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By Cleophus Short

[Of the many occupations in and about the coal mines, those of the haulage crews are among the most hazardous. Statistics ship that the second greatest number of fatalities about the coal mines occur during haulage ion and through the use or misuse of haulage equipment. During the five year period between January 1, 1957 and January 1, 1962, the m stone mine had a. Sack haulage frequency of 4098 and mined 3, 541,939 toads per haulage fatality. Coal mire haulage is similar in respects to railroading. We gee very serious consideration to the instillation of tack and to the selection of the haulage crews. In doing this, we are attempting to have our coal mine haulage as. Safe as that of the railroads.]

Jan 1, 1963

By B. Listerud, G. Zhan, M. A. Jones

Barrick Goldstrike Mines Inc. (BGMI) operates the Betze-Post openpit and the Meikle and Rodeo underground mines. Because the majority of the orebody is located below the water table, mining at BGMI requires a significant dewatering program. BGMI has a comprehensive dewatering and water management system that experienced a peak dewatering rate of 4,400 L/s in the mid 1990s. Changes to the hydrologic/hydrogeologic system caused by the mine dewatering have been monitored by an extensive network of groundwater monitoring wells and surface water monitoring stations, which cover about 1,550 km2. In addition to the monitoring program, a new tool, called Interferometric Synthetic Aperture Radar (InSAR), has also been used to enhance the evaluation of changes. Finally, a groundwater flow model has been developed that successfully simulates and predicts aquifer responses in the mine area and region. The well-calibrated flow model has served as a reliable tool to develop dewatering and mining plans, and project post-closure hydrologic conditions in the region. This paper introduces the BGMI dewatering and water management system and the means used by BGMI to evaluate and anticipate hydrologic responses in the region. The water management and analysis system has been and continues to be an integral part of managing ongoing operations, planning and pricing out future activities and evaluating the long-term effects of mine water handling.

Jan 1, 2011

By Klaus Beckmann

Gentlemen : My object reads "Longwall Rapid Advance of Coal Mining in the Federal Republic of Germany". It is true that the percentage of coal obtained in your country from longwall faces, with at present 1.2, is still rather low, but it increased considerably since 1966 with 0.4 %. The coal mines of the Federal Republic of Germany ever used longwall as the classical method of coal getting. All attempts to introduce bord and pillar mining did not lead to any wider application of this method. The principal reasons, for this appear to have been: - the deeper depth of our workings, - the wish to keep working losses as low as possible and to utilize the deposits opened up by deep and therefore expensive shafts to the furthest possible degree, - the dense sequence of seams and the mutual influencing of the working points, - the high number of disturbances in the geologically much stressed deposits, - and the necessary considerations to the protection of the densely built-upon surface.

Jan 1, 1970

By Edward J. Adams

In recent years, there has been a shortage of individuals trained in the technical skills entering the mining industry. The university and industry, both indicating their concern, have joined efforts in an attempt to do something about this situation. An example of such an effort is the Pennsylvania State University's Student-Trainee Program in Mining Engineering, now in Its third year. The program is a five-year plan in which six months of schooling and six months of on-the-job training are alternated, climaxed by the student trainee earning a Bachelor of Science Degree in Mining Engineering plus two years of practical experience. The student trainee accepts the work-study plan as a satisfactory method of receiving a thorough education and preparing fog a career in the mining industry. Inasmuch as the work and study-periods are alternated, the trainee has an opportunity' to integrate his practical experience with his academic knowledge. He receives a chance to observe others perform she duties of the profession he is preparing to pursue, and he regards this as an essential part of any such cooperative effort. Even though there are some disadvantages, the trainee feels that the advantages of the program are definitely more decisive.

Jan 1, 1963

By Robert S. Lehto

Zinc concentrates received in La Oroya zinc refinery are marmatitic in nature, contain about 11% iron and traces of other metal values, Figure 1 shows the zinc circuit. The calcine from the roasted concentrates is leached in spent zinc electrolyte. Major part of the impurities is iron which has been oxidized to its trivalent form, This is the origin of the zinc leach residue for which the ZILERET process was developed and so named. The impure liquor from the leach is sent for purification and thence to electrolysis- zinc deposits on aluminum cathodes from which: it is stripped, melted and cast into slabs Typical assays of zinc calcine and leach residue are given in Table 1. Metal values contained in the leach residue, without counting any value of iron, amount to roughly $130 per short ton.

Jan 1, 1969

By Allan Gebhard

The purpose of this paper is to summarize the role of water resource monitoring in mining activities and to discuss the considerations that go into designing and implementing a monitoring program. The design of a monitoring program is invariably based on sound engineering and scientific judgement since no design formulas exist that can be universlly applied to the monitoring of all activities. As discussed in this paper, however, a methodology of designing a water resource monitoring program does exist. In order to cost-effectively monitor the water resource impacts of mining activities, the following three monitoring related items should be understood: 1. the role of water resource monitoring in the planning, construction, and operational stages of mine development, 2. the available water resources monitoring methods and the proper role of each method in the various scages of mine development, and 3. the strategies that should be followed in designing and implementing a water resource monitoring program.

Jan 1, 1976

By Martin N. Kelley

The Great Belt Link is a $3.5 billion fixed link across an 18 km (12 mile) wide body of water that separates the island of Zealand, on which Copenhagen is situated, and the main land mass of Denmark, Jutland, which is part of the European continent. The project consists of three main contracts. The first contract is an 8 km (5 mile) long, two-bore railway tunnel for the eastern half, the second contract is a 6.6 km (4 mile) combination railroad and highway bridge for the western half, and the third contract is a 6.7 km (4 mile) long high-level highway bridge for the eastern half. This paper will discuss the Eastern Railway Tunnel Project and the methods of construction that the joint venture consortium plans to use, along with its equipment selection. The ground conditions to be encountered begin with glacial tills, which are a mixture of clay, silt, sand, gravel, cobbles, and granitic boulders. The boulders can be up to 1-3 m (3-10 ft) in diameter. Underlying the till is a marl which is sometimes highly fractured with hydrostatic pressures of up to 8 bar. About 40% of the tunnel is in till and 40% in marl, with the remaining 20% being a mixed face of the two formations.

Jan 1, 1991

By R. L. Miller

The potential for recovery of enriched uranium from spent nuclear fuel which has been consolidated into a nuclear waste form was explored in the studies reported here. The waste form of interest is iron-enriched basalt (IEB)--a silicate-based, fused-cast ceramic. IEB samples were prepared containing fuel assembly materials that simulate the core debris of Three Mile Island Unit II;1,2 the nominal composition of the consolidated waste form is given in Table 1. Ore Types The IEB samples, or man-made uranium ores (MMUO), are in two different mineralogical forms. Each MU0 was made by melting the constituent materials and holding at about 1500°C for 1 h. The MMUOs were then heat treated to control crystallization and crystal growth and then cooled to room temperature.

Jan 1, 1983

By William Lyman

GENERAL DESCRIPTION Shrinkage or shrinkage stoping refers to any mining method in which broken ore is temporarily retained in the stope to provide a working platform and/or to offer temporary support to the stope walls during active mining. Since ore "swells" when broken, it is necessary to shrink the muck pile a corresponding amount by draw¬ing some of the broken ore out as the stope is advanced-hence the name. Broken ore retained during stoping is drawn out after the stope has reached its limits. The stope may be left empty or may be filled with waste contemporaneous with, or subsequent to, the final draw. Traditionally the method implies conventional overhand stoping methods with miners working between the muck pile and the stope back, in a space which advances updip with mining and is maintained by balanc¬ing "swell" with "shrink." The shrinkage classification is also applicable to so-called "semishrinkage" methods in open pillar-supported stopes where broken ore is temporarily retained as a working platform but offers no wall support; and to various blasthole shrinkage methods which utilize broken ore temporarily retained in the stope for wall support, but which do not require miners to work from muck pile in the stope. The method is generally applied to steeply dipping veins of strong ore between strong walls. APPLICATION Geometry The geometry of a shrinkable vein is described in terms of dip, width, and regularity along dip. Overall strike and dip dimensions and irregularities along the strike generally impose no restrictions on the method. Dip is ideally 1.2 to 1.5 rad (70 to 90°). As dip falls below 1.2 rad (70°), the shrinkage draw begins to strongly favor the hanging wall side, thus leaving a poor working platform for conventional overhand work. This is particularly true in relatively wide stopes. The sup¬port afforded to the hanging wall also diminishes with decreasing dip, reaching nil as the dip approaches the repose angle of broken ore. Dips below 0.78 to 0.87 rad (45 to 50°) are not generally shrinkable except by open stope "seinishrinkage" methods. Minimum mining width is fixed by working space requirements in the stope-generally about 1 m. Shrink¬age in narrower veins requires that waste rock from one or both walls be broken with the ore and the attendant dilution accepted to achieve the minimum width. Nar¬row stopes are less suitable, encouraging hang-ups and bridging of broken ore, with the attendant problems of erratic draw and incomplete recovery of broken ore. Maximum practical width may be 3 m or less to over 30 m, depending upon the competency of the ore and its ability to stand unsupported across the stope back. This is a vital safety consideration in conventional over¬hand stopes, but is much less of a factor in blasthole shrinkage methods. Very wide veins and massive ore bodies have been mined by transverse vertical shrinkage panels separated by transverse vertical pillars which are either abandoned or recovered later by other methods. Regularity along the dip is a prerequisite of shrink¬age as there must be no serious obstruction to the flow of broken ore downward through the stope to the sill level. Gentle rolls along the dip are acceptable if the local footwall dip everywhere exceeds 0.78 to 0.87 rad (45 to 50°). Off-dip hanging wall and/or footwall splits can generally be mined selectively from a conventional shrink stope as they are encountered without ad¬versely affecting subsequent continuation of shrinkage mining updip on the main vein. Vertical offsets or major rolls along the dip which cannot be "smoothed over" generally require that a sublevel be established with new draw control development. Blasthole shrinkage methods are much less flexible (and thus less selective) in their ability to accommodate any of these irregularities. Ground Conditions The wall rock must be strong enough to stand with the minimal support afforded by the dynamic mass of broken ore in the stope. During active mining, local sloughing from the walls is restrained, but the broken ore affords little, if any, useful resistance to closure of the stope walls. Such squeezing, if present, may bind up the stope and cause the loss of much ore. Pillars left between and/or within stopes are effective in preventing closure but reduce overall recovery. Walls may be re¬inforced by bolting after each stope cut in conventional shrinkage but not in blasthole shrinkage. Ore in place must be strong enough to stand with no natural support across the stope width, although tem¬porary artificial support or reinforcement may be used locally in conventional stopes. Some spalling or sloughing is permissible in blasthole shrinkage as men are never present in the stope. Physical and/or mineralogical characteristics of the broken ore may impose restrictions on stope design and/or operational plan¬ning, and may even preclude the use of shrinkage al¬together. Examples include: ores which, when broken, are cohesive or which tend to pack or cement together under the influence of ground water, wall pressure, and/ or chemical reaction. Such conditions precipitate er¬ratic draw during mining and often result in difficult and/or incomplete final draw; pyritic ores which oxidize very rapidly in the stopes and may generate heat, imposing a fire hazard by spontaneous combustion; sulfide ores which oxidize sufficiently in the stopes to adversely affect mill recovery by flotation; and ores (es¬pecially those containing uranium minerals) which ex¬ude radon gas and thereby impose ventilation constraints on stope design. In most cases these problems can be minimized by limiting the size of stopes, by minimizing the duration of mining activity in each stope, and by promptly drawing each stope empty following comple¬tion of mining.

Jan 1, 1982

By D. Christofferson

As an alternative power source to eliminate trailing cables, ESD Corporation is installing a flywheel system on a shuttle car. Flywheel power is extracted by a high-speed generator, developed by Lear Siegler Corp,, and the system -- including vacuum and lubrication and cooling auxiliaries -- is supplied by the aerospace group, Rocketdyne Division of Rockwell International. The flywheel system is being developed under a three-year contract with the Department of Energy. It is a follow-up contract to a previous DOE-contracted study by General Electric Co. in which it was shown that a flywheel can be a feasible power source for a shuttle car from technical, economic, and safety standpoints. This paper addresses the status of the program, design decisions established, and plans for laboratory test procedures and underground demonstration. The flywheel-powered shuttle car is a conventional 6-ton capacity shuttle car equipped with a 7-rotor flywheel energy storage package. The energy package is the sole source of power for the shuttle car through a complete mission duty cycle (MDC) of tramming to the miner, receiving a load of coal, and returning to the secondary haulage system. Energy stored in the system exceeds MDC requirements and waiting times to provide an ample margin of reserve energy. The energy storage system is recharged by spinning the rotors back up to maximum speed each time the shuttle car comes back to the secondary haulage system. The electrical charge motor is connected to a power source to recharge the system while the load of coal is being discharged.

Jan 1, 1982

By V. W. Smith

For the past 50 years, the primary crushing of stone at the Dolase Bros. Co. Richards Spur Quarry. 13 miles north of Lawton, Oklahoma, has been accomplished by a Traylor 42-inch gyratory crusher. The production capacity of the primary system, consisting of a feeder, grizzly, and the gyratory crusher, was approximately 2100 tons per hour. Shot-down scone was hauled from the working face about one mile to the feeder by a fleet of Caterpillar Model 773's and WABCO 60- and 65-ton trucks. In order to maintain production, nine to ten trucks and four Caterpillar Model 992 front-end loaders were required to be operational at all times.

Jan 1, 1986

By M. L. Leming

The mechanisms of Alkali-Silica Reactivity (ASR) are briefly reviewed, test methods are examined, and typical specifications are discussed. In addition, views on responsibility of the aggregate supplier regarding specifications are presented.

Jan 1, 1995

By John S. Owens

The National Steel Pellet Project and the Butler Taconite Project are operated by The Hanna Mining Company in the vicinity of the towns of Keewatin and Nashwauk, on the western Mesabi Range. Production began in 1967, after seven years of exploratory and development diamond drilling and reconnaissance magnetic surveys, Previously, direct shipping hematitegoethite ores and gravity concentrates had been produced in the area from numerous open pits and several underground mines since the start of the century. Total shipments of these oxidized ores amounted to more than 200 million tons, but at the present time such reserves are nearly exhausted, and there are no mining operations in the Keewatin-Nashwauk area except at the two taconite projects. The locations of all of the present taconite operations on the Mesabi Range are shown in Figure 1, extending for a distance of about seventy miles from the Butler plant to the Dunka River area. The Butler and National plants have a combined rated capacity of 4.4 million tons of pellets. Their reserves cover a combined strike length of about eight miles on the Biwabik iron formation. All of the intervals between present taconite operations on the Mesabi are potential sources of additional magnetic taconite; in particular, exploration and economic studies have been carried out by Jones and Laughlin Steel Corporation in the Biwabik area between Aurora and Virginia, and by Pickands Mather and Company in the Hibbing area. However, west of the Henna and Butler holdings, it appears unlikely that magnetic taconite exists in commerical quantities at economic depths due to extensive oxidation of magnetite to hematite.

Jan 1, 1968

By J. R. Allan

Loki Gold Corporation of Vancouver, B.C. is developing the Brewery Creek Mine, an open pit heap leach gold mine, 55 km East of Dawson City in Yukon, Canada. Mineable reserves are 17.1 million tonnes of ore grading 1.45 grams/tonne, containing 24.8 tonnes (797 000 oz) of gold. Ore processing will employ a cyanide heap leach using run of mine ore. Permitting this mine has drawn significant attention because the heap leach technology, while proven in other jurisdictions, has not been used in Yukon. Engineering design of the heap leach was similar to that for heaps in more temperate climates, with the added issues of permafrost and cold weather operations. Solution balance with seasonal placement of ore and year -round leaching requires very large pond capacity for spring thaw conditions.

Jan 1, 1996

By C. M. Marquardt

The materials handling systems in the large concentrating plants have required the employment of a considerable number of workmen, many of whom had very little to do except to act as watchmen to avoid bad spills at belt junctions and to operate tripper cars, shuttle belts, etc. Much time also was spent in watching bins to make sure they were properly filled. Approximately four and one-half years ago the author, Yin coopera¬tion with the engineering and supervisory personnel of The Anaconda Company at Anaconda, Montana, began to give this problem serious consideration. Prior to this the author had developed, at the request of The Anaconda Company, a transistorized resistance-sensitive probe relay system for detecting the level of ore in bins. With this system cables or chains were suspended from insulators above the bins and were of suitable length to determine the elevation of the ore in the bins.

Jan 1, 1962

By Jaime Lomelin

[First of all I want to thank the Society of Mining Engineers of AIME for the opportunity to present what Industrias Penoles, S.A. is doing in Mexico to reach the basic objetive of the enterprise without compromising, in short or long term, the living conditions of the community or attempting in an irreversible form against Nature. Industrias Penoles, S.A. is one of the largest mining and metallurgical companies in Mexico. It was founded in 1887 and at the turn of the century installed a lead smelting operation close to the village of Torreon, which became city five years after the start up of the Penoles smelter. Now Torreon has a population close to 300,000 inhabitants. In 1974 Penoles is still the largest industry in Torreon and the dynamic growth of the city is close related to this factor. Today Penoles in Torreon has a lead smelter with a capacity of 130,000 metric tons/year of bullion, an electrolitic zinc plant of 105,000 metric ton/year, and it is modernizing its lead smelter to control pollution and expand it to 190,000 metric ton/year of bullion including all the services and refinery. The Penoles complex in Torreon is the biggest in the non-ferrous metals field in Latinoamérica.]

Jan 1, 1974

By Lynn B. Hales

Everywhere you turn today there are articles on artificial intelligence and the rapid emergence of expert systems. Expert systems form a class of software that has developed as a result of the large research effort to develop computers and software that think intelligently. By definition, an expert system is a computer program that contains the knowledge component of an expert skill, can offer intelligent advice and justify its line of reasoning. Expert systems can advise people on what actions to take and when, assist in the diagnosis of the physical condition of a human patient or piece of equipment, or even take actions without human guidance, as in process control applications. Expert systems can also explain the line of reasoning behind a particular piece of advice or query for information from the user. Expert systems can be used as advisors to newcomers in any field in which mastery is attained by many years of experience. They often can provide expertise more uniformly and rapidly than human experts. Expert systems can also provide a means of documenting expert knowledge and procedures and provide a common repository for a changing knowledge base. The expert system can represent the best expertise available, thought out in the absence of pressure situations. Each of these attributes or characteristics should be helpful in improving typical concentrator control systems.

Jan 1, 1987

By Douglas M. Deason

Swelling clays, such as montmorillonite, contribute significantly to the poor dewatering and consolidation behavior of the Florida phosphate clay wastes. Understanding and to a degree, control of the forces which cause the swelling behavior may aid in supplying a solution to this problem. The technical feasibility of utilizing control- led dispersion for aiding dewatering of phosphatic slimes was investigated. This technique is based upon inhibition of swelling and self-dispersing tendencies of the montmorillonite clays by dispersing the solids in electrolyte solutions. Through this process, significant improvements in settling rates and sediment solids content were achieved in both pure clay systems and on simulated phosphate slimes.

Jan 1, 1983

By John J. Mulligan

Coal is found in every major geographic region throughout Alaska and in two offshore areas. Since about 1852 over 100 small mines have opened and closed. Last years production was almost entirely from one mine in central Alaska. Clearly the utilization of Alaska's abundant coal resources presents political, economic and technical problems that are far from solution. Location and Physical Features Figure one illustrates the geographical and geological similarity between Alaska and western United States. The Arctic region of Alaska generally resembles Wyoming and the Dakotas. The Brooks Range is an extension of the Rocky Mountains. The Central region of Alaska between the Brooks Range and the Alaska Range bears a general resemblance to the basin and range country of western United States. The Southcentral and Southeastern regions has a similar resemblance to the Sierra Nevadas and the west coast of the United States.

Jan 1, 1982

By S. C. Sethi

The paper presents an analysis and discussion of the underground ventilation system at the waste Isolation Pilot Plant (WIPP), with particular emphasis on specific repository-related requirements and the gradual evolution of engineering designs relative to the WIPP Project scope. The underground facility has been constructed with three shafts. Additional studies, coupled with actual site-specific experience, have established? the need for construction of a fourth ventilation shaft to double the under-ground airflow. As a research pilot project, and the first of its type in combining mining and nuclear technologies, the WIPP Project is accumulating data and experience that may be fruitfully applied in the future designs of ventilation systems for planned commercial nuclear waste repositories.

Jan 1, 1988