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By Gilbert Doan

AN extensive program of investigation is being carried out at Lehigh University in the study of arcs and arc welds of high-purity iron1, spon-sored by the Engineering Foundation. The part of that program reported in the present paper deals with welds made of high-purity iron in an argon atmosphere and for comparison with them welds made of the same iron in ordinary air. Welds of commercial steel also were made in argon and in air. The primary purpose of the study is to discover the basic physical constants of iron welds when not contaminated either by impurities in the iron or by the action of oxygen and nitrogen of the air during welding. Upon these constants can be founded such future studies as will determine what effects the various impurities and alloy elements present in steel have upon its welding characteristics, and what influence is exerted by the action of oxygen and nitrogen. The welding of steel involves such a multitude of variables, both of composition and of procedure, that development in the fabrication of this most important metal has necessarily been slow, wasteful, and in many instances discouraging. In the present investigation, the simplest possible condition has been selected; namely, iron practically free from contamination and a nonparticipating atmosphere, the inert gas argon. This simplification reduces the number of variables to a point where more rigid control of the system is possible. Although this study is significant for the contributions it makes to the science of steel fabrication, yet it is hoped that it will not be without value also in increasing knowledge of the nature and behavior of iron and steel in general. From the standpoint of open-hearth practice, and to

Jan 1, 1936

Some years ago it was my good fortune to inspect some coal properties in Germany, and the most striking impression I received on my trip was that in that country every one in the coal industry, miners and operators, was proud of the fact-not apologetic about it-and that industrially coal was looked upon as a King. The explanation, of course, was that at least 90 per cent of the entire mineral value produced in Germany was from coal, and that it was the very foundation of the nation's industrial life. The feeling was so different from that existing in the United States among those engaged in producing coal that it made a profound impression on me, and many times since then I have speculated about the reasons for the difference in opinion in the two countries. Here, of course, our units are much smaller and more numerous, there is not so large a proportion of technically trained men, and we have the American trait of depreciating the things we do at home; but among those not actively

Jan 1, 1939

By E. S. Greiner

Germanium and silicon have been plastically deformed in torsion at elevated temperatures. Slip took place on the four {Ill} planes. Dislocations, revealed by etch pits on a (111) face, occurred in rows that were traces of operative slip planes. THE plastic deformation of germanium and silicon by bending and tension at elevated temperatures has been reported by Gallagher.&apos; Transla-tional slip during plastic flow in these materials, according to Gallagher&apos; and Treuting,&apos; occurs on (111) planes. Recent work by Treuting&apos; indicates the direction of slip to be <1l0>. The present paper describes the plastic flow characteristics of germanium and silicon deformed by torsion. Torsional deformation was accomplished by twisting 1/4x1/4x2 in. specimens held in molybdenum grips and contained in an atmosphere of helium in a transparent quartz tube and heated by an external resistance furnace. The angular displacements were measured on a graduated circle with a pointer attached to the movable grip. Temperatures were measured with a chromel-alumel couple; the hot junction was within the quartz tube and in close proximity to the specimen. Photographs of samples of germanium and silicon twisted at 850" and 1180°C, respectively, are shown in Fig. 1. The germanium was twisted 230" per in. and the silicon 80" per in. These deformations are larger than those used in experiments to be described later and are presented only to emphasize the extensive plasticity of these materials. Germanium A single crystal specimen of germanium (n-type, 7 ohm-cm resistivity) with a (111) plane normal within 3" of the torsion axis, Fig. 2, was chemically polished with CP-4 solution" and then twisted 9" during the twisting of these specimens of germanium, the slip lines from the (lli) plane should have appeared in the four lateral faces instead of in only two. Perhaps the absence of rotational slip is brought about by the square cross-section. A cylindrical specimen would have a more uniform stress distribution in torsion than one with a square cross-section, and may deform by rotational slip. A specimen of germanium (n-type, 5 ohm-cm resistivity) twisted less than 8" per in. at 550°C, was cut to expose the (111) face 19" 28&apos; from the torsion axis, Fig. 4a. This face, after metallographic

Jan 1, 1956

By Ralph A. Sherman, J. M. Pilcher

BY surface treatment of coal is meant the application of a material, either solid or liquid, to the surface of pieces of coal. The purposes of surface treatment are varied. They may be to identify or "trade-mark" the coal, to modify the burning characteristics, the coking tendencies, or the behavior of the ash, to prevent the freezing of wet coal, or to control the dust. The control of dust is the usual purpose of surface treatment. TRADE-MARKING COAL The application of color to the surface of coal for the purpose of identification and registration of the trade-mark has been practiced to some extent. In 1928, the Glen Alden Coal Co. began to color its coal and adopted the trade-mark, "Blue Coal." The Old Ben Coal Co. later followed a similar practice with "Green Coal." A commoner means of identification of coal has been the stenciling of designs or pasting labels on large lumps or in the distribution of small cardboard tags through the smaller sizes. The details of the method used to color coal have not been revealed. Usually all of the coal is not treated, because of the expense. Only enough pieces are colored to show clearly when distributed through the coal. The patent literature gives information on some of the methods proposed. Esselen and Weiss 1 have patented the deposition of a coloring material in the valleys of the surface of the coal. Sperr2 covers the quenching of coke with water containing a pigment or dye that will deposit on the coke. He also suggests electroplating with copper or nickel. Glinsmann 3 subjects the freshly fractured coal surface to the action of an alkali or alkali earth ferricyanide and a ferric salt. Barsky and Hanson4 specify a method for the application of the same chemicals covered by Glinsmann.

Jan 1, 1943

By S. Usui, I. Iwasaki

The effect of pH on the adsorption of dodecylamine at the mercury-aqueous solution interface was investigated by differential capacity and electrocapillary measurements. With dodecylammonium acetate, the differential capacity curves showed two desorption peaks in the cathodic branch with their relative intensities varying with the solution pH. With dodecyltrimethylammonium chloride, only one cathodic de-sorption peak was observed in the same pH range. Through thermodynamic analysis of the electrocapillary curves, the adsorption density of undissociated amine was evaluated separately from that of aminium ion. The adsorption densities of the un-dissociated amine and of the total amine increased with increasing pH. The ratio at the interface of undissociated amine to aminium ion was several orders of magnitude greater than the ratio in the solution and increased with increasing pH. The potential at the closest distance of approach of counter ions to the mercury surface was compared with values of zeta potential on quartz previously reported. The most important variable in the flotation separation of minerals is probably the pH of the pulp, and a number of theories have been proposed to explain its effect on the condition of the mineral surfaces, on the dissociation of collectors and of inorganic and organic species (accidentally present or intentionally added) in the pulp, and on the mineral-collector interaction. In the development of a theoretical background for oxide flotation systems, an experimental approach based on electrokinetic measurements has been of much value, although the effect of pH becomes confounded since it governs both the electrochemical conditions of the oxide surface and the dissociation of the collector. For investigation of the adsorption behavior of long-chain collectors on oxide minerals, however, electrokinetic potential measurements are the most widely used technique. Hydrogen and hydroxyl ions are found to be the potential determining species, thereby governing the interfacial electrical conditions. The electrostatic interaction between the charged mineral surfaces and ionized collectors is regarded as the driving force for the adsorption of the collectors. An association of alkylamine collectors adsorbed on quartz surfaces has been postulated from streaming potential measurements, and a term "hemi-micelles" has been proposed.&apos; The possibilities of coad-sorption of undissociated amine along with aminium ion has been inferred from contact angle measurements? and from adsorption studies.~ Electrochemical titration as applied to silver sulfide provides a more quantitative approach to the analysis of the electrical double layer at an ionic solid-solution interfaceqG and the electrochemical evidence for the adsorption of amine at pH 4.7 indicates a specific affinity of dodecylammonium ion towards silver sulfide surfaces, whereas at pH 9.2 the adsorbed species might be free arnine." A combination of differential capacity and electrocapillary measurements on a dropping mercury electrode was reported to be a sensitive method of provid- ing reliable information on the adsorption behavior of dodecylammonium acetate (DAA) at a natural (near neutral) pH.? It was also shown that there were striking similarities in the properties of the double layer and in the adsorption behavior of the amine on mercury and on such ionic solids as quartz, silver sulfide, and silver iodide. The effect of pH on the differential capacity curves at a mercury-sodium fluoride solution interface has been investigated by Austin and Parsonss who reported that between pH 7 and pH 11 there was very little effect. In the present paper, the adsorption behavior of DAA was investigated as a function of pH through differential capacity and electrocapillary measurements and the information gathered was correlated with that available in literature on quartz and silver sulfide. Experimental The apparatus and the method used for determining the differential capacity and the electrocapillary curves were identical to those described previously.&apos; The ionic strength of the supporting electrolyte was fixed at 0.1 M with potassium fluoride, and the pH of the solution with potassium hydroxide. Only the neutral to alkaline range was covered in order to avoid the dissolution of the glass vessel with hydrofluoric acid. Results In Fig. 1 the differential capacity has been plotted against the applied potential at a DAA concentration of 10-&apos; M at three different pH values. The curves are characterized by one capacity peak in the anodic branch, by two capacity peaks in the cathodic branch, and by a marked depression in capacity between the peaks. The depression indicates an adsorption of the arnine in this potential range. One of the cathodic peaks appears at pH 7.3 near -1.4 v and decreases with increasing pH. The other appears at pH 8.9 near —1.2 v and increases with increasing pH. At pH 9.6 only the latter peak is observed. Beyond the cathodic peaks, all the curves tend to converge with the curve in the absence of DAA, implying that two different species are being desorbed in this potential region. The anodic peak near 0.0 v increases markedly with increasing pH. The well-defined anodic peaks at pH 8.9 and 9.6 were accompanied by an appreciable increase in the current flow (in excess of O.luA), and, therefore, is a "pseudo-capacity"&apos;" due to a

Jan 1, 1971

By R. S. Bradley, B. K. Miller

The principal producing areas of fire clay in Missouri are: (I) the east central district, which includes Audrain, Callaway, Montgomery, Warren, and Boone Counties (Fig. I); (2) the St. Louis district, which includes St. Louis and St. Louis County; (3) the north central Ozark district, which includes Franklin, Gasconade, Osage, Maries, Phelps, and Crawford Counties. Most of the semiplastic‡ fire clay is found in Audrain, Callaway, Montgomery and St. Louis Counties, and in St. Louis. Flint fire clay is found in Callaway, Audrain, and Montgomery Counties and in most of the north centra! Ozark district. High-alumina diaspore clay is found only in the north central Ozark district, except a few deposits found in Montgomery County. This paper is concerned with the semi-plastic fire clay that occurs in the east central Missouri district near Mexico, Audrain County, Missouri, which is mined by the open-pit method as practiced by the A. P. Green Fire Brick Co. About one-fourth of the semiplastic fire clay in that district is mined in shaft mines, and three-fourths in open pits.

Jan 1, 1942

By B. K. Miller, R. S. Bradley

The principal producing areas of fire clay in Missouri are: (I) the east central district, which includes Audrain, Callaway, Montgomery, Warren, and Boone Counties (Fig. I); (2) the St. Louis district, which includes St. Louis and St. Louis County; (3) the north central Ozark district, which includes Franklin, Gasconade, Osage, Maries, Phelps, and Crawford Counties. Most of the semiplastic‡ fire clay is found in Audrain, Callaway, Montgomery and St. Louis Counties, and in St. Louis. Flint fire clay is found in Callaway, Audrain, and Montgomery Counties and in most of the north centra! Ozark district. High-alumina diaspore clay is found only in the north central Ozark district, except a few deposits found in Montgomery County. This paper is concerned with the semi-plastic fire clay that occurs in the east central Missouri district near Mexico, Audrain County, Missouri, which is mined by the open-pit method as practiced by the A. P. Green Fire Brick Co. About one-fourth of the semiplastic fire clay in that district is mined in shaft mines, and three-fourths in open pits.

Jan 1, 1942

Some years ago it was my good fortune to inspect some coal properties in Germany, and the most striking impression I received on my trip was that in that country every one in the coal industry, miners and operators, was proud of the fact-not apologetic about it-and that industrially coal was looked upon as a King. The explanation, of course, was that at least 90 per cent of the entire mineral value produced in Germany was from coal, and that it was the very foundation of the nation&apos;s industrial life. The feeling was so different from that existing in the United States among those engaged in producing coal that it made a profound impression on me, and many times since then I have speculated about the reasons for the difference in opinion in the two countries. Here, of course, our units are much smaller and more numerous, there is not so large a proportion of technically trained men, and we have the American trait of depreciating the things we do at home; but among those not actively

Jan 1, 1935

By Robert L. Zook, Bernard J. Olup, James J. Pierre

Coal refuse slurry impoundments are dams constructed of coarse coal refuse to impound fine refuse (slurry) and water (25 to 30% solids). Both products are waste from coal preparation plants. A number of these structures in West Virginia, Pennsylvania, and Kentucky were investigated to determine embankment stability. During the investigation a variety of embankment designs were encountered. The investigation determined the soil and geological characteristics of the embankments and the sites. This was accomplished by a test drilling and monitor installation (observation wells and piezometers) program, geologic study, and large-scale mapping which allowed subsurface profiles of the embankments to be constructed. The laboratory testing program concentrated on textural classification of the coal refuse, permeability, and determining strength parameters to be utilized in the stability analyses. For the stability analyses, the modified Fellenius slip circle, simplified Bishop slip circle, and analysis for translational failure were utilized. In all stability analyses hydrostatic pressure and seismic acceleration probability were considered. This investigation indicated that 62% of the embankments analyzed were in a stable condition. The coal seam, the type of roof rock, and the gradation of the refuse influence the degree of compaction obtainable and the permeability of refuse. The shear strength of coal refuse appears to be controlled by its composition, moisture content, degree of compaction, amount and grain size of fines present. This investigation demonstrated these embankments should not be treated as pure state-of-the-art dams consideration must be given to the particular properties of coal refuse and the total refuse disposal system. Refuse dam slurry impoundments generally lack the site selection phase that is standard practice with siting most other types of dams.

Jan 1, 1976

By B. R. Palmer, M. C. Fuerstenau

Oxide and silicates respond to flotation with a large number of anionic collectors. These include carboxylates (fatty acids), sulfonates, alkyl sulfates, and certain chelating agents. In contrast to sulfide mineral flotation, relatively long-chained collectors (generally longer than 10 carbons) are required to effect flotation of this group of minerals. The structural formulas of these various anionic collectors are presented in Table 1. Formulas and solubilities of various fatty acids are presented in Table 2. These solubilities are those of the dissolved and undissociated species of the acid, e.g. oleic acid, HOl(aq). Of the compounds listed, oleic acid and abietic acid, which IS a major constituent of talloel, are used most commonly in commercial applications. The usage of these two collectors is related to cost and effectiveness. In addition to their high molecular weights, oleic acid contains a double bond in its hydrocarbon chain, while abietic acid is comprised of aromatic rings containing double bonds. The presence of double bonds increases solubility significantly over that of saturated homologues. Stability of metal-collectors assumes a most significant role in these systems, and the solubility products of various metal carboxylates and sulfonates are listed in Tables 3, 4 and 5. In addition to these properties, strength of the acids of these various anionic collectors is also important. The carboxylic and hydroxamic acids are weak acids whereas sulfonic and alkyl sulfuric acids are strong acids. All of the carboxylic acids fall in the range of pK = 4.7 ± 0.5 ([2]); the pK of hydroxamic acid is around 9 ([3]); and the pK of sulfonic acid is about 1.5 ([4]).

Jan 1, 1976

By H. J. Wasson

Published literature regarding the nation&apos;s oil reserve has been largely concerned with the estimated quantities in sight in known producing fields. This proved reserve has never been large in relation to demand. It has been the practice to consider the total future reserve (beyond that in sight within known fields) in the light of the broad potentialities of vast areas of partially explored sedimentary rocks, which are regarded as possible oil territory. Until recently, but little attention has been given to the rate at which the unexplored potentialities may be. converted into the proved reserve classification. To a certain extent, therefore, our contemporary viewpoint on the subject of national oil reserves is characterized by a pronounced contradiction. On the one hand, we measure known reserves as sufficient for only a few years of consumption—i.e., relative scarcity; on the other hand, we are confident that millions of unexplored acres will yield many new oil fields and that countless deeper productive formations underlie many of our known productive fields—i.e., infinite abundance. Of greater significance than the quantitative measure of either of these reserve classifications is the rate at which reserve replenishment must be accomplished in order to maintain an adequate time supply of proved oil reserves. The accumulation of geological data covering broad areas supports the belief that the remaining undiscovered oil reserve is exceedingly large. The distribution of oil in sedimentary formations of practically all ages, from Cambrian to Recent, is suggestive of almost unlimited possibilities; and the relatively small proportion of these possible areas that has been intensively explored in this country is a further index of the probable magnitude of the undiscovered future reserve. The implication that may reasonably be drawn from these observations is that oil, though distributed with less regularity and concentration than its related hydrocarbon, coal, nevertheless is a relatively abundant natural commodity of which the exhaustion appears remote. Final exhaustion of our oil reserve, if not infinitely remote, is a future contin-

Jan 1, 1937

By Sir John Cadman

IN THE changed circumstances which now confront the world, an international open-door policy is the only way to keep pace with the world&apos;s demand for oil. You may rest assured that as far as the British Empire is concerned, American capital for the develop-ment of oil resources is welcome, and little obstruction will be found in the way to permit the use of foreign capital in the group of countries which constitute the British Empire. In the war days we worked in close cooperation and harmony, but in disbandment of the Petroleum War Service Committee, when the war ended, I feel that it left its task unfinished. In the wake of war there appeared a ghost of war-time conditions in the form of belief that Great Britain was straining to corner the petroleum resources of the world. I am certain that if the war-service committee had continued its work in the period of reconstruction the real story would be known and this sinister ghost would have long since vanished before the truth.

Jan 2, 1922

By Robert L. Voss, Richard D. Hagni

Sparry dolomite from all of the operating mines in the Viburnum Trend of Southeast Missouri have been found by cathodoluminescence microscopy to reveal a systematic pattern of banding resulting from a growth zoning within individual dolomite rhombs. Four principal bands have been recognized throughout the entire Trend and each of the major bands contain even finer internal banding. Minor bands a few microns in width can be correlated in specimens collected ten&apos;s of kilometers apart along the trend. The first three principal dolomite bands decrease from south to north. This feature, together with the fact that the white sparry dolomite crystals decrease in abundance from south to north in the Trend, suggests that a major source for the fluids was from the south. The application of cathodoluminescence microscopy to crystalline dolomite demonstrates a strong correlation between ore grade and the intensity of internal banding and dissolution textures.

Jan 1, 1985

By James Kemp

(New York meeting, February, 1913.) IN the study of ore deposits water plays a very prominent part. The small group of igneous ores involve it least, but in all the rest it is an invariable feature. The ground-water, therefore, is perhaps as appropriate a subject for discussion before a session of the American Institute of Mining Engineers as any topic which might be selected. The theme is if anything the more appropriate, because two very important contributions to it have already appeared in the Transactions. The great essay in 1893 of Franz Posepny,1 systematized and classified the subject, and was doubtless not without its influence in leading to the presentation in 1900, by C. R. Van Hise, of an important contribution entitled Some Principles Controlling the Deposition of Ores.2 We all recall the discussions of 10 or 12 years ago, and the interest in these themes which then prevailed in the Institute. They are collectively accessible in the separate edition wisely assembled by Dr. Raymond, and now to be supplemented by the Emmons Volume. Views have been progressing in the past decade or more, and new evidence has been brought to light. A general summary and concise statement may, therefore, not be without interest.

Jan 4, 1913

By C. B. Dudley

In October, 1878, and again in February, 1881, I had the honor to make public, through the medium of the American Institute of Mining Engineers, the results of an extended study of steel rails which had been in service, and which mere taken for the purpose from the tracks of the Pennsylvania Railroad Company. These studies appeared in three papers. In the first of these papers the question. what kind of steel is least liable to fracture or disintegration in the track, was the principal one considered. In the second paper the question discussed was, does the power of steel to resist wear increase with the hardness ? In the third paper the relation between wear and the chemical and physical properties of the metal was the principal point considered. The general results arrived at, or the cooclusions reached, were, as follows: 1. That a mild steel is less liable to fracture, and if properly made, less liable to crushing or disintegration in the track than a harder steel. 2. That the wearing-power of steel in rails not only does not increase as hardness increases, but, on the contrary, diminishes; or, in other words, that a mild steel gives less loss of metal under the same service than a hard steel. These conclusions may be briefly stated in a single sentence—namely, in rails mild steel is not only less liable to fracture and disintegration in the track, but it also gives longer life, or wears more slowly under the same traffic; than harder steel. It is perhaps hardly necessary to add that by mild steel is meant steel

Jan 1, 1891

By John Hays Hammond

This is an era of " expansion; and, conformably with the change in commercial conditions, the function of the mining engineer, as well as that of his confreres in many other professions, has also expanded. From the position of an engineer, limited to the determination of technical questions, the engineer of to-day has come to assume an economic importance in those branches of industry dependent upon engineering skill for their development. He is indeed an engineer of limited usefulness who does not go further professionally than to submit a purely technical report on subjects presented for his consideration. While he has the same responsibility as formerly in the solution of the technical problems involved, he is further expected to supplement his report with advice on the financial and commercial aspects of these problems. For the great majority of problems presented to the engineer ultimately involve the determination of the pecuniary, relations of the propositions under consideration. The great corporation lawyer no longer earns his fee by merely submitting his opinion as to the legal issues involved in law-suits affecting the corporation; he now assumes charge of the entire legal work, including both the organization of the corporation and the maintenance of its legal status thereafter. In like manner, the engineer, whose report was, as I have said, formerly confined to the determination of the geological and other cognate features of a mining enterprise, is now expected, not. only to embody information on these subjects in his report, but also to give his opinion whether the property offered for sale in pursuance of such an enterprise is worth the price asked for it. Moreover, if he recommends the purchase of a property, he incurs a certain moral responsibility for its efficient manage-

Nov 1, 1908

By A. D. Wilkinson

A CROSS-SECTION of the converter aisle through one of the converters and reverberatories is shown in Fig. 5. The aisle is 280 ft. long by 60, ft. wide by 681 ft. to the roof trusse, which have a 63-ft. span and are us )ported by steel columns spaced at 2b-ft. centers. Two 80-ton electric trails, supplied by the Welman Smith .Owen Engineering Co., with 20-ton auxiliary lifts, serve this building. Matte shells and converter-slag shells are dumped into heavily con¬structed flat-bottom bins located on the south side of the converter aisle and 1.0 ft. above the floor. The material is broken by ball and by hand, shoveled off into ladles for unloading on to the reverberatory charge floor, and charged into the furnace as previously mentioned.

Jan 1, 1934

By A. M. Gaudin, R. T. Hukki

PREVIOUS work on the principles of comminution has shown: (I) that the surface produced is proportional to work input (Rittinger law, 1a-3); (2) that there is regularity to the weight distribution of the fragments according to size.4-10 In this paper it is brought out that the surface on the fragments is distributed in definite and simple relation to size. The experimental work has involved: I. Construction of an apparatus capable of measuring the surface of mineral fragments independently of the chemical composition of the fragments and independently of the site of the surface; 2. Refining the methods available for measurement of particle size; 3. Designing and building a crusher capable of operating on very small quantities of mineral, if necessary on single crystals, and in such fashion as to minimize handling losses of material. Complete experiments have been carried out with massive quartz and individual quartz crystals. Partial experiments, lacking surface measurements, have been made with glass spheres, galena, sphalerite, fluorite, salt and coal.

Jan 1, 1944

By JAMES H. McGRAW

P UBLZCLTY and engineers do not mix. In the very words of my subject, there is an apparent contradiction. In the past, publicity has been abhorrent to the engineer. It seems to be true that the engineer, because of his training or his background, has developed a state of mind which omits publicity. At any rate he has done a poor publicity job for himself. The average engineer is self-conscious; he ought to be class-conscious. If T should ask the men in this hall to get up one by one and tell who they are and what they have done, there would be an instinctive reaction in the mind of each man-a feeling that this was out of place. If I should ask each man to get up and tell something about his neighbor, I should find that each neighbor, once he got acquainted with the man next to him and understood what he was doing, would be as human and as generous-hearted in telling about his brother engineer as is any professional man.

Jan 1, 1920

By Ma Guang, Huang Jinshou

In this paper we briefly describe measuring techniques and their practical use in the mining industry of China. A strain coefficient matrix of triaxial strain cell for a flat ended borehole is also introduced.

Jan 1, 1983