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By W. K. Wedge

The chemical composition of the Pennsylvanian Bethany Falls Limestone Member of the Swope Formation was investigated using optical emission spectroscopy and both flame and flameless atomic absorption spectroscopy. Elements determined were Ca, Mg, Fe, Mn, AI, Si, Na, K, P, Ti, Zn, Cd, Ni, Co, Cu, Pb, Cr, V, and Mo. Over 100 samples were collected from active quarries along a 320-km-long (200-mile) outcrop in northwestern Missouri. Intervals were sampled representing uniform lithology to determine vertical and lateral geochemical variation. The Bethany Falls Limestone is the most extensively quarried Pennsylvanian limestone in Missouri. In 1975, 42 active quarries produced almost 5.4 million tons (6 million st) of stone valued at over 15 million dollars.

Jan 1, 1977

By Yuting Xue, Lihong Zhou, DAVOOD BAHRAMI

The paper discusses the use of machine learning (ML) to develop a predictive model for determining the location and size of underground mine fires using simulated ventilation data. The study highlights the importance of prompt fire location determination for effective firefighting strategies and reducing injury risks. The ML model was trained with simulated data and achieved an accuracy score of 0.920, which improved to 0.962 by grouping closely connected airways.

Sep 1, 2023

By Gilbert Sauriol

The mining complex, which the Mines Gaspé division of Noranda Mines Limited has operated in Murdochville since 1954, includes open pit and underground mines, two mills, one leaching plant and a smelter. The under- ground mining uses predominantly a large scale room and pillar method, rooms 15 m wide, 30 m high and 300 m long being common. Ore production is effected by 4.5 m3 front-end loaders and 32-tonne trucks powered respectively by 225 and 325 kW diesels. Daily dust and gas readings show that air quality can be maintained at an acceptable level with much less ventilation than that normally specified. This paper emphasizes the point that air requirements should be based on Air Quality Standards, thus allowing an operation to benefit from favourable conditions or from improvements such as exhaust treatment, fuel alteration, etc.

Jan 1, 1983

By Tom Michaud, Rob Albinger, Ian Turner, Michael Rispin

Data transmission, communication, tracking, and the connection of equipment such as gas detectors, cameras, and collision avoidance systems in today's tunnel industry are critical pieces of the constructor's infrastructure. Reliability, flexibility, redundancy, and cost-effectiveness are key in selecting and implementing inte- grated systems. Both wired and wireless components are used to deliver custom solutions and can involve interconnectivity between backbones. Systems integration is important as industry adopts proven technologies from other industries. Case stud- ies are given showing how tailor-made approaches deliver needed functionality, with varying degrees of com- plexity, in various classifications of environment, in order to meet a project need.

Jun 23, 2024

By David Maust, Rob Albinger, Mike Walling, Michael Rispin

The safeguarding of health and life is the number one priority for underground infrastructure projects. While culture and approach are critically important, the industry has also seen the development of innovative tools and technologies that assist in making the underground environment and working places more safe and secure, both on an everyday basis and in the event of an unexpected occurrence.

Dec 1, 2022

By Myron W. Mellor

Much has been published concerning the subject of coal preparation as related to electric power generation however it is always a most vital topic for both utilities and coal producers, It also constitutes a field of study that is never finished since new concepts and changing demands continually require altered perspectives. One graphic illustration that has been used to emphasize the rapidity with which times are changing is the fact that during World War I, a station that consumed 1000 tons per day was looked upon as a large central station, while today some single generators require 1500 tons during the same period, For further emphasis, at that time a 20,000 horsepower turbo-generator was a mighty large machine; today, a unit of this size is planned for driving the boiler water feed pump required for a single large main unit. During the past ten years alone, electric utilities have more than doubled their percentage of coal consumed as compared to the total market. They now account for approximately 40% of the United States consumption and one-third of all production including export, Conversely, approximately 70% of all U. S. steam electric generation is by coal and this percentage is expected to increase. It is further predicted that utility consumption will increase from the current 160,000,000 tons per year to between 400 and 500 million tons in 1975 which is approximately equal to todays total production

Jan 1, 1959

By Irving Hauser

The determination of new ways to cut costs in then times of economic uncertainty is essential in running a successful business. Arco Petroleum Products Company a Division of Atlantic Richfield Company recognized an opportunity for a substantial cast savings in transporting calcined petroleum coke to market by simply building an economical port facility at a location that would enable them to drastically cut their normal rail haulage distance.

Jan 1, 1982

By R. Fedel-Moen, R. W. L. Kimber, B. D. Williams, S. R. Ragusa

The use o f cyanide to extract gold from ores is widespread. In the process of extracting gold, cyanide may form metal cyanide complexes with a variety of other metals present in the ore. This study was carried out to investigate the biodegradation of the Cu(I)-cyanide complex and tetracyanonickelate under varying pH and nutrient additions. Detailed studies using shake flask cultures and bioreactors showed that naturally occurring bacteria residing on gold-leach-pad ore uti¬lized the Cu(I)-cyanide complex (CuCN) and tetracyano-nickelate, Na2(NiCN4), as carbon and/or nitrogen sources. Ammonium-nitrogen (NH4+-N) and/or cyanate (CNO-) accumulated in solution as the metal cyanide complexes were degraded. The accumulation of cyanate as a product is a concern due to its toxicity. Degradation rates were increased if a growth substrate (peptone, 0.1%) was added to the medium or if bioreactors were primed with peptone before addition of the metal-cyanide complex. Tetracyanonickelate was degraded at pH 8 without added peptone, but it was not degraded at pH 10. The addition of peptone was required for degradation of the Cu(I)-cyanide complex at pH 8 and pH 10. At pH 8, the addition of peptone resulted in the accumulation of cyanate, whereas, at pH 10, cyanate was not detected in the cultures. Biodegradation of metal-cyanide complexes was faster (approximately 1.5 to ten times faster) in bioreactors than in shake flask cultures. The addition of peptone was not required for degradation of metal-cyanide complexes in bioreactors. However, priming the bioreaetor with peptone resulted in higher metal-cyanide degradation rates over multiple cycles.

Jan 1, 2000

By J. E. Urosek

In October, 1990, a fire started in a large underground coal mine in Western Pennsylvania. During fire-fighting activities, an explosion occurred and all personnel were evacuated. Safe re-entry into the mine was not possible and the mine was sealed. Recovery efforts began in January, 1991 and continued until March, 1991, when permanent underground seals were installed between the fire area and the mine openings. This paper describes an extensive atmospheric monitoring program conducted by the Mine Safety and Health Administration (MSHA), Pittsburgh Safety and Health Technology Center (PS&HTC) including the analysis of mine fire gases, natural ventilation, fan pressure and air quantity distribution.

Jan 1, 1993

By K. N. Han

The dissolution kinetics of cobalt in iodine/ iodide solutions were investigated using a rotating-disc technique. Variables studied included temperature, rotating speed, concentration of lixiviants and the pH of the solution. The overall dissolution reaction appeared to be limited by the mass transfer of tri-iodide through the diffusion boundary layer with an Arrhenius activation energy of <16.2 kJ/mol (4 kcal/mol) over the temperature range of 2 to 42ºC. The pH of the solution had little effect, as long as the pH of the solution was <8. However, when the pH of the solution became >8, the dissolution rate decreased dramatically, due to passivation. The rate of dissolution was in good agreement with the dissolution model developed by the authors earlier.

Jan 1, 1995

By B. A. Waite

The new OSH regulations concerning ground ward monitoring of underground coal mines has been the source of many concerns for the mining industry. Because the regulations were initially written at the federal level but are being administered at the state level, considerable confusion exists within the industry as to what is actually required. Based on the preparation and submission of over 30 monitoring plans for existing deep mines in Pennsylvania, West Virginia, and Ohio, we now have a very good feel for the detail the monitoring plans, as well as the costs to im plement the plans. We do not, however, feel confident in our evaluations of the long-term impact the ground water monitoring regulations may have on the industry.

Jan 1, 1980

By G. J. Karabin

The Boundary Element Method of Numerical Modeling has become an increasingly popular rock mechanics -mine design tool. It has been used by the Roof Control Division, Pittsburgh Safety and Health Technology Center, MSHA, to aid in the resolution of complex ground control problems since 1985. This paper will present an overview of an evolving simulation process and details of methods utilized to generate necessary coal, rock and gob input properties. Also included is a description of a Deterioration Index System that is used to link model output to observed mine conditions and two case studies to illustrate that process.

Jan 1, 1995

By E. L. Montgomery

Salar basins in the Andean Highlands of Northern Chile contain ground-water resources which could be used to satisfy requirements for the mineral industry in the region. Salars occur in arid zones; average precipitation is about 200 millimeters per year at altitudes of about 4,000 meters, and average annual evaporation is two meters or more. The salar basins are hydrogeologic sinks where water flows from recharge areas at the margins of the basins to discharge areas at the salt encrusted salar at the lowest point of the basin floor. Groundwater circulation occurs principally in the alluvial and fractured bedrock aquifers. Results of pumping tests for exploration and production water wells indicate a range in maximum sustained pumping yield of 62 to 126 liters per second, and where abundantly fractured, ignimbrite comprises the most prolific aquifer. Chemical quality of groundwater is good. Long-term pumping from properly located production wells in the salar basins would result in lowering of groundwater levels and salvage of water in areas where groundwater is lost via evaporation.

Jan 1, 1986

By Muriel S. Robinette

Ground-water contamination from uranium operations could be avoided with proper site analysis techniques. Contamination from tailings disposal sites is carried downgradient within permeable hydrostratigraphic units which can be located and delineated with a combination of drill holes, borehole geophysical logs and surface geophysics. Several case studies are presented to illustrate this application.

Jan 1, 1980

By M. Gershon

Four computerized approaches for coal blending are described and their strengths and weaknesses are explored. Spreadsheet analysis Other than word processing, spreadsheet software is the most commonly used software. Its wide availability and ease of use are two desirable features that have led many to try to adapt it to the purpose of coal blending. These are the two main advantages of this approach. To use a spreadsheet for coal blending, each row of data represents one source of coal. Each column represents a quality of the coal, with the last column specifying the tonnage of that coal in the blend. The calculated figures are. the blended qualities, which can be programmed to appear in the bottom row. A trial-and-error approach is then used to develop the best blend. Inserting any blend in the last column provides the blend characteristics at the bottom of the page. If any specifications are not met, the blend can be changed, all calculations being immediately updated. This process is repeated until all specifications are satisfied. A third advantage of this method is that it is exactly the procedure that one would go through if doing this by hand. With a spreadsheet, many more blends can be evaluated in much less time, allowing the designer to try to improve over satisfactory blends to find the best of them. The resulting improved blends or cost savings are a fourth advantage of this approach. There is only one major disadvantage of using the spread- sheet. This is that most probably the best blend is not found. As an inexpensive introduction to computer-assisted blending, which can be easily understood and cost just a few hundred dollars, this is a recommended place to begin.

Jan 1, 1987

By Leon D. Keller

Fine screening, as discussed in this paper, pertains to the use of the Rapifine DSM Screen to make a 65 to 325-mesh separation at production tonnages. The greatest number of Rapifine Screen installations are in magnetic taconite plants where the unusual relationship between the grinding mill, cyclone classifier, magnetic separators, and fine screens makes the Rapifine Screen application unique. Since the initial fine screening installation on magnetite in 1961, (1) additional installations and further testwork have contributed to the fund of information which is the basis of this paper. The addition of fine screens to the grinding-classifying circuit of a magnetic taconite plant creates a change that effects all components of the circuit. Pine screens in a non-magnetic plant have also been investigated, but here the benefits have not&apos; been as clearly defined. Screens classify according to the particle size. Hydrocyclones classify by a combination of particle size and particle weight. The change in the type of classification minimizes overgrinding of the mineral. The resultant savings in grinding power can be used to increase the throughput, upgrade the product, or increase recovery.

Jan 1, 1971

By B. E. Davis

A technique was devised by the Bureau of Nines to recover coarse (plus 1.7 m) North Carolina phosphate now discarded as waste. Concentration utilizes the difference in particle sphericity between the relatively flat calcite and the rounded phosphate pebbles. Sizing, treatment in a continuous hydraulic classification system, and grinding upgraded a 17.0-pct-P205 reject to 24.5 pct P205 with a phosphate recovery of 63 pct.

Jan 1, 1985

By W. Choi

The present study revealed that the bioleachability of a chalcopyrite flotation concentrate is influenced by the semiconductor properties of CuFeS2. The overall reaction of biooxidation,

Jan 1, 1991

By John B. Mitchell

Approximately 90% of all potash produced is employed as a fertilizer, either directly or with nitrogen and phosphorus. The remaining 10% is utilized in the manufacture of other chemical products, The original source of potassium was wood ash (hence the name potash), However, today the term potash refers to all commercially important salts of potassium. Sylvite, usually found associated with halite, is the predominant economic potash mineral; carnallite a lesser important source of potassium chloride, while langbeinite is important as a source of potassium sulphate. The world&apos;s first potash mining operation commenced in Strassfurt, Germany about 1860, Since that time the industry has grown steadily to its present annual volume of about 30, 000, 000 tons of potassium chloride products or 18, 000, 000 tons of K2O equivalent, potassium chloride or "muriate of potash" being equivalent to 63. 1% pure K2O, WORLD POTASH RESERVES ARE NOT EVENLY DISTRIBUTED The earth&apos;s crust contains 2 to 3 per cent potassium, mostly in the form of insoluble silicate minerals. The economically important deposits, however, are formed from brines concentrated by evaporation. The world&apos;s most important commercial deposits are of Devonian and Permian age, however soluble potassium bearing salts are presently being concentrated by evaporation in several drainage basins, notably Searles Lake, California, Great Salt Lake, Utah&apos; and in the Dead Sea. At least twenty-four countries are known to have reserves of potash: Canada and the USSR have over 80% of the presently known world reserves, (Figure 1)

Jan 1, 1972

By J. Kalliokoski

As part of a funded project we have completed a comparative literature survey of the US regional Proterozoic geology. For our com¬parative study model we used the geological settings of the very large pitchblende deposits in Saskatchewan, Canada and the Northern Terri¬tory of Australia. These occur in a variety of Archean and Lower Proterozoic host rocks, at and below a regional unconformity that is capped by subhorizontal Middle to Upper Proterozoic conti¬nental sedimentary rocks. We find that there have been recorded in some parts of the US similar unconformable sequences of Middle to Upper Proterozoic continental sedimentary rocks that overlie older basement rocks.

Jan 1, 1979