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By Tetsuo Yamazaki

Natural methane hydrate has been scientifically studied as a carbon reservoir globally. However, in Japan, the potential for energy resource has been industrially highlighted. There is less domestic oil and natural gas resources in Japan, but many potential deposition areas for methane hydrate in ocean around Japan are the reasons. Less CO2 discharge from methane compared with coal, oil and conventional natural gas when the same calorie value we get is considered as the advantage for energy resource. However, because methane hydrate distributes in shallower sediment layer in ocean floor, accidental leakage of methane may occur while we utilize methane hydrate. Methane itself has 21-times impact on the greenhouse effect, if it reaches the atmosphere. Therefore, it is necessary to estimate the behavior in the environment after the leakage, if we want to use methane hydrate as energy resource. The mass balance after leakage of methane on seafloor and in water column is numerically studied through the analyses of methane emissions from natural cold seepages and hydrothermal activities in this research. The outline structure of mass balance ecosystem model shown in Fig. 1 is introduced. A numerical early diagenetic model CANDI (Carbon And Nutrient Diagenesis) developed by Boudreau (1996) for simulating the biogeochemical processes such as organic matter, oxidant, nutrient, bi-product, and pH diagenesis in aquatic surface sediments and C. CANDI improved by Luff and Wallmann (2003) for describing the formation process of calcium carbonates in CANDI are used as bases of the ecosystem modeling in surface sediment layer around seafloor methane emission. Two functions such as methane bubble dissolution and bacterial methane oxidation in water column are added to an existing physical plume dispersion model by Doi et al. (1999).

Jan 1, 2005

By Denise Y. Dizon

The objectives of this study were to document the hydrologic impacts of longwall mining on streams, identify the factors affecting the extent of stream dewatering, and develop empirical trends to predict the extent of dewatering and recovery of streams in advance of mining. This study on stream impacts is a companion to a stud; conducted on ground water impacts from longwall mining, which was done as part of the same research project at the' same locations and times. The study areas are three mine sites in north- central West Virginia. Mine A, located in Upshur County, has relatively thin mine overburden under the valley streams (105-115 feet). Stream monitoring there continued the earlier work of Cifelli and Rauch (1). Stream dewatering was severe with streams often going dry over the longwall panels during baseflow conditions. The lost water was probably flowing to the mine. Dewatering began in streams over the mine entry areas adjacent to the panels and as much as 380 feet from the nearest panel edge. The angles of dewatering influence ranged 22 to 72 degrees with respect to the nearest mined panel edge. Discharge then typically increased as the streams- flowed across the panel edge, but then decreased again over the panels. These streams were often ponded by local reversals in hydraulic gradient caused by land subsidence, and often dried up after flowing a few hundred feet across the panels. This occurred over panels that were previously mined up to eight months before. Mine B, located in Monongalia County, has relatively thick mine overburden (475-485 - feet) under the major stream. Stream dewatering was severe there during warm season baseflows, with complete dewatering occurring then over the longwall panels. This dewatering occurred over mined panels up to five years old, probably in response to a major anticlinal axis lineament and fracture zone in the stream valley. Mine C. located on the West Virginia -Pennsylvania border, has relatively thick mine overburden (about 585-630 feet) under the monitored streams there. stream dewatering was only partial, and these streams typically recovered their lost discharge downstream of the mine, indicating that lost water was not recharging to the mine. Only longwall panels less than one year old were associated with stream dewatering.

Jan 1, 1990

By F. C. Stanford

THE work of an engineer is to direct natural forces so that they bring about the results that he wishes to secure. Heretofore he has concerned himself chiefly with physical forces and inanimate objects, until he has secured a truly marvelous degree of control over them. The great problem of the present age is to secure a like degree of knowledge and control of the human factor. Progress has already been made along this line, but, it is only a beginning. Wilhelm Ostwald says that scientific knowledge enables a man to be a true prophet; but it must be remembered that a good many people do not seem to be able to maintain a high average in prophecy. In short, the average of knowledge is not equal to the average needs of the present time, but continually fails to keep pace with it. It has been aptly said that the really essential need of the period is for more brains; if we only had sufficient knowledge and sagacity we could not only solve all difficulties, but prevent them from arising. This generalization holds good for an industrial organization. The most vital need of the management is for more brains. The logical course for an engineer in charge of an industrial organization is, therefore, to direct whatever forces may be at his command toward the development, training, and guiding of all the brains in his organization. This is easier said than clone, for it involves the carrying on toward two objectives, the maximum of productive work, and the development of the individuals who perform it. This is essentially like the rebuilding and enlarging of a plant, keeping it in full operation the while. On the other hand, if the aim is merely for maximum production from an organization, without offering opportunity for development, the final outcome will necessarily be like that f a plant that is driven at full capacity without stopping for repairs or improvements; it eventually becomes so run down that either a complete rebuilding is necessary or else it has to be abandoned.

Jan 2, 1918

By Betty L. Gibbs

The ultimate objective of mine design is to determine the development and untilization of mining resources. Computer Aided Design (CAD) and automated mapping are becoming very popular in engineering and in mining. Any computer program which produces a design or model with the interaction of an engineer can be considered computer-aided design (CAD), but' the term CAD is often associated with interactive graphic design and mapping capabilities. Graphics can be effectively used to describe and model two-or-three dimensional mine workings, orebodies, and geologic structures. Interactive computer graphics is applied to mine design with a combination of deposit modeling techniques and the use of AutoCAD for interactive graphics and mapping. The combined system can perform a large part of the calculations and drafting work for geologic and mining design. Using computer calculation and graphics techniques, comparisons of alternatives, can be made quickly.

Jan 1, 1989

The necessity for good management and economic working in our mines and ore-dressing sheds is impressed upon us by the present low prices of all our metals. Silver, lead, copper, and tin have all suffered a heavy decline during the last six or twelve months, and many mines have been shut down simply on account of the low market value of the ore produced. After fully considering the position of the mining industry. I am convinced that considerable improvements will have to be made to make it as prosperous as it ought to be. The most obvious of these improvements are good management, good machinery, and as little interference by directors as possible. If these conditions are insisted upon and carried out efficielltly a poor mine may have a chance to weather the storm.There is no doubt that the present depression is the refilult of over-speculation and general loss of confidence by which the whole commercial system has been affected, and every branch has suffered more or less, mining not excepted. It has suffered heavy losses in the past, and the future is not over bright we are, therefore, compelled to be careful in everything by which mining is affected and savings can be secured.

By R. W. Raymond

HAVING had recently the opportunity of examining a transit and a plummet-lamp, manufactured by Messrs. Heller & Brightly, of Philadelphia, and intended for the use of mining engineers in under

Improved Process & Practices Result In: ? Reduction of undesirable downtime, & expensive secondary damage ? Improved equipment performance & health ? Extension of equipment life, & reduction of operating costs ? Safety and environmental performance improvement Equipment knowledge capture and consistently applied

May 1, 2010

By Charles Wert

THE diffusion and precipitation of carbon and nitrogen in a iron have previously been investigated using the internal friction as a measuring tool.' Most of this work has been done on rather pure iron; no effect was observed which would indicate that either of these phenomena is affected by the rather small amounts of impurity found in these samples of iron. Fastz observed, however, that both the diffusion rate and the aging properties of nitrogen in iron were sensibly changed by the addition of Vz pet Mn. The diffusion rate at a given temperature is reduced and the nucleation of nitrides is apparently changed somewhat. He observed no such changes for carbon in this alloy. Later Dijkstra and Sladek" extended these observations on nitrogen to other alloys of iron. They found that metals other than manganese also influence the behavior of nitrogen in iron; chromium, molybdenum and especially vanadium affect the diffusion and precipitation of nitrogen even more than manganese does. Their results have been verified in all essential details by this author, who finds in addition that small additions of nickel have about the same effect on the diffusion of nitrogen as the same amount of manganese. The present work was undertaken to study the effect on carbon in iron of these alloying elements. The alloys used had two sources. The material used as a "standard" (designated Fe in this paper) in the measurements was some iron supplied by J. K. Stanley, of Westinghouse Electric Corp., who reported 0.01 pct 0, as the only major impurity. He also made up an alloy of 0.26 pct Ni and one of 0.9 pct Mo using this same iron as a base. They were supplied by him in 2 lb billets, which were sawed into rods and cold formed into 0.030 in. wires for measurement. The alloys of chromium, manganese, and vanadium were prepared by the metallurgy section of the Institute for the Study of Metals, University of Chicago, by adding these metals in turn to vacuum melts of National Research Corp. iron. The small castings prepared in this way were also cold formed into 0.030 in. wires. After these wires had been prepared they were decarburized for 30 min at 730°C in wet Hz. After this treatment, no trace of carbon (as measured by internal friction) could be found. All specimens were then carburized for about 15 min at 710°C and water quenched. By this treatment the internal friction at 40°C was raised to a Q-' ~ 0.015. The diffusion of carbon in these alloys was studied by observing the shape and position of the internal friction peak at 0.9 cycles per sec. These measurements were made using a torsional pendulum in a manner described earlier.' The data are plotted in Fig. 1. It is seen that there is no apparent difference in internal friction between the various alloys. This is in marked distinction to the broadening and shift-

Jan 1, 1953

By E. T. Boshoff

Paper written on project work carried out in partial fulfilment of B. Eng. (Metallurgical Engineering) The weathering of kimberlite can be accelerated with cations in solution if swelling of the kimberlite occurs in contact with the weathering medium. The type and amount of swelling clays present, along with the surface charge and cation valence, determine the degree of swelling that can occur. Crystalline swelling occurs by the incorporation of cations in the interlayer spacing of the silica sheets. Kimberlite exposed to cupric cations showed very strong weathering, indicating that this type of weathering may be considered a viable process option. Kimberlite fines generated after weathering with monovalent cations showed poor settling behaviour compared to kimberlite weathered with di-, and trivalent cations.

Jan 1, 2005

By J Lim, M Powell, P J. Scales

The current philosophy employed in the design of mineral processing plants effectively involves bolting together segmented unit operations both chosen and optimised from a product-centric perspective. In this context, integration of water saving technologies at an overall plant level becomes difficult and often only local water efficiency improvements are feasible. In general only limited benefit can be obtained from such add-on solutions. It is therefore proposed that to obtain significant savings in water consumption and reductions in the volume of discharged contaminated water in the mining process, the entire process along the mining and mineral processing chain should be addressed This paper explores aspects of the processes that may be modified to provide an integrated and combined step change saving in water consumption. It is also apparent from this study that taking a more holistic view of the process can provide significant benefits in energy savings and total cost of production, providing the potential of a substantial win-win outcome.

Jan 1, 2009

By R. O. Williams

A recent article by Chernock, Singer, Mueller, and Beck 1 which supports the use of the integral of I sin $ d$ for comparing fiber texture data does not settle what happens to I sin ø as ø approaches zero, where I is the diffraction intensity for poles oriented 0 deg from the fiber axis. They indicate that they believe that it should approach some constant value (that is, I increases without bound) and the fact that in reality it does not was a result of the diffraction

Jan 1, 1960

By N. Vasumathi

Most of the Iron ore washing plants set up in India in the earlier days consist of sizing of the ore by dry / wet screening, washing and classification by screw classifiers. In this classical approach, iron values were lost in the form of fines and ultrafine into the tailing ponds as they had little commercial value in those days and accumulated in huge quantities over the years. As the high grade deposits are getting exhausted and the demand for high grade finer material for pellet making is ever increasing, focus is shifting towards recovering the values from the erstwhile tailing ponds by column flotation. This is also supposed to mitigate to a certain extent the environmental problems caused by the ever expanding and unmanageable tailing dams. A case study is presented wherein a composite sample is prepared from samples drawn systematically from multi - locations in a sprawling tailing dam. Laboratory scale column flotation tests on this composite tailings sample, basically originating from two operating iron ore beneficiation plants of JSW Steel Ltd., one of the leading producers of steel in India are found to be encouraging. Desliming followed by reverse and cationic flotation tests using flotation column resulted in the concentrate of 61.88% Fe, 4.81% SiO2, 2.52% Al2O3 and 3.30% loss on ignition (LOI) from the tailings analyzing 57.86% Fe, 7.10% SiO2, 3.52% Al2O3 and 6.14% LOI with 52% weight recovery. The causes for the quality improvement could be attributed to desliming of un-liberated ultra fines of kaoline and hydrated iron oxides and their further reduction by efficient flotation process. The process and the cationic collector developed for this purpose are adopted in the new flotation plant created to treat these tailings. Keywords: iron ore, washing, ultra fines, tailings pond, column flotation

Sep 1, 2012

By S. V. Krusiewski, J. W. Gabelman

Regional metallogenic zones and areas of equal paragenetic range have been interpreted from a compiled metallogenic map. of Mexico. Mineralization gradients of the pattern subsequently identified extend inland from coastal zones of high-temperature mineralization, and join in a central longitudinal zone of relatively low-temperature mineralization, apparently leaving no zonal room for lowest temperature deposits. The striking regional zoning pattern can be correlated with regional deformation gradients of similar position and orientation. The gradients represent at least three major orogenic cycles in two structural belts. Paleozoic structural belts existed along each coast with deformation gradients diminishing inland toward a narrow, central peninsular craton. The Mesozoic-Tertiary Mexican (Cordilleran) belt covered the entire country with a gradient oriented toward the Gulf of Mexico. Most ore deposits in this belt are of Tertiary age, although Tertiary mineralization gradients seem to have "inherited" the pattern left by Paleozoic tectonic gradients. Mineralization gradients can be used to identify the regions most favorable for the occurrence of selected metals. A metallogenic province is characterized by particular proportions of various metals, and the relative proportions can vary from province to province; but within any province the same intensity of mineralization would produce similar deposits in different places. Declining intensity of minetalization produces different kinds and sizes of deposits in zones that are concentrically arranged around sites of strongest rock alteration. On a regional basis, districts of similar average intensity of mineralization occur in zones that generally parallel some tectonic grain with the result that tectonic deformation has been designated a principal cause of mineralization. Variations in the type and intensity of deformation would determine the type as well as size of metal deposits. Mexico is especially favorable for such a study be- cause of its great abundance and variety of epi-genetic mineral deposits in various lithologic, structural and tectonic environments. The concept is also useful in recognizing portions of Mexico favorable for the occurrence of specific metals. METALLOTECTONIC ZONING IN MEXICO Theory: In studies of individual districts and groups of districts throughout North and South America, areal zoning of metal deposits generally seemed to respond to the paragenetic sequence of iron, gold, copper, zinc, lead, silver, antimony and arsenic, gold and fluorite. However, the definition of district zones is greatly obscured by contemporaneous or rhythmic deposition of metals, especially in the middle of the paragenetic range, and by the common superimposi-tions of different generations of metals. Zones could usually be distinguished only for groups of metals, such as early precious metals, base-metal sulfides, sulfosalts and late precious metals. The best defined zoning in a district is normally the spatial separation of the greatest volumes of altered and metallized rocks.' Exceptions are districts representing the high- and low-temperature extremes of the mineralization range where the former creates a matrix for the latter. In most districts the total quantity of alteration products is greatly in excess of, and appears to be roughly proportional to, the total quantity of metallization products. Subsequent to the bicomponent nature of each district, the most important mineralogical feature is the great excess of one to several metals or minerals which results in a district identifiable as one of predominantly gold, copper, lead-zinc, fluorite, etc., although a great variety of other elements may be present. The para-genetic range for the abundant elements in any district is only a portion of the entire possible range for all the elements representing the complete process throughout the region. Early during investigations of this type, it became apparent that the consistent bicomponent character of districts allows two methods for studying epi-genetic mineralization patterns. One is to identify and plot altered rock "pipes,"* which are easily recognizable in the landscape by their anomalous

Jan 1, 1969

By D. Kump

The Bullfrog Mine is an underground gold mine that uses the underhand-cut-and-fill mining method. The portal was established on June 18, 1991. Mining is expected to be completed by the summer of 1999. This paper starts by discussing what it took to get from nothing to 2000 tons-per-day backfill, and ends with a hindsight commentary on things that did and did not help.

Jan 1, 1999

By Dale K. Fields

With today's technological advances in mineral processing equipment, there is an increasing demand for accurate system control. This can only come about through representative sampling. The purpose of this paper is to guide in the selection of sampling equipment and outline design parameters for the cutters used in dry and wet sampling without adding redundant mathematical probability formulas. Special attention will also be given to the equipment wed in conjunction with samplers and sampling system, such as feeders, crushers, chutes, launders, and controls.

Jan 1, 1980

Mineral formations, accumulated during technogenic activities greatly influence an economic and ecological situation in the Kola North. On the one hand, the dumps from extraction of mineral resources, tailing ponds of beneficating plants, ash dumps, wastes of metallurgical and mechanical engineering productions destroy the regionÆs environment and require taking certain measures and costs to bury or protect from weathering, oxidation, etc. On the other hand, technogenic mineral formations contain a lot of valuable scarce components. The amount of solid wastes increases annually, causing damage to ecology and economy. Researches conducted in recent years showed a possibility and economic expediency of comprehensive processing of wastes from different enterprises in Murmansk region and their use for production of new competitive commodity output, possessing high consumer properties. Thus, involving mineral wastes from Khibiny apatite deposits into hydrometallurgical industrial processing provides the basis for setting up a large beneficating-metallurgical complex. In this case ores and wastes from other deposits on the Kola Peninsula, containing titanium, rare, rare-earth and other valuable elements, may be involved into processing. Establishing such a complex will allow to organise a deep processing of natural resources, utilise some production wastes, improve ecological security and supply production with competitive output. Expanding the complex implies not only involving new mineral raw material into processing, but mainly deepening raw material processing, maximum utilisation of local natural resources and obtaining a wider variety of prime products.

Jan 1, 2002

By William A. Price

The objective of this paper is to outline the approaches used in British Columbia to address the challenges posed by metal leaching and acid rock drainage (ML/ARD). Challenges include the large financial costs, the need for site-specific assessments, the large information requirements, the need for mitigation measures to be designed and financed in a manner that permits long-term performance, the lack of long-term operating experience, the ongoing changes in many important processes, the need for pro-active detection and resolution of concerns, difficulties in predicting the potential for ARD or significant metal leaching, the need for new tools, and the multidisciplinary, highly specialized nature of the work. Consequently, mines must be planned, operated and closed in a manner that permits regular review, detailed monitoring and adaptive management. Proper consideration of the challenges involved, including a plan of how all outstanding concerns will be addressed, studies to address areas of significant uncertainty and caution in the absence of the required understanding, should ensure environmentally safe practices in the future.

Nov 1, 2002

By William T. Boyd

Foreign mining publications describing successful hydraulic mining installations, and successful domestic hydraulic mining in a gilsonite bed, have prompted the Federal Bureau of Mines to conduct a literature survey of foreign publications to determine if the hydraulic mining method can be applied to domestic coal mining. Most foreign publications do not give detailed data about the water pressures, water capacities, and production and manpower requirements for successful hydraulic mining, However, they do provide enough general data on mining conditions, manpower, and equipment used to show that conditions in many bituminous coal deposits in the United States may be favorable for economical coal extraction, using high-pressure water jets. Therefore, the Bureau proposes to conduct a field investigation to determine the most appropriate natural conditions, water pressures, and equipment for successful hydraulic mining of coal beds in the United States with variable dip, thickness, and hardness. In the past, technical personnel reviewing foreign mining reports assumed that a steeply pitching coal bed was necessary for successful hydraulic mining. Although the structure of the coal bed may be a factor in gaining assistance from overburden pressures or help in an integrated hydraulic mining and transportation system, the coal is broken mainly by the action of high-pressure, water-penetrating cracks, fissures, or cleats; therefore, the slope of the coal bed is not necessarily a determining factor in hydraulic mining.

Jan 1, 1959

By Erie F. Wolstenholme

The purpose of this paper is to describe work undertaken, within the System Dynamics Research Group at Bradford Management Centre, into the development and application of a System Dynamics model of an international mineral industry; aimed at providing a basis for analysis of the interrelationship of supply, consumption and price over time, under different production and stocking policies. A review is presented of some of the major characteristics and problems associated with such industries. This is followed by an outline description of the model and the way it has been applied to examine various supply responses, in the light of changing consumption patterns. Demonstration results deal with model validation and with analysis of international buffer stocks and conflicting supply policies on the historic situation in the copper industry.

Jan 1, 1979

By Lowell L. Patten

The Federal Bureau of Mines participated with the National Aeronautics and Space Administration and Martin Marietta Aerospace in developing, building, and testing a portable X-ray fluorescence spectrometer for use as an analyzer in mineral-resource investigative work. The prototype battery-powered spectrometer, measuring I1 by 12 by 5 inches and weighing only about 15 pounds, was designed specifically for field use. The spectrometer has two gas-proportional counters and two radioactive sources, 109Cd and 55Fe. Preliminary field and laboratory tests on rock specimens and rock pulps have demonstrated the capability of the spectrometer to detect 33 elements, to date. Characteristics of the system present some limitations, however, and further improvements are recommended.

Jan 1, 1982