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By Robert Thomas

DURING the past 20 years the advantages of reinforced concrete as a substitute for timbering in so-called permanent mine openings have been fully recognized, and its use has become almost general practice in the larger mines. The term "permanent mine openings" is used advisedly and is assumed to embrace such openings as ventilation shafts, material shafts and main hoisting shafts, with their adjacent stations, ore pockets, etc. In the concreting of such openings, the actual cost as compared with that of timbering has been of secondary consideration, the support of large openings, elimination of fire hazards, and prevention of inter-ruptions to production being the primary objectives. The ultimate economy, however, of lining such openings with concrete when they are to remain in use during the entire life of the mine, and especially when they are in bad ground, will seldom be questioned. During this 20-year period there have appeared in engineering publi-cations a number of interesting articles on the use of concrete in mines, nearly always describing some specific project of major proportions, such as the concreting of ore pockets, large stations or main hoisting shafts. Such articles are unquestionably of interest, since the projects require considerable engineering thought, not only in the method of excavating large openings, but in their engineering design as well. Concreting of main hoisting shafts, particularly when this is done with the least possible interruption to production, provides some interesting problems. The concreting of haulage drifts of the dimensions commonly found in mines, on the other hand, soon develops into a routine operation, there-fore it is with some hesitancy that the author attempts to prepare an article on this subject. The writer can recall only one article on the concreting of mine haulageways, although several articles have been written concerning the concreting of tunnels considerably larger in dimensions than those required in general mine practice.

Jan 1, 1936

By L. J. Cabri

Although no complete mineralogical balances have been published, the background knowledge and proven, highly sensitive analytical techniques to produce them already exist. For PGE-Cu-Ni sulphide ores a combination of ore microscopy, image analysis and electron microprobe analysis with proton microprobe analysis of sulphides for Pd, Rh and Ru and ion microprobe analysis for Pt, Ir and Rh (in some minerals) should provide the necessary data when combined with reliable assays. Other sulphide ores, such as the Cu-Ni-(PGE) ores of Sudbury, Ontario, require a similar approach except that the ion microprobe would be more suitable for the analysis of Pd, Pt and Rh because of its greater sensitivity. Oxide-silicate ores may be harder to deal with quantitatively, although the potential to confirm the presence of trace PGE within silicates and oxides may be greater than in PGE sulphide and Cu-Ni-(PGE) sulphide ores. However, solid solution of PGE in oxides and silicates still requires thorough documentation and evaluation in terms of their significance for the overall metallurgical balance

Apr 1, 1994

By C. W. Owings

"PURPOSE OF REPORTMany bituminous coal-mine officials realize that coal dust presents an ever-present coal-mine explosion hazard, and that persons forced to breathe large quantities of it may be more subject to respiratory infection than persons working in less dusty atmospheres. As an outgrowth of the realization that coal dust should be allayed at its source, many mining companies have expressed the desire to install dust-allaying equipment, and in a number of mines, water or wetting solution is being applied on the cutter bars of mining machines, on mobile loaders, belts or conveyors underground, and tops of mine cars. Spraying equipment also has been installed on dumps to allay dust during dumping operations. Dust-allaying equipment has not been standardized, however, because manufacturers have found that many prospective purchasers of such equipment have different ideas. These manufacturers wish to standardize, so far as feasible, the types and placement of such equipment. Many mine officials, although interested, do not know the best or most effective methods for allaying dust.For a number of years the Bureau of Mines has advocated allaying dust by applying water or, more recently, water modified by a wetting agent on the cutter bar of mining machines and by applying water to loaded and empty mine cars in order to keep as much dust as possible from spilling onto the haulage roads. In recent years this Bureau has also advocated applying water with or without a wetting agent during mechanical loading of coal and during unloading of coal from trackless cars or buggies and from elevating conveyors. It has now become apparent that specific arrangement of pipes, hose, and nozzles should be standardized to at least some extent. It is the purpose of this report, therefore, to give in detail suggested arrangement of dust-allaying equipment in the hope that both manufacturers and mine officials will have available dust-allaying equipment with maximum efficiency to do the desired work."

Nov 1, 1945

By J. W. Walkiewicz

The U.S. Bureau of Mines has conducted studies using microwave energy to stress-crack iron ores. In a microwave chamber which simulates a continuous throughput operation, the Bond grindability of a taconite sample was improved by 13 pct at a bulk temperature of 197? C. To further improve the economics of microwave fracturing, higher powers up to 16 kW were used to rapidly heat samples to relatively low temperatures in a continuous belt-fed applicator. A significant enhancement of grindability was obtained with a minus 1.9-cm taconite rod mill feed. At a sample temperature of 130? C, the grindability was improved a maximum of 26.1 pct over the non-microwaved sample.

Jan 1, 1993

By McHenry Mosier

Mechanical loading, adopted long ago in open-pit, coal, and non-metal mines, was not used extensively in underground metal mines until the World War. In less than a decade it became standard practice in underground work in many mining districts. In 1924 the Missouri School of Mines and Metallurgy, in cooperation with the Federal Bureau of Mines, published a bulletin entitled "Mechanical Underground Loading in Metal Mines," which was prepared by Charles E. van Barneveld, mining engineer, Bureau of Mines.

Jan 1, 1940

By Wendy L. Naysmith

This paper deals with the various options considered and factors that influenced the final selection of the headframe, shaft layout and hoisting systems required at the Impala No 16 Shaft in order to hoist both the required 3 Mt of ore per annum, and transport men, material and equipment between the surface and the underground workings to a depth of 1640 m. The layout and construction method used for what is at present the world?s tallest concrete headframe is discussed together with the integrated hoist room foundations designed to suit multiple mechanical and electrical hoist supplier?s solutions. The mechanical components of the two tower mounted 6,5m 4 rope Koepe hoists and deflection sheaves and their layout is dealt with in detail. Various features of the bearing type, brake units and brake control system are also discussed. Installation of the mechanical and electrical hoist equipment in the headframe took place during the sinking phase of the project and placed severe restrictions on the use of the heavy lifting facilities. This required a well-managed and systematic approach to delivery of the hoist components and associated equipment, as well as close co-operation between all contractors on site.

Oct 1, 2010

By Orlando Martino

This regional report covers the mineral industries of Canada and 40 countries and areas in Latin America and the Caribbean Basin. Also included is a brief description of the mineral potential of Antarctica. The Latin American region encompasses an area twice that of the United States. Latin America and Canada have a rich and diversified endowment of mineral fuels, metals, and industrial minerals. Tables 2 and 3 provide a summary view of the importance of Latin America and Canada's output of its major mineral commodities in world mineral supply in 1989 and 1990.

Jan 1, 1993

By Joseph D. Davis, GEORGE S. POPE

This bulletin is the fourth of a series a showing the results of the purchase of coal by the Government under specifications. The work of inspecting and analyzing coal delivered on Government contracts was transferred to the Bureau of Mines by an act of Congress effective July 1, 1910. It had been carried on for several years before that date by the technologic branch of the United States Geological Survey. The purchase of coal on the dealer's statement as to quality or on the reputation of the mine or district producing the coal is gradually being discontinued. At present most coal-purchasing contracts make definite provision regarding the desired heating value of a coal and the composition as shown by analysis. The heating value is usually expressed in British thermal units" and the composition specified is that shown by proximate" analysis. The price to be paid for delivered coal is made to depend on whether the analyses and heating-value tests of samples representing the delivery show the quality to be above or below the quality set forth in the contract. Large coal consumers are beginning to appreciate more and more the importance of the cost of power as a factor in the cost of producing a finished article. The endeavor to increase the efficiency and the economical operation of a power plant calls for an intimate knowledge of the quality of the coal being used. The purchase of coal under specifications insures the purchaser getting what he pays for and the coal being of the quality guaranteed. In addition, the analyses and tests of the delivered coal furnish data whereby the power-plant results can be comprehensively studied and a continuous check maintained on the conditions of operation.

Jan 1, 1912

The Ministry of Commerce has been carrying out an evaluation of the resources of the Northwest Nelson region. In part this was to revisit the issues covered in the earlier proposal to close part of Northwest Nelson to mining under section 24 of the Mining Act (1971) initiated in 1990. In addition, the option of using GIS to integrate a variety of spatial data sets to aid policy formulation could be tested. The Northwest Nelson assessment would be a useful trial. The subsequent national park proposal provided a major impetus to the project and resulted in the scope of the study being broadened to include all energy and minerals resources.

Jan 1, 1993

By A. H. Daane, B. J. Beaudry

The Sc-Y and Sc-Zr systems were studied by thermal and X-ray methods. Both systems are characterized by complete solid solubility in the low temperature hexagonal form and in the high temperature bcc form. In the Sc-Y system, there is a minimum in the solidus at 50 at. pct and 1365°C, while the solidus in the Sc-Zr system follows a nearly straight line relationship between the melting point of scandium and zirconium. There is a minimum in the temperature of transition from hexagonal to bcc in the Sc-Y system at 43 at. pct Y and 1175°C; while the temperature of transition is raised in the Sc-Zr system to a maximum of 1415 °C at 30 at. pct Zr. INTEREST in the metals of the first transition series has usually stemmed from their useful properties; however, there is now a great deal of interest in determining the fundamental nature of these metals. Since scandium is the first of these transition metals, a study of the preparation and Properties1 and the alloying behavior of scandium2 was initiated. In a continuing study of the alloying behavior of scandium, the systems of scandium with zirconium and yttrium have been established. Extensive solid solubility in both the Sc-Zr and Sc-Y systems was expected from application of the classical rules of Hume-Rothery. Also, the modified Darken and Gurry plot as suggested by Gschneid-ner3 showed ideal conditions for solubility in the Sc-Zr system with less favorable conditions in the Sc-Y system. The effect of scandium on the transformation temperature of zirconium and yttrium was of interest, since a recent empirical observation by Uly and Burr4 predicted that the solute scandium would raise the transformation temperature of zirconium and lower the yttrium transformation. In addition to noting the validity of the above predictions, the SC-Y and Sc-Zr systems were established. EXPERIMENTAL METHODS Materials. The metals employed in this investigation were crystal bar zirconium, distilled scandium prepared by the method described by Spedding, et al.1 and yttrium prepared by the method described by Carlson, et a1.5 The major impurities present in these metals are listed in Table I in ppm. Alloy Preparation. All the alloys examined were initially formed by comelting the two metals in a nonconsumable electrode arc-melting furnace under an atmosphere of purified helium or argon. The buttons were inverted at least five times and re-melted each time to ensure homogeneity. During preparation of Sc-Zr alloys, approximately 1 wt pct was lost which was attributed entirely to the loss of scandium by distillation. When preparing Sc-Y alloys, approximately 1.5 wt pct was lost, but it was assumed that the intended composition was maintained, since the relative weight lost when arc melting the component metals was nearly the same. Samples weighing 15 to 20 g were prepared for time-temperature thermal analysis, while only 1- to 2-g samples were prepared for the optical pyrometer and X-ray diffraction studies. Thermal Methods. The solidus and the melting points of the metals were determined by an optical pyrometer method described previously.2 The temperatures at which the transformation from hexagonal to bcc occurs were determined by differential thermal analysis. Several points on the solidus and liquidus in the Sc-Y system were also determined by this method and are in good agreement with those obtained by the optical pyrometer method. The procedure followed in the preparation of samples for thermal analysis and the furnace used have been described elsewhere.2'6 Since a limited quantity of scandium was available, most of the alloys were not melted during thermal analysis, thus avoiding contamination by the crucible. The alloy could then be reused and the composition changed by adding the desired quantity of solute to obtain the next alloy. Heat Treatment and X-Ray Methods. In order to ensure homogeneity, the "as arc-melted" alloys Were wrapped in tantalum foil, sealed in quartz capsules and heated at 1100°C for 15 hr and then cooled at a rate of 8 deg per min. Samples for X-ray diffraction were filed from these heat-treated alloys, sealed in 1/8 in. by 1/2 in. tantalum capsules under

Jan 1, 1963

By W. A. Stickney

This report summarizes the results of laboratory tests of five samples of low-grade phosphate ores from Idaho. The laboratory test work has demonstrated that by grinding, desliming, and flotation a portion of the siliceous gangue can be removed. The highly carbonaceous ores responded successfully to treatment after preroasting, to produce a plus-30-percent-P205 product. It has been found that highly siliceous ores, as represented by the samples treated, are more readily amenable to concentration than ores high in calcium carbonate. Of the five samples tested, four were amenable to concentration to a product containing over 30 percent P205. One sample, from the Conda, second bed, was not amenable to mineral-dressing treatment to produce a plus-25-percent-P205 product.

Jan 1, 1955

By R Tweedie

'The politics of mining in New Zealand' is a topic I chose myself because of its importance in the future of the New Zealand mining industry. There are many people in the industry who are cynical about politics, cynical about politicians and definitely cynical and often critical of political decisions. In fact, many industry people say they don't want to get involved in politics, they just want to get on with the business of exploration or mining. The point of my address is that politics is important and the industry cannot afford not to participate in the political process.

Jan 1, 1991

By M. Soleymani Shishvan

"Continuous mining systems containing multiple excavators producing multiple products of raw materials are highly complex, exhibiting strong interdependency between constituents. Furthermore, random variables govern the system, which causes uncertainty in the supply of raw materials: uncertainty in knowledge about the reserve, the quantity demanded by the customers, and the breakdown of equipment. This paper presents a stochastic-based mine process simulator capturing different sources of uncertainties. It aims to quantify the effect of geological uncertainty and its impacts on the ability to deliver contractually defined quantities and qualities of coal, and on the system efficiency in terms of utilization of major equipment. Two different areas of research are combined: geostatistical simulation for capturing geological uncertainty, and stochastic process simulation to predict the performance and reliability of a large continuous mining system.The process of modelling and simulation in this specific production environment is discussed in detail. Problem specification and a new integrated simulation approach are presented. A case study in a large coal mine is used to demonstrate the impacts and evaluate the results in terms of reaching optimal production control decisions to increase average equipment utilization and control coal quality and quantity. The new approach is expected to lead to more robust decisions, improved efficiencies, and better coal quality management.IntroductionContinuous coal mining systems containing multiple excavators producing multiple products of raw materials are highly complex and exhibit strong interdependencies between constituents. A network of conveyor belts is used for transportation of the extracted materials to different waste dumps or the coal stockpile.Optimal decision-making in short-term planning and production control are impacted mainly by geological uncertainty associated with incomplete knowledge of the coal deposit represented in the reserve block model. These uncertainties cause deviations from expected process performance. For more robust decision-making, understanding the impacts of these stochastic elements plays a key role."

Jan 1, 2016

By Shreyas Giridharan, Fursan Hamad, Sujith Gowda, Christian Moormann

"Pile installation in soil is a dynamic process which exhibits large deformation in the soil region. Experimental investigation of pile installation is both time and resource intensive. Numerical investigation can be a helpful tool for the analysis of the installation process. Furthermore, numerical analysis allows simulating various soils and loading conditions with ease. Finite Element Method (FEM) – a widely used framework for numerical simulations - fails to perform well for soil mechanics where large deformation and heavy material movement exists. In order to alleviate this shortcoming, Material Point Method (MPM), advancement to FEM has been used. In MPM, material points (particles) are used to represent the domain which carry the information and move over a fixed computational mesh where the governing equations are solved.In the present work, a variation of MPM, called CPDI (Convected Particle Domain Interpolation) is utilised which handles large deformation problems better than the classical MPM. Here, the material points are represented by a spatial domain which deforms according to the particle deformation. This eliminates stress oscillations while particles cross the grids. Implementation is validated and applied to pile installation in dry and saturated soil conditions. A 2D axisymmetric model is chosen, with penalty function method being used for evaluating contact between soil and pile. Sand is modelled via the hypoplastic constitutive description that takes into account large deformation, as well as small strain stiffness. From these simulations, various parameters like stress, void ratio and friction angle are studied.INTRODUCTIONOffshore piling is challenging in terms of testing and execution. Before the execution, predicting an efficient installation method requires study of various parameters, like soil conditions, type of loading, force requirement etc., and are the minimum parameters to be known beforehand. To obtain these parameters, testing a real scale prototype under different conditions is not feasible. Scaled model tests in lab can support in making certain decisions, but fail to replicate real behavior fully. Therefore, the need for a numerical simulation technique emerges, which can provide early predictions easily and accurately. This later can be extended to real scale tests, reducing the number of experimental investigation required.Simulation of displacement pile installation in sand involves large deformation due to penetration process, thereby making the application of FEM impossible, where large deformation causes heavy mesh distortions. Due to this, meshless methods are developed to treat large deformation in a better way. Among various meshless methods, Material Point Method (MPM) shows more applicability to geomechanical problems. This is mainly due to the ease of handling soil, structure and water in a unified manner."

Jan 1, 2017

By Berger

A detailed description is given of radio apparatus for controlling a coincidence outfit for relative gravity measurements. This is probably of little interest, since many types of apparatus could be used. The general method employed is the interesting thing about this paper. As long ago as 1883 von Sterneck made a proposal to control two coincidence boxes with the, seine, clock, and many persons have suggested the use of radio for this purpose. In accomplishing this it would appear to the reviewer that this method is probably inferior to that used by the Marland Oil Co., but Berger and Brückner must be given the credit for important advances in the coincidence method. In their apparatus a clock at a central station actuates a relay, which operates a short-wave transmitter (40 m.). At the receiving station the amplification is accomplished at low frequencies... The signal operates a relay which moves a slitted screen in a coincidence apparatus. This screen has been improved considerably, to decrease the mean error in observing a coincidence. As usual, a telescope is used to observe the flashes of light. It has a scale in its focal plane and positions of successive flashes are easily read off and recorded by a second observer. This makes possible' a: higher accuracy in determining the exact instant at which coincidence would have occurred at the zero point on this scale. This method obviously depends on the constance of the mechanical and electrical lag inn both sending and receiving apparatus, and may be adversely criticized from this standpoint. -- A. E. Ruark.

Jan 1, 1929

By L. C. Brichta

During a study of the Badger-Peacock area from October 1950 to June 1953, the Federal Geological Survey and the Federal Bureau of Mines completed nearly 98 miles of resistivity profiling and drilled 96 test holes aggregating 17,628 feet of bore, In addition, seismic profile measurements were made along 8 traverse lines for an aggregate length of about 16,600 feet. The geophysical surveys were conducted by the Geophysics Branch of the Geological Survey; the drilling was done by the Bureau of Mines. Electrical-resistivity measurements disclosed 21 low-resistivity anomalies and 1 high-resistivity anomaly. Correlation of the resistivity data with the geological information revealed by the drilling disclosed that the low-resistivity anomalies indicated either slumped shale deposits in limestone sinks or undisturbed deposits of shale lying in erosional depressions in the limestone. The high-resistivity anomaly indicated hard, undisturbed limestone at or near the surface.

Jan 1, 1958

By G. L. Oldright

This paper is the thirteenth of the series on Smelting in the Lead Blast furnace, and the third of the series on Handling Zinciferous Charges. Two other papers have been written on the Rate of Descent of the Stock Column, and Formation of Accretions. These are Reports of Investigations 2963 and 3094, for the Tooele plant and the Bunker Hill plant, respectively.

Jan 1, 1934

By G. L. Oldright

The data in this paper were collected at the Trail smelter of the Consolidated Mining & Smelting Co. of Canada, Limited, through the courtesy of S. G. Blaylock, vice president and general manager; James Buchanan, smelter superintendent; George Murray, assistant smelter superintendent; and the staff members given in Paper XI, Report of Investigations 3243. INTRODUCTION This paper is the thirteenth of the series on Smelting in the Lead Blast Furnace, and the third of the series on Handling Zinciferous Charges. Tyro other papers have been written on the Rate of Descent of the Stock Column, and Formation of Accretions. These are Reports of Investigations 2963 and 3094, for the Tooele plant and the Bunker Hill plant, respectively.

Jan 1, 1934

By Robinson KJ

Education in Australia now has to respond to a very wide political and policy agenda. The political emphasis is upon increasing participation and retention rates with a view to greater graduation rates in `high-tech' disciplines. There is an implied linkage between `education' and `economic well-being'. Our argument is that equalitarianism in education tends towards mediocrity. In this context many Geoscience educators view the future with pessimism. The argument is that science has been `sold short' and needs revitalising. We contend that Geoscience coursework should be a feature of both secondary and tertiary education in Australia. To this end we propose six policy initiatives to increase the content of Geoscience in education programmes.

Jan 1, 1989

By Charles Zahn

Direct mass spectrometric determination of alcohols in the presence of hydrocarbons has not been possible because of the similarity of hydrocarbon and alcohol mass spectra. Experiments have demonstrated that by converting the alcohols to their trimethylsilyl derivatives, characteristic mass spectra are obtained free of interference from hydrocarbon ion fragmentation. Hexa- methyldisilazane is the reagent selected for the conversion, An improved method of preparing the reagent is given, Mass spectrometric determination of alcohols as trimethylsilyl ethers now is not only possible without prior separation from other materials, but the range of the room-temperature mass spectrometer is also extended to include the C10 alcohol region. Water does not interfere because it is converted to hexamethyldisiloxane, which has its own distinctive mass spectral peak, Experience indicates that other compounds such as glycols, amines, and phenols probably could also be determined by mass spectrometry of their trimethylsilyl ethers. Studies on the similar detemination of phenols in coal oils have been started, When mass spectrometry is not available, gas-liquid chromatography of alcohols before and after their conversion to the trimethylsilyl derivatives probably could be performed. The preparation and properties of the trimethylsilyl derivatives of 23 alcohols, 2 glycols, 3 amines, and 1 mercaptan are detailed. INRODUCTION During investigations by the Bureau of Mines at the Pittsburgh Coal Research Center relative to the development of Fischer-Tropsch processes, complications were encountered in the mass spectrometric analysis of alcohols in hydrocarbon oils. The fragmentation peaks of the alcohols and the hydrocarbons were so similar that an accurate analysis was not possible, Since involved separation techniques are necessary to isolate alcohols from hydro-carbons for separate determinations, efforts were turned to the search for a

Jan 1, 1962