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By A. C. Richardson

The mine of the Porter Coal Co. is located at the town of Porter in the northwestern part of Jefferson, County, Ala., about 20 miles west of Birmingham. The operations in this mine are confined to the middle and bottom benches of the Mary Lee bed. The coal from the Porter mine is handpicked and washed before being placed on the market. The handpicked lump coal and the washed egg and nut, coal are sold chiefly as domestic and steam-raising fuel. The coal finer than 1 inch is washed in 2-compartment jigs and utilized in the manufacture of metallurgical coke. The coal company has found that, when coal ranging in size from 1 to 0 inch is washed in jigs, a considerable amount of high-ash material finer than 3/16 inch remains in the washed coal. This paper gives the results of an investigation which was conducted for the purpose of determining the washing characteristics of the through 316-inch raw coal and the extent to which the ash might be reduced by means of coal-washing tables. This investigation has been made in connection with an. extensive study of the coal-washing problems now being conducted by the United States Bureau of Mines and the University of Alabama, with the cooperation of the coal-mining companies of the State.

Jan 1, 1933

By I Halikia, T Lilis

Lead smelter slags, produced during the last century in quantities ofmillions of tonnes at Lavrion, Greece, have recently been used in theconstruction of Lavrion harbour. In order to evaluate the geochemicalstability of slags and assess their environmental impact on the aquatic environment, a detailed study on lead leachability under conditions that simulate subsea environments was carried out. Leaching experiments using magnesium chloride solutions under mild temperature conditions were conducted and the effect of main parameters on lead solubility was examined. Furthermore, kinetic analysis on the experimental results was performed. Based on the results, lead dissolution increases by increasing the reaction time, magnesium chloride concentration in the bulk solution and temperature, whereas it decreases by increasing the slags particle size. The reaction order was found to be approximately 0.5 at the initial extraction stages and the activation energy value from the Arrhenius plot was estimated to 29.8 KJ/mole. Diagnostic equations applied to all the experimental data reveal that lead dissolution is mainly controlled by diffusion through the ferrosilicate matrix of the slag particles, which is in accordance with the low activation energy value. The JanderÆs diffusion equation [1-(1-a)1/3]2=kt was proposed as the equation representing the reaction of lead dissolution from slags using magnesium chloride solutions.

Jan 1, 1999

The lead concentration of flotation feed ore slurries is determined using two ?-ray absorption gauges mounted directly on a 6 in. diameter flotation feed pipeline. One gauge is a conventional "density" gauge using CS137. The other is a "lead-sensitive" gauge, which depends on the preferential absorption. by lead of 225 key y-rays resulting from Compton backscatter of CS137 y-rays.Gauge outputs are combined using an analogue computer the output signal of which is directly proportional to the lead concentration of the pulp. The accuracy of measurement of the pulp lead concentration is ± 3·6 per cent for ore slurries with lead concentrations in the range 0'07-0·16 g/c.c. and pulp densities 1.43-1.60 g/c.c.This paper sets out the development of the technique and details are given of the two experiments (1964, 1966) conducted in the plant at North Broken Hill Limited. The installation of the two-gauge system inthe plant during May 1968 is described. Details are given of the calibration technique used and the results obtained.

Jan 1, 1969

By I M. Platten, C J. S Sangster, Y Xie

The Cononish gold-silver deposit is a steep, relatively narrow quartz-vein system, with a current total mineral resource of 154 000 oz Au and 589 000 oz Ag. The northeast-southwest trending system was emplaced into late Proterozoic metasediments, and postdates metamorphism and associated Caledonian Orogenic foliations. Assay and mineralogical data show that gold and silver is spatially associated with sulfides in quartz. The main sulfide is pyrite, but galena, chalcopyrite and sphalerite occur in small amounts. Gold occurs as electrum, with minor native gold, and silver occurs additionally as tellurides and native metal. The gold/electrum is fine-grained, generally less than 100 microns in size. The main ore shoots plunge 45¦ south-west, have a 40 m to 80 m intersection with the existing underground development and extend between 40 m and 260 m down plunge. Small-scale sulfide-bearing domains within the vein carry the highest gold grades. They collectively define the ore shoots, where one or two, and rarely three, of the domains are present at an individual site in the vein. Discontinuity of individual domains, variation in domain thickness and internal heterogeneity results in short scale variation in grade across the structure. Geological mapping along a 1.2 km exploration adit has provided critical æconditioningÆ data to support resource evaluation based on development and relatively wide spaced drilling. In addition, it has provided an indication of potential challenges that could be encountered during production.

Jan 1, 2009

By Tad S. Golosinski

The paper describes Online Master of Engineering Program at the University of Missouri-Rolla and discusses the experience gained during the first three years of its offering. This innovative educational program is designed primarily for mature students with an engineering or science background who want to acquire or upgrade their knowledge of mining engineering. Students can specialize in several different areas of mining, such as surface mining, underground mining, mine environment and the like. All courses constituting the program are taken online, through the Internet, without the need to attend the UMR campus in person.

May 1, 2004

These proceedings consist of papers presented at two Bureau of Mines Technology Transfer Seminars for the purpose of disseminating recent advances in mining technology related to coal mine fire and explosion prevention. Primary, although not exclusive, emphasis is placed on underground coal mining. The papers address research accomplishments ranging from methods for detecting mine fires to remote sealing systems for extinguishing coal mine fires. Each paper represents the current state-of-the-art in the respective research categories. Presentations include research occurring from both Bureau in-house and contract efforts.

Jan 1, 1978

By C A. Locke, M Stevens, P Vidanovich, J Cassidy, J L. Mauk

The Karangahake adularia-sericite epithermal gold-silver deposit, located at the southern end of the Waitekauri Corridor, Hauraki Goldfield, occurs as quartz veins with associated alteration haloes. Integrated geophysical studies were undertaken to determine the expression, location, and extent of these alteration zones. Aeromagnetic data show an extensive, magnetic æquietÆ zone over Karangahake and the southern Rahu Ridge that represents a zone of magnetite destruction resulting from hydrothermal alteration. Analytic signal data are used to define the boundary of this zone; the resulting 6 km2 area is elongate north-south with an irregular boundary. A detailed gravity survey over the area reveals a positive residual gravity anomaly, up to 30 gu in amplitude, over the Karangahake deposit. Density measurements on near-surface rocks give low values indicating that the source of this positive gravity anomaly must be deep; possible causative bodies include an igneous intrusion or dense sulfide mineralisation. To the west and east of the host Waipupu Formation, strong gravity gradients of 100 gu/km and 65 gu/km reflect the faulted boundary of the Hauraki Rift, and the edge of the Waihi Basin respectively. High resolution airborne radiometric data define a 2.2 km2 area of potassium enrichment. This area is elongate north-south and has an irregular boundary. It coincides approximately with the centre of the magnetic quiet zone and the peak of the gravity high, and correlates with known areas of intense mineralisation. Anomalously high potassium counts and elevated K/Th ratios correlate with areas of potassic alteration that have undergone K-metasomatism. Underexplored portions of this zone may indicate areas of gold-silver prospectivity. Combined geophysical data therefore reveal the extent of hydrothermal alteration, and the central zone of Kmetasomatism that is most likely to contain orebodies.

Jan 1, 2005

The Oregon-Idaho graben evolved after widespread tholeiitic flood basalt volcanism associated with the arrival of the plume head of the Yellowstone hotspot beneath southeastern Oregon approximately 17 - 16 Ma. The north- to north-northeast-trending, 50 km-wide graben evolved between 15.5 and 10.5 Ma during east-west extension. The graben is part of a middle Miocene back-arc rift (1100 km long) that includes the northern Nevada rift, the Baker and LaGrande grabens, and the Chief Joseph dike swarm of the Columbia River Basalt Group. The graben ceased to be a volcanotectonic depression as the cross-cutting western Snake River plain began to evolve at approximately 10.5 Ma. At about 14.3 Ma and continuing to approximately 12.6 Ma the Oregon-Idaho graben began to break up into subbasins that were bounded by intragraben fault zones. The break up was accompanied by a change to calc-alkaline volcanism that persisted within the Oregon-Idaho graben until 8.1 Ma, approximately 2.5 million years after subsidence within the graben ceased. Three intragraben fault zones have been identified and a fourth is inferred. The easternmost, the Devils Gate fault zone, coincides with the magmatic axis of the graben at approximately 14.3 Ma. By approximately 13.5 Ma the magmatic axis had shifted to the west along the Dry Creek Buttes and Wall Rock Ridge fault zones. A diffuse magmatic axis developed at approximately 12 Ma farther to the west where the fourth intragraben fault zone is inferred. In addition to serving as conduits for the ascent of basalt, basaltic andesite, rhyodacite, and rhyolite magmas, the zones focused the discharge of large geothermal systems. The intragraben fault zones display a common evolutionary pattern. The 2 to 3 km-wide zones initially control the distribution of facies in volcaniclastic sediments and the location of basalt hydrovolcanic vents. During this stage, the fault zones may have had no surface expression other than a low elevation change on a relatively low-relief landscape. As relief developed by continued deformation along the fault zones, strike-length of individual faults increased and weakly consolidated volcaniclastic sediments, silicified sediments and hot-spring sinter, and palagonite were eroded from the uplifted blocks and deposited in neighboring subbasins. It is during this stage that the large hot-spring precious-metals bearing prospects evolved. Displacements of over 150 m on a few faults within the zones and possible reversal of the sense of displacement along the zones occurred in this final stage of development. Locally, the fault zones were remobilised during the subsidence of the cross-cutting western Snake River plain. The intragraben fault zones within the Oregon-Idaho graben illustrate the relations among syntectonic volcanism and sedimentation and the evolution of geothermal systems within continental rift systems.

Jan 1, 1995

By Leslie F. Ruppert

The US Geological Survey (USGS) is currently conducting a coal resource assessment of the coalbeds and zones that are projected to provide the bulk of the nation’s resources for the next few decades. The Pittsburgh and Upper Freeport coals are the first two beds in the northern and central Appalachian basin region to undergo fully digital coal assessments. The bed-specific assessments are being carried out in partnership with the state geologic surveys of West Virginia, Ohio, Pennsylvania and Maryland. Comprehensive stratigraphic and geochemical databases have been developed for both of the beds. The extent of the bed with mined areas, structure contour, isopach, and overburden thickness maps for the Pittsburgh coal bed have been released as USGS open-file reports.

Jan 1, 1999

By S. Ndlovu, M. Malatse

"The Witwatersrand Basin is the heart of South Africa’a gold mining industry. The cluster of gold mines located in the Witwatersrand Basin generates a significant amount of mine tailings, which have adverse effects on the environment and ecological systems. In addition, disposal costs are very high. The exponential population growth in the Witwatersrand area has resulted in pressure on the reserves of traditional building materials. Quarrying for natural construction material is very expensive and damages the landscape. This work therefore examines the use of gold mine tailings in the production of bricks.Different mixing ratios of gold tailings, cement, and water were used. The resulting bricks were then cured in three different environments - sun dried, oven dried at 360°C, and cured in water for 24 hours. The bricks were then tested for unconfined compressive strength, water absorption, and weight loss. The results showed that the mixture with more cement than tailings had a compressive strength of approximately 530 kN/m2. It was also found that the best brick curing system was in a water environment. Bricks made from tailings cost more than conventional bricks because of the higher quantity of cement used, but the manufacturing process consumes less water. Overall, the results indicated that gold mine tailings have a high potential to substitute for the natural materials currently used in brickmaking.Paper written on project work carried out in partial fulfilment of BSc. Eng. (Metallurgyand Materials Sciences)"

Jan 1, 2015

By Arun .. J. Basu

The paper introduces Intelligent Air Management (IAM) as the core activity of M&I Group of Companies (M&I) for providing a total solution to any air management problems for mining and mineral processing operations implementing a comprehensive systems approach through a world-wide network of strategic alliance partners and in-house engineering team and manufacturing facilities in Mississauga, Ontario, Canada. Recommendations for energy-efficient ventilation in a vibration and noise free environment are made with the patented and innovative solutions supported by extensive computational fluid dynamics (CFD) studies. The solution scope extends from an intelligent and integrated exhaust silencer to a complete ventilation sys-tem solution including inlet and outlet control design and ducting for diffusers and silencers.

Apr 1, 2005

By Clarke DS

The igneous intrusions in SE Papua New Guinea are part of a sub-volcanic to plutonic, high-K calc-alkaline to shoshonitic suite. High-K andesitic to dacitic intrusives on Misima and Woodlark Islands, and shoshonitic intrusives in Milne Bay and the eastern Owen Stanley Ranges are related to late Cenozoic andesitic volcanism. Both suites are associated with epithermal Au-Ag deposits and weak porphyry Cu-Au mineralisation. All significant alluvial and lode gold occurrences in the region are spatially related to intrusions. Intrusions in the D'Entrecasteaux Islands and near Mt Suckling are core plutons related to basement doming, and appear to have no association with either volcanism or hydrothermal mineralisation. The core plutons are not petrochemi:ally distinct from the volcano-re:-ed Intrusions.

Jan 1, 1991

Characteristics Analysis of a Bastnaesite Rare Earth Mineral for Recovery of Cerium

Sep 13, 2010

This paper reviews the manpower requirements of the Australian mining industry. It has been necessary to provide general background information in order to support the view that university education in mining and mineral process engineering should be strengthened rapidly in Australia to provide graduates for the industry.

Jan 1, 1969

By Robert Torbin

The objectives of the Continuous Shaft Lining (CSL) System are to reduce the costs, safety hazards, and time currently required in lining mine shafts with concrete. The CSL will line machine bored shafts downward from the shaft collar on a continuous basis using an inverted, pressurized slipforming technique. The technique for slip-forming downwards has been demonstrated and refined under this program. The approach taken involved laboratory scale testing of key features of the CSL concept. These feature tests included concrete distribution, concrete sealing, concrete slipforming and development of a reliable concrete mix. Based on these results, a full scale above-ground test facility and CSL were designed and fabricated. The objectives of these tests were to demonstrate the viability of the basic concept; to establish operating limits; and to provide input data and information for the design of a second generation shaft lining system. The results of the program have led to a CSL design and operational philosophy which will need to be tested in an underground environment before industry will accept the technology. However, the next generation CSL promises to meet all the original program technical objectives.

Jan 1, 1983

IT has often been stated in the past that the materials known as inert fillers were merely adulterants nsed in the manufacture of paint, and that their purpose was to cheapen paints made from more expensive pigments, such as zinc oxide or white lead. In recent years, however, practical tests in various parts of the world have proved that many of the inert fillers, when used with wisdom, possess very definite and advantageous properties.Another oft-repeated statement which had a far-reaching effect in the past, and which is not without influence to-day, is that the very best paint must always be made from a pure pigment, without admixture with either a fellow pigment or an inert filler. Both or either of these statements may be true in a few isolated instances, but for the vast majority of ordinary painting conditions there is an abundance of experimental evidence to prove that neither is true.With the desire to further investigate these points and po 'determine the best combination of pigments and fillers for use as an outside white paint on plant buildings, a number of panels were prepared in the laboratory of this company.

Jan 1, 1924

This paper aims to collate the metallurgical test work undertaken on the Barrytown mineral sands deposit. It is intended to serve as a summary of mineral dressing work undertaken by all interested parties up to the time of writing. Areas requiring further investigation are: in situ grades and recoveries of accessory minerals,the question of 'rank' of ilmenite within the deposit,flow sheet development for the recovery of gold and monazite, andcost analysis to investigate the relative worth of other minerals; notably rutile. Flow sheet development with respect to the Accessory Minerals cannot be accurately defined until the importance of each mineral in terms of grade, recovery and expected revenue is determined. To date, ilmenite and zircon flows are well documented. Further work is needed to quantify recovery's and flows of the other minerals; notably monazite, gold and rutile.

Jan 1, 1989

By O. P. Garg

"The Iron Ore Company of Canada (IOC) operations in Labrador and Quebec, in Canada, is among the largest openpit mining complexes on a world wide basis. Since the 1981-82 recession, IOC has embarked on a comprehensive cost reduction and productivity improvement program in order to survive in the world iron ore market.This paper will outline the approach used in prioritizing the cost reduction items.IntroductionMuch of the mining industry in North America is in a crisis state. Most producers are operating at production levels well below capacity, some have been merged or sold, while others have been mothballed or closed permanently. For many of us still operating, the future is uncertain. Despite the many cutbacks and closures, there is still an abundant supply of minerals in the world market and there is almost no hope for any relief on price pressures on most mineral commodities in the near future. The Iron Ore Company of Canada (IOC) operates an iron ore mine, a concentrator and a pellet plant known as the Carol Project located in Labrador City, Newfoundland. This concentrator and the pellet plant have the annual capacity to produce 20 million and 10 million tons respectively. A company owned and operated railway links this operation with the dock terminal facilities in Sept-Iles, Quebec.In the past decade the Iron Ore Company of Canada has been one of the largest producers of iron ore products in the world. Its pellets and concentrates as well as natural ores were sold in North America, Europe and the Far East. In 1981-82, sales, particularly in North America, went into a serious decline. For almost 30 years, the gospel IOC preached to employees was ""production, production!"" There were many innovations, and millions of dollars were spent on the biggest and best equipment, on research and development, on training and developing employees."

Jan 1, 1987

A single compartment 100 A electrolytic cell charged with AICla-KCl-NaCl at 750°C was studied during an experimental campaign of 4 months. About 10 1b of aluminium were produced in continuous runs which lasted up to 1 week. The highest cathode current efficiency determined was 80 per cent. Anode current efficiency. cathode potential, analyses of melt, sublimate, and product, and reactivity of cell materials were also recorded and interpreted in terms of the role of lower valent aluminium species in the electrolysis mechanism.

Jan 1, 1971

The two candidates in the upcoming presidential election in the United States each say that they have their own solution to the nation?s energy problems - solutions that will increase the amount of energy available, lessen the nation?s dependence on foreign sources and reduce the amount of pollution released to the atmosphere. Democratic nominee Sen. Barack Obama and Republican candidate Sen. John McCain both advocate research funding for coal-to-liquids and clean coal technologies. McCain also supports increased oil and gas drilling offshore. And Obama has even made some noises in that direction, although his plan leans heavily on the increased use of renewable energy sources. The energy debate is not new to this election. Congress and whichever party is in the White House has for years been trying to craft a comprehensive energy policy. One difference in this latest debate is that the increased use of nuclear energy has gained more attention. Current President George W. Bush has said he favors the increased use of nuclear power as part of the nation?s energy package. And McCain said he supports the building of more nuclear power plants. Obama has not said much about that. The American public is also showing signs of changing its stance on nuclear energy. To be sure, images of Three Mile Island and Chernobyl are still alive in some minds. However, the American public has said it wants cheaper energy and they want it produced more cleanly. With nuclear, the nation can have both. In the United States, nuclear accounts for slightly less than 20 percent of the electrical power used (see interview with Gary Steele of Energy Fuels on page 27). Globally, that figure is about 15 percent. And there are several nations that derive better than half of their power from nuclear sources. Add to that the world?s increasing need for more energy and the future of nuclear is bright.

Jan 1, 2008