ores is widespread. In the process of extracting gold, cyanide may form metal cyanide complexes with a variety of other metals present in the ore. This study was carried out to investigate the biodegradation of the Cu(I)-cyanide complex and tetracyanonickelate under varying pH and nutrient additions. Detailed studies using shake flask cultures and bioreactors showed that naturally occurring bacteria residing on gold-leach-pad ore uti¬lized the Cu(I)-cyanide complex (CuCN) and tetracyano-nickelate, Na2(NiCN4), as carbon and/or nitrogen sources. Ammonium-nitrogen (NH4+-N) and/or cyanate (CNO-) accumulated in solution as the metal cyanide complexes were degraded. The accumulation of cyanate as a product is a concern due to its toxicity. Degradation rates were increased if a growth substrate (peptone, 0.1%) was added to the medium or if bioreactors were primed with peptone before addition of the metal-cyanide complex. Tetracyanonickelate was degraded at pH 8 without added peptone, but it was not degraded at pH 10. The addition of peptone was required for degradation of the Cu(I)-cyanide complex at pH 8 and pH 10. At pH 8, the addition of peptone resulted in the accumulation of cyanate, whereas, at pH 10, cyanate was not detected in the cultures. Biodegradation of metal-cyanide complexes was faster (approximately 1.5 to ten times faster) in bioreactors than in shake flask cultures. The addition of peptone was not required for degradation of metal-cyanide complexes in bioreactors. However, priming the bioreaetor with peptone resulted in higher metal-cyanide degradation rates over multiple cycles.

Jan 1, 2000

By Fathi Habashi

SOLVENT EXTRACI ION involves two operations: 1) Extraction The metal values in the aqueous phase are extracted by agitation with an organic solvent immiscible in that phase. The two phases are then allowed to separate; the aqueous phase is discarded or recycled and the loaded organic phase saved.

Jan 1, 1970

By S. O. Ogden

As most of you have probably surmised from the title of my paper, I am here today to talk with you about the use of diesel engines in the American mining industry and whether or not the free choice to use such equipment will continue to be available to mine operators. Of course, I will present to you my prepared remarks, however, these remarks may be essentially academic in light of a news release, parts of which I would like to read to you. Washington, D. C., The Department of Health, Education, and Welfare today announced proposed new regulations to reduce occupational health risks to workers in the U. S. mining industries by requiring the removal of all diesel powered equipment from American mines by December 31st "While we do not have complete and conclusive information to quantify these health risks we feel it is prudent to undertake this restriction on the use of diesel powered equipment without waiting for the completion of studies that are currently underway to identify and quantify these health risks," said a Department spokesman. HEW has been concerned about the health risks of diesel emissions in the underground coal mines for some time and have investigations underway designed to conclusively demonstrate the nature and magnitude of any health risks. However, HEW has decided to proceed with these regulations without waiting for the final results of these investigations. Further, HEW feels there is sufficient probability that diesel health risks do exist in all mining applications and consequently, the proposed regulations will apply to all surface and underground mining operations. It goes on a little further and indicates that due to the necessity of finalizing these regulations without delay, a period of fifteen days has been provided to receive comments regarding these proposed regulations.

Jan 1, 1978

By T. E. Walsh

I will address two important alternative energy resources, solar and geothermal, with emphasis on their potential application in electric power generation. As a result of this presentation, I hope to leave you with a realistic view of the principal technology options that are being developed or that are available. Solar Types of Collection In terrestrial solar applications, the biggest challenge is to find ways of collecting the sun’s relatively low intensity energy so it can be converted economically to useful thermal or electric energy. Fig. 1 shows that there are both natural and technological ways of collecting solar energy. In nature we find that solar energy aids in the production of biological growth, rainfall, and wind, all of which can, in one form or another, be put to use in the production of heat or electric power. The sun’s rays also are collected and stored naturally in the form of heat in the upper layers of the ocean which can be put to use in the production of electric energy by means of ocean thermal energy conversion (OTEC) approaches. On the technological side, the sun’s rays can be intercepted by materials that directly absorb and convert its energy to low-grade heat, or by mirrors or lenses that focus the rays onto a material to produce high-temperature heat. The higher temperature systems can be used to drive efficient heat engines in the production of electricityy. The sun’s rays also can be collected on photosensitive materials, in either a direct or concentrated form to generate DC electricity directly. The systems I will discuss employ all of these means of collection and conversion, excluding biological and hydroelectric. The former is too exi

Jan 9, 1980

By T. E. Walsh

Introduction I will address two important alternative energy resources, solar and geothermal, with emphasis on their potential application in electric power generation. As a result of this presentation, I hope to leave you with a realistic view of the principal technology options that are being developed or that are available. Solar Types of Collection In terrestrial solar applications, the biggest challenge is to find ways of collecting the sun’s relatively low intensity energy so it can be converted economically to useful thermal or electric energy. Fig. 1 shows that there are both natural and technological ways of collecting solar energy. In nature we find that solar energy aids in the production of biological growth, rainfall, and wind, all of which can, in one form or another, be put to use in the production of heat or electric power. The sun’s rays also are collected and stored naturally in the form of heat in the upper layers of the ocean which can be put to use in the production of electric energy by means of ocean thermal energy conversion (OTEC) approaches. On the technological side, the sun’s rays can be intercepted by materials that directly absorb and convert its energy to low-grade heat, or by mirrors or lenses that focus the rays onto a material to produce high-temperature heat. The higher temperature systems can be used to drive efficient heat engines in the production of electricityy. The sun’s rays also can be collected on photosensitive materials, in either a direct or concentrated form to generate DC electricity directly. The systems I will discuss employ all of these means of collection and conversion, excluding biological and hydroelectric. The former is too ex

Jan 1, 1980

By S. E. Phillipson

Slickensides cause potentially hazardous ground conditions in underground coal mines. Investigations by MSHA’s Roof Control Division indicate that many slickensides represent bedding plane faults and drag folds that formed during coal bed decollement, a style of faulting that occurs in shale units above coal seams. These slickensides formed in response to regional tectonic compressional stresses, rather than by differential compaction, and are parallel to folds and thrust faults. This paper relates slickensides in the Appalachian, Illinois, and Black Warrior basins to the structural grain of the Appalachian Mountains, provides descriptions of slickensides, and advocates geologic mapping as a predictive method for identifying areas with adverse ground conditions.

Jan 1, 2003

By K. Hanumantha Rao, K. S. E. Forssberg, H. R. Manouchehri

This paper summarizes the practical considerations of the various electrical separation methods used in mineral processing. The effective factors related to mineral characteristics and equipment attributes are described and analyzed with reference to conventional industrial applications of the electrical methods. Some new aspects of electrical methods application and their potential for mineral beneficiation, apart from the mineral systems that have been successfully beneficiated, are also presented. In addition, wet dielectric separation, which now appears to be promising, is briefly cited.

Jan 1, 2000

By Marian Radetzki

The economic developments and industrial behavior patterns that led to a lasting excess capacity in the world non-ferrous metals industries from the aid-1970s are explored. Detailed attention is devoted to analyzing and defining crucial concepts like "capacity", "excess capacity", "capacity maintenance" and "investments". Empirical evidence of capacity utilization and capacity growth in the industries under study is provided. The coincidence of excess capacity and low prices on the one hand, and investments in capacity maintenance and capacity expansion, on the other, is seen as a consequence of substantial declines in the metal industries' investment and production costs during the period studied.

Jan 1, 1989

By Richard Louis Viner, William D. Leech, Walter A. Mergelsberg

With the construction management team established and a full funding agreement secured the Washington Metropolitan Area Transit Authority (WMATA) now has the manpower and the financial resources to continue Metrorail construction into the 1990's. This paper describes WMATA's new role as construction manager after the transition from Bechtel Associates and gaining the full funding agreement with the Urban Mass Transit Administration (UMTA) and regional governments to complete 84.7 Metrorail miles (136km). The authors review the most recent station and line tunneling projects. WMATA's contractors have employed the state of the art soft ground and hard rock tunneling equipment and methods - an earth pressure balance TBM, a closed face TBM, and the New Austrian Tunneling Method (NATM). In final, the paper previews future underground work to be let under the funding agreement.

Jan 1, 1987

By Wayne P. Myers

Electricity, as normally thought of by a layman's definition, is a man- made force that has no color, no odor, is not visible, cannot be heard, yet man can control it and make it perform his work for him. A person dare not cheat on it, for it then will master him. It has laws, rules, and regulations that must be strictly adhered to if it is to perform in the safest, most reliable, and economical manner. In the early days of coal mining the power source was man himself. Later man employed steam and compressed air to reduce his muscle power requirements needed in the extraction of coal. By the turn of the 20th century, electricity had become the most common source of power for the coal industry. Steam and compressed air are still found in use in isolated cases today for specific applications; however, they are rapidly being replaced by electricity. Electrical laws and regulations are quite extensive and somewhat complex for the proper generation and use of electricity. Man-made laws, rules, and regulations for the care and handling of electricity, designed for man's safety, are rigidly enforced by Mine Safety and Health Ad- ministration (MSHA), as well as the various state departments of mines.

Jan 1, 1981

By S. Zaharia

The authors present the state-of-the-art regarding natural and anthropic hazards on the stability of the saliferous Costiui basin. The factors that may potentially result in sliding, piping and collapse, are emphasized, given the existence of a large number of old salt mines. Also, a geotechnical risk map of this hydrosalt complex in Romania is presented.

Jan 1, 2008

By Eddie Woods, Jon Hurt, Roger May, Paul Watson

The Channel Tunnel Rail Link (CTRL) will be Britain’s first major new railway for over a century—a high-speed line running for 109km (68 miles) between St. Pancras station in London and the Channel Tunnel. The new line has been under construction since October 1998 and the first phase will open in October 2003. The project includes22km of twin 7.15m ID TBM bored tunnels under London and the River Thames, and the 3km North Downs Tunnel, the first major NATM tunnel to be constructed in the United Kingdom since the collapse of the Heathrow Express Tunnels in 1994. This paper will discuss the design of these tunnels and describe the construction progress to date. The discussion will include details of segmental lining design, TBM specification, and sprayed concrete lining design.

Jan 1, 2003

By B. Waquet

The genesis of a hydrothermal subsea mound, by chimney debris heaping and mineralizing fluid circulating upward, induces a vertical maturation gradient. Connected porosity is easy to measure and, after mineralogical evidence, can be use as a maturation index. Thus, to understand how a rock property evaluates with maturation, it is possible to plot it against connected porosity. Results are that uniaxial compressive strength, Young's modulus, and in a lesser certitude tensile strength, abrasivity and hardness, increase very weakly with maturation until a maturation threshold (equivalent to a connected porosity equal to 0.2), and rocket to much higher values after it.

Jan 1, 2011

By S. Nunoo

The shape of particles has a significant effect on the shear strength and deformational characteristics of granular materials. Weathering can change the grain shapes. For example, more weathered sands tend to be rounder regardless of particle size. Particle shape analysis was performed on samples collected from the Questa mine rock piles, a debris flow and the pit alteration scar. In order to increase the validity of the particle shape analysis, 4 persons including 2 geologists and 2 mining engineers were involved in describing the particle shapes. The results of this analysis indicate that rock fragments in the collected samples are mainly subangular, subdiscoidal and subprismoidal. The sphericity and angularity of the rock fragments of the older analogs are similar to those of the rock piles. This suggests that short-term weathering (<100 years) has not noticeably changed the particle shapes at the test locations. Rock piles made of more angular particles are more stable compared to rock piles with rounded particles.

Jan 1, 2009

By S. A. Voltura

The Phelps Dodge Miami smelter has smelted copper concentrate using the ISASMELT technology since 1992. The design throughput rate was 591,000 tonnes/year and after a slow start-up, the production rate has exceeded the design after the seventh year of operation. In 2002, the smelter consumed 719,000 tonnes of copper concentrate and has the potential to hit the permitted rate of 772,000 tonnes/year. Improvements to the smelting vessel and the surrounding support processes have allowed for continuous improvement from start up until now. This presentation will outline the chronological events and the improvements completed to accomplish these improvements

Jan 1, 2004

By Paul F. Richardson

Liquids containing suspended solids are encountered in most mineral processing applications. Solids levels cover a very wide range, from ppm levels in cooling water systems to slurries containing greater than 70% solids. When the aqueous phase is recycled or further processed, a solid/liquid separation process is used. Chemical additives used to carry out this process are called coagulants and flocculants. In other cases, one seeks to control or modify the properties of the suspension. Dispersants are chemicals used to aid in suspending solids in a liquid as well as to control the properties of the resulting suspension. Dispersants find a range of uses in mining and mineral processing such as scale control, filter aids, flotation aids, and slurry viscosity modification. Materials used as dispersants include inorganic salts, alkalies, organic surfactants, and polyelectrolytes. This paper discusses the use of dispersants in mineral processing, with an emphasis on control of slurry viscosity. The mechanism of dispersion and factors that affect the choice of dispersant will be discussed.

Jan 1, 1986

By T. N. Moore, E. M. De Souza

Vibratory hand-tools can produce Hand Arm Vibration (HAV) Syndrome in their operators. This disease, often called Vibration White Finger, can cause varying levels of hand-arm discomfort and, in severe cases, impairment. In addition to the human suffering, there are also significant economic repercussions for industry. These include reduced operator efficiency, lost time through increased absenteeism and increasing compensation awards. In the mining industry, jackleg rock drills are a particularly troublesome source of hand vibration exposure. As a result, a significant amount of work has focused on redesigning rock drill handles to minimize hand-transmitted vibration. This paper details the results of a study undertaken to determine the effectiveness of using elastomer covered ("cushioned") handles in place of the standard steel design. The results indicate that, for a particular cushioned design, the overall acceleration level experienced at the hand-handle interface can be reduced by as much as a factor of three, relative to the steel handle. It is also shown that this reduction takes place predominantly in the frequency range above 500 Hz, with performance improving with increasing frequency. Qualitative evaluation of the cushioned handles by the drill operator indicates a significant increase in comfort over the standard steel handle.

Jan 1, 1992