Search Documents

By Clare B. Carlson, C. P. Proctor

THE history of the froth flotation of coal is relatively short. The flotation process was applied to fine-coal cleaning about the time of the end of World War I. Coal flotation finds more widespread use in Europe than in the United States and is used on a commercial scale in nearly all major coal-producing countries in the world. In Fig. 1 the general arrangement of a froth-flotation plant at a British colliery is shown. GENERAL FEATIJIEES OF THE PROCESS Application The flotation process is applicable to the cleaning of the fine sizes, particularly minus 48-mesh coal, although it may be used on sizes as coarse as 1/8 in. Since most cleaning processes usually are not effective on sizes smaller than 48-mesh and certainly not effective on minus 100- mesh, the froth-flotation process offers a solution to the problem of cleaning these sizes. This process consists-of agitating the feed pulp with a small amount of reagents, usually 1.0 to 2 ½ lb. per ton of feed in the presence of water and air; the reagents help to form small bubbles that collect on the particles having a greater affinity for the bubble surface than for the water surface, in this case the fine coal, and the bubbles buoy these particles to the surface to form the frothor concentrate. Slate and shale particles remain wetted and suspended in the water to be drawn off as tailing. The frothers commonly used in coal flotation are cresylic acid, pine oil, and alcohols. More expensive frothers, used in ore flotation, work satisfactorily but do not compare with these cheaper reagents for over-all cost. Collectors- used are low-grade petroleum fractions, such as cheap, partly refined fuel oil, or lubricating oil, sometimes mixed with small amounts of kerosene. Other collectors used are the fatty acids and their

Jan 1, 1943

By Henry E. Colton

NeaR the town of Christiansburg, Va., occurs a singular feature in topographical as well as geological structure, which may be said to have an important bearing on a large area to the southwest. The great water-shed ridge, which divides the waters flowing into the St. Lawrence from those flowing into the Atlantic ocean, coming southwestward, forms all of what was the boundary of Maine as agreed upon by the treaty of 1783, and a part of the present boundary, all of the northern New Hampshire boundary, and entering Vermont, continues south of Lake George. Passing irregularly through New York, it enters Pennsylvania, and there bifurcating, sends one prong to the west as a divide between the waters of the lakes and the Ohio, while the other becomes the steady, regular ridge which gave it the name of Alleghany, and thus passes on southwestward through Virginia. At no point has it ever been the geological divide. Its course, commencing in the Archean rocks, has passed through nearly every series of formation, and comes into Virginia in the Carboniferous strata. The geological divide—the line between the fossiliferous and the non-fossiliferous rocks—lies, in Canada, to the west of it, but from New York south into Virginia is far to the east. Reference to Dr. Hitchcock'k map will show this. But at the locality noted these positions are changed; the water-divide becomes the eastern chain, and the geological divide is the western, returning, it may be said, to the positions occupied in the region where they originated. These relations are shown on the large map accompanying the present paper. For several miles, the track of the Norfolk and Western Railroad

Jan 1, 1888

By James P. Kimball

In a paper which I had the honor to present to the Institute at the Montreal meeting, September 1879,I took occasion to refer incidentally to certain practical difficulties in the sampling of coal-seams {Trans. Vol. VIII., p. 181-3). This reference was particularly to the unequal distribution of sulphur in the form of pyrite, and to the necessity of discriminating between the several members or " benches " of a coal seam as to their relative proportion of visible sulphur. What is a practically truthful estimation of the sulphur of a coal seam, is not necessarily the estimation of an average of sulphur in any given line of cross-section of the seam. Cornparatively speaking, the range of sulphur in quantity is generally so low that errors in its determination, arising from neglectful sampling or from slips in the laboratory, fall chiefly upon this single ingredient. Not so,

Jan 1, 1884

By Pope Yeatman

In my experience, perhaps the most interesting problems came up during the testing, prospecting, developing and equipping of the Chuquicamata and Braden Copper Mines in Chile, and it is proposed in this article to give as briefly as possible what some of those problems were, their solutions, and the decisions made as to the different methods to be employed. The romance of mining is still a great lure to the young man who is making a choice of a profession to follow. The thought of travel to strange and out-of-the-way places, the glamor of pioneer life, the excitement of discovery, the constructive work of building something, entirely "from the grass roots up," or of reconstructing a played-out property and making a success of it-all of these phases have a strong appeal and often influence the young man in the choice of mining as a profession. That great engineer, Col. Seeley Wintersmith Mudd, whom we are endeavoring to honor, while having too much common sense to have been materially influenced by the romance of mining, certainly experienced all of the

Jan 1, 1932

By Charles R. Keyes

Prefatory,........323 Foundation of classificatory schemes in general..325 Past opinion on the classification of ore-bodies,.326 Nature of ore-deposits,....... 326 Definition........326 Fundamental law of origin.... 327 Significance of ore-bodies,.... 327 Date of origin........328 Original source of ores..... 328 Alteration of ore-bodies,....329 General methods of ore-formation.... 330 Ascension verm lateral secretion... 330 Replacement.......330 General factors in classification....332 Genesis in ore-classification....332 Literature of ore-deposits...... . 333 Criteria of ore-classification,..... 335 Primary grouping of ore-deposits..... 338 Hypotaxic deposits......341 Eutaxic deposits...... 341 Ataxic deposits....... 313 Secondary categories of ore-bodies....343 Ternary phases of ore-deposition.....344 Types of hypotaxic or surface deposits..... 344 Illustrations of eutaxic ore-bodies.... 347 Examples of ataxic ore-bodies.....352 Recapitulation.. .. .. .. 355 Prefatory. Much has been written on the genesis and classification of ore-deposits. Much remains yet to be written on the subject

Jan 1, 1901

By Thomas Cox

THIS paper makes no claim to any new idea; it simply reviews the Treasury Department Regulations pertaining to the practical application of depreciation and depletion and other allowances governing taxation of oil and gas properties. Other methods may be existent, but as they may not conform to the legal status they must be discarded. In complying with the present laws governing the, industry with regard to taxation and the allowable deductions therefrom, the following considerations are essential: Depletion, depreciation, amortization, other allowances, and items not deductible. It is definitely understood that depletion is the loss or exhaustion sustained in the continuous operating of an oil and gas property, and that each unit of oil or gas taken out reduces the value of the property until its final exhaustion. Depletion applies only to the natural deposits of oil and gas due to their-removal in the course of exploitation of any property. Depreciation is defined to cover the waste of assets due to exhaustion, wear and tear, and obsolescence of the physical property, and is separate and distinct from depletion; its allowance is that amount which should be set aside for the taxable year in such sums as for the useful life of ,the property will suffice to repay its original cost-or its value as of Mar: 1, 1913, if acquired by the taxpayer before that date-less the salvage value at the end of such useful life. Amortization is allowed for such facilities as were built or acquired on or after Apr. 6, 1917, for the production of articles contributing to the prosecution of the war and, in the case of vessels, those built and acquired after that date. The amount to be extinguished, in general, is the excess of the unextinguished or unrecovered cost of the property over its maximum value under stable .post-war conditions.

Jan 9, 1920

By Henry M. Bates, Roscoe Pound

Mr. Chairman and Gentlemen: I accepted your Chairman's invitation to speak to a group of experts in this field with the greatest hesitation, because I know little or nothing about it. Certainly I can make no detailed suggestions, or suggest planning along very definite lines. You cannot do that sort of thing in a vacuum, and as I have suggested, my knowledge of the whole oil problem is next to nothing. It is possible that as a student of our public law, constitutional law particularly, for a number of years, I have acquired a perspective that may enable me to offer, for what they are worth, some general thoughts on these problems. I think that nothing in the whole field of law requires more definitely and clearly the functional approach than does the problem of a sound legal solution of the difficulties of the oil and gas industry. The industry is dealing with substances that are peculiar, and one must know how those substances act and what has been the history of the industry, to undertake to make anything like specific suggestions. I certainly am not qualified.

Jan 1, 1935

By D. Swan

Industrial research may be defined as a critical and exhaustive investigation to create new and better ways of doing things. The results of industrial research are new and improved products, processes, and techniques. This broad definition, of course, covers investigation of all subjects by either individuals or groups of people, and this chapter aims to examine the purpose (what research tries to do), and methods (or how research is done) as applied in the mineral industries. Concepts and History The idea or concept of organized research probably originated in the universities of Europe. There, groups of scholars banded together for discussion and application of their particular specialty to a common problem. Publication of the conclusions drawn from such investigations gave scholars in other areas the opportunity to review and criticize the work of their colleagues, and one of the hallmarks of scientific research work is the publication and criticism of the results of the investigation. It was not until the late nineteenth century that the concept of organized research for the profit of industry was recognized. During the late nineteenth and early twentieth centuries, a large number of industrial enterprises sponsored organizations to study the application of the physical sciences with the aim of making discoveries that would result in profit to the sponsoring organization. The tangible benefits accruing from these activities were so great that they, in turn, fostered several other methods for the support of organized research activities. For the large problems involving public interest, United States Government scientific re- search laboratories were set up. As the demand of smaller enterprises for research activities increased, research institutes and consulting laboratories were organized. In Europe the idea of common industry sponsorship of research centers grew and many large research organizations there were sponsored by associations of manufacturers. Finally, in the United States

Jan 1, 1959

By A. C. Fieldner, W. A. Selvig

Ash in coal has always becri regarded as an undesirable substance, as the heat content of a coal dccreases in direct proportion to its ash contcnt. It represents so much inert materid that has to be transported, handled when the coal is burned, and finally disposed of. W. R. Roberts, in an address bcfore the Engineers' Society of Western Pennsylvania, Pittsburgh, on Sept. 29, 1925, said that on an annual output of five hundred rnillion tons of coal, a reduction of 3 per cent. of ash means fifteen million tons of refusc and a decrcase of $30,000,000 in freight charges. Ash also often prevents effieient utilization of the coal through the formation of clinker causcd by the mcltirig of the ash constituents when subjected to heat. The mineral constituents of coal may be of such nature as to make the coal unsuited for speeifie uses as for instance, high-sulfur coal for making metallurgical coke. While the usual proximate analysis of coal gives the amount of ash, it gives no information as to the nature and coniposition of the ash nor of the minera1 constituents from which the ash is produced. For the efficient washing of coal to remove ash-forining constituents it is desirable to know the composition and distribution of the ash-fonning constituents. Obviously such information is also desirable for the most efficient utilization of coal. Nature and Composition of Coal Ash Coal ash may be defined as the inorganic residue remailning after cornplete ignitior of coal. It is dcrived from the mineral constituents of thc coal. The ash-forming constituents may be roughly classified as inherent impurities and extraneous impurities. The former are mixed intimately with the coal substance, and arc derived either from the original coal-forming material or from external sources such as sedimentation and preeipitation while the vegetal coal-forming plant remains accumulated. The latter are present in the coal bed as partings, bands or nodules of pyrite! slate, shale, calcit,e, bone, etc. These are formed either during the laying down of the coal bed, or subsequently. Flag-

Jan 1, 1927

By G. St. J. Perrott

A study of certain fundamental characteristics of liquid-oxygen explosives has been made. A discussion is given of the factors affecting the life of the cartridge and the relation between explosive strength and oxygen content. The explosive properties of L.O.X. cartridges packed with a variety of lampblacks, gas blacks, and other materials have been experimentally determined by means of the ballistic pendulum, Bichel gage, and measurement of the rate of detonation. DURING the past year, the Bureau of Mines has carried on an investigation of liquid-oxygen explosives (L.O.X.) to supplement the work described in previous publications.' The present paper gives results of the first part of this work, which was a laboratory investigation of the properties of typical combustibles used in L.O.X., and the relation of these properties to the absorption and retention of oxygen by the explosives and their explosive characteristics. No attempt will be made to describe the development of liquid-oxygen explosives, because this phase of the subject has been well covered. The L.O.X. cartridge consists of a paper wrapper filled with an absorbent combustible material that is saturated with liquid oxygen by soaking it therein. After saturation, the cartridge is removed from the liquid and fired with fuse and cap, or electric detonator, in a manner

Jan 12, 1924

By K. C. Sclater, B. R. Stephenson

Recent progress in oil-recovery methods has brought into prominence gas-energy relations in oil sands. The greater the effort made to utilize this gas-energy relationship to the best advantage in oil recovery, the greater becomes the need for more precise information concerning physical conditions as they actually exist in an oil well. The intelligent use of gas-oil ratios when considering production efficiency has been the subject of much recent discussion. It has been stressed that the pressure as well as the volume of gas must be known when considering the efficiency of a producing well on an energy basis. When methods of production are compared on an energy basis it implies a knowledge of pressure, temperature and physical properties of the fluids at the bottom of the well. In questions concerning gas-lift and the pressure control of wells usually there is a wide variance of opinion among engineers when energy relations come up for discussion. Perhaps this difference f opinion can be traced to erroneous assumptions made with regard to the physical conditions existing within the well. If erroneous assumptions are made it follows that computations based on these assumptions will give results which also will be in error. That erroneous assumptions are made is not to be wondered at because when handling a fluid composed of gas and oil, we are dealing with a complexity of hydrocarbon components each varying to some degree in physical and chemical properties. This means that the physical state of the gas and oil will depend not only on temperature and pressure but that it will be influenced also by the relative amounts of the various hydrocarbon components present. If water is present the problem becomes still more complicated. From these considerations alone it would appear that we can well afford to give some thought to devising more positive methods or means for obtaining data on physical conditions within the well rather than depend entirely on computations from casinghead data. If these data

Jan 1, 1929

By J. D. Lubahn

Prior tests by Dorn, where the strain rate in a tensile test was suddenly changed, have shown a small, but definite rate-history effect to exist. If this effect is neglected in the calculation of creep behavior from tensile results, an error should occur. This paper shows that this error is smaller than experimental scattering, and may be neglected. DORN1 has found a small but definite rate-history effect in the aluminum alloy 250 at liquid-nitrogen temperature using tensile tests with an abrupt rate change. Such an effect is to be expected from pre-viously known2-6 temperature-history effects, together with general experience that effects produced by changing the strain rate a large amount are simi-

Jan 1, 1959

By B. Tani, K. Anderson, I. Johnson, R. Schablaske

INVESTIGATION of the various rare earth-cadmium binary systems discloses the existence of a compound corresponding to the composition MCd6 in all systems save the La-Cd system. Lattice constants for all of the MCde compounds, except LaCd6 which apparently does not form, and PmCd6 whose synthesis was not attempted, are also recorded herein. Iandelli and Ferro 1 report the existence of the compound CeCd6. No additional information, structural details, and so forth are given. Elliott and Lemons2,3' have measured the vapor pressure of cadmium over CeCd6 and have calculated the activity of cadmium in solid CeCd6. These authors find that CeCd6 exists over a composition range from 5.967 to 6.098 (Cd:Ce ratio) at 584oC, and from 5.971 to 6.118 at 639°C. The following is an excerpt from the paper by Elliott and Lemons: 2 "Recently Mr. F. H. Ellinger of this laboratory has indexed an X-ray diffraction powder pattern of CeCd6.00 which we had prepared by gas phase reaction. The compound has a primitive cubic unit cell with a = 15.783 + 0.001A Based on the volume of the cubes surrounding an elemental cerium or an elemental cadmium atom, Mr. Ellinger finds room for 24.10 CeCd6 formula units in the CeCd6 unit cell; similar calculations based on CeCd2 and CeCd11 yield 24.18 formula units per unit cell. The presence of 24 CeCd6 units per unit cell seems probable with an X-ray density of 8.255 grams per cubic centimeter. The most one can say about in-terstitial~ is that there appears to be room in the crystal even at room temperature." Measurements of the solubility of the rare earths in liquid cadmium4 led to the discovery of GdCd6,

Jan 1, 1964

NEW MEMBERS The following list comprises the names of those persons who became members during the period of Apr. 10, 1917, to May 10, 1917. ANDERSON, GEORGE K., JR., Supt., Iron Ore Mines, The Low Moor Iron Co. of Va., Longdale, Va. AVERY, DAVID, Met Collins House, Collins St., Melbourne, Vic., Australia. BATES WILLIAM T., Shift Foreman, American Zinc Co. of Tenn., Mascot, Tenn. BIRD, ELMER, Min. & Civil Engr P. O. Box 1483, Boise, Idaho. BLACKBURN, JOSEPH R., Vice-Pres. & Genl. Mgr., Austen Coal & Coke Co., Austen, Preston Co., W. Va. BOTSFORD, FRANK P., Asst. Genl. Supt., Eastern Mesaba, Pickands Mather & Co., Gilbert, St. Luis Co., Minn. BRADEN, SPRUILLE, Min. Engr., Andes Exploration Co. of Maine, Casilla 83-D, Santiago, Chile South America. BROWNE, DAVID G., Mill Designer, New Jersey Zinc Co., 55 Wall St., New York, N. Y. BRUDERLIN, EMIL J., Met. Engr., Ohio & Colorado Smelt. & Ref. Co., Salida, Colo. CAMPBELL, DONALD C., Min. Engr., Campbell Wells & Elmendorf, 114 James St., Seattle, Wash. CARRIGAN, J. J., Asst. Genl. Supt. of Mines, Anaconda Copper Min. Co., Butte, Mont.

Jan 6, 1917

By C. S. Duncan, S. Scuro, D. R. Muss

Work is vepurted which was aimed at accentuating the pec14liar attributes of the GaAs laser diode, namely its sutzull size and its high efficiency. This has been done by reducing- transport losses in the bulk p and n regions of the diode and combining many of. these diodes into series stacks with common optical cazlities. The result of this effort is a nearly monochromati source at about 8450A With a luminous areu 0.05 by The GaAs laser diode is an attractive pulsed light source in the near ir because of its ability to emit very large pulse powers and its small size. In addition to this, the device is efficient; and the higher the 0.05 cm emitting peak pulse po we rs at greater than 300 LC at repetition rates below 200 pps into a cone about 0.01 steradians when operated at 77°K. The results of nzeasuvetnents of peak optical power and spectra frorr~ these stacks are reported and some conclusions are drawn about the vole the individual diodes play in the stacked operation. peak output power, the more efficient it is. The limit for the amount of power that these diodes can emit is the transient and average dissipation associated with the pumping pulse. This power dissipation arises primarily from transport across the bulk regions of the diode; this fact, along with the relatively low thermal conductivity of the GaAs, led us to the conclusion that higher power

Jan 1, 1968

By J. A. Danko, C. D. Pears, L. D. Schmidt, J. P. McGee

This paper describes a pilot plant built on the campus of West Virginia University by the Federal Bureau of Mines station at Morgantown, West Virginia, for gasifying pulverized coal in a mixture of oxygen and steam at pressures in the gasifier up to 450 psig. The work upon which this report is based was done under a cooperative agreement between the Bureau of Mines and the West Virginia University. The goal of Bureau of Mines work at Morgantown is development of a low-cost process for producing mixtures of carbon monoxide and hydrogen for the modified Fischer-Tropsch synthetic-fuel plants, which may be shifted to produce hydrogen for coal-hydrogenation plants. Gasification with oxygen offers the inducement that the gas may be generated at the pressure at which the gas will be utilized in a gas-synthesis plant. Since the optimum pressure for the synthesis appears to be about 400 psig, the gas should be produced at approximately 450 psig to take care of pressure drops in the purification train and control valves. If the gas is generated at the pressure of utilization, only the oxygen need be compressed, not the raw synthesis gas. This means a saving in power of 5 hp per hour per 1000 cu ft (CO + H2), which is approximately a saving of 4 cents per gallon of gasoline. For example, consider a commercial plant generating 18,000,000 standard cubic feet per hour of raw gas that would produce approximately 10,000bbl of liquid product per stream-day. Assume that this gas would be 85 pd CO + H2 and that the oxygen required would be 320 cu ft per 1000 cu ft of CO + H2. The following estimate is based on a commercial centrifugal compressor. If the 18,000,000 std cu ft per hour of synthesis gas is compressed to 450 psig with 74 pd efficiency, 107,000 hp is required for compression. If the synthesis gas is generated at 450 psig pressure, only

Jan 1, 1953

By C. F. Frey, P. J. Ahern, J. F. Wallace

THE high affinity of molten titanium for oxygen and nitrogen has resulted in considerable difficulty in developing a satisfactory melting procedure. It has been found necessary to perform melting operations either in a vacuum or inert atmos-phere, and failure to obtain a satisfactory crucible material has necessitated the use of special melting techniques. These techniques have included cold-mold arc-melting utilizing both consumable and nonconsumable electrodes, skull-melting, drip-melting, and levitation melting.' It has been recognized generally that the melting of both titanium sponge and titanium scrap would be expedited by the use of induction-melting procedures but the lack of a crucible capable of containing molten titanium without objectionable contamination thus far has prevented the use of induction-melting procedures. An extensive investigation: which included the common refractory materials was not successful in developing a satisfactory crucible for induction-melting. Some success in induction-melting has been attained with the use of a graphite crucible material, but in all instances sufficient carbon contamination was encountered to cause an appreciable reduction in the optimum mechanical properties of the titanium or titanium alloys. These investigations"" report an increase in the carbon content from approximately 0.3 to 1.0 pct. A serious reduction in the tensile and forming properties has been observed as a result of this carbon contamination. The development of a satisfactory induction-melting procedure for titanium without undue contamination undoubtedly would have considerable economic significance. Such a process would be particularly useful in melting the large quantities of low-cost scrap now available that can only be reprocessed at considerable expense and difficulty by the more elaborate techniques referred to previously. In addition, the process could provide a satisfactory method of melting and alloying of bri-quetted sponge for forging ingots.

Jan 1, 1959

By Herbert D. Drechsler

Mining Finance-is the interrelated aspects of "determining the total amount of funds to employ in a mining firm; allocating these funds efficiently to various assets; and, obtaining the best mix of financing in relation to the overall valuation of the firm". The first section is an overview of the financing problem through examination and discussion of the Balance Sheet and Income Statement. The next section is a discussion of the nature of the criteria developed in feasibility study. The third section describes type of capital funds, and the final section describes case studies of mining finance.

Jan 1, 1978

By A. J. Lyon, J. B. Johnson, Samuel Daniels

The wrought alloys of aluminum with small amounts of copper and of magnesium have, with the development of the automotive and aircraft industries, sprung into prominence through the medium of duralumin; but the cast alloys remained in the background because their possibilities in the heat-treated condition were either not recognized or not fully investigated. In 1919, the Bureau of Standards published a preliminary survey1 of this field, which pointed out that, in general, the ultimate strength and the percentage of elongation of the alloys of aluminum with and without magnesium could be improved by so simple a treatment as heating at 932' F. (500" C.) for 2 hr., cooling in air, and aging at room temperature for several days. British investigators, too, working with chill-cast material, found that" considerable improvement in the mechanical properties of copper-aluminum alloys may be obtained from suitable heat treatment applied to castings."' Jeffries and Gibson8 made the first contribution to the literature dealing exclusively with the heat treatment of sand-cast aluminum-base alloys, describing the effect of small additions or of combinations of copper, magnesium, and iron on the response to a short heat treatment comprising heating at 932" F. in a nitrate bath for 1 hr., quenching in fish oil, and reheating at 300' F. for for 1 hr. Their results disclosed the facts that the ultimate strength and the percentage of elongation of sound alloys were usually, and quite uniformly, improved by heat treatment; that with the iron content ranging between 0.36 and 0.88 per cent. and the silicon content between 0.24 and 0.60 per cent. the effect of increasing the copper content (Tables 10

Jan 1, 1925

By E. A. Lucero, H. E. Robbins, T. H. Dudley

EL Salvador mine of Andes Copper Mining Co., E subsidiary of Anaconda Co., is in northern Chile about 18 miles north of Potrerillos, 7825 ft above sea level. Initial production is planned for the first half of 1959. Plant capacity will be 30,000 tpd, and there are 308,835,000 tons of proven ore reserves, averaging 1.49 pct Cu. The Inca adit is being driven as part of the mine-to-mill haulageway. Because of the overburden it is planned to mine the deposit by block caving. Ore will be dropped from upper gathering levels through ore passes to the Inca adit, through which it will be transported out of the mine to the primary crushing plant located a half mile from the portal.

Jan 3, 1958