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By S. Harries Daddow

IN order to get an idea as to the strength of steel rails, it will be well to review the tests to which iron rails have been subjected. In England, Mr. Ashcroft found that the best 80 pound rails broke under a 300 pound weight, falling 15 feet. In Germany the Society of Railway tyfanage1-s determined 011 and have long applied a test of 1000 pounds falling 101/2 feet, as the standard which all first-class iron rails must reach. In this country no inspection nor test is applied, but tests made show that iron rails fro; our most reliable makers, break under a G foot fall of a 1500 pound drop as an extreme test, most of those tested breaking under a far less test; some breaking with less than a 3 foot fall of the same weight. Everywhere where steel has been used, engineers have come to the conclusion that some test is required to show the regularity and strength of the product. As compared with iron, the tests which steel will stand are wonderful. After numerous experiments partially based on the experience of the rail-mill at Graz, belonging to the Southern Railway of Austria, the Society of German Railway Managers fixed upon a test of 2000 pounds falling 138 feet. They found that this test represented the steel which suited their necessities, and also found that with steel of otherwise average purity, this test represented about one-half per cent. of carbon, and made it a rule to take no steel containing under three-tenths of a per cent. of carbon, because it was too soft. They expressed a hope that a harder steel could soon be made tough enough to stand the same test. I n England, a test was adopted of 2240 pounds, falling 15 to 17 feet on the rail on heavy bearings. This test has been found satisfactory under heavy traffic on average road-beds, and has been invariablyPILLAR of coal, which are designed and left in our mines as the means of supporting the overlying strata of our coal-beds, and securing protection to the miner, are not only insufficient for these purposes, but the most objectionable means of providing the desired security to life and property. Though such pillars are left at a great sacrifice to the owners of collieries and mineral lands, loss to the resources of the commonwealth, and ultimate privation to the public, they defeat the very ends for which they are designed, and not only do not secure life and property, but are as fatal to the one as ruinous to the other. Propositions.-It is eminently desirable that the resources of the Common wealth-particularly our mineral wealth in anthracite coal, which is limited-should be carefully utilized and made available, not only to ourselves but our posterity. Yet, speaking as an anthracite miner, we are wasting our resources of coal with a recklessness which will bring ruin in the end, unless checked, not only to the iron manufacturing interests of the East, whose chief protection, in competition with the iron-masters of the interior, lies in a cheap and abundant supply of anthracite furnace fuel, but to the best interests of the State. It is, consequently, not only desirable, but necessary, that we should realize every ton of coal from each colliery, and every acre of coal area, in order that our resources may not be wasted at present, to breed want in the future, and to realize the greatest present benefit to the mine, the miner, and the public. It is not possible, however, to secure these ends, if we continue to leave, as we do at present, from one-third to one-half our resources in anthracite as pillars in our mines. But our sad bills of mortality, our abandoned collieries, and our yawning mountain-sides, present ample evidence that even this enormous waste of coal, though left for the purpose of protecting life and property, is as totally inade-

By Edward Hanrahan

September 1981 I'm here today to report on a revolution -- a revolution in the way the Federal Government looks at energy. I'm not talking about a simple change in the relative emphasis on sources -- such as more recognition for coal and nuclear power, with less rhetoric about "soft- technology." Nor am I describing a mere change in focus -- from the demand side to the supply side. And I am not referring exclusively to our obvious goal of budget cuts. No, I'm here to discuss a fundamental change in Federal direction -- one that started as soon as President Reagan was inaugurated, and one that is articulated in the National Energy Policy Plan he sent to Congress in July. That brief policy document was backed up by three volumes of supporting data; but I think I can catch it's flavor for you in just three phrases: * First, various energy forms complete with each other and complement one another. * Second, fair competition among them (which includes honest pricing) will give us the best "energy mix." • And, finally there may be ligitimate arguments about where Federal responsibility in regard to energy spills over into Federal interference; but it's about time we drew the distinction -- and eliminated the latter. This Administration's national energy policy is quite different from any we have had in recent years. It is tuned to human nature and changing times. We are seeking the best practical solutions in the energy -a lot better than the ones we have been offered before, but still something less than perfection. One way we do that is by counting on a fully informed public to guide it's own destiny. And, instead of treating energy as an isolated entity, we recognize it as part of the overall economy. The President's Program for Economic Recovery is as much a factor in energy policy as the specific actions of the Department of Energy. One striking difference from the past energy policy 1s that this policy plan does not say: "In 1985 we will -produce so many hundreds of millions of tons of coal: . . . or . . . "By the end of this century the Nation will be deriving X percent of it's electricity from wind generators." Unfortunately, targets like these are what many people have come to expect from the Federal Government -- and what they think of as energy policy, whether the figures hold up in the long run or not. But . . . think about it! Nether the Department of Energy nor any other part of the Federal Government produces coal, or mines uranium, or manufactures solar collectors. There are only a few sections of the country where the Federal Government generates and sells electricity. So it does not take any great insight to recognize that the amount of energy we will produce or consume as a Nation In the future depends on many factors beyond direct government action. And those future totals cannot be predicted precisely, anyway -- by the Government or by anybody else. According to our way of thinking, the choices should be up to the people. When the free market works within a healthy economy, individuals express their preferences in the marketplace -- adjusting the balance of all energy factors continually in a way that no computer could be programmed to reflect perfectly. So, instead of having the Government issue a rigid set of numerical goals, our main concern simply is that there be enough energy. We want the Nation itself to decide how much that should be, what form it should take, and how that energy should reach consumers. The marketplace decides. Considering the recent past, this is indeed a revolutionary idea. It has some pitfalls, and we won't reach this ideal of free choice overnight. But that is where we are headed. And I'll offer some evidence in a few minutes that the policy has already started working. First, let me give you some of it's highlights: 1) Nobody who appreciates the philosophical underpinnings of this Administration will be surprised that the energy policy shows faith In domestic energy production and the supply side of the economy; but it also recognizes the important role of energy conservation -- the wise and efficient use of energy resources.

Jan 1, 1982

By Owen F. Jensen

CONSTRUCTION of a ground-water supply includes many operations, which do not end with completion of facilities. Evaluations must be made of the quality of water in various areas and the history of production. Following an analysis of geologic, hydrologic, and chemical data there must be an exploratory drilling program and a study of resulting information. When the well is completed a continuous survey of operating records and basic data is necessary, since designs for future wells are varied as more data becomes available for those already completed. As the following discussion must be limited to a single undertaking, the customary procedure will be outlined for development and construction of a ground-water supply in which more than three wells are involved. Parts of this procedure are applicable for all ground-water supplies. Three possible sites were selected for construction of a paper mill. The problem was that the industry daily required approximately 15 million gallons of water of the best quality available; however, if water of the best quality were not available in the desired amount, water of a poorer quality could be used up to half the required amount, about 7 million gallons. In the preliminary survey approximately 1500 to 2000 square miles were covered for each site. Collected data consisted of several hundred electric logs of oil and gas wells; reports by the U. S. Geological Survey on ground-water resources of localities in and near the area; unpublished records of several hundred water wells including chemical analyses of the water produced and drillers' logs of the wells; records of periodic water-level measurements made in observation wells by the USGS; topographic maps drawn up by USGS and by army engineers; and highway and county road maps. A preliminary report based on study and evaluation of these data was presented to the client, recommending the site with the most favorable and economical ground-water conditions. The study indicated that water of the quality and quantity desired could be developed. In this particular area there were indications that the aquifer could be separated into two zones con- taining water of different chemical character. This chemical character varied somewhat with area, but principally with depth, a factor which later proved an economic advantage in design of the well field. After studying the preliminary report, the client weighed other economic factors as well as ground-water advantages and selected a plant site. Authority was given to proceed with detailed study of the chosen area. Evaluation of preliminary data concerning the area indicated that it should be supplemented with additional information derived from actual exploratory drilling and testing. A flexible plan of exploratory drilling was devised so that data obtained as each test hole was drilled could be correlated with existing data and additional test holes could be located and drilled accordingly. Specific data to be obtained from each test hole were: samples of all formations penetrated; the driller's descriptive log of formations; electric logging surveys; one or more samples of water from selected water-bearing formations; temperature; and water levels and their recovery after periods of production. The area studied in such detail was approximately 400 square miles. Choice of location for the original test holes was based on the preliminary study. The pattern for these test holes was designed to require a minimum number of holes and to allow for interpolation of data between two, three, and four holes. Geologic, hydrologic, and chemical data gathered after completion of the first four test holes showed that the north section was the most desirable in the area, which was then reduced from the original 400 square miles to about 150 square miles for more detailed and intensive study. On the basis of findings from the current test a tentative well field was laid out and a drilling program devised. One test hole was located on the actual plant site and later developed into a small pilot production well equipped with a deep well turbine pump. Water from this well was used for general construction requirements. Another test hole drilled near the pilot production well and adjacent to the proposed route of the well-collection system was used during the pumping test of the pilot production well to determine the degree of interference. From the data thus obtained, calculations were made to determine the coefficients of transmissibility and storage. Three additional holes

Jan 1, 1955

By Henry M. Howe

A discussion of the paper published in Bi-Monthly Bulletin, No. 20, March, 1908, pp. 227 to 237, and No. 22, July, 1908, pp. 615 to 620. PROF. HENRY M. HOWE, New York, N. Y. (communication to the Secretary *) :-Mr. Hibbard's definition of steel would be the best yet offered were it not for its one defect, the vagueness or equivocalness of "fusion-process." Puddling is surely in one sense a fusion-process, and so are the charcoal-hearth or knobbling-processes. But what he says suggests the following definition, which seems to me a good one: " Steel: any variety of iron which is usefully malleable at least at some one temperature, and is either cast when molten into a malleable mass, or if not so cast can be much hardened by sudden cooling." It is not necessary in a definition that quantitative bounds should be set up, for instance, that the exact height at which dwarf apple-trees cease and standards begin, or at which hills cease and mountains begin, should be stated. These quantitative measures are proper for specifications and contracts, but are not necessary for purposes such as the present. HENRY D. HIBBARD, Plainfield, N. J. (communication to the Secretary t) :-Professor Howe's criticisms of my definition of steel are not, it seems to me, well founded, for the . following reasons: The term "fusion-process" has been used during the past quarter or half century to distinguish the crucible, Bessemer and Siemens-Martin processes from the puddling- and cementation-processes, and probably no one at all conversant with the art of iron-metallurgy would now mistake its meaning. Moreover, no steel-metallurgist is in doubt of the meaning of the term "hardened? as applied to steel. If it were really necessary to describe what is meant by the term then it would

Nov 1, 1908

By Scott W. Hazen

COMPREHENSIVE summary is presented of results of several years of research at the Bureau of Mines Mining Research Center at Denver on adapting and applying techniques of statistical analysis in mine and mineral-deposit sampling and in computing grade and tonnage of ore for a mineral deposit. In addition to elementary statistical theory the material presented in the bulletin includes: (1) Certain special statistical techniques that have been found useful in mining applications; (2) problems, implications, and limitations that may be encountered in applying these techniques in mine sampling and evaluation; and (3) numerous examples to demonstrate application of the theory and techniques.

Jan 1, 1967

By J. Clark

The objective of this study has been to determine the state of the art in underground, thin-seam-mining systems, to identify new technology and procedures that would reduce the hazards of thin-seam mining and to recommend areas for further research. The study was carried out in two phases, the first of these being devoted to a survey of authoritative literature. Subsequently, the practices adopted in the various mining countries were analysed and comparisons made to identify machines and methods with the potential for application in the USA. Published figures on US bituminous coal reserves show the high proportion contained in thin seams and US accident statistics demonstrate that the risk is greater in thin-seam operations. A comparison has been made with the experiences of foreign operations. The Phase 11 study proceeded along two separate avenues to examine the distinctive problems associated with seam thicknesses above and below 30 in. Current systems of mining appropriate to seams greater than 30 in were elaborated and compared by means of a simulation exercise in terms of safety, production and cost. For seams below 30 in, less conventional systems, some presently disused, were studied and their potential evaluated; the research and development work necessary to make them viable has been indicated.

Jan 1, 1980

By J. W. Thompson

AN ACT prescribing the mode of maintaining and defending possessory actions on lands belonging to the United States. The People, etc. SEC. 1. Any person now occupying and settled upon, or who may hereafter occupy and settle upon any of the public lands belonging to the United States, unoccupied, except upon lands containing mines of any of the precious metals, may commence and maintain any action for interference with, or injuries done to his possession of said land, against any person or persons so interfering with or injuring such land or such possession. SEC. 2. On the trial of any such cause, the possession or possessory right of the plaintiff shall be considered as extending to the boundaries embraced by the claim of such plaintiff, so as to enable him to have and maintain any action as aforesaid, without being compelled to prove an actual inclosure; provided, that such "claim" shall not exceed in any case one hundred and sixty acres of land. SEC. 3. Every such claim, to entitle the holder to maintain any action as aforesaid, shall be marked out, so that the boundaries thereof may be readily traced, and the extent of such "claim" easily known, and no person shall be entitled to maintain any such action for possession of, or injury to, any claim, unless he occupy the same, or shall have made improvements thereon to the value of $100. SEC. 4. A neglect to occupy or cultivate such "claim," for the period of three months, shall be considered such an abandonment as to preclude the claimant from maintaining any action as hereinbefore mentioned. Sec. 5. Any person or persons claiming the right of possession to land under this act shall have the right to defend said possession and the claim thereto, and all the rights and privileges given them by this act.

Jan 1, 1918

By M. B. McClenaghan

"This paper summarizes diamond exploration techniques used in glaciated terrain, focussing on indicator mineral and geochemical methods applied to glacial sediments. Understanding the ice flow history, depositional history, and stratigraphy of glacial sediments is essential to successful sampling, interpretation and follow-up of indicator mineral and geochemical anomalies related to kimberlites. Kimberlite indicator minerals survive glacial transport over long distances and the relative abundance of each mineral in till is a function of the primary mineralogy of individual kimberlites. Indicator mineral distributions observed at a regional scale define the net effect of glacial dispersal, often along different ice flow directions. Local-scale distributions define individual dispersal trains. The medium sand (0.25 mm to 0.5 mm) fraction of heavy mineral concentrates, * GSC Contribution No. 2002028 prepared from glacial sediment samples, is best suited for indicator mineral surveys. The application of till geochemistry to diamond exploration is increasing because it is significantly cheaper than indicator mineral analysis and it can be performed quickly. The <0.063 mm (silt+clay) and 0.5 mm to 2.0 mm (coarse sand) fractions provide the best geochemical contrast between background and kimberlite-rich till. Kimberlite pathfinder elements that provide good contrast include Ni, Cr, Ba, Co, Sr, Rb, Nb, Mg, Ta, Ca, Fe, K, Ti and LREE, the relative importance of which will depend on kimberlite composition and that of the surrounding bedrock.IntroductionIn Canada, glacial erosion is the principal means by which kimberlite and its associated minerals have been dispersed, from a few tens of metres to tens of kilometres down-ice. Post-glacial weathering has had little impact on kimberlite debris in the glacial sediments, thus boulder tracing, indicator mineral methods and trace element geochemistry of the fine fraction of till (“drift prospecting” methods) can be used to detect kimberlite dispersal within areas covered by glacial sediment. This paper provides a summary of drift prospecting methods for kimberlite exploration in glaciated terrain, and includes examples of reconnaissance- , regional- and local-scale kimberlite indicator mineral and till geochemical distribution patterns.Weathered kimberlite is more susceptible to glacial erosion than the surrounding bedrock, thus many kimberlites in glaciated terrain are found in low or swampy ground, under small lakes, or covered by thin (< 1 m) to thick (>50 m) glacial sediments. Glacial erosion has removed varying amounts of the pre-glacially weathered kimberlite and, in some cases, the hard competent kimberlite below. For example, glacial erosion of the Peddie, McLean and Seed kimberlites near Lake Timiskaming, Ontario, removed pre-glacially weathered kimberlite, leaving a polished striated subcropping surface (McClenaghan et al., 1999a). In contrast, glacial erosion of the B30 kimberlite, near Kirkland Lake, Ontario (Fig.1), was much less vigorous and left a >10 m cap of soft and highly weathered dark green clay-rich kimberlite (McClenaghan et al., 1996). The thickness of remaining pre-glacially weathered kimberlite will influence the geophysical signature of the kimberlite."

Jan 1, 2002

By R. T. Hukki, P. Voutilainen

This paper describes a new apparatus for continuous wet fine-screening. Its preferred size range seems to be from 0.1 to 1 mm. The supercritical trommel screen is a short cylindrical trommel of wedge-bar type construction operated at a speed greater than the calculated theoretical critical speed and at a speed lower than the speed at which particles introduced into it will centrifuge. The paper describes results obtained with the prototype supercritical trommel screen in pilot plant scale. The results point to a high capacity and simultaneously to a high sharpness of screening. Finally, an analysis is presented of the forces acting in screening on a supercritical trommel screen. In the era of high speed, high capacity processing of raw materials the conventional slowly rotating trommel screen is often considered a relic from the times passed. A typical trommel screen is the cylindrical trommel rotated about a horizontal or slanting axis at a relatively low speed. Its screening characteristics are well known. Trommel screens of various types of construction, methods of operation, performances and other characteristics have been described in detail by Taggart.1 The theoretical critical speed of a trommel screen is defined by the same well known equation as that applied for grinding mills: where ncritical = the numerical value of the theoretical critical speed in rpm, D 1 = the inside diameter of the trommel in feet, and D2 = the inside diameter of the trommel in meters. ncritical corresponds also to the centrifuging speed provided that the coefficient of friction f between the trommel surface and the outer layer of the charge is = 1.0. In a general case: From Eq. 2 it is seen that in all cases where f < 1.0 the centrifuging speed of the trommel is greater than the theoretical critical speed. The supercritical trommel screen concerns screening operations within that speed range which is between the theoretical critical speed defined by Eq. 1 and the centrifuging speed defined by Eq. 2, under conditions such that the coefficient of friction f<1.0. It is reported by Taggartl that the optimum speed of a conventional cylindrical trommel screen 36 in. in diam was experimentally found to be about 16 rpm. From Eq. 1, the critical speed of this trommel is 44.2 tpm. The indicated optimum speed corresponds to (16/44.2) x 100% = 36.2% of the theoretical critical speed. The optimum speed range based on information available seems to vary from 33% up to 45% of the theoretical critical value. The trommel screen operated at a supercritical speed: operates at a speed greater than the calculated theoretical critical speed; operates at a speed lower than the speed at which the charge introduced into it will centrifuge; operates within the supercritical speed range in such a way that the coarse fraction of the charge must slide in respect to the inside surface of the trommel; the outer layer of the said fraction next to the screen tends to proceed in the same direction as any selected point on the trommel surface, but now at a lower speed, and indeed at a subcritical speed; allows to a certain degree adjustment of the maximum determining particle size x of the fine product simply by a variation of the speed of the trommel within the supercritical speed range. With increasing trommel speed, finer and finer material only will get the opportunity to find its way into the fine product while the screen opening remains constant. In conventional practice, the low speed trommel is generally used for sizing of coarse and medium coarse material, but seldom for fine screening. The characteristic feature of the product passed through the conventional trommel is that the determining size x of the biggest particle is barely smaller than the nominal size of screen opening. The supercritical trommel screen, on the other hand, is best suited for sizing of relatively fine material. Furthermore, the characteristic determining size x of the biggest particle in the fine product can be substantially smaller than the nominal width of the screen opening or slot. In the trommel screen best suited for the applications

Jan 1, 1965

By H. A. Steane

THIS BRIEF PAPER presents the information available on the use of Dorrclon?is in the middling re-grind unit at the lead-zinc mill of Canadian Exploration Limited. The plant throughput is 1,650 tons per twenty-four hours. The flotation feed is ground to 60 per ?Cent passing through 200 mesh. It contains some composite 11articles of sphalerite in calcite, and these reported either in the final zinc concentrate, thus lowering the grade, or in the tailing, with loss of zinc. The re-grind unit was set up in the zinc flotation circuit to liberate the sphalerite from these middling particles, to raise the grade of concentrate and improve recovery. Grinding through 325 mesh should give substantial liberation of locked sphalerite. The middling regrind unit consists of two Dorrdones and one ballmill arranged as shown in the -accompanying flow-sheet. The Hardinge ball-mill, size 7 ft. x 36 in., was free for this use as a result of recent plant expansion. The two Dorrclones were purchased, and the necessary pumps and pipe lines were installed to complete the regrind unit. The unit has been developed over a period of two years by several steps and various flow schemes until reaching tl1e present flow scheme. These steps are not elaborated here, because the changes were made to determine the best product to work on for flotation metallurgy, and not because of the Domrolone classifying ability.

Jan 1, 1956

By Lawrence Devon Smith, Keith Spence, William Roscoe

"In March 2003 the CIM Council adopted and approved the document “Standards and Guidelines for Valuation of Mineral Properties” as developed by the Special Committee of the Canadian Institute of Mining, Metallurgy and Petroleum on Valuation of Mineral Properties (CIMVal). The document is referred to as the CIMVal Standards and Guidelines. The document evolved from a specific recommendation by The Mining Standards Task Force (MSTF) of the Toronto Stock Exchange and the Ontario Securities Commission in its Final Report (January 1999) that the CIM form a committee of valuation practitioners to review and advise on approaches to valuation of Mineral Properties. The CIMVal Standards and Guidelines are organized into two parts: •,Standards which are general rules in the Valuation of Mineral Properties. The use of the Standards is mandatory if the Valuation Report is stated to follow CIMVal (although not mandatory in the sense of having regulatory authority). Definitions are given at the beginning of the Standards. •,Guidelines which elaborate on the Standards and, while not mandatory, provide guidance and best practices which are highly recommended to be followed in the Valuation of Mineral Properties.CIMVal specifies requirements for the Qualified Valuator who has the responsibility for choosing the appropriate approaches and methods for the valuation of mineral properties. With regard to the specifics of the application and practice of valuation approaches and methods, CIMVal directs the Qualified Valuator to the large body of published papers, published valuations, presentations and court judgments to guide his or her choice. This is also the approach taken by VALMIN (Australia) and SAMVAL (South Africa). To facilitate the dissemination of industry practice, the CIMVal Committee organized a “Valuation Day” at the CIM Annual General Meeting in Toronto (Mining Millennium 2000), on March 8, 2000. Industry experts presented papers on valuation of Mineral Properties which were subsequently published in a proceedings volume and individually ad technical papers in the CIM Bulletin. The Management and Economics Society of CIM has continued to identify and publish papers on valuation in the CIM Bulletin and Magazine. The present document gathers in one place the CIMVal Standards and Guidelines, the papers from the 2000 Valuation Day, and a number of subsequent papers that illustrate industry practice for the valuation of mineral properties."

Jan 1, 2003

By John F. Wiss

A series of controlled experiments was conducted at four surface coal mines to study the effects of certain blast parameters upon the ground and air vibration. Preliminary scale-model blasts were conducted at a quarry to provide basic data. It was found that the amplitudes of the ground and air vibration were controlled by the maximum explosive weight per delay. Either cube root or square root scaling could be used for the seismic amplitudes, and cube root scaling could be used for the overpressure amplitudes. Both amplitudes were not significantly affected by the total charge weight per blast, the attitude of the boreholes, or the charge length or diameter. The overpressure amplitudes were affected by the charge depth, the use of cover over surface detonating cord, and the use of adequate stemming. The length of the delay intervals and the spacing of holes were important in determining the potential for reinforcement of the amplitudes in certain directions from the blasts. In downwind directions from the blast, the attenuation of the overpressure with distance decreases. Surface terrain did not significantly affect the overpressure amplitudes within the range investigated. The type of overburden affects the generation of both amplitudes and the propagation of the seismic amplitudes. Spectral analysis of the ground and air vibration is reported. A scaled distance of 300 ft/lb1/3 should produce a peak particle velocity of less than 1 ips and an overpressure of less than 128 dB linear peak. For square root scaling, a scaled distance of 75 ft/ lbl/2 should limit the ground vibration to less than 1 ips.

Jan 1, 1978

By Arno C. Fieldner

Six years ago, I addressed the annual meeting of the American Society for Testing Materials on "Fuels of Today and Tomorrow."3/ Since then, our country has been drawn into another great war of veritably global extent, with unprecedented demands on fuels, foods, and materials in general. My purpose in this address is to review the changes in fuel supply and demand since 1937 and to give you my views on the outlook for the future. CONDITIONS IN. 1237 Daring 1936 the United States produced and consumed one-third of the world production of coal, two-thirds of the petroleum, and about 95 percent of the natural gas. Two-thirds of the oil produced in all countries since the discovery well was drilled in 1859 had come from American wells. With the exception of the three depression years 1931, 1932, and 1933, new oil reserves were being discovered since 1924 well in excess of our increasing rate of consumption. Discoveries of natural gas, likewise, were tremendous in volume, and this fuel was being transported to most parts of the country by pipe lines; some of them more than 1,000 miles long. We had all kinds of mineral fuels in abundance and at prices that did not stint anyone in the maximum utilization of the mechanical devices that were being developed on every hand. No one suspected that the time might come in a few years when, gasoline would be doled out to some of us at the rate of 1-1/2 gallons a week or that many of our fuel-oil furnaces would have to be converted to burn coal. Of course, these restrictions are due to unusual war conditions, such as lack of coastwise tanker transportation, unprecedented demand for aviation gasoline, and the shortage of rubber for automotive tires. However, these shortages do call our attention to the vital part of petroleum reserves in our country&apos;s future position among nations. Therefore, it is of special interest to review briefly the relations of recent supply and demand with respect to our various mineral fuels.

Jan 1, 1943

By H. W. Clair, E. V. Potter, M. J. Speedlove

"INTRODUCTION The behavior of particles in a sound field has long been of scientific interest since Kundt (1) 5/ made his classic experiments on some of the interesting effects of standing waves in cylindrical tubes. With the development of the electronic tube and its application to continuous generation of sound, experimental investigation of the Kundt tube was renewed (2). The more intense vibrations set up by a continuously vibrating diaphragm or rod produce even more striking effects than those observed by Kundt. Instead of the striations at the antinode produced by the stroked rod, then, wafer like barriers are formed at the antinodes, sometimes extending over the entire cross-section of the tube. Furthermore, it was observed independently by Andrade (3), Brandt, Freund and Hiedemann (4); and by investigators in the Bureau of Mines laboratories (5) that aerosols, such as ammonium chloride or tobacco smoke, could be flocculated quickly if passed through an intense sound field, particularly when a standing wave field was set up by a resonant enclosure. Because of its possibilities as a new means for removing suspended particles from dust-laden gaseous furance or smoke, the phenomena attending the behavior of suspended particles in a und field have been studied intermittently by the Bureau of Mines over the past decade.The first experimental work was done with a magnetostriction vibrator and a Hartmann air-jet generator as sound sources. It soon became evident that neither type was entirely satisfactory. Low mechanical efficiency is an inherent characteristic of magnetostriction generators, and the air-jet generator is difficult to control and does not permit accurate measurement of the acoustic output. The search for a suitable sound source led to the development of an electromagnetic generator, which is by far the most suitable for study of the effects of intensive high-frequency sound fields in gases (6)."

Mar 1, 1948

By James C. Barker

The analytical variability encountered when sampling for platinum-group metals (PGM) was statistically evaluated during a 1983 study by the Bureau of Mines and the University of Alaska. Sampling procedures were designed to systematically incorporate commonly used reconnaissance exploration techniques under actual field conditions. Analytical variability was evaluated at each procedural step. Analytical data from each sample from a single deposit grouped relatively well around the calculated mean for that deposit. Standard deviations did not exceed 43 pct of the mean for any of the deposits; more commonly, the deviation was about 25 pct. Statistical treatment of the data by analysis of variance indicated the most important source of error is selection of the sample site. Two or more replicate samples appear necessary to adequately quantify the PGM content. Secondly, significant variation occurs during preparation of a pulverized split for fire assay. The optimum sample size was in the 11-lb range; larger samples did not appreciably reduce variability. Smaller samples generally indicated a higher degree of variability. Evaluation of the sample method suggested the common grab sample, if carefully taken, is a useful indicator of the general range of PGM concentration but potentially includes a considerable margin of error.

Jan 1, 1985

By August J. Kwitowski

This Bureau of Mines report summarizes the development of a protective operator compartment for a new generation thin-seam mobile bridge carrier. The developed compartment is commercially available and is currently employed on approximately 15 bridge carriers used in the mining industry. The design of the compartment, which employed human factors engineering and small- and full-scale mockup models, is fully described. Details of the compartment&apos;s fabrication, evaluation, and demonstration in a commercial low-seam coal mine are also provided.

Jan 1, 1986

By Rolland L. Blake

The Bureau of Mines is concerned with extracting minerals from residual geothermal brines after their heat content and some demineralized water have been recovered. This literature study is based on a survey of the literature and discussions with individuals knowledgeable on various aspects of the subject. This report examines the potential of the domestic geothermal mineral resources, considers the technical problems involved, and outlines possible effects on the environment from reservoir fluid withdrawal and reinjection. Geothermal resources in the Western United States were extensively explored during the 1960&apos;s. Limited development operations included exploratory drilling and operating wells producing hot brine, separating steam for experimental electric power generation, and recovering minerals in solar evaporation ponds or in extraction plants. Interest in the recovery of minerals and salts from geothermal fluids waned because of corrosion and scaling problems and low or no market value of the mineral products. Most of these problems can be controlled with existing technology and careful planning of processes and equipment. Extracting geothermal minerals is technically feasible, but the problems of low or no market value for major mineral products, and insufficient amounts of more valuably major products, make mineral recovery uneconomical at present.

Jan 1, 1974

By J. B. Clemmer

Fluorspar is one of the most important nonmetallic minerals and is used extensively in the metallurgical, ceramic, cement, and chemical industries. The steel industry consumes most of it, but as the Mineral is the chief source of fluorine, it is becoming increasingly valuable to the chemical industry in the production of fluorine compounds The development of nontoxic organic fluorides for use as refrigerants in mechanical refrigeration and air-conditioning units illustrates the increasing use of fluorspar in the chemical industry. Most domestic flurospar comes from deposits in the Illinois-Kentucky district, which centers around Rosiclare, Ill. About a dozen companies operate in the district, which comprises parts of Pope and Hardin Counties in southern Illinois and Crittenden, Livingston, and Caldwell Counties in western Kentucky. According to the latest available statistics, this district supplied 1/5,960 short tons of fluorspar in 1937, compared with the total domestic production of 181,230 tons. Imports totaled 37,063 tons.

Jan 1, 1939

By G. A. Smyres

A GaC12--B2 l-eachtng procedure and meEal-recovery method for treating an arsenical Cu-Co sulfide concentrate was developed by the Bureau of Mines as an alternative to smelting, which is no longer considered an environmentally acceptable method for treating arsenic-containing ores. The procedure involved leaching in a CaC12 solution with CaC03 for 96 h at 26 pct solids (concentrate and CaC03), 1150 C, and a pressure of 50 psig (345 kPa) with oxygen. More than 98 pct of the cobalt and 97 pct of the copper were extracted, and 99.98 pct of the arsenic and 99.9 pct of the iron remained in the leached residue. A filtration rate of 2.9 gal/(ft2.h) [118 L/(m2.h)] and a cake formation rate of 36 Ib/(ft2.h) [172 kg/(m2.h)] were obtained by filtering reacted pulp at 1000 C. More than 99 pct of the copper in the pregnant solution was extracted as CuCl2 by golvent extraction with a new copper extractant. Copper was stripped from the loaded organic with a sulfate-chloride solution, which was used as the anolyte for electrowinning of copper in a membrane cell. Copper plate produced was more than 99.99 pct pure and requi.red 0.81 (kW&apos;h)/lb Cu [1.78 (kW·h)/kg Cu]. Cobalt sulfide was precipitated at pH 3 with Ca(HS)2.

Jan 1, 1986

By A. Gronningsater

Introduction As is well known, the fight between the blast furnace and the reverberatory furnace in copper smelting during the second decade of the century ended with a victory for the latter, a result which must largely be attributed to the introduction of flotation methods. To my knowledge, no new blast furnace has been blown-in at any American copper smelter since the War. As the metallurgy of nickel, up to and including matte smelting, is generally considered a close parallel to that of copper, the introduction of reverberatory smelting in the big new smelter of the International Nickel Company at Copper Cliff, built in 1928-30, seemed a logical adherence to a well established trend. In view of these facts, considerable comment was made when Falconbridge Nickel Mines decided to retain the blast furnace in their smelter built about the same time, in 1929. A presentation of the reasons governing this choice should therefore be of interest. The basic principles underlying the Falconbridge practice, and the considerations guiding the successive steps in the operations, will be discussed in the following. To understand the problems involved, the character and mode of occurrence of Sudbury ore must be kept in mind. Large amounts of disseminated ore are generally present. Although the gangue usually runs only about 50 per cent Si02, the ore hoisted as a rule contains more silica than needed in the smelting operation; until recently this excess was removed entirely by hand picking (in later years supplemented by magnetic sorting methods), a difficult and not very satisfactory method, in which &apos;the border line between ore and waste is entirely arbitrary, and therefore too much depends on the judgment of the picker.

Jan 1, 1934