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By Hans Smit

The face of mining as we know it is set to change in the very near future as mining companies all over the globe realize the implications of accessing the vast mineral wealth contained on, and under, our ocean floors. With some land based mineral deposits being fully exploited across the world, deep sea mining is set to revolutionize global approaches to the search for precious metals and other sought after minerals. [ ] Previously, the financial implications of deep sea mining outweighed the benefits of access to the mineral rich deposits identified all around the world. The process of marine diamond mining off the west coast of southern Africa started in the late 1950?s by a Texan, Sammy Collins, and subsequently continued by De Beers to the present day, has proven to be an excellent proving ground for the development of technology and mining systems that ensure a sustainable and financially viable business. [ ]

Jan 1, 2008

By Robert J. F. Goodfellow, William A. T. Meakin, Kevin Clarke, Eric Cole

INTRODUCTION New York City Water Supply—Background and History Since the 1840s New York City has been developing the largest, and perhaps, the best urban water supply and distribution system in the world in terms of quality and reliability. One of the engineering marvels of the modern world, the New York City water supply and distribution system serves a population of almost nine million, including residents in nearby Westchester, Putnam, Ulster, and Orange Counties of New York State. The average daily supplies presently are running at almost 60 m3/sec(about 1,350 million gallons per day). The watershed for the New York City water supply system, under the jurisdiction of the New York City Department of Environmental Protection (NYCDEP), consists of19 reservoirs and three controlled lakes, and covers an area of approximately5,000 square kilometers (about 2,000 square miles) north of New York City. The watershed total available storage capacity is about two billion cubic meters (560 billion gallons) and is divided into three reservoir systems: the Catskill and Delaware watersheds located West of the Hudson River; and the Croton watershed, located east of the Hudson River, see Figure 1. The first element of the system, the Croton Aqueduct, started operations in 1842.Through several updates and expansions, the present-day Croton system was in place by 1911, providing a potential maximum supply of about 15 m3/s (about 340 mgd). The system includes ten reservoirs and three controlled lakes. In the late 1800s, with the tremendous growth of the City, New York City water engineers began to look for additional sources. Between 1907 and 1929, the City acquired water rights and constructed a new 148 km (92 miles) Catskill aqueduct to convey water from the Ashokan Reservoir to the City. The Catskill system also included the construction of the Kensico and Hillview Reservoirs just north of the City,

Jan 1, 2005

By Göksel Hızlı, Selim Ertürk, Ayşegül Bilen, Raşit Sezer, Cüneyt Arslan

The carbothermic reduction of celestite is the first step in producing many strontium products. The way materials move in the rotary kiln has an essential effect on the carbothermic reduction efficiency as well as the temperature. In this study, the reduction of celestite ore and excess carbon blend in a laboratory-scale rotary kiln was investigated. In the experiments carried out at three different temperatures, the rotational speed and slope of the furnace tube were altered, and their effects on the reaction efficiency were examined. The leachability of the reduced powders and the content of the unburned coke indicated the optimal parameters for the reaction.When the speed was increased to 10 rpm, the powders weremoremobile in the stack and could react more easily with the furnace atmosphere. According to the results, celestite can be reduced by carbon at temperatures of 1000–1200 °C, at rates of between 5% and 75%. The maximumreaction yield (75%) was obtained with a slope of 2° and a rotational speed of 6 rpm at 1100 °C.

May 7, 2020

By M. V. T. Da Silva, J. C. Harrison

Eldorado Gold Corporation of Vancouver, B.C. owns and operates three gold mines. The São Bento underground gold mine in Minas Gerais State, Brazil produced 105,907 ounces in1997. The La Colorada and La Trinidad open pit, heap leach mines in Mexico produced over 83,000ounces in 1997. With a deteriorating gold market plaguing the industry throughout 1997 Eldorado had to take critical measures at each mine to enhance gold production while lowering cash operating costs. Each mine had its own unique problems to confront. This case study will discuss three distinct courses of action taken at the three mine sites.

Jan 1, 1999

By Raj K. Singhal

Canada produces close to 42 million tonnes of coal per annum of which some 38 million tonnes is produced by surface mining methods. The two Western Canadian provinces, Alberta and British Columbia, produce 31 million tonnes of coal by surface mining. These two provinces provide the bulk of the metallurgical coal for export. The geological conditions in the Western provinces particularly in the mountain region are complex. The coals are friable and the seams are steeply inclined, sheared, intensely folded and faulted. There may be as many as 15 to 20 coal seams present with true thickness ranging from 2.5 m to over 8 m. This paper reviews the surface mining methods used to extract such seams. The difficulties associated with steep seam and multiple seam mining of friable coal resulting in lower coal recovery, high dilution and the problem of cleaning fine coal in the wash plant have been highlighted.

Jan 1, 1984

By Robert Charles Alfred

Evolution is continuing in the field of rock drilling, Campbell Limestone Company is experimenting in the higher air pressure phase of drilling, It has been determined that there is a definite relationship between Air Pressure, Penetration Rate, Bit & Tool Wear and Life, In our drilling we have determined that &e higher air pressure gives a better penetration rate with less bit wear per foot. Drilling with 180 to 200 PSI air pressure, instead of 100 PSI for air and/or churn drills, has decreased our primary costs by approximately one half.

Jan 1, 1963

By Erwin A. Morlan

Present methods of boring large hole mine openings are briefly reviewed. Factors that influence the design and choice of down-the-hole equipment for rotary drilling large holes are discussed. With formation drillability taken as a starting point, graphs and charts are given as an aid in the selection of bit load, circulation system, flow rate, drill stem, cutter design and rotary speed.

Jan 1, 1961

By Richard R. Klimpel

Part 2 of this article continues the discussion of a 10-year, multimillion dollar research and plant testing program on slurry rheology and grinding circuits. The first part of the article (ME, Dec. 1982) presented the basic concepts identified by the research and some laboratory test results. This section Illustrates typical Industrial scale test results and Identifies some industrial operating implications of controlling rheology by different methods. At least four controllable factors decide the rheological character of a slurry-slurry density or percent solids, particle size distribution, chemical environment, and slurry temperature. The second factor has two interrelated facets: the shape of the particle size distribution which controls packing behavior of the solids, and the fineness of the distribution. Finer particles increase interparticle forces and viscosity. As indicated in Part 1, during a given grinding test it is possible for all four factors to change. However, regardless of the particular settings of the four factors in a given test, if the resulting rheological character is either dilatant, pseudoplastic, or pseudoplastic with yield, the associated breakage rate is correlated with the current rheological character. It is obvious, for example, in batch grinding tests run at constant percent solids, that the second and third factors, where appropriate, are changing during grinding because size distributions are changing and the production of fresh surface area takes up unadsorbed chemical. Thus the corresponding rheological character change in batch tests with increasing grind time would be dilatant to pseudoplastic to pseudoplastic with yield. The degree to which this transformation occurs depends on the changing setting of the four factors over grinding time. In continuous grinding tests, one might logically expect that dramatic changes in any one of the four factors will be less likely to occur. It will be shown that continuous mill operations offer some unique opportunities to take advantage of possible rheological transformation by more direct operational control of the settings for the four factors. One extra observation noted in the rheological studies was the variability in the location and extent of region B (pseudoplastic behavior) for the various coals and ores tested. The location of region B was usually in the region of 45-55% solids by volume and was of the extent of 0-8%, or 2-11% with chemical addition. The corresponding increase in net production ranged from 0-10% in region B and 0-21% in region B&apos;. When region B is small or zero (no pseudoplastic character is exhibited) no increase in production will be observed and the use of chemicals is often marginal. There are several reasons for some materials exhibiting this quick transformation from dilatancy to high yield values often at surprisingly low percent solids by volume such as 30%. One condition identified was for materials containing high levels of viscosity-producing elements such as- carbonates or clays. A second condition documented was for materials that exhibited unusually fine primary fragment distributions (fine B1,; curves). This corresponds to materials having small y values of < 0.5. Such a slurry developed a yield value quickly during grinding because of the rapid buildup of fines. A related problem can be presented by materials exhibiting excessively coarse primary fragment distributions, y values > 0.9. Breakage of this type of material produces size distributions that give poor packing efficiencies even at long grind times, thus hindering the normal rheological transformation presented earlier. A final condition that can cause the occurrance of region B to be small or zero is when the media void volume filling of slurry is < 100%. Figures 5a and 5b use previously published data of this study to demonstrate the influence of solids loading and weight percent solids on the net production of taconite ore in a laboratory batch ball mill. In particular, Fig. 5a illustrates several trends not generally recognized until this study. They include these two: • Increased slurry density allows for increased solids loading before passing through the maximum in the net production curve where the fall-off is due to non first order breakage. • The use of rheology control chemicals such as GA-4272 allows this trend to be extended to higher slurry loadings with an increase in net production over any previous condition by keeping grinding first order. Figure 5b shows the same data as Fig. 5a plotted for constant weight loadings. These various figures of net production versus percent solids show the location and extent of the regions A, B, and C presented in Part 1 as a function of solids loading. It is obvious that the rheological transformation pattern described earlier does not hold true for slurry loadings corresponding to less than the void volume of the media, which is also a region of

Jan 1, 1983

By M. A. Cristovici

The use of surfactants as wetting agents to suppress sulfide ore dust has been investigated. Numerous surfactants were examined to determine their characteristics and to investigate their ability to improve the wetting of the sulfide ore dust. However, the surfactants selected as suitable dust suppressors proved to have a negative effect on the flotation of ore contaminated with such reagents. A method was developed to eliminate the detrimental influence of dust-suppressing surfactants. It consisted of surfactant adsorption on activated carbon and separation of loaded carbon prior to flotation. The technique is simple and requires minimal changes in the plant flowsheet.

Jan 1, 1992

By T. Cyrul

The Polish underground mining has its long lasting tradition. High production of coal, that has recently been approaching 200 milion tons per year, put this small country among the bigest world producers of coal. To achieve such a high production, which mainly originate from very unfavourable mining and geological conditions, Polish scientists and engineers have to introduce new and original solutions to the mining practice. Many of the solutions on mining methods, ventilation, stability, subsidence etc., have had the world wide reputation, however, insufficient translations from Polish cause , that many of the recent Polish mining achievements are not known to foreign specialists.

Jan 1, 1986

By E. R. Bollinger, N. S. Tanious, R. D. Beckett

The US Bureau of Mines developed hand-made, steel-fiber-reinforced concrete (SFC) blocks for building mine cribs. To ensure wider usage of these cribs, US Steel Mining Co. initiated a joint development and evaluation program with Burrell Construction Co. to mass produce SFC blocks of reasonable dimension, weight, and cost. Small specimens and full-size cribs were evaluated to determine their compressive strength and post failure characteristics. After testing and adjusting of various concrete mixtures, a final formulation was selected that gave a nominal crib strength of 22 MPa (3200 psi) and a nominal modulus of elasticity of 6.9 GPa (1.0 x 106 psi.) These SFC cribs can support 6.4 times as much as a wood crib with the same load-bearing area. The SFC crib was proven to be an economical and effective roof support system through various underground installations.

Jan 1, 1987

By Joyce A. Ober

Minerals for electronic and optical uses divide easily into two sections: 1) quartz and 2) minerals other than quartz. QUARTZ The properties of quartz crystal that make it useful for radio communications were discovered in 1918. Since that time, an in¬dustry for the mining and processing of natural quartz crystal has grown, matured, and been almost entirely replaced by new tech¬nology. The new technology still involves quartz crystal, but ma¬terial that is grown rather than mined. An economic summary of the commercial growing of quartz crystals has a place in a handbook directed to the mineral engi¬neering industry because quartz crystals have long been an impor¬tant commercial mineral, and the raw material for cultured quartz - ¬that is to say, quartz crystals grown through the ingenuity of man - is still natural quartz. Nearly all the natural crystals that have been used for elec¬tronics and optics came from Brazil. The larger pieces which met rigorous standards of quality were used for electronic and, to a lesser extent, optical components. Smaller pieces and fragments were used for vitreous silica. The need for high quality material in quantity led to US government sponsored research and exploration programs in the 1940s. No deposits meeting the very rigid requirements for electronic-grade quartz were found, but other projects resulted in the development of a process for the factory growth of beautiful crystals of prescribed shape, size, and quality. Domestic deposits of appropriate quality were identified to use as raw materials for the quartz culturing process. The development of the cultured quartz crystal illustrates the success that technology can have in adapting a product of the mine to increasingly sophisticated uses. A remarkable achievement per¬haps, but foreshadowed by experiments by Giorgio Spezia (1908), an Italian geologist studying the relative effects of temperature and alkaline environment on the solubility of quartz. Modem radio equipment is most often controlled as to fre¬quency by the presence in the circuit of a separately added crystal¬ - the 1918 discovery responsible for the existence and growth of the quartz industry. The crystal is quartz, but this component is a carefully oriented and prepared slice from a crystal, but not a crystal as recognized by a rock hound or seen in a museum. How quartz operates to control frequencies is not a proper subject for a handbook on industrial minerals, and references should be consulted (Cady, 1964, Mason, 1964). Quartz belongs to a class of materials called dielectrics: those that do not conduct an electric current but permit electric fields to exist and act across them. Quartz shows the piezoelectric effect, which means that when a quartz plate is mechanically deformed against its natural stiffness, one of its surfaces becomes negatively charged, the other positively charged. When the plate is released quickly from the stress, the charges disappear as the plate regains its original shape, but because of mechanical momentum the plate deforms in the opposite direction (to a lesser amount) and the surfaces correspondingly become charged in the opposite direction. By thinly coating the two surfaces with metal and attaching flexible wires, these charges can be brought into an electronic circuit. If the surfaces are suddenly electrically charged by movement of current through the wires, the converse piezoelectric effect occurs and the plate deforms. Carry the thought further and it is realized that an alternating current flowing through the wires responds to the mechanical oscillation. By controlling the thickness of the plate, its mechanical vibration frequency can be varied through a wide range. One type of quartz plate, the AT-cut, has a precisely defined orientation with respect to the crystallographic axes of the crystal and vibrates on a microscopic scale much as a book would deform when placed flat on a table and the top cover moved parallel back and forth with the hand. At least 17 other orientations have been studied, some of which have preferred uses in various applications (Cady, 1964). The quartz crystal industry is composed of three main segments (excluding fused quartz and quartz used for optical purposes): 1. Natural electronic-grade quartz crystals. Mined quartz suitable for fabrication into piezoelectric units. Zlobik (1981a) esti¬mated the waste to ore ratio at 1:1000 to 1000 000, depending upon the deposit. 2. Lasca. Mined quartz usable as feedstock in the production of cultured quartz. Approximately 0.63 kg of lasca are required to produce 0.45 kg of cultured quartz. 3. Cultured quartz. Cultured quartz is produced from lasca feed¬stock in a process of crystal growth in an autoclave under conditions of heat, pressure, and time. It is estimated that 0.45 kg of cultured quartz is equivalent to 1.4 to 4.5 kg of natural quartz crystal in yield of commercial quartz suitable for slicing into piezoelectric units. The chronology of the development of the quartz crystal industry both natural and cultured follows: Date Comment 1918 Discovery of the piezoelectric effects of quartz crystal 1921 Application of the piezoelectric effects of quartz crystal in the circuitry of radios 1948 Establishment of a quartz crystal commodity stockpile by the US Government 1952 US consumption of natural quartz crystal at an all time high of 228 t 1958 First commercial production of cultured quartz crystal 1970 Cultured quartz crystal production exceeds imports of nat¬ural quartz crystal 1971 Cultured quartz crystal consumption surpasses natural quartz crystal consumption

Jan 1, 1994

By Thomas B. Faddies

The Trixie mine is located in the East Mining District. Since production began in 1970 over 450 000 tonnes of ore grading 239 grams of silver, 6.9 grams of gold, and 1.2% Cu have been mined from veins in Cambrian Tintic Quartzite. Detailed geologic mapping and extensive sampling are essential for compiling the data base required for efficiently developing and mining known reserves as well as planning exploration and development work. Although the basic techniques used by the geology group at the Trixie were developed many years ago, the reduced activity in underground precious metal mining in the U.S. have made these techniques less familiar to many presently active geologists. The increased activity in precious metals search and exploration again offer cause for the application of these techniques as a prerequisite to efficient exploration, development and production.

Jan 1, 1983

By Peter Zhang, Daniel Su, Mark Alexander Van Dyke, Heather Dougherty, Bo Hyun Kim

The National Institute for Occupational Safety and Health (NIOSH) has been evaluating longwall mining-induced strata fractures and their impacts on casing stability of Marcellus shale gas wells located in longwall pillars. To understand the extent of overburden fractures after longwall mining, NIOSH researchers drilled a post-mining corehole into the fractured strata above the Pittsburgh coal seam longwall gob. Knowing the extent of the fracture zone height will help gas operators minimize the hazards of drilling into longwall gobs. The core was retrieved from the surface down to the top of the gob void. Various fractures were encountered varying from 35 to 64°, depending on lithologic type and relative closeness to the gob. The longwall panel dimension was 457-m wide and 3657-m long, in which the total fracture zone height was found to be at 141 m and the hydraulic connected fracture zone at 87.7 m above the top of the Pittsburgh seam. In addition to core drilling through the gob, FLAC3D modeling was also used to simulate the formation of fracture zone and the orientations of longwall-induced fractures. This study provides much-needed evidence on the fracture zone of Pittsburgh seam longwall gobs to help gas operators avoid potential hazards associated with drilling through highly fractured zones in longwall gobs.

Jun 9, 2022

By Richard Gertsch, Jack Eloranta, Leslie Gertsch

An ongoing research program is characterizing the ore qualities that most affect mine and mill processing of iron. Current practice uses assays of magnetic iron and silica, but additional qualities are needed for advanced process control. If additional qualities can be measured from core, blastholes, or process samples, they can be modeled and controlled similarly. What qualities, other than assays, hinder or facilitate beneficiation at each processing step, and how can they be measured in the mine/mill ore stream? This paper describes preliminary determinations of the effects of ore chemistry, hardness, blasthole drill performance, fragmentation control, and grindability on mill performance.

Jan 1, 2005

By Bright Oppong Afum, Kojo Boakye, Kwaku Boakye

This research developed and simulated a novel multi-indicator Fatigue Detection and Alert System (FDAS) designed to enhance fatigue detection accuracy in mining environments. The system integrates a comprehensive set of inputs: eye blink rate, eye closure duration, yawning frequency, distraction levels, Pre-shift Check-in Scores (Self-report) and Electroencephalography (EEG) Levels. Using MATLAB’s Fuzzy Logic Rule Viewer (FLRV) and Simulink, simulations demonstrated the FDAS’s robust ability to process these diverse physiological and behavioural indicators accurately. It effectively classified operator fatigue into low, moderate, and high fatigue levels, consistently providing appropriate outputs and corresponding intervention recommendations across various mixed-signal scenarios. The system achieved a calculated accuracy of 85.19% across 27 test entries, with a standard deviation of approximately 1.8459, confirming its reliability for real-time fatigue monitoring. These findings highlight the significant potential of this fuzzy logicbased approach to proactively identify early signs of fatigue, substantially enhancing safety and operational efficiency in demanding mining operations.

Feb 22, 2026

By T. Peter Philip, Erich U. Petersen, William J. Tafuri, Donald M. Hausen, Douglas N. Halbe

Scarcely a month goes by that I or someone else at Newmont Mining or Newmont Gold isn&apos;t asked to give a talk on the topic I was asked to discuss today. Investors, financial analysts, geologists, metallurgists, even our government--everybody wants to know what the future holds for gold mining. Well, you&apos;re not going to get exactly what you asked for. Today, I&apos;m prepared to focus primarily not on what the future will bring to us, but rather on what the future will demand from us. More than that, I cannot undertake because it isn&apos;t within my scope to predict how wise and resourceful everyone in our industry will be in the future. What our future will hold, as I see it, will depend on our--and our colleagues&apos;-- responses to these very real demands. Three critical issues stand out in my mind as to what the future will demand of us in the gold mining industry. And these demands will be for: 1. The very greatest of technical expertise and innovation. 2. The highest order of environmental sensitivity and timely accommodation. 3. Planning, planning and more planning. All of these flow inexorably today from the traditional objective of any mining company--or any company in any business, and that is, to make money. Nothing as I see it, should be undertaken by a geologist, metallurgist or even an environmental department, unless the exercises will enhance profits; and nothing may be ignored which can have consequent damage to the bottom line. Thus, the three issues I&apos;ve listed for you subordinate themselves to the objective of making money, although at least in the environmental area, it might seem to some that we can only incur additional costs without even a dollar-for-dollar return. I hope to disabuse you today of any such out-of-date notion. Let&apos;s tackle the first issue-- Technical Expertise and Innovation. Newmont Gold Company this year is celebrating its 25th anniversary of successful and profitable operations on the Carlin Trend. Carlin in 1961, which is when exploration began on the "Trend" by Newmont, actually may share a lot of similarities with Carlin today. They didn&apos;t then know where the gold was and, if they found it, they had one hell of a challenge mining and processing ore at a profit because gold was selling at only $35 an ounce. Today, we know where the current reserves are. But we don&apos;t know where our future reserves lie. Furthermore, we don&apos;t know exactly how we&apos;re going to mine them, and, as everyone here knows too well, we don&apos;t know what the optimum metallurgical treatment is, even if we can find and mine them. And all that despite the abundant level of modern experience and skills within the current generation of mining companies, and the fact that, even taking inflation into account, gold sells at a higher price today than in 1965 when Carlin began operations. But, of course, I&apos;m telling you what you already know.

Jan 1, 1990

By D. F. O?Connor

The health & safety of all workers in an underground environment is paramount to the success of our operations. The diesel emission reduction projects are key to improving such an environment. However, care must be taken to reduce the risk to personnel during such tests and prevent exposure to other hazards. VALE Inco works in a close partnership with its unionized employees, manufactures, suppliers, researchers and government officials to ensure projects are done safely and efficiently to successful completion. The Creighton Mine Diesel Particulate Filter (DPF) project is an example of such a project that is currently under way to evaluate new and innovative technology that will further our search for improved environment for our workplace. This paper will discuss the issues and processes that are followed to ensure Diesel Particulate Filter (DPF) field tests are conducted safely and productively.

Jan 1, 2009

By Cem Şensöğüt, Özer Ören, Yaşar Kasap

The mining sector is one of the leading sectors where work accidents are most intense because of the constant change of work environment and heavy working conditions. The losses and the halt of production after the accident negatively affect productivity and production efficiency. It has been found that there are very few studies on the use of Data Envelopment Analysis (DEA), which is one of the nonparametric efficiency analysis methods, in the evaluation of mining sector occupational accidents. According to parametric activity measurement methods, it has been tried to show that the DEA can also offer the opportunity to interpret work accidents by taking advantage of its advantages. Due to the application of open-pit mining methods along with underground working techniques which increase the risk factors with respect to accidents at work that occurred between 2012 and 2018 of Western Lignite Corporation (WLC) were tried to be analyzed in the present work. As a result of the analytical work using Data Envelopment Analysis (DEA) for the years 2014, 2015, 2016, 2017, and 2018, inefficiency has been determined in both underground and surface operations. According to the results obtained, it was determined that WLC could not produce enough production in both the underground and surface coal mining operation, despite the accidents that occurred, while it had the opportunity to produce more. In addition, it was found that the increase in accidents occurred more than the increase in the amount of production during the years studied.

Jul 4, 2021

By William Lodding

That grinding may change a crystalline material both in a physical and in a chemical sense has been shown by a number of authors in recent years. Thus Mackenzie (1) and Bartha (2) reported the effects of careful grinding on muscovite, quartz, gypsum, dolomite, etc. Increase in specific surface produced by grinding implies increase in total energy of a system. Newly produced surfaces are chemically more reactive; dislocations may be introduced during grinding, and existing strain may be released by the same process, as shown by Holt et el. (3) All these changes are easily detected by thermal analysis, but it is not easy to separate the multiplicity of effects registered and to arrive at quantitative interpretations. This paper is an attempt to analyze by the use of thermal analysis some effects produced in grinding. In differential thermal analysis (DTA) one measures all thermal changes occurring in a substance during heating or cooling. Chemical changes, such as decompositions, synthesis, oxidation, reduction, etc., and physical changes such as phase transformations, changes in specific surface and in thermal conductivity, strain release, etc. By thermo gradmetric analysis (TGA) on the other hand only chemical changes involving weight loss or gain are recorded. Similarly gas evolution analysis (GEA) will register only reactions involving gas evolution, including water vapor, and oxidation-reduction. By performing two or all three of these thermal methods of thermal analysis simultaneously and on the same specimen one can separate the different effects registered and by difference evaluate their magnitude.

Jan 1, 1966