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By Earl T. Hayes

THIS BIBLIOGRAPHY has been assembled to aid research by the Bureau of Mines, and others on high-purity tungsten. It appears approximately 50 years after the development of ductile tungsten-one of the first metals to be produced in a high-purity form. Requirements of the missile age are ever more demanding that engines rout hotter and space vehicles fly higher and faster. Thus, it has become necessary to reexamine all conventional materials of construction as well as to investigate new combinations. At this stage of our technology we have alloys capable of operation at 1,800° F. and several possibilities of developing some. that will be satisfactory up to 2,500° F. Strength-weight comparisons, detrimental to tungsten at, lower temperatures, disappear at this point, mid tungsten or its alloys appear to be the only metal capable of operation at truly high temperatures. The aim of this bibliography has been to include only references that concern improving the purity of tungsten-from processing the ore to treating the finished metal. In this sense it is a selected and not a critical bibliography. The period front January 1911 through February 1959 has been covered. Because repent literature has the greatest, value, most of the selected items refer to publications issued within the pest 5 years.

Jan 1, 1960

By John W. Fredland

Many accidents occur in the mining industry as a result of the instability of material during handling and processing operations. Accidents due to dump point instability at stockpiles, and at spoil or waste piles, for example, occur with alarming frequency. Miners must be trained to be better aware of these hazards. Information on safe working procedures at stockpiles and surge piles is provided. Mine operators must review their training and operating procedures regularly to ensure that hazardous conditions are avoided.

Jan 1, 1993

The optimum cut-off grade policy maximizes the net present value (NPV) of an open pit mining operation subject to the mining, processing, and refining capacity constraints. The traditional approaches to cut-off grade determination ignore the escalation of the economic parameters such as metal price and operating costs during life of an operation, and consequently lead to unrealistically higher values of the objective function. Further, the NPV of a mining operation declines due to the depletion of the available reserves, causing a decline in the optimum cut-off grade, i.e. higher cut-off grades in the early years of an operation and lower cut-off grades during the later years. Hence, low grade material mined in the earlier years may be stockpiled for processing during later years to offset the effect of escalating economic parameters on NPV. This paper demonstrates the combined impact of introducing economic parameters, escalation and stockpiling options into the cut-off grade optimization model. The model promises an enhancement in NPV as illustrated in a case study incorporating practical aspects of an open pit mining operation.

Jan 1, 2011

By Milford L. Skow

MICA is a group name for a number of complex hydrous aluminum silicate minerals that have a sheet or platy structure and extremely variable and complex compositions containing various metallic ions, particularly those from the alkali group. Muscovite and phlogopite, the two varieties of significant commercial value, are the principal consideration of this report; muscovite has major importance industrially. The mica crystal, because of its laminated structure, can be split easily and accurately into thin films that are transparent, flexible, elastic, tough, and waterproof and have outstanding dielectric and insulating characteristics. This combination of properties is not duplicated in any other known substance. The world production of mica can be divided into two main classifications: (1) Sheet mica and (2) scrap mica (including flake mica). In general, separate divisions of the industry produce these two classes of mica, which differ widely in their uses and in the forms in which they are marketed. A glossary of mica terminology is given in appendix A.

Jan 1, 1962

By Stephen A. Orr

Underground mining is a dynamic art and science with a diverse set of design, production, and economic criteria that must be considered before selecting an optimal method to extract the ore. While all methods can be technically classified as either self-supported, supported, or caving, the multitude of subsystems and existing variations bear witness to the fact that each orebody is unique and, as such, justifies an individual approach to optimize mineral extraction. In this sense, underground mining is an art. The ability to evaluate the unique characteristics of each ore body and utilize sound engineering principles to design the optimal system constitutes effective method selection. The task by no means ends at this juncture, however. Subsequent implementation requires an ability for modification. Very rarely are all the facts available to make a concrete decision prior to development of the resource. As a result, the risk of a wrong decision can never be eliminated. This requires a significant degree of flexibility with each method. Each unit of exploration, development, or exploitation work contributed to a deposit enhances knowledge of the ore body. The best mining methods are those that correctly account for the known parameters but provide an allowance for change at minimal cost and adapt to unanticipated conditions.

Jan 1, 2008

Identifying Opportunities to Reduce the Consumption of Energy Across Mineral Processing Plants

Sep 13, 2010

By Xiaofei Guan, Adam C. Powell, Uday B. Pal, Srikanth Gopalan

This paper reports a solid oxide membrane (SOM) electrolysis experiment using an LSM– Inconel inert anode current collector for production of Mg and O2 at 1423K. The electrochemical performance of the SOM cell was evaluated by using various electrochemical techniques including electrochemical impedance spectroscopy, potentiodynamic scans, and potentiostatic electrolysis. The effects of Mg solubility in the flux on the current efficiency and the YSZ membrane stability during SOM electrolysis were discussed and examined through experiment and modeling. The electronic transference number of the flux were measured to assess the Mg dissolution in the flux during SOM electrolysis. A negative correlation between the electronic transference number of the flux and the current efficiency of the SOM electrolysis was observed.

Jan 1, 2014

This report provides concepts for two automated longwall mining systems; one for operation in a 42 to 57-inch thick section of the Lower Kittanning coal seam, the other in a 57 to 72-inch thick section of the Pittsburgh seam. The Lower Kittanning concept uses a single-drum bidirectional shearer and 500-ton capacity 4-leg chocks and the Pittsburgh concept uses a double-drum shearer with 500-ton shields. Each concept is designed to produce in excess of 2,500 tons of clean coal per shift with a 6-man face crew. The automated longwalls consist of off-the-shelf control system hardware attached to standard longwall equipment. Control hardware includes a control and display console; prime and backup mini-computers; multiplex data transmission, power, and control lines; several remote terminals which serve as interface junctions; and various sensors and actuators located on the longwall equipment. The system can be operated either fully automatically, remotely or manually.

Jan 1, 1976

By Hamid Maleki

A comprehensive study consisting of stress determinations, core logging, laboratory testing, and numerical analyses was conducted to investigate the cause and potential alternatives to the coal bump conditions that developed in the Second North Panel of the Little Dove mine near Buntington, Utah. Roof rock characteristics were such that a cave did not develop above this 420 ft wide panel. After 700 ft of pillar retreat, severe coal bump conditions developed during pillar mining. The coal bump conditions resulted from excessive pillar stress which was caused by load transfer from the extracted, noncaving, portion of the panel. Site specific data and numerical modeling techniques were used to back-analyze the bump prone condition. This back- analysis lead to the identification of critical stress, closure, and energy release levels. These critical levels were then used to evaluate alternative pillar mining sequences in the hope that the potential for coal bumps could be reduced. It was found that while alternative sequences offered some potential improvement over the pillar mining sequence used in the mine, alternative pillar mining sequences would not significantly reduce the potential for bumps. For the roof characteristics at this mine, coal bumps are best avoided by developing narrow panels or significantly wider panels, which incorporate properly sized barrier pillars. Narrow panels, on the order of 300 ft, would not cave, but panel pillar stresses and the potential for umps would be moderated by the reduced r' panel width. Wider panels, of approximately 650 ft, would allow a cave to develop, also reducing panel pillar stresses and coal bump potential.

Jan 1, 1987

By J. E. Johnson

IT is the purpose of the present paper, while not excluding chemical considerations, to deal more extensively with some of the physical and mechanical aspects of the blast-furnace process, and to point out its dependence in these respects on well-known laws. The quantity and cost of ore and flux required to make a ton of iron being determined by circumstances over which the furnace-man, under given conditions as to quality and quantity of product, has commonly little control; the principal item of cost, apart from the saving of labor, which he can aspire to reduce, is that of fuel. To determine the limits of possibility in this direction is clearly the first step in d practical inquiry; and this step is represented herewith in Fig. 1, a diagram showing the total useful effect obtained from a pound of fuel under various conditions, and thus permitting direct comparison, under any given conditions, between actual results and the maximum possible results. The following statements will explain the basis upon which this diagram has been constructed. One pound of fuel, containing 90 per cent. of fixed carbon (which represents average conditions), is taken as the unit. The degree of oxidation of the carbon is measured by the ratio of the two oxides of carbon contained in the top-gases. It is necessary to remember that a considerable quantity of carbon is brought in as carbon dioxide by the flux, and to take account of it and of its condition. It is here considered that the carbon dioxide liberated by the limestone does not affect the analysis of the toll-gases, and that the ratio of CO to CO., will remain unchanged by the addition of limestone; enough CO, being reduced by the solution

Sep 1, 1905

By H. H. Schrenk

The purpose of respiratory protective equipment is to prevent the inhalation of harmful or objectionable atmospheres. Although constituents or contaminants that may render an atmosphere irrespirable or objectionable are numerous, they may be classified broadly as follows: I. Gaseous substance: n. A. Toxic. B. Inert (oxygen deficiency). II. Particulate matter (dispersoids). A. Solid. a. Dust (formed by disintegration). b. Pure (formed by condensation). B. Liquid. a. Mist (formed by disintegration). b. Fog (former by condensation).

Jan 1, 1940

By William O. Vanderburg

[This circular is one of two papers on the tungsten industry in the United States end contains general information on the subject. The second paper which will be issued in the near future deals with the methods ailed costs of mining and milling tungsten ores. These two papers are abstracts from the general bulletin on tungsten which will be issued at some future time Modern civilization and progress depend largely on tools wherewith the forces of nature are brought under control and directed toward human comfort. These tools are made chiefly from metals derived from the earth's crust. During the present century powerful tools have been made available through the development of ferrous and. nonferrous alloys containing such elements as molybdenum, vanadium, titanium, tantalum, and tungsten, which were little used before 1900. One of the most important of these so-called rare elements is tungsten; its use ins alloys for high-speed cutting tool is partly responsible for the era of mass production. So widespread has the use of alloys become that the period may be termed an "Alloy Age".]

Jan 1, 1935

By Dexter C. Hatch

At MacIntyre Development of the National Lead Company, Taha s, New York,, the flotation plant was set up to recover ilmenite from the finer size fraction of the ore that cannot be efficiently treated in the main gravity-magnetic separa¬tion process. It was later expanded to handle the reground middlings from the tables wetherill magnetic separators. The ilmenite-magnetite ore is ground to minus 20 mesh in five 6 x 12 ft. rod mills in closed circuit with DSM screens. The minus 20 mesh screen undersize is pumped to four parallel sections each consisting of two rougher wet-magnetic separators and one cleaner separator for magnatite removal. The screen undersize from the fifth section is distributed to all four sections. The magnetite removed in the roughers is pumped back to the cleaners and the cleaner magnetite is dewatered in rake classifiers and carried by belt to the winter plant or the stockpile area. The nonmagnetic sands from rougher and cleaner magnetic separator are sized for table feed in eight pocket hydraulic sizers. The slime overflows from the Crocketts, the sizers, and the magnetite rakes are collected and pumped to three-inch cyclones for thickening and desliming. The cyclone underflow is the principal flotation plant feed.

Jan 1, 1962

By George Chung

"The Iron Ore Company of Canada's Carol Lake Project is Located near the western boundary of Labrador, 960 air kilometers northeast of Montreal (Figure 1).The Concentrator operation was started in 1962 with a capacity to produce 7 million tonnes of concentrate per year. The bulk of the concentrate was pelletized at a 6 million tonnes per year pelletizing plant completed in 1963. The remaining concentrate was sold in the international market. The concentrator was first expanded in 1966 to 10 million tonnes per year capacity with the pellet plant also expanded in 1967 to match the increase in concentrate production. In 1973, the concentrator was further expanded to gear with the increase in concentrate sales. In 1977, more than 40 million tonnes of crude ore was processed to produce in excess of 17.4 million tonnes of concentrate and 10.4 million tonnes of pellets."

Jan 1, 1980

By J. J. Montoro

The influence of blasting on the excavators’ efficiency, defined as mucking rate (amount of rock mucked per unit time) and mean bucket load (amount of rock loaded in each bucket operation), is investigated. Rock characteristics, blasting parameters (drill pattern, explosive energy, and charging), and the excavator’s performance (truck loading time and number of buckets to fill a truck) were monitored in eleven blasts in an open pit iron ore mine. ANFO, ANFO/emulsion blend, and watergel were used in the blasts and the powder factor was varied between 0.98 and 1.45 kg/m3. The mean bucket load is mainly affected by the bucket size, which is independent of the blasting parameters. Besides the relation with the mean bucket load, the mucking rate was found to be positively correlated with the explosive energy, whereas no significant correlation with the rock properties was found. The analysis of the data, together with other published works, suggests a non-monotonic relation of the mucking rate with the powder factor, with a maximum mucking rate at a certain powder factor. This is especially true when the useful work of the explosive per unit rock volume is used rather than the classical mass powder factor and when only the amount of explosive above grade is considered.

Jan 1, 2007

By J. Reed

The RockWorks EarthApps represent a free collection of 74 geology-related programs that read data from a built-in datasheet and create diagrams within Google Earth. EarthApps also includes programs that extract data from Google Earth. The programs that create diagrams include: point mapping (e.g. borehole locations), proportionally scaled icons (e.g. geochemistry), and strike & dip symbols. Line mapping utilities include; polylines, parabolas and pipelines. Polygon mapping programs include; thematic mapping (e.g. geology), mining claims, and public land survey sections. Image overlay capabilities include; draping (e.g. geologic maps) and time-based animations. Vertical image display capabilities are centered on either midpoints (e.g. drill-hole logs) or stretched between endpoints (e.g. cross-sections). The Flyover programs create virtual tours for site presentations. The cell-mapping includes a variety of algorithms (e.g. geochemical and geophysical contouring). Survey programs convert and export survey data to Google Earth as points and polygons. Programs that extract data from Google Earth include; points, lineations, polylines, and polygons. The RockWorks/EarthApps collection is developed by RockWare Incorporated based in Golden, Colorado.

Feb 27, 2013

This: symposium was sponsored by the Bureau of Mines, U.S. Department of the lnterior, in order to critically examine the state-of-the-art of sulfide flotation chemistry and to define current and emerging problems that should be emphasized in future fundamental research. The topics covered through invited papers include both reviews and recent research results in the areas of thermodynamics of reagent-mineral interactions; collector adsorption processes; the effects of solid-state point defects on flotation; activation and deactivation phenomena; the electrochemical role of oxygen in sulfide flotation; environmental problems in flotation; and selective flocculation of fines. Papers riving perspectives on flotation research in relationship to our national mineral requirements and the relationships between industrial flotation research and academics are also presented. An edited summary of the symposium follows the papers.

Jan 1, 1980

By L. Andrews

Mineralogy, traditionally associated with concentrator studies, is being increasingly applied to problems in pyrometallurgy. Such investigations commonly make use of a number of techniques, and the results are combined for a meaningful interpretation, which can lead to a successful solution for the problem. Mineralogical techniques are described for various pyrometallurgical operations. Examples are given of studies and investigations involving mineralogy in chemical-looping combustion, feed monitoring to platinum-smelting furnaces, and losses to slag in base metal and platinum smelting.

Jan 1, 2011

By Eugene Frey

"INTRODUCTION The Iron Mountain deposits were examined in the summer of 1943 by engineers of the Bureau of Lanes, and a diamond-drilling project was set up under the Strategic Minerals Program. Actual drilling operations, under the supervision of a Bureau engineer, commenced November 9, 1943, and were completed on November 1, 1944. When the Bureau began detailed exploration of the Iron Mountain deposits, the Federal Geological Survey participated. Dr. I. W. Newhouse, of the Survey, and Dr. A. F. Hagner, of the Wyoming Geological Survey, were assigned to the investigation.ACKNOWLEDGMENTSIn its program of exploration of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, R. G. Knickerbocker, chief, analyzes samples and performs beneficiation tests. Both these branches are under the supervision of Dr. R. S. Dean, assistant director.With respect to this report, acknowledgment is made to S. R. Zirrmerley and F. T. Allsman, Bureau of Mines, Salt Lake City, Utah, who supervised the work of this project."

Nov 1, 1946

By HOWARD RICHARDS

THE dollar was, selected as the unit of currency by the Congress of the United States of America on Apr. 2, 1792. This "Dollar" currency is so much more convenient than the older British currency that the Canadian Government, among others, has adopted it with corresponding success. Just as the dollar is the unit of United States currency, so the meter is the international unit for measuring length. The various weights and measures used in - the United States have since Apr. 5,. 1893, been based on the metric standards. These fundamental standards are kept by the International Bureau of Weights and Measures, which is supported by the United States, Great Britain and the, other leading countries. of the world. Copies are held-in Washington and other capitals. (2) As the dollar is divided into 100 cents, so the meter, which is 10 per cent. longer than the yard, is divided into 100 centimeters or cm. And as the cent is divided into 10 mills, so the centimeter is divided into 10 millimeters or mm. In measuring clothing and other articles which do not require great accuracy, the centimeter is most con¬venient, so that such work is done in terms of centi¬meters.. Instead of speaking of a 15;2-in. collar, a 40-centimeter or 40-cm. collar is referred to. Where accuracy is needed, as in mechanical drawing, machineshop work, etc., millimeters are employed. Thus 8 mm., is the convenient equivalent for 5/16 inch.

Jan 1, 1921