Search Documents

By W. A. MacWilliams, R. G. Reynolds

"This paper describes, for the first time, a patented method of extracting sodium sulphate from a natural deposit in Western Canada. The method resembles, but is not, strictly speaking, solution mining. The fact that a plant based on this method has been in successful operation since late 1969 will be of added interest. The deposit in question is located near Metiskow, Alberta, and conventional surface recovery methods could not be applied because of heavy concentrations of mud. Considerable pilot work went into the separation and recovery process on which the plant operation is based. The history of the industry is covered briefly as background to this development. Today it is clear that the method has broader application within the industry and, in concept, may generate interest in many other applications."

Jan 1, 1973

By H. F. Haller

Large volume sand plugs are placed in tunnels to stem underground explosions at the Atomic Energy Commision's Nevada Test Site. Placement through long, narrow accessways is like stemming coyote holes and blast chambers in mining and construction. Experience with several other methods showed that pipeline conveying could be preferable. Small scale tests justified predicting a placement rate of 20 y. p. h. at 1000 feet, with a modified gunite placer. The initial production trial placed over 2000 c. y. and was estimated to effect a small cost saving after paying for new equipment. Initial problems included duct replacement and supply delays, dust, and other personnel hazards. Operations analysis and SOP'S reduced delays during the second field trial, minimized hazards, doubled production. Re cent re search and operations analyses produced data on abrasion resistant ducts, identified minor equipment modifications which can improve production, developed techniques for impact compaction to 90% ?maximum? and for extension of the practical range to 2000 feet. Twenty-two illustrations include an air consumption-distance chart.

Jan 1, 1967

By Chulgi Suk, Hoon Park, Hyonsoo Kim, Hakman Kim, Sangho Cho

Dust emission from blast demolition and other construction activities can be a nuisance; it is widely recognized that fine particles less than 10 µm in equivalent diameter (called PM10) may cause health problems. Mist spray systems, such as rain guns, sprinklers, water/surfactant sprays (or foams) etc., are some of the most effective dust suppression methods. A large amount of research has showed that when water droplets are produced in an equal amount to that of dust particles, the airborne dust is suppressed by the agglomeration of dust and mist particles. A method for generating micro-sized mist from water, achieved by the detonation of explosives in the water tube, was suggested and is called the ‘detonationdriven water bag burst system’. There are many experimentally observed limitations of the explosioninduced water break-up process. The water bag explosion tests were simulated using the AUTODYN software, in order to investigate the aerosolization mechanisms of the detonation-driven water and water break-up process into micron-sized droplets. As a result of the numerical analyses, the diffusion direction of water when detonating in the central interior part of water tube was radioactive and significantly stronger than when detonating in the bottom exterior part; this is due to the compressive flow of the volume change inside of the water tube, which resulted from the blasting wave inside of the tube, as well as the reflected pressure on the ground. Blast tests of full-scaled reinforced concrete columns were conducted to verify the effectiveness of the suggested detonation-driven water bag burst system. The water breakdown and dispersion that occurred while blasting the reinforced concrete columns were observed using a high-speed camera, and dust generation was monitored using four density detectors. The suggested detonation-driven water bag burst system showed that the average dust density decreased by up to 7 mg/m3.

Jan 1, 2016

By Paul J. Henkels

Synthetic gypsum is the calcium sulfate co-product of a number of industrial processes. Synthetic gypsum utilization as an alternative to the naturally occurring mineral continues to grow in the gypsum industry. In particular, flue gas desulfurization (FGD) gypsum produced by the electrical utility industry has had a significant impact and a far-reaching effect on the gypsum wallboard manufacturing industry. This paper will discuss the various synthetic gypsum sources verses natural gypsum and highlight issues of use in gypsum wallboard and related products.

Jan 1, 1999

By R. H. Pemberton

"THE Mattagami district of Quebec has, during the past few years, experienced intense exploration by virtually every mining company operating in Canada. As a result of this activity, a number of well-mineralized zinc-copper bearing bodies have been found, some of which will almost certainly go into production. Much of the area has undergone what is now termed ""Saturation Prospecting"" or intense and detailed geological and geophysical surveying, followed by the drilling of nearly all possible bets. Considering only the airborne geophysical surveying, some blocks of ground have been flown by virtually every geophysical instrument which has to date been installed in an aircraft. A list of these different geophysical instruments would include: l. Fluxgate-type total field magnetometers 2. Vertical field magnetometer ,3. Nuclear-precession magnetometers 4. Single-frequency out-of-phase electromagnetometers 5. Dual-frequency out-of-phase electromagnetometers 6. Horizontal component measuring electromagnetometers 7. In-phase and out-of-phase electromagnetometers8. Dip-angle measuring electromagnetometers."

Jan 1, 1961

By James J. Scott

Friction Rock Stabilizers, trade name II Sp 1 it Sets'" have been under research and development by the author and the Ingersoll-Rand Company since February of 1973. The United States Bureau of Mines and the Mines Enforcement and Safety Administration as well as many mining companies have cooperated in field testing the device. Split Set rock anchors are distinctively different from the widely used mechanical rock anchors or fully grouted rock anchors. They control ground movement internally in a manner that allows controlled deformation during the early phase of the ground reaction curve but then, as secondary creep develops, anchorage per unit length increases and they serve to strengthen and stabilize the opening for long periods of time. The history of research and development of the Scott Split Set rock anchor system with accompanying laboratory and field test data is presented in this paper.

Jan 1, 1977

By B Dold

"Mining has still today high potential for improvement in the exploitation efficiency. Especially low-grade ores have very low recoveries. In Cu bioleaching operations from porphyry copper deposits extraction of only five and 15 per cent with maximum of 40 per cent are reached. This means that 60–95 per cent of the resource is not exploited. Consequently, any metal not extracted will end up in the waste material, therefore increasing the risk of environmental pollution. This inefficiency is mainly due to the use of element concentrations for decision-making on the daily basis of a mining operation (eg cut-off ore grade, acid-base accounting – ABA). If, instead, quantitative mineralogical and geochemical data together with information on the bioleaching behaviour of the ore assemblage (the biogeometallurgical approach), is used for decision-making right from the beginning of the exploitation, higher recoveries and less environmental impact can be achieved, ie an increase in sustainability can be reached.CITATION:Dold, D, 2016. The Biogeometallurgical Approach – the Information We Need to Increase the Sustainability of Mining, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 169–172 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By J L. Macdonald, G S. King

"The development of a predictive geometallurgical model is a multidisciplinary and iterative task that involves both discovery and integration aspects. In this paper, the authors discuss the concepts of geometallurgical modelling in terms of the underlying relationships that are used to connect geology, metallurgy and economic value, and how the early-stage preparation of a spatial geometallurgical model enhances project value and provides a sound basis for future studies and test work programs.Hot Chili’s (copper-gold-molybdenum) Productora Project, which is located in northern Chile, is a porphyry-copper style deposit that can be exploited using open pit mining and preparation of a saleable concentrate from fresh ore, as well as heap leaching, solvent extraction and electrowinning (SX-EW) extraction of copper from oxide ores. To enhance project value in the Productora prefeasibility study (PFS), Hot Chili developed a geometallurgical model that was used to predict the process responses of both sulfide and oxide ores. The Productora model incorporates test results from mineralogical, metallurgical and comminution testing, as well as other studies completed on a suite of samples collected from the many geological domains of the deposit.Using Bond Work Index and Abrasion Index proxies in the geometallurgical model, Hot Chili estimated the variability of sulfide ore throughput and comminution costs. Heap leach acid consumption in oxide ore was estimated from drill hole calcium concentrations. The model was then used in mine scheduling to identify high and low throughput or high and low acid ore zones so that the processing of these zones could be advanced or deferred to improve net present value (NPV). Additionally, the cost benefits of preparing an early-stage geometallurgy model were quantified through a comparison to a conventional model that was based on test work averages.CITATION:King, G S and Macdonald, J L, 2016. The Business Case for Early-stage Implementation of Geometallurgy– an Example from the Productora Cu-Mo-Au Deposit, Chile, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 125–134 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By James A. Deane

Strip mine reclamation Fs the process of restoring the land affected by the mining process to its most productive use. This can be timber production, pasture, crop land, wildlife and/or recreational use. The mining companies must determine, through the advice of their technicians, what the most advantageous use of the land will be. If the Company does not own the surface, the owner or owners must be contacted to determine their desires as to how the land should be reclaimed. Many times, in making the plans to restore an area with vegetative cover, the watershed and the quality of the water in the area is overlooked. The water itself must be an integral part of the reclamation plan. Many lakes and/or pits can be created with proper planning. In areas in the Midwest, where lakes are a scarcity, these strip mine lakes can become storage reservoirs for large amounts of water, They can help control runoff and low flow augmentation. The strip mining operation will affect the watershed regardless of whether a reclamation plan in made or not. It is up to the reclamation technician to see that the plan benefits the watershed instead of affecting it adversely. This can be done during the operation by intercepting the water before Pt enters the active pit. Diversion ditches above the highwall will handle the runoff water from the watershed. Water that does gain entry into the pit should be removed as quickly as possible. If the rules and regulations adopted by the Ohio River Valley Sanitation Commission in Resolution 5-60 are followed, water encountered during the operation can be handled with little or no adverse effect to the receiving watershed.

Jan 1, 1965

By Randall L. Neal

This paper discusses the impact of taxes at the state and federal level on typical on-shore oil and gas exploration economics in the USA. Taxes considered are the windfall profits excise tax, state production (or severance) taxes, state income tax, and federal income tax. Also considered will be market prices for oil and gas in the USA. The effect of government take as a percent of revenue, on rate of return, discounted Payout, and discounted cumulative cash flow is shown on the attached tables. The conclusion drawn is that tax laws, while rarely the most important factor to be considered when drilling a well, can have significant impact on the profitability of oil and gas ventures, and should be considered when determining where to drill. Hypothetical exploration wells were analyzed for the impact of tax laws on project profitability. The results of this study show that when factors other than taxes are postulated to be the same (such as producing rate, capital, operating costs, and prices), cash flow can vary by as much as 68% due to the differences in the tax laws. Other significant findings for the cases studied include: (a) that discounted payout varied by as much as 1.8 years, (b) that rate of return differed by up to 67% and (c) the total tax rate as a percentage of revenue had a maximum variance of 33%.

Jan 1, 1982

By Ulrich O. Lange

Coal is America's most abundant energy resource. Therefore, it IS logical to assume that coal must be produced in much greater quantifies in order to make the United States self-sufficient, as far as energy is concerned by 1985. However, there are a number of obstacles which have to be overcome in order to achieve such a great task. According to one of the most outspoken American Mining men, there are three major obstacles. Those are: (1 ) Mining technology (2) Public image of the coal mining industry (3) Governmental policy toward the mining industry The following will be dealing with Shortwall Mining, which is a very specific part of mining technology and which might influence the image of the coal mining industry as well as the governmental guidelines, at least to make it easier to live with those guidelines. During recent years the operation of coal mines has been more expensive than ever. Since 1970, the cost of producing coal increased by 30% and the productivity dropped by just about the same amount. Those are alarming signs.

Jan 1, 1975

By A. L. Jones

The subject assigned to me of "The Power" Problem of the Mine" is so broad that I have decided to confine myself to the question of the power supply itself, rather than the application of electricity throughout the property. We will look over certain economic aspects of the problem, particularly in the way it affects the mine manager or executive and his attitude toward the power plant. The accepted method of power application to the mine is by electric power, and the experience of each of you is that the job is never complete as you are always undertaking some further electrification which necessitates the stiffing up the power house to care for the additional load. The mine executive, then, is wrestling almost continuously with the problem of his power plant. Either it is overloaded and must be enlarged and rebuilt; or its operating costs are excessive; or it breaks down and limits coal output; or some one wants to sell new and improved machinery, until the manager almost hates the thought of such a restless part of his property. If he purchases power, every day new uses for it seems to be found. In many ways this unrest is due to short-sighted policy toward the problem, and the tendency when the problem of extension has to be met, to dispose of it in the cheapest way and without thought as to where the future is leading. The day when each opening had its own boiler plant, steam hoist, steam driven fans, steam pumps, steam loaders, etc., seems to be far behind us. The recognized method of power distribution today is by electric power, except for rather limited applications of compressed air; most of which is electrically compressed. During fifteen years contact with mines of Colorado and Wyoming the writer has seen nearly every mine power house double or triple in capacity or abandoned in favor of purchased power, worn. out and inefficient machinery thrown out, isolated boiler plants dropped, seam pumping at great depth changed to electric drive, all resulting in greatly reduced labor and fuel costs. Power costs, which in such isolated plants were considered normal, would be unthinkable today. One property where the main power supply was by compressed air from steam driven com¬pressors used under boilers 8.35 per cent of all the coal mined. The cost of power was 12 1/2 cents per ton of coal mined. Another property of four openings, each with its own boiler plant and usual equipment of hoists, pumps, etc., had a power cost of 10.3 cents for each ton mined; and these were days when you did not get very high prices for coal. Another property operating two mines mostly by steam used 11.1 per cent of the coal output under their own boilers and the power cost was 19.45 cents for each ton mined. Each of these properties is now electrified and power costs are from 3 to 4 cents per ton, and the fuel burned runs from 1 to 2 per cent of the output. With the broadening market and high prices for slack coal and the high prices for labor in boiler and engine rooms, the cost of steam is reaching a high figure, and efforts must be made to keep this down, by more efficient steam production and by utilizing this steam in better machinery which will increase the work done by each pound of steam. It must not be overlooked either, that the plant which is very wasteful of fuel is usually a pretty old one and one far from reliable. In a general way the more efficient the plant, the greater its reliability. Ample and reliable power supply means ability to get out coal when there is a market. The increasing use of purchased power is largely due to changing conditions which are tending constantly to push up the cost of power, unless the most efficient machinery is used and large scale production possible. The

Jan 1, 1923

By Michael S. Koleda

Less than two years ago, the, Congress, with broad bipartisan support, passed the Energy Security Act of 1980. A decade marked by ten- fold increases in world oil prices and two major interruptions in oil flows from the Middle East had ended. An all-out national commitment to transform America's vast tar sands, oil shale and coal resources into conventional fuels had begun. The national synfuels effort was to be public-private cooperation at a scale unmatched in peace time. Private industry would own and operate the synthetic fuels facilities. Government would reduce market uncertainties to acceptable levels. The potential government commitment was substantial. Up to $88 billion would be available through the Synthetic Fuels Corporation, principally in the form of contingent financing. Billions more would be spent through Department of Energy programs. Additional incentives for alternate energy development were contained in the Energy Tax Act of 1978. The Energy Security Act clearly specified national synthetic fuels production objectives: 500,000 barrels per day by 1987 -- 2 million barrels per day by 1992. Finally, said Congress, Uncle Sam was going to do something about rapidly rising oil prices, uncertainties of energy supply, and the resulting disruption to the U. S. economy. Simply put, the purpose of the Energy Security Act of 1980 was to provide government guarantees sufficient to get synthetic fuels projects off the private sector drawing boards and into commercial production. Because of their huge cost, technological uncertainty, and lengthy pay-out period, these projects were always second place to projects of smaller size, known technology and more rapid pay-out. The Energy Security Act was the legal expression of public policy to bring the free-market synfuels timetable into line with the faster paced political timetable in the interest of national energy security.

Jan 1, 1982

By Heribert F. Broicher

By the very nature of mineral deposits the quality of the raw material generally fluctuates and should be known for optimum processing. Early classification, for example, of limestone into road-metal grade or lime grade or of run-of-mine ores into high grade, low grade and waste as well as information for blending or for dosage of reagents are prerequisite for economic processing. Non-contact, real-time and on-line rock identification or assessment of quality parameters can be realised by introducing the analysis of laser-induced fluorescence (LIF) into the mining industry. LIF analysis is an optical method evaluating the basically known photoluminescence properties of matter, however, extending the application into hitherto unimagined fields by use of high-energy pulsed lasers and time-resolved analysis of fluorescence in the ultra-violet, the visible and near-infrared domains of light. LIF analysers and test work in a limestone quarry and a cement plant in Germany as well as in an iron ore mine in Sweden are described. First results of test work are available and proof this technology to be promissing.

May 1, 2002

By S. M. J. Mirazimi, F. Rashchi

Recovery of vanadium from LD (Linz-Donawits) converter slag was evaluated by means of microbial leaching. Vanadium leaching was performed in two stages. In the first stage, the bacteria were grown in a culture medium and in the second stage; vanadium containing slag was added to the metabolites produced by bacteria. Bioleaching was performed using heterotrophic bacteria Pseudomonas Putída. Control tests without bacteria inoculation were also performed and the results were compared with bioleaching outcomes. Optimal conditions for the bioleaching of vanadium containing slag were determined.

Jan 1, 2011

By Rusty Mchenry, Craig Dickerson, Robin L. Oldham

"It has been proven that longwall faces can be moved safely and efficiently. However, abutment pressures and poor ground control conditions can halt operations and be hazardous to coal miners. Recently at a mine in Southwestern Pennsylvania, roof material collapsed above shields that created two large voids and caused major challenges for shield recovery. A unique, engineering solution was developed that utilized a modified concrete material to fill the voids, creating stability in the affected area. The many phases of this project included the construction phase, void pumping, cutting out, and bolting of the concrete material. This project eliminated the hazards associated with bolting the recovery face and removing shields in adverse conditions, making it possible for the mine operator to safely complete the longwall move.INTRODUCTIONFrequently in the mining process, especially during the recovery phase, voids above the longwall supports have occurred. These voids are simply roof cavities caused by falling rock strata above the longwall face. Most often, this condition slows down or halts mining operations and creates hazardous work conditions for coal miners. Numerous methods of supporting void areas on longwall faces have been attempted and utilized throughout the mining industry since the advent of the longwall mining system. These methods have utilized many different materials and processes and have included the installation of steel or wooden beams, crib blocks, and various types of roof bolts. However, these methods can be dangerous due to exposure of personnel to the mine voids, falling roof material, and the necessity to handle large amounts of heavy support materials.This paper describes a unique case study in Southwestern Pennsylvania where longwall recovery methods, through two void fills, were successfully completed, eliminating exposure of coal miners to the rock voids above. At the start of this endeavor, normal recovery operations were halted, and hazardous conditions became a concern when the voids were encountered. However, in the interest of safety, the decision was made to try a unique method to completely fill the void from the bottom of the coal seam to the top of the void with a cementitious material and then mine through it. This is in contrast to traditional methods where beams and support materials are used to stabilize the area above and in front of the mine shields, which can expose miners to the void above."

Jan 1, 2015

By Jeff Friedman

This paper addresses certain problems to be encountered when a blasting contractor agrees to provide indemnification. Nearly 100% of all blasting work is performed pursuant to a contractual agreement. Whether the explosives engineering firm works directly for the property owner, or for a general contractor by way of subcontract, indemnification agreements are generally required to protect owners, operators, general contractors, and other interested parties in the event there is subsequent litigation. These contractual requirements are typically referred to as indemnification and “additional insured” agreements. We will address the ramifications of contractual indemnification as well as “additional insured” agreements in this presentation. Some of the aspects of this paper will include:

Jan 1, 2004

By K. L. Marshall

A facetious title was purposely given this talk, so that a formal paper would not be expected. TWO or three days ago, while discussing with Mr. Dickinson some of the details of the dust explosion demonstrations we are planning for this coming Saturday, I remarked that we would like to have as many people as possible see some samples of 20 and 200 mesh dust, so they would more fully understand just what was causing the explosions. Mr. Dickinson requested that I bring samples and screens and in this informal manner, give you all a ".close-up" of coal dust which is considered in Explosion Hazard reports. While sampling mines, for road, rib, and roof dust, in connection with safety service and hazard reports which the Bureau of Mines Engineers make at the request of coal operators, I have often been assisted by under- ground mine officials or other men of many years experience and on almost every occasion, while we were carefully brushing the very fine dust from timbers or coal surfaces, they would make some remark such as: "never had noticed this kind of dust, didn't know it was here", or "well, that's the first time I really understood what all 'this dust talk was about." Such experience makes me believe that the much published terms, 20 mesh and 200 mesh are just numbers to the great majority of both miners and operators. We are now going to have lesson one in the primer of coal dust explosions and I want to say, in all sincerity that a complete course in the hazards of mining is deserving of a place in the curriculum of the best mining schools of this country. Sample No. 1 is fine coal and dust and is a fair sample of what can be found every where in rooms and entries of a mine, as it is too small to be gathered up with a shovel and is left in the ordinary mining at the faces and is spilled along the entries in haulage. In this you will see some quarter inch coal, much eighth and sixteenth inch coal, in fact those are the sizes I find many people have in mind when they are asked about the dust made in mining. Although the sizes mentioned are the ones which seem to almost entirely make up this sample, such is not the case, for from 10 to 20% of such a sample will usually pass this 20 mesh screen and in Sample No. 2 we have 20 mesh dust. Result of many tests, supports .the statement of the coal mining division of the Bureau, that it is quite probable that coal over 20 mesh does not take part in any but the most violent of explosions and that all dust under 20 mesh may take part in any explosion. The largest particles in this sample will not be over .03 inches in their largest dimension and a pound of dust to a foot of average heading is very easily found in most every mine I have visited and usually a great deal more can be readily gathered up. It was .found early that the finer the dust the more dangerous it was for a given coal. So for the early explosion tests conducted by the Bureau a commercial pulverizer was used and it turned out a 20 mesh dust of which about 75% would pass 200 mesh. Some men question whether the ordinary mining methods made such a dust and so doubted the explosibility of the dust in their own mines. The question was well taken, and hundreds of dust samples were taken by the field men of the Bureau to determine the kind of dust being made in all methods of mining and all classes of coal. The result of such sampling showed some coals. resisted breakage more than others and that actual mine road dust, through 20 mesh, would show from 10 to 20% through 200 mesh, and for actual rib and roof dust through 20 mesh, they would get from 20 to 40% of 200 mesh dust. In testing the

Jan 1, 1924

By I Basson, J A. Miller, M Becker, F C. de Beer, L C. Bam

"Geometallurgy brings together geologists, mine planners and process engineers to extract meaningful mineralogical and textural information from an orebody, with a view to predicting its metallurgical response. Preferably, automated analytical techniques, which provide mineralogical and textural information, should process a large number of samples quickly, relatively inexpensively and reliably. Microfocus X-ray computed tomography (µXCT) is capable of producing 3D volumetric information on texture and mineralogy that satisfies some of these criteria. µXCT has been used extensively to study the porosity and internal pore structure of iron ore pellets as part of downstream processing. It has not been widely applied to earlier mineralogical and textural analysis of unprocessed ore, due to the limited ability of X-rays to penetrate high-density samples. In this contribution, we propose scanning methods to overcome this limitation, thereby facilitating a broader application of µXCT to iron ore resource management.CITATION:Bam, L C, Miller, J A, Becker, M, De Beer, F C and Basson, I, 2016. X-ray Computed Tomography – Determination of Rapid Scanning Parameters for Geometallurgical Analysis of Iron Ore, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 209–220 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By G. C. Bateman

THE cause of silicosis and its prevention have held the attention of medical men and mine operators for many years and at the present rime the study of this disease is more than ever to the fore, even though a considerable abatement in the incidence of silicosis has been noted of late. This abatement is due to individual and collective efforts. The Industry is keenly alive to the situation and much research is being carried on. Silica dust is assumed to be a contributing factor in the cause of silicosis. How it acts progressively in the early silicoric is nor fully understood. As the study advances, more effective measures of control may be evolved. At present the Industry has three known methods of reducing the incidence: 1. By thorough X-ray examination of all applicants, with special reference to chest conditions. Those who are considered to be susceptible to the disease are prevented from entering the industry. 2. Thorough ventilation of the mine. 3. Control of tuberculosis in mining centres and removal of miners when first symptoms of tuberculosis become apparent. In 1934, the Ontario Mining Association formed a Committee, known as the Technical Silicosis Research Committee, to study and supervise work on problems related to silicosis. This Committee obtained the full-rime services of a mining engineer to carry our research work at the mines in the Province of Ontario. The Ontario Mining Association has also provided funds for the purpose of carrying on research work along pathological and biological lines. This work is being done in the Department of Medical Research of the University of Toronto, in the Banting Institute, under the supervision of Sir Frederick Banting. The Silicosis Committee work in full cooperation with the doctors in the Banting Institute and provide material from the mines for the it use.

Jan 1, 1936