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By M. E. Poad

In 1986, a cooperative effort by the Homestake Mining company, the U.S. Bureau of Mines and the University of Utah was initiated to determine shaft stability while recovering high grade ore in a nearby pillar. Premining finite element simulations indicated the shaft would remain in elastic ground. Six years have elapsed and, despite some initial concern during the first lifts, it appears that the bulk of the original reserve will be safely and profitably recovered. An integrated application of rock mechanics tools from laboratory testing through numerical modelling to mine measurements and observations contributed substantially to the operational success of the project.

Jan 1, 1994

By E. Rigopoulos

Mining disturbs the environment, even when the ores or the minerals extracted are non-toxic. Silver & Baryte Ores Mining Co S.A (S&B) is committed to minimizing the environmental impacts of its mining activities, by implementing an integrated rehabilitation program wherever it operates. The paper discusses the principles for mining-disturbed land restoration activities on Milos Island for a successful outcome.

Jan 1, 2003

By L. Adler

To properly analyze and apply mining equipment, a systematic, current, inclusive, and simple classification scheme is required. This paper provides such a classification for Roadheaders. This Roadheader classification is based on factors, such as the rock cutterhead, the boom type, and the chassis configuration. It first assigns Roadheaders as an equipment type within the larger group of Integrated Excavators. The Roadheader type is then delineated into the following subtypes: the standard, the extended boom, the tunnelers, and the miscellaneous. Next, these subtypes are devolved into kinds, and finally variants and attachments are considered. To resolve inconsistencies in characterizing the Roadheader, cross-referencing is employed within the classification scheme.

Jan 1, 1996

By K. N. Mayfield, T. Novak

"The applications for automation continue to expand within the mining industry. These applications can range from the startup, control, and shutdown of processing plants to the autonomous operation of surface haulage trucks. However, the term “automation” should not necessarily be interpreted as the total elimination of human interventions since numerous mining processes can be partially automated. The future survivability of many mining operations will be influenced by a company’s willingness and ability to understand, accept, and utilize this technology. The mining workforce, including management and engineering, should be familiar with the technological capabilities and limitations for effectively implementing automation into mines for improving safety and productivity. The Department of Mining Engineering at the University of Kentucky has recognized this educational gap and developed an automation laboratory, along with project-oriented courses at the undergraduate and graduate levels. The laboratory and the course objectives are described in this paper, as well as the skills and abilities that students obtain at the completion of the course(s). BACKGROUND The touted benefits of automation include: improved productivity, lower operating costs, reduced drudgery of repetitive operations performed by workers, and the removal of workers from hazardous locations. The acceptance of advanced technology by the mining industry, however, has traditionally been slow. This cautious approach is understandable considering the complex and harsh conditions routinely encountered in mining operations. Bad experiences with some premature installations of newly hyped technologies may have also resulted in lingering skepticism by many mine operators. Nonetheless, with thoroughly demonstrated reliability and proven applications, automation based on programmable logic controllers (PLCs) has made significant inroads into the mining industry. Programmable logic controllers (PLCs) are the workhorses of automation. They were originally conceived in the late 1960s, long before the invention of the personal computer (PC). Initial PLC applications were directed towards sequential relay control in manufacturing plants, which subsequently eliminated the use of “relay logic” that was based on hard-wired electromechanical relays. With continuous advancements in electronics and computer technology over the years, PLCs have evolved into sophisticated and powerful devices with very stable operating systems. They are designed for deterministic logic execution with extreme consistency in timing, along with a high tolerance to temperature, humidity, and vibration (Smith 2003). Because of their robust characteristics, PLC networks now provide the backbone for most industrial automation applications."

Jan 1, 2017

By Giovanni Osellame, Jean Habimana

"The Montreal Metro Blue Line Extension Project is part of a metropolitan Program that was launched in 2009 by the Transportation Ministry of Quebec to add additional extensions to existing metro lines in the cities of Montreal, Longueil and Laval with the intention to meet current demand and future growth within the Montreal agglomeration. Specifically the Blue Line Extension Project will add five underground stations to the East of the Montreal. The paper addresses the preparation and the implementation of a three-step geotechnical and geo-environmental investigation program and preliminary design considerations such as the selection of a preferred horizontal and vertical alignment, the selection of construction methods based on previous local experience and current industry trends, as well as preliminary sizing of underground infrastructures. PROJECT BACKGROUND An agreement between the three mayors of the Montreal Metropolitan City agglomeration, namely, Montreal, Longueil and Laval prompted the Government of the Province of Quebec to create a project office to oversee the studies of extending the existing metro network. The last extension of the existing metro network was completed in 2008 with the Laval extension, which consisted of adding three stations from the existing Orange line. The current extension Program consists of three different extensions, namely extending the Orange Line to Laval and finishing the loop, extending the Blue Line to the East of Montreal by adding five stations, and adding five stations on the Southshore of the St-Lawrence River for the Yellow Line extension. The extension program also requires the construction of an underground storage and maintenance garage located to the north-west of the existing Cote-Vertu station on the Orange line. Figure 1 shows the overall extension program with the existing network."

Jan 1, 2016

In spite of our deep conviction that it would be wrong for the United States to enter World War II, when, after Pearl Harbor, we were actually in it, I felt that I must do all I could to help. The country had been so good to me that I could not decently stay on the sidelines. My first thought was that I might help with supply and administration in the Air Force, as in World War I. So on the evening of Pearl Harbor I wired the chief of our Air Force in Washington saying that I had been on Gen. William Mitchell's staff in World War I and was offering my services again. I received a noncommital answer, but after a couple of weeks was told to take my physical examination. I passed it, but nothing further happened. After helping to make plans for the wartime operations of Summit King and Desert Silver, Dorothy and I went to New York to spend Christmas with Molly and Peter, both of whom were in college in the East. I had to complete a report on the Argonaut mine in California first, though the war made my recommendations of dubious validity. Before Christmas I received wires from Temple Bridgeman, Phil Wilson, and other friends who had taken positions with government agencies responsible for securing mineral products needed for war use. They urged me to join them. It was evidently a case of not whether but how I could be most useful. After six uncertain days with the family in New York I took the night train to Washington on the 28th of December. I had a hectic day there. First I saw Arthur Bunker and Phil Wilson at what became the Aluminum and Magnesium Division of the War Production Board. Their office was in an old converted barracks. They asked me to examine magnesium deposits in Nevada at once, and then to look at other magnesium and aluminum properties. After leaving

Jan 1, 1976

By J. Hazen, R. Jenner

This project was developed at the PCS Phosphate Mine in Aurora, NC. This site includes a surface mining operation, beneficiation plant and chemical processing facility located in the coastal plain of eastern North Carolina. The phosphate ore being mined at this operation is a 10 to 12 meter (35 to 40 foot) thick colloidal deposit located approximately 30 meters (100 feet) below the ground surface. The ore is pumped to the beneficiation facility where it is separated into clay, sand and concentrate streams. The concentrate product is utilized at the chemical plants to produce a wide range of products including fertilizer, industrial phosphates and animal feed products. The Cyclone Dike Builder (CDB) project developed a technique for dewatering the beneficiation tailing sand stream and providing innovative placement for dike construction. Future material balance requirements at the PCS Phosphate mine required an improvement in tailing sand placement technique to accomplish strategic objectives. The water volume of the sand slurry forces significant quantities of sand out of the dike profile during deposition. PCS Phosphate and MetPro Supply of Florida developed a mobile high-density hydro-cyclone station to remove most of the water and significantly increase the density of the sand being placed for dike construction. This high-density sand slurry is then effectively controlled using minimal heavy equipment operation.

Jan 1, 2004

By Murali M. Gadde

Perimeter mining is a special form of very productive partial extraction method practiced at some mines in the United States. In the Illinois Basin mines where all major coal seams have weak underclay in the immediate floor, experience shows that any long-term ground control issues will arise due to floor failures rather than instability of the coal pillar itself. While there is a significant amount of work done on floor stability associated with regular pillars, no work has been done so far on the stability of perimeter pillars. This paper reports the results of a comprehensive study that was conducted for the first time on floor stability during perimeter mining in the Illinois Basin mines. A special plate template, which mimicked a common perimeter pillar configuration was created to conduct in-situ bearing capacity tests at five mines in three states of the Basin. Additionally, because of the complex shape of pillars created in perimeter mining that defies any closed-form solution, floor bearing capacity was studied using three-dimensional nonlinear numerical modeling. Based on these in-situ and numerical studies, some guidelines are provided for perimeter pillar stability analysis.

Jan 1, 2009

By Michael D. Sopko

This paper describes the project implementation from financing, through the engineering and construction phases, mine and process plant commissioning as well as operating experience realized to-date. The single line flowsheet used to process the lateritic nickel ore to a 75 percent nickel matte is presented with emphasis on the main pyrometallurgical operations. These include a rotary dryer, a unique reduction kiln, a 45 000 kVA electric furnace and two Pierce-Smith type converters. Associated infrastructure facilities and services necessary to sustain the 11 300 tonnes (12 500 short tons) per year nickel production rate are also described.

Jan 1, 1979

By Martin L. Smith, John M. Kemeny

In blasting, an optimal muckpile size distribution can be found in terms of mining and milling productivity and cost. Fragmentation control requires a means of modeling and evaluating blast results. A principle problem in the practical application of empirical blast fragmentation modeling is the evaluation of the muckpile's size distribution. Image analysis of video and photographic records of production size blasts at Cyprus's Miami and Thompson Creek mines is being used to provide data for estimating parameters relating fragmentation to blast design, energy factor and rock quality. The application of image analysis to the estimation of particle size distribution is reviewed with regards to the problem of fragmentation modeling.

Jan 1, 1993

By R. F. Shurtz

This paper uses a simple model to illustrate the fact, widely known to information theorists, that the covariogram represents only half the information in the data used to construct it. It suggests and illustrates methods of putting the other half to use in describing mineral deposits. It also identifies applications in which the phase information is not needed.

Jan 1, 1986

By Aldo F. Barsotti

The production and consumption of industrial minerals in the United States traditionally have played important roles in mining and in the supply of the bulk of basic raw materials to the economy. This diverse group of minerals extracted and consumed by a variety of industries accounts, on a weight and volume basis, for most mineral-based products consumed in our economy. Industrial minerals form the bulk of the basic raw-materials feedstock for most of the construction, agricultural, and inorganic-chemical-manufacturing sectors, and a good portion of the transportation, manufacturing, organic chemical, and service sectors of the U.S. economy. In this presentation, I discuss current estimates of the amount and value of industrial minerals mined compared with all mining in 1997. I then present a summary of 1997 production of industrial minerals by several end-use industries. This is followed by a historical perspective of the consumption of industrial minerals as a subset of all basic materials, with special emphasis on the aggregates industry. The presentation concludes with a look at the geographic distribution of industrial mineral operations in the United States and some thoughts about the future.

Jan 1, 1999

By A. D. Hoagland

There are large areas on all of the continents with environments which are favorable for deposits of zinc and lead of Mississippi Valley type. In the developed countries, these environments have for the most part been quite thoroughly explored for the near surface deposits, and it will be necessary to direct more effort to the search for deeper buried deposits from which much of our future production must come. The difficulties of exploration for deep ore of this type are many and formidable, but the area of permissive environments beneath deep cover is many times as great as the area of the known near surface ore districts. It is a reasonable assumption, therefore, that numerous deposits wait for discovery and development. The finding cost, however, is certain to increase, and it is essential that concepts and techniques of exploration be improved if we are to sustain a reasonably strong productive capability into the 21st century. Exploration for deeply buried deposits requires at the outset relatively large areas of favorable geologic environment. The favorable horizons must be within economic limits of depth for the exploration as well as for the mining techniques which are currently available; and there must be some condition, design or strategy which will assure the explorer a reasonable chance of obtaining maximum benefit from discoveries which he may make.

Jan 1, 1973

By J. R. Dillon

Today more than ever, there is an increased demand for higher plant production capacities and efficiencies to offset the increasing costs for labor and materials. Plants involved in processing large volumes of bulk materials are particularly interested in more efficient material handling systems to (1) reduce labor and maintenance costs, (2) improve blending of non-uniform raw material feed to processing facilities, (3) improve blending of finished bulk materials from storage. DragScraper systems are being used effectively for handling a variety of bulk materials in both indoor and outdoor storage. Materials being handled include ores, chemicals, coke, clay, and stone, to name a few. Handling capacities these machines can provide vary from a few tons to over 1500 tons per hour. The basic components of a DragScraper machine consist of a bottomless Crescent scraper, a two or three-drum DragScraper hoist assembly including gas, diesel, or electric power unit, operating cables, guide blocks, and either fixed or mobile head and tail structures. They are presently available in sizes through 15 cubic yards, for operating spans up to 1000 feet.

Jan 1, 1969

By A. L. Muler

Since 1956, when Broadbent and Callcott 1 proposed to analyze breakage processes by matrix methods, several authors and their co-workers have proposed various models of grinding that, in principle, could lead to fully automated grinding circuits. In particular, Meloy and Gaudin2, Gardner and Austin3, Kelsall and Reid4, Neloy and Bergstrom5, Callcott and Lynch 6, and Draper and Lynch have, by either computer simulation or by experimental data, or by a combination of the two, verified that comminution is reasonably well described by at least two functions: a selection function and a breakage function. The stage concept proposed by Callcott and Lynch6 requires that a classification matrix be included to completely describe breakage in an open circuit rod mill. The purpose of this work, portions of which are herein described, is to accumulate sufficient information on the breakage characteristics of quartz and magnetite in an open circuit rod mill, so that several of the theoretical and experimental approaches proposed in the literature can be compared with each other. Data is being gathered to compare the experimental method used by Kelsall and paid against the stage approach of Callcott and Lynch.

Jan 1, 1968

By L. F. Delgado

Environmental and cost pressures sparked renewed interest in gravity separation. Industrial sands in Mexico are generally processed by screening, desliming, and flotation. Gravity separation with spirals was evaluated as an alternative to flotation in order to lower operating costs and decrease water pollution. Outstanding operating results are obtained in glass and foundry sand operations, plus a more competitive position for Mexican producers due to lower operating costs. Coal fines, generally recovered by flotation, have the same cost and environmental advantages when processed with spirals.

Jan 1, 1994

By E. William Rossi, Audrey F. Glowacki, Richard L. Unger

The U.S. Bureau of Mines has developed a graphics-based computer model to assess operator visibility for continuous miners, shuttle cars, and scoops. Using digitized drawings of the machine, the program can analyze visibility for both 5th percentile female and 95th percentile male operators. This model was used to predict 95th percentile male operator visibility for two shuttle car designs. These results were then compared to those obtained from a manual assessment of visibility using the actual shuttle cars. The methods showed good correlation except for several cases which were attributed to imprecise digitization of the machines.

Jan 1, 1992

By Kerstin Malmqvist

Simulation technique has been used for a feasibility study of a deep exploration project for massive, sulphides in an old mining district, the Skellefte field. An interactive computerized mathematical model of an ore field and a drilling procedure has been constructed. It is possible to represent varying geological structures. The model also takes in consideration economical factors such as drilling costs and ore values. On this model Monte Carlo simulations and probability calculations are done in order to estimate the outcome of different drilling strategies under varying geological assumptions. Under the specific conditions of the well known Skellefte field, it is found to be possible to even calibrate the mathematical model.

Jan 1, 1979

By S. S. Vasan, K. A. Natarajan, J. M. Modak

The biological removal of calcium from a bauxite ore in the presence of the soil bacterium Paenibacillus polymyxa is demonstrated. A column bioreactor that can be either operated in a fluidized-bed (FB) mode for coarser particles or in a total-recycle-slurry (TRS) mode for finer particles was designed, fabricated and tested for this purpose. For the efficient removal of calcium from the ore to the required levels, leach solution should not be allowed to accumulate in the reactor. Therefore, the solution needs to be drained out periodically. Cascade leaching was found to be more effi¬cient. A direct correlation between pH changes in the leach solution and calcium solubility could be made. More than 85% of the calcium could be removed through cascade leaching.

Jan 1, 2000

By Carlos Kovacs-Figueroa

Because of air pollution control regulations in the early 701s it became necessary to clean effluent gases from the Morenci Reduction Works Smelter. Feasibility studies indicated that this could be accomplished most efficiently by using the smelter gaseous effluent to feed a sulfuric acid plant. Complying with air pollution control regulations thus created the need to dispose of relatively large amounts of concentrated sulfuric acid. Typical Morenci ores contain substantial amounts of oxidized copper minerals which are not recoverable by flotation. In addition, there is low sulfide, high oxide material which can be leached, but is not suitable for flotation concentration. Early in 1971 sufficent data had been accumulated to show that a leaching plant for the Morenci tailings could use a large portion of the sulfuric acid produced by the Smelter. It was determined that for all practical purposes leaching of the available copper was complete in two hours or less. Capital expenditures could not be justified for more than two stages of counter current decantation for recovery of the leached copper, and the plant was designed with these criteria in mind.

Jan 1, 1976