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By C. M. Young

THIS is an attempt to bring together some of the knowledge of the .coal-forming conditions obtaining during the Pennsylvanian period in the Western Interior Coal Province, to sketch briefly the present extent and character of the coals produced, and to show the beginning of cor-relation of beds over wide areas. Coals of later age than the Pennsyl-vanian are not included and, for reasons that will appear later, little attempt is made to cover the districts of eastern Oklahoma and western Arkansas, and northern Texas is omitted entirely. GEOLOGICAL CONDITIONS The conditions that made possible the formation of large coal beds in the United States were most favorable in the Pennsylvanian period, formerly known as the Upper Carboniferous. The geological conditions can be determined from the records, but not the reasons for them. Preceding the Pennsylvanian was the Mississippian, formerly known as the lower Carboniferous and still later as the sub-Carboniferous. Dur-ing this time, large bodies of limestone were deposited and at the close f the Mississippian they were warped upward and for along period were eroded. Then there began a period of subsidence, more or less inter-rupted at times, during which the Pennsylvanian strata were deposited (see table on page 2). " These consist of sandstones, limestones and shales, with occasional coal beds: At the beginning of the Pennsylvanian there was subsidence, which allowed the sea to extend over the eroded Mississippian surface to the north and east, extending over eastern and central Texas, a large part of Oklahoma, with a projection into Arkansas, over Kansas and part of Nebraska, all the northern and western part of Missouri, a large part of Iowa except a strip in the north, most of Illinois, practically all of Ken-tucky, northern Tennessee, most of Indiana, all of the eastern part of Ohio, practically all of West Virginia, western Maryland, the west end of Virginia, and a large part of Pennsylvania. The Ozarks were already

Jan 1, 1935

By M. King Hubbert

In 1856 Henry Darcy described in an appendix to his book, Les Fontaines Publiques de la Ville de Dijon, a series of experiments on the downward flow of water through filter sands, whereby it was established that the rate of flow is given by the equation: q= - K(h2- h2)/I1 in which q is the volume of water crossing unit area in unit time, I is the thickness of the sand, h1 and h2 the heights above a reference level of the water in manometers terminated above and below the sand, respectively, and K a factor of proportionality. This relationship, appropriately, soon became known as Darcy's law. Subsequently many separate attempts have been made to give Darcy's empirical expression a more general physical fornzulation, with the result that .so many mutually inconsistent expressions of what is purported to he Darcy's law have appeared in published literature that sight has often been lost of Darcy's own work and of its significance. In the present paper, therefore, it shall be our purpose to reinform ourselves upon what Darcy himself did, and then to determine the meaning of his results when expressed explicitly in terms of the pertinent physical variables involved. This will be done first by the empirical method used by Darcy himself, and then by direct derivation from the Navier-Stokes equation of motion of viscous fluids. We find in this manner that: q = (N4(p/p)[g - (l/p) gradPI = WE, is a physical expression for Darcy's law, which is valid for liquids generally, and for gases at pressures higher than about 20 atmospheres. Here N is a shape factor and d a characteristic length of the pore structure of the solid, p and IL are the density and viscosity of the fluid, a = (Nd2)(pip) is the volume conductivity of the system, and E = [g - (l/p) grad p] is the impelling force per unit mass acting upon the fluid. It is found also that Darcy's law is valid only for flow velocities such that the inertial forces are negligible as compared with those arising from viscosity. In general, three-dimensional space there exist two superposed physical fields: a field of force of charucteristic vector E, and a field of flow of vector q. The force field is more general than the flow field since it has values in all space capable of being occupied by the fluid. So long as the fluid density is constant or is a function of the pressure only, curl E = 0, E = - grad F where F = gz + dp/p The field of flow, independently of the force field, must satisfy the conservation of mom, leading to the equation of continuity div pq = — f ap/at , where f is the porosity, und t is the time. For steady rnotion ap/at = 0. and div pq = 0 .

Jan 1, 1957

L. C. GRATON, Cambridge, Mass.-I should like to ask the authors if they attempted to draw any analogies with the manganese deposits at Franklin Furnace, N. J., and whether there are. any traces of zinc in these Brazilian-deposits. J. T. SINGEWALD, JR.-We did not think of them at all as analogous to the Franklin Furnace deposits and there is no appreciable percentage of zinc present. If these ores do contain zinc it could be there 'only as a fraction of a per cent. F. LYNWOOD GARRISON, Philadelphia, Pa. (communication to the Secretary *).-There is no disputing the fact that the manganese ore ,supply situation in this country demands serious consideration and is a matter of fundamental public concern. We are consuming this material at a steadily accelerating rate and there is no hope for a proportionate increase in the domestic supply. In the year 1916, this country imported 560,000 tons and produced only 27,000 tons from our own territory In 1915, the local production was 9,709 tons, which on its face shows the American output to have tripled during the past year. Those of us who are familiar with the

Jan 4, 1917

By G. L. Corrigan, J. R. Coleman

Four factors that largely determine the end product obtained when cement and water are mixed are the chemical compo ition of the cement, the fineness to which the cement is ground, the amount of mixing water used, and the procedure used in mixing the slurry. In order to study the effect of two of these factors, the other two, the chemical composition and method of mixing, are kept constant, leaving as variables fineness and water-cement ratio. Through years of experimentation and usage it has been well established that the reduction of cement clinker to a very fine state by grinding improves its cementing value, principally because the reaction between cement and water takes place only at the surface of the cement particle, further action being hindered by the accumulation of reaction products that tend to coat the unreacted material. Therefore, the more finely ground a cement, and the greater the surface exposed in proportion to its mass, the more rapid is the hydration rate. Similarly, the greater the surface exposed, the greater the proportion of the cement that reacts, and the lower the amount of residue that is unreacted and so remains inert and unable to make any contribution to cementing properties.1 Although it is more expensive to manufacture a finely ground cement than a coarser cement, the advantages of fine grinding of construction cements were so marked that the fineness of cement has increased considerably in past years. When the manufacture of special oil-well cements was begun, it was necessary to consider properties of cement that previously were considered of minor importance, foremost of these being pumpability. Since, with the water-cement ratio constant, a finely ground cement will produce a neat slurry of higher consistency and shorter time of pumpability than will a coarser cement, there is a tendency to grind oil-well cements to a lower degree of fineness. Therefore, in order to produce oil-well cements that will make a slurry having a long time of pumpability, cements are manufactured that because of their coarseness generally are poorer cementing materials than some of the more finely ground construction cements. On the other hand, often it is necessary to pump oil-well cements for long periods of time to place them properly behind a string of casing in a deep well, and since high strength is not of foremost importance for such cement, there is room for considerable controversy concerning the proper fineness range.

Jan 1, 1941

By N. H. Emmons

In the United States the value of gold- and silver-ores is everywhere reckoned in ounces troy of the metal per " short ton " (2000 lbs. avoird.) of the ore. In the case of silver, which fluctuates in market value, the New York quotation on a given day must be known, in order to determine the gross value of an ore at that date. In Mexico the assay is reported 'in kilogrammes of silver or grammes of gold per metric ton. As everyone is aware, this is practically a percentage system, 1 kg. of silver per metric toll (1000 kg.) being 0.1 per cent., and 1 gramme of gold per metric ton, 0.0001 per cent. The notation is simple and convenient for both assayer and miner.* The Mexican government purchases at an unvarying price for silver, payable in silver, and at a fixed price for gold, payable in gold if the seller insists, but preferably in silver at about the rate of exchange between U. S. gold coin and Mesican silver coin. The value of silver is $40.915 per kilogramme in Mexican silver dollars. That of gold is $675.416 per kilogramme in gold coin. The mints do not, as a rule, issue gold dollars, as the government keeps them to pay the interest on the national debt. Almost all bullion containing a considerable percentage of gold is shipped to foreign countries (principally the United States) to be refined. The Mexican mint receives for refining and coining no bullion which is not at least .950 fine in gold and silver, separately or

Jan 1, 1902

By P. M. Budge, William L. Fink, Kent R. Van Horn

The investigation of the phase relations of high-purity aluminum-base alloys is a part of the fundamental research program of the laboratories of the Aluminum Company of America. The results of a number of binary and ternary systems have previously been published in the Transactions of this society. The aluminum end of the binary aluminum-titanium system has been studied. This system has received relatively little attention. To the authors' knowledge, there are two previous papers on this subject. E. van Erckelensl determined the constitutional diagram reproduced in Fig. 1. According to this diagram, the liquidus represents the separation of TiA14, (Ti = 30.7 per cent.). He concluded that this is the composition of the compound, because in his work the eutectic horizontal terminated at 30.7 per cent. titanium and the metallographic examinalion of a sample of this composition revealed only one phase. According to the constitutional diagram developed by W. Manchot and A. Leber,² reproduced in Fig. 2 from data given in their article, the liquidus represents the separation of the compound TiA13 (Ti = 37.2 per cent. ). The composition of the compound was derived in a manner similar to that utilized by van Erckelens. Moreover, Manchot and Leber confirmed the composition of the compound by analysis of the constituent left as a residue after dissolving the alloys in weak sodium hydroxide solution. Although these are the only publications describing the constitution of the system, other investigators have studied the composition of the titanium compound. L. WÖhler3 says that there is a compound TiA13 which was later confirmed by W. Manchot and P. Richter4 and by

Jan 1, 1931

By Howard S. Strouth

Investors and mining companies in the U. S. have recently shown increased interest in the Union of South Africa. This has been sparked partially by the founding in the U. S. of a large investment trust which will hold substantial shares in many of the leading gold and uranium producers. The average U. S, mining man's judgment of the Union, however, may be somewhat clouded by recent headline news. We are inclined to take a strong dislike to the stern measures of the present Union government with regard to its native majority. Others possibly think of South Africa in krms of a British colony which, under pressure of rising African nationalism, must eventually be abandoned. These concepts frequently suffer for lack of precise information.

Jan 5, 1959

By C. E. Reinhard

A USEFUL accelerated weathering test should be capable of placing any series of metals quantitatively in the same order of endurance as that noted under a particular set of actual exposure conditions. The development of such a test must necessarily depend to a considerable extent upon data obtained from a wide variety of exposures. This paper offers preliminary data from exposure tests on nine metals placed in 11 locations in the Lehigh Valley, within a radius of 20 miles from Palmerton. The exposure conditions vary from a severe industrial atmosphere to a pure rural atmosphere. The data are offered as evidence of the necessity for the identification and evaluation of the variables of corrosion and as illustration of some of the variations to be considered in the development of a useful accelerated test. It is quite clear, from this evidence, that a useful accelerated test must be versatile to the extent of showing the probable variations of corrosion resulting from differences in atmosphere as well as from differences in the metals. The paper is presented solely with the object of pointing out the wide variations in relative merits of several common metals in resisting corrosion and without any thought of initiating controversy regarding the, merits of particular metals. For this reason the metals are designated only by symbols in the tables and no key is given to these symbols.

Jan 1, 1929

By E. B. Swanson

There is only one way to transport natural gas and that is by pipe lines. In the past few years, these lines have been extended rapidly into areas which previously had been served mainly by solid and liquid fuels. In the subject given me, this extension is referred to as an invasion, which implies a rather forceful entry. Whether or not such an implication may be applied to recent natural-gas developments is unimportant. It is the fact of the extension, not its definition, which is important. For centuries, natural gas has been utilized for various purposes in many parts of the world. It was the foundation of fire worship at Baku. The Chinese used it for the evaporation of brine in salt manufacture. In our country, its history seemingly dates back 110 years to the vicinity of Fredonia, N. Y., where seepage gas was assembled and used for lighting purposes. A few years later, a %inch pipe was laid to a lighthouse on Lake Erie, and the early records of the Lighthouse Service tell of the difficulties surrounding this use. With the discovery of oil in Pennsylvania, there followed further development; the town of Titusville was piped with natural gas and, some few years later, gas was made available for manufacturing plants adjacent to the oil fields. For more than a half century, the industry was concentrated in the

Jan 1, 1932

By George A. Johnson, Leon H. Banks

The Missouri-Kansas Zinc Corpn., operating in the Waco district, 15 miles northwest of .Joplin, Mo., owns large tailing piles made during milling operations of the years 1918-28 by the Butte-Kansas, Acme, and Barnsdall mining companies, whose holdings have been purchased and consolidated under the ownership of the Missouri-Kansas Zinc Corpn. These tailings had been considered too low in value to be worth retreating by the ordinary methods. C. Erb Wuensch, consulting engineer of the Missouri-Kansas Zinc Corpn., noted the difference in the type of tailing from upper-level and lower-level ore. The latter contained hard lime chats. He also found that mill losses had been due to particles of blende on the corners or sides of the chats and to the existence of soft, porous, cellular, lime chats containing varying amounts of blende. He conceived the idea that a quick grind in rolls or hall rnills might change the type of the rnaterial so that jigging could rnake a clean tailing for discard and a partly concentrated product sufficient in blende content to justify the expense of fine grinding in hall mills to free the mineral entirely. A laboratory was equipped with the necessary machines and the writers were assigned the problem of developing a method of retreating the tailings. Laboratory Testing From preliminary drill sampling of each pile was obtained the blende content, the soluble sulfate content, and the general characteristics of the material to he treated. The tailings were a mixture of lime and flint with some shale. Visual examination showed most of the blende to be in the dolomite and very little in the flint, although there were some flint particles with blende on the cleavages. The blende was found as particles on the corners or cleavage faces in one type of chat and in another disseminated in a soft, porous, cellular lime. Because of the porosity of the latter type of chat, the apparent specific gravity, under hindered-settling conditions, is less than that of a solid piece of lime or flint. That it,

Jan 1, 1930

By C. E. Nelson

THE purpose of this discussion is to outline briefly the practices commonly followed in this country for the melting and refining of magnesium and its alloys. The processes used for the various forms of primary magnesium, as far as there are differences in the physical shape or behavior, will be discussed. The refining of general fine scrap or secondary magnesium was presented in an earlier paper.1 Inasmuch as the use of fluxes is an essential part of all the melting and refining processes, the principal aim of this paper will be to deal with these in sufficient detail to point out their unique characteristics, in order to make their use more effective. TYPES OF MELTING PRACTICE All melting and refining processes for magnesium and its alloys require the use of fluxes. These fluxes have a magnesium chloride base and other halide salts or oxides are added to give a density or behavior exactly suited to the particular melting practice. The successful handling of magnesium depends upon the proper use of the correct fluxes. There are four general methods of melting, summarized in the following paragraphs and treated in more detail in the section on Melting and Refining. Open-pot Method The open-pot method makes use of No. 230 flux.* The flux provides protection during melting and a molten pool of flux into which the solid magnesium melts. It is stirred through the molten metal bath and agglomerates oxide or similar foreign bodies; then on quiet standing separates away, leaving the refined metal ball floating in an encircling layer of molten flux. It forms only a thin fluid film over the surface of the molten metal, which may be parted for hand-ladling processes and tends to cover the metal again after the ladle is removed. A very light dusting of the pot surface with fresh flux immediately after the ladle is removed is usually desirable. The open-pot method is used generally in the following processes: (I) alloying and secondary smelting in the production of ingot, (2) in sand foundries for premelting and to a smaller extent for the production of small castings requiring hand ladling, (3) in permanent-mold founding for premelting and also direct ladling to castings, (4) for continuous methods of preparing metal in the production of billets or ingots from which wrought products are fabricated, (5) in general scrap recovery. Crucible Process The crucible process makes use of No. 310 flux, which has the property of being thinly fluid at the start, to provide protec-

Jan 1, 1944

By Emory Kemler

The problem of determining the most desirable operating conditions of an oil-well pumping unit or rig front, the selection of the proper material and size of sucker rods, and the design of a pumping unit require that sucker-rod loads be known with a reasonable degree of accuracy. The segregation of rig losses, the proper selection and operation of prime mover and reduction unit, and the analysis of the operation of subsurface equipment require a knowledge of polished-rod horsepower. The investigation of such problems as the instantaneous stresses set up in a pull-rod line or backside crank installation when the well is suddenly hooked on, a study of such problems as the effect of anchoring the tubing on rod load, tubing stresses and rod horsepower, and an analysis of the effect of subsurface equipment on rod loads make it necessary to have a dynamometer that is rugged, which can follow the sudden changes in load without any lag or damping effect, which will record the load in its true position with respect to polished-rod movement, and which will give a card large enough to allow the desired effects to be measured accurately. The inadequacy of the spring or fluid-pressure type of dynamometers has been covered in detail1. The data given show that dynamometers of the spring or fluid-pressure type exert a damping action on the peak loads and the inertia and friction of their load-indicating mechanism introduces a phase lag in recording the load. A dynamometer of that type will not give the load in the correct amount and will not record it in its true position with respect to stroke or time. New Type of Dynamometer Fig. 1 shows a magnetic strain-gage type of dynamometer, to be described in this paper. The strain gage A is used for measuring the load in the polished rod, a washer B and knife edge C take care of initial misalignment and reduce bending in the compression tube of the strain gage. The complete instrument can be transported in the carrying case E.

Jan 1, 1935

By J. J. Bodmer

THE substances or materials employed in this manufacture, are the same as those used in the preparation of mortar and concrete, viz., the different kinds of lime and sand. Instead of, or in conjunction with, sand there may be used calcined clay, blast-furnace slag, clinkers or ashes from furnaces, natural puzzolana, powdered chippings from stone quarries, etc. Of the different kinds of sand, pit-sand-siliceous sand, as it commonly occurs mixed with gravel-and the sand found on the seashore, where the salt has been washed out by long exposure, whilst out of reach of the tide, may be used. The purer the above-named materials are from admixtures of clay, earth, or organic substances, the more complete will be their combination with the lime, the quicker will the manufactured brick or block set, and the more satisfactory will be the quality which it ultimately attains. For this reason, subdivided blast-furnace slag is preferable in most cases to sand, and the only sand which, in reference to setting capacity, is analogous to blast-furnace slag, is the volcanic sand occurring in different localities in North and South Wales, as an almost pure calcined silica. The lime used for the manufacture may be either slaked or unslaked. In the first case, (slaked), in order to obtain satisfactory results, the lime must be strongly hydraulic. The use of unslaked lime, however, is by far preferable. A process for using fresh or unslaked lime has been patented in England by Major-General Scott. Lime thus prepared is called " selenitic lime," and consists of a mixture of fresh (un¬slaked) lime with sulphate of lime, or plaster of Paris. The gray-stone lime, for instance, found by the Medway, is mixed with from 5 to 7 per cent. of plaster, which has the effect of keeping the lime from slaking when water is added. This mixture also partakes of the nature of cement, and when used for mortar, or concrete, attains in a shorter time a greater degree of hardness than the same lime would ever have obtained after being slaked. Bodmer's process for the manufacture of artificial stone bricks consists chiefly in the use of automatic measuring, forwarding, and mixing apparatus, by means of which the materials are supplied and unite in a continuous stream, and are accurately measured. They

Jan 1, 1874

[JAMES A. BARR Consulting Engineer Mt. Pleasant, Tennessee Washington, D.C. BEHRE DOLBEAR & COMPANY Consulting Mining Engineers and Geologists 11 Broadway New York 4, N. Y. BLANDFORD C. BURGESS Registered Professional Engineer Mining Consultant Montieello, Georgia GLENVILLE A. COLLINS Mining Engineer Uranium examinations Cable "Coins" 210 La Arcada Bldg. Santa Barbara, Calif.]

Jan 1, 1952

JAMES A. BARR Consulting Engineer Mt. Pleasant; Tennessee Washington, D.C. BEHRE DOLBEAR G COMPANY Consulting Mining Engineers and Geologists 11 Broadway New York 4. N. Y. BLANDFORD C. BURGESS Registered Professional Engineer Mining Consultant Monticello, Georgia LENVILLE A. COLLINS Mining Engineer Uranium examinations Cable "Coins" 210 La Arcada Bldg. Santa Barbara, Calif.

Jan 1, 1952

JAMES A. BARR Consulting Engineer Mt. Pleasant. Tennessee Washington. D.C. BEHRE DOLBEAR G COMPANY Consulting Mining Engineers and Geologists 11 Broadway New York 4, N. Y. BLANDFORD C. BURGESS Registered Professional Engineer Mining Consultant Monticello, Georgia GLENVILLE A. COLLINS Mining Engineer Uranium examinations Cable "Coins" 210 La Arcada Bldg. Santa Barbara, Callf.

Jan 1, 1952

By A. R. Rule, D. C. Dahlin, D. E. Kirby

The US Bureau of Mines is currently engaged in research to characterize complex, low-grade western phosphate rock and to develop methods for economic recovery of phosphate, as part of a government effort to assure an adequate supply of fertilizer minerals. Western phosphate varies from soft, friable, altered phosphatic shale to hard, tightly cemented, unaltered phosphate rock. To supplement current methods of beneficiation (normally restricted to sizing), the USBM has developed a flotation procedure that includes depression of phosphate minerals with H2SiF6 and anionic flotation of carbonate minerals, followed immediately by cationic flotation of silicate minerals. Tested on several different ore types, the procedure has yielded phosphate concentrates that range in grade from 28 to 31% P2O3 with a phosphate recovery factor of 60 to 70%.

Jan 1, 1978

By A. K. Sinha

The market for thermal coal has recently been growing rapidly and it is projected to continue to do so in the foreseeable future. Both the national and international markets often demand high-Btu low-sulfur thermal coal in order to minimize the cost of utilization and meet the environmental restrictions. High quality thermal coal can be prepared to compete in the utility market by desulfurizing the high-Btu midwestern coal and blending it with low-sulfur western coal which is usually low in Btu content. The methods that can be used for optimizing the coal preparation plant operating parameters for physically desulfurizing coal are presented.

Jan 1, 1985

By Frank C. Greene

Drilling in Missouri in 1943 continued at a lower rate than in 1942, only 28 wells being completed. Following the completion of the Cities Service Oil Company's No. I Jim Cook near Tarkio, in the northwest corner, NW. 'fi sec. 32, T. 65 N., R. 39, W., Atchison County, four dry holes were drilled by other parties, all a mile or more from the Cook well. Later the Cities Service Oil Co, completed No. 2 Cook for 60 bbl. Table I gives a summary of activities by counties. The total footage drilled was 23,83134 ft., of which 12,802 1/2 ft. was by cable tools and 11,029 by rotary. Four of the dry holes were drilled into Mississippian or older beds.

Jan 1, 1944