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By S E. Wallah, D Hardjito, B V. Ran

The manufacture of Ordinary Portland Cement (OPC) is not only energy-intensive but also releases a significant volume of carbon dioxide (CO2) to the atmosphere. In addition, OPC in concrete often causes premature deterioration that affects the durability of concrete structures. This paper explores an alternative to OPC concrete called geopolymer concrete.The present research utilises low calcium (class F) fly ash as the source material to produce geopolymer concrete. Several factors that affect the mix design process such as mix proportion, curing time, and curing temperature have been studied. In addition, the long-term properties such as drying shrinkage, creep, and exposure to sulfate attack are also being investigated.The test data presented in this paper reveal that geopolymer concrete possesses high compressive strength, undergoes very little drying shrinkage and moderately low creep, and shows excellent resistance to sulfate attack. The result is extremely promising and demonstrates the sustainability of geopolymer concrete as a construction material for a sustainable future.

Jan 1, 2004

By William J. Campbell

This study was a part of two programs: The first, to develop and evaluate high-temperature refractories; the second, to investigate reaction-rate kinetics and phase equilibria in the sinter step of the lime-soda process for the recovery of alumina. High-temperature X-ray diffractometer techniques are to be used extensively in both programs. This paper summarizes developments in the field of high-temperature X-ray diffractometers through 1959, evaluates various furnace designs, and describes briefly the X-ray diffraction facilities of the Federal Bureau of Mines. A more detailed description of the equipment and its calibration is planned in a future paper on thermal expansion and phase inversion of rare-earth oxides.

Jan 1, 1961

By V. R. Bovino

You have afforded me the challenge of saying something profound in 20 minutes that will stay with you for 20 years. My hope is that from this presentation you will extract ideas that will move you? out of your offices, into the mine to seize upon the concepts that we will discuss. Your challenge is to transform those concepts into action and give life to the ideas discussed here. The notion of achieving limitless productivity produces peak levels of enthusiasm in today's mining leaders. Highly-productive mines do not happen by chance --they are created by progressive leaders. The quest for productivity improvement, exclusively through capital investment and technological advances, is an incomplete process. Improvement, through capital and technology, is often not achieved because we fail to energize the true potential and commitment in our employees.

Jan 1, 1991

By Glenn A. Shirey, Robert D. Stoessner, S. Gopalakrishnan

Under a contract awarded by the U.S. DOE-PETC, the Pennsylvania Electric Company and New York. State Electric and Gas Corporation are conducting a test program to evaluate and optimize the performance of a two-inch air-sparged. hydrocyclone (ASH) for cleaning fine coal. The test program is being conducted at the Homer City EPRI Coal Quality Development Center, utilizing Upper Freeport coal classified to minus 0.15 mm as the process feed material. A matrix of experiments has been conducted to establish the influence of significant design and operating variables (including overflow and underflow orifices, inlet slurry pressure, airflow rate, and reagent dosage) on the production of deep cleaned coal. Performance of the ASH is being compared to conventional froth flotation, utilizing advanced techniques and selected flotation reagents. This paper focuses on work completed to-date to optimize the performance of the air-sparged hydrocyclone for cleaning fine coal. INTRODUCTION The Pennsylvania Electric Company (Penelec) and New York State Electric and Gas Corporation (NYSEG) have been evaluating advanced fine coal cleaning processes for the production of compliance grade coal (1.2 pounds S02/million Btu). Laboratory bench-scale froth flotation results were compared with results of advanced flotation processes as performed by various organizations, utilizing the same coal feed. Among the processes evaluated, the air-sparged hydrocyclone (ASH) - developed by Dr. Jan Miller at the University of Utah - was considered to offer the best potential for retrofitting into an existing coal preparation facility because of the increased capacity per unit volume. The ASH has been shown to process over 100 times the throughput of conventional froth flotation cells. In May of 1988, Penelec/NYSEG was awarded a contract from the Department of Energy's Pittsburgh Energy and Technology Center (DOE-PETC) to optimize the performance of a five cm (two inch) ASH for producing compliance grade coal from raw classified minus 0.150 mm (1.00 mesh) Upper Freeport coal, and to compare its performance with conventional froth flotation utilizing advanced techniques and selected flotation reagents. The test work is being conducted at EPRI's Coal Quality Development Center (CQDC) in Homer City, Pennsylvania, utilizing a circuit processing 0.10 to 0.25 tons of coal per hour. Other members of the Penelec/NYSEG contract team include the University of Utah, Advanced Processing Technologies, Inc., Davy Dravo, Kaiser Engineers, Ebasco Services, and Management and Technical Systems. ASH DESCRIPTION AND OPERATION The ASH-2 System is a five cm ID (actually 4.76 cm) air-sparged hydrocyclone manufactured by Advanced Processing Technologies, Inc., under license from the University of Utah, for the purpose of research, evaluation and development. A schematic drawing of the air-sparged hydrocyclone is presented in Figure 1. Basically the air-sparged hydrocyclone consists of two concentric right-vertical tubes, a conventional cyclone header at the top, and a froth pedestal at the bottom. The inner tube is a porous tube through which air is sparged radially. The outer nonporous tube simply serves as an air jacket to provide for even distribution of air through the porous inner tube. The slurry is fed tangentially through the conventional cyclone header to develop a swirl flow in the radial direction. Air is sparged through the jacketed, inner porous tube wall and is sheared into small bubbles by the swirl flow. Hydrophobic particles in the slurry collide with these bubbles and, after attachment, are transported radially into a froth phase which forms on the cyclone axis. The froth phase is stabilized and constrained by the froth pedestal, thus moving towards the vortex finder of the cyclone header and discharged as an overflow product. Hydrophilic particles generally remain centrifuged in the slurry phase and are discharged as an underflow product through the annulus created by the froth pedestal.

Jan 1, 1989

By M. Dworzanowski

The difference in the magnetic properties of minerals is the basis for magnetic separation. All minerals can be generally classified as ferromagnetic (strongly magnetic), paramagnetic (weakly magnetic) or diamagnetic (non-magnetic). Magnetic separation can be conducted dry or wet. The majority of the applications of wet magnetic separation in the mining industry are based on the wet drum magnetic separator. The wet drum magnetic separator has been in use for over 50 years and its design is based on a rotating drum installed inside a tank. Inside the drum are stationary, permanent magnets arranged in an arc to provide the magnetic field. These magnets can be of the ceramic ferrite type providing a low intensity magnetic field or of the rare earth type providing a high intensity magnetic field.

Jan 1, 2010

By P Moynagh

"A plan is critical but on its own it is a bit one dimensional, the three dimensions critical to success over the long-term, through changing economic, geological and management conditions are:the quality of your planning an ability to see and adapt to change a disciplined continual improvement/learning system.This paper will examine how a number of major Australian resource companies have used a commitment management system to connect the ‘theory’ embodied in plans (whether mine, project, maintenance or training plans) and immediate reality ‘practice’ as experienced by supervisors and their crews in the workplace. This paper draws on management theory embodied in management operating systems (MOS), Lean, Theory of Constraints and Six Sigma approaches to continuous improvement and a good dose of real world experience. It is embodied in the statement: ‘successful organisations are driven by a series of commitments that people make to each other and deliver on’.Citation:Moynagh, P, 2016. Everyone Has a Plan Until They Get Punched in the Mouth – Creating Trust, Commitment and Results in Tough Times, in Proceedings Ninth AusIMM Open Pit Operators' Conference 2016, pp 293–299 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 15, 2016

By Terry Braden

"Meeting probable world mineral demand in the years ahead will almost certainly require an ability to economically treat lower grade and more complex ores. Achieving this will require extensive research and technical development across the full spectrum of mineral processing.For mid-sized or smaller companies the most effective way to participate in such extensive programs - and gain access to the technology required to stay competitive - may be through collaborative research.This paper explores the recent history of collaborative research in mineral processing and in particular its ability to attract world-class multi-institutional research teams with sufficient resources to make step-change advances. It chronicles the advances achieved, but also explores the research architecture and administrative structures required to deliver research outcomes and technology transfer mechanisms to a range of often disparate sponsoring companies.INTRODUCTIONIn medieval times the dream of alchemists was to turn base metals into gold. We modern alchemists, of course, don’t waste our time on that sort of foolishness: we turn base metals into dollars. When I see the profit reports filed by some companies recently, I can only conclude that a lot of those present today must be pretty good at this.But the fact that we are here at this conference reminds us that an alchemist’s work is never done; turning base metals into dollars is not a one-trick wonder but an art that we must extensively refine year after year if we are to survive in a competitive marketplace.It is not that demand for metals is likely to slow; most people seem to think that China, India, Brazil and other emerging economies are still at the lower end of their demand curve. They will need significantly larger volumes of metals in the years ahead. The challenge for us as processors is that to supply increasing tonnages of those metals profitably we will almost certainly need to process more complex or lower grade ores and probably to do so with reduced energy inputs."

Jan 1, 2009

By William O. Vanderburg

This paper gives the results of a reconnaissance of the mining districts in Pershing County, Nev., made from March 9 to April 1, 1936. During the field work nearly all of the mining districts in the county were visited, and considerable data were obtained on active and inactive properties. The report covers the location of the various mining districts, nature of the deposits, information on past

Jan 1, 1936

As part of a continuing program of evaluating the Nation's crude-oil resource, this report presents information pertaining to resource, primary reserve, and potential waterflood reserve for 3,209 selected reservoirs contained in 24 oil-producing States, as of January 1, 1968. To that date the selected reservoirs had not been subjected to pressure-maintenance or secondary-recovery operations. These reservoirs also met the following parameters: (1) a minimum of five oil-producing wells on January 1, 1968, (2) a minimum of 50 acres areal extent, (3) a minimum of 50,000 bbl of oil ultimate primary recovery, and (4) the principal reservoir energy was other than active water encroachment. The selected 3,209 reservoirs produced 527 million bbl of oil in 1967, about 17 pct of U.S, total production. Primary oil reserve was 4,983 million stb; in addition, there was 6,043 million stb of potential water- flood oil reserve. Oil resource in the selected reservoirs was 59,547 million stb. A brief history and outlook of waterflooding are presented for each State. Depth and producing rate statistics and geologic distributions of production, resource, reserve, and potential waterflood reserve for the selected reservoirs are presented by States in the appendix. Also included in the appendix are description, history, and technique modifications of waterflooding, and a preliminary cost estimate of a closed-system water-injection project.

Jan 1, 1970

By W. P. Yant, R. R. Sayers, G. W. Jones

In the treatment of any illness the early diagnosis is of very great importance . This is especially true in cases of carbon monoxide poisoning , whether acute or sub-acute in character. A diagnosis of CO poisoning is usually made from a correlation of the history , the possible place of exposure , and the symptoms produced . This , however, is not positive evidence because CO often is present in unsuspected places and can be absent in suspected places . Also , the symptoms of this type of poisoning are common to other causes . In many such cases the correct diagnosis may be very difficult , if not impossible by this method and as a result little or no treatment is given . Sub- acute cases , those in which the subject is exposed to concentration sufficient to cause only headaches , malaise , feeling of weakness and dizziness , may be incorrectly diagnosed and as a result , improperly treated . Probably the best method of diagnosis is by examination of the subject's blood . Many methods for the detection of CO in the blood have been developed , but owing to their various individual disadvantages have never come into common usage . Some of the quantitative methods are satisfactory with regard to accuracy but require elaborate and expensive apparatus , special technique and training, or are too delicate and cumbersome for field use . It is of vital importance in all industrial and domestic accidents occuring at places where CO might be suspected or where the symptoms are typical of CO poisoning that a qualitative and preferably a quantitative determination be made the extent of poisoning being of importance in deciding whether CO was the direct or contributary cause) to show the presence or absence of 0. This is indeed essential from a medical standpoint as it aids in prescribing treatment and from a legal standpoint to insure justice in the claims that are often unjustly decided for want of positive evidence.

Jun 1, 1923

By Charles A. Hickey

The dining industry game tome Spruce Pine area a few years after tine Civil War. Two Yankees came down from Massachusetts to mine sheet mica to sell to the stove manufacturers for windows in heating stoves. At this time the method of mining was very crude; it was done only with pick and shovel. They were mining mica from the soft veins. Later they progressed to hand grilling and blasting. Hand drilling was quite an art in the area. One man would hold and turn the steel while one or two other men would drive the steel with hammers. In shaft raining, the muck and water was removed by hand winches called windlasses. About 1920 air compressors and jack hammers came into use. These were perhaps tide greatest improvement that has ever come to the area's mining industry. Later carne gasoline hoists, air drive water pumps, and all electrical equipment. Mica mining has, for the past few years, been very modern and efficient.

Jan 1, 1962

By Karin Bäppler

Lyon with half a million inhabitants is the third largest city in France. Urban agglomerations such as Greater Lyon demand intelligent underground solutions for the freedom of mobility of its inhabitants. The city and metropolitan area of Lyon provide an example of a city strategy adapted to the changing needs due to demographic and living standard trends. The Lyon Metro Line B with a length of 2.4 km is one of the strategic projects with regard to city planning and future mobility. The paper will highlight on this special area of application in singular diverse geology with sophisticated mechanized tunnelling technology.

Jun 13, 2021

By K Cochrane

Time and time again history shows us that mine closures are sustainability failures. Mine operators do not know how to turn the mine closure into an asset and communities around the mine do not know how to plan or what to implement to be sustainable when the mine needs to close. If we want to achieve sustainability when we close a mine, we generally need to consider what economic activity we will have to create leading up to the mine closure to ensure that the communities remaining in the area are not worse off after mining than before. There is not one silver bullet solution to mine closure, as all mines are affected by different environmental and socio-economic conditions. That is one of the reasons why mine closure is so difficult.Effective stakeholder engagement is the nucleus around which sustainability is built. Achieving sustainability as part of mine closure means not only a self-sufficient community, but also could lead to transformation of that asset.A key issue is that neighbouring communities become completely reliant on the mine. The mine has influenced the economic, environmental and social aspects of the community and with no alternative economic sources. The community and municipality will struggle with capacity to maintain infrastructure, services and jobs. This not only impacts the mine workers and their families but also other businesses and people in the town that make a living by servicing the needs of the workers and their families. Social problems associated with a mining operations and closures need to be considered. The misuse of alcohol, domestic violence, breakdown in law and order, economic and health issues all have a severe influence. Families often need to relocate from the mining town to find work. This further perpetuates the impact of the mine closure to the economic viability of the town. CITATION:Cochrane, K, 2018. Is your mine closure a sustainability failure? Transform your asset and create a self supporting neighbouring community. It’s as easy as ABCD!, in Proceedings Life-of-Mine 2018, pp 38–42 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

By G Luxbacher

Computer simulation of mine ventilation systems is rapidly becoming an essential tool in mine planning and design. This paper examines the utilization of ventilation simulation techniques to evaluate the number, shape, size and layout of mine entries in a typical coal mining system. Since the mains and sub-mains serve mainly for transportation and ventilation and the ventilation system is critically important to the health and safety of the workers, there exists a great need for optimal designs in this area. Evaluation criteria, could include, among others, minimization of power costs, shaft requirements and leakage. Constraints of this optimization problem include health and safety regulations and production and mine infrastructure requirements.

Jan 1, 1977

The original JKMRC AG/SAG mill model was developed over 30 years ago and has been upgraded a number of times since then, with the current published version being the Variable Rates model that is now over 15 years old. Since this model was developed further enhancements have been derived, some of which are applied in-house and some which have yet to be incorporated. The published and the commercially available model in JKSimMet is currently undergoing a comprehensive overhaul with a vastly extended data base for model evolution and validation. Improvements developed within the AMIRA P9 project, in-house development and a number of collaborative projects, are being incorporated into the upgraded model structure. Enhanced capabilities will include: power-based breakage rates scaling; a far wider mill filling range (from 10% to 40%) that exhibits peak in throughput as mill filling increases; higher ball loads; improved pebble discharge function; improved slurry discharge function incorporating important mill design and operational influences; and the new size dependent breakage function. The model will also be able to accommodate some influence of liner design and multi-component ores (blends of hard and soft components). This upgrade is still a work in progress but substantial changes have been made to date. This paper presents some of the new improvements and their influence on the predictive capability of the model.

Jan 1, 2012

By John K. Alley, Robert C. Johnson

The primary objective of the research was to grow aluminum borate whiskers or fibers and to determine their properties . Molten salt bath and vapor deposition methods were used for synthesis . Whiskers exceeding 25 mm in length were grown . The best results were obtained by vapor deposition and most of the data presented were determined on whiskers produced by this method of synthesis . Three different aluminum borate compositions ( 4.8A1203 B₂03 , 3.8A1203 B203 , and 2.5A120, B203 ) were identified by X- ray and chemical analyses . The aluminum borates 4.8A1203 B20, X- ray diffraction pattern was indexed . Optical data were obtained on the three aluminum borates . In addition the following whisker properties and growth factors were determined : ideal atmospheric dewpoint for vapor deposition method , near 65 ° F ; temperature range of whisker formation , 1,000 ° to 1,400 ° C for the molten bath method of synthesis , > 1,000 ° to < 1,400 ° C for the vapor deposition method ; whisker growth rates by the vapor deposition method , maximum 12 mm per hour ; raw material vaporization , 50 to 60 percent of the fluoride lost in 1 hour ; tensile strength , maximum obtained 174,162 psi ; melting points , ranged from 1,675 ° to 1,795 ° C.

Jan 1, 1965

By John H. Bassarear

Large scale equipment can reduce both capital and operating costs for concentrators. Large semiautogenous mills can be effectively utilized in big mills but they must be kept fully loaded to take advantage of their great potential. With varying hardness ores, controlling throughput is difficult and careful design must take this into consideration. A variable speed drive on large primary semi- autogenous mills can overcome this problem to a considerable degree. This paper provides a base case using standard accepted technology of two wound rotor single speed 4,476 kW (6,000 hp) motors to drive the primary SAG mills of a hypothetical 36,364 mtpd (40,000 stpd) typical porphyry copper mill. One other fixed speed drive will be described and five variable speed drive configurations will be reviewed. Capital costs for the entire grinding circuit, from crusher product to flotation feed, were developed for the base case and each of the alternatives. A technical evaluation comparing the advantages and disadvantages of each drive is presented.

Jan 1, 1985

By R. W. Nash, A. E. Schwaneke, V. R. Miller

The Bureau of Mines developed a detector for controlling sorting devices to separate the copper-bearing fragments from the barren portion of Michigan native copper and western prophyry copper ores. A successful sorter could be used to preconcentrate the ore and eliminate costly hoisting or hauling of waste. An induction balance unit was developed and used in sorting tests on crushed sized - 2.5 + 1. 3-cm (- 1 + 1/2- in.) ores from the Kingston (0.9% Cu) and Centennial (1.6% Cu) mines of Upper Michigan. Concentrates of 4.0% and 7.5% Cu, respectively, were obtained at recoveries of 85 and 80% of

Jan 8, 1978

By Robert F. Chaiken

An absorption-desorption model of particle reactivity was employed to describe the observed relationship between two apparently diverse phenomena which have been the subject of considerable study at the U.S. Bureau of Mines: (1) coal-rock dust reflectance and (2) coal-rock dust explosibility. The model accounts for heterogeneities in particle-size and material properties; however, in the present report, only particle-size distribution is considered. A mean particle-size parameter, appropriate to the explosion extinction process, is derived, and then taken as appropriate to describing optical reflectance. The derived form-to-function relationships for the two processes, when compared with experimental data, suggest that a problem exists with previously derived theory relating optical reflectance to rock dust concentration. A reexamination of that theory leads to a new theoretical expression, changed by a factor of 2, for the variation of rock dust concentration with reflectance which is in quite good agreement with experimental results. The current work offers justification for measuring and establishing rock dust requirements for specific coal dust size distribution(s) found in the mine-distributions that undoubtedly depend on the mining method and the type of coalbed.

Jan 1, 2010

By D. L. Stevens

Following an in-depth scenario and strategic planning exercise in 1997, Noranda&apos;s mine production goal was set at 500,000 tonnes per year of both copper and zinc metal within five years. There had been no recent discoveries, reserves were shrinking and things had to be done differently and quickly. Change is now continual in our program but here is what we did first: Combined the exploration and business development groups Formed teams to search for and respond to opportunity Made our geologists more business minded and our engineers more optimistic Went global Set clear thresholds, farmed out the marginal properties, fast tracked the others Focused reconnaissance exploration where we had a clear competitive advantage Became a "flexible" partner to both juniors and seniors Is it working? A number of successes, near successes, and outright failures are discussed. The main result is a much higher rate of opportunity flux which is essential for success in the mining industry.

Jan 1, 1999