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By J. Fred Johnson

COROMANT is the trade name of the alloy-steel drill rod tipped with a chisel-type tungsten-carbide bit manufactured by Sandvik Steel Works Co., Ltd. Other names, such as Swedish or air-leg method of drilling, are used in various localities. Coromant drilling in Sweden was the natural sequence of the adaptation of tungsten-carbide inserts to the already established routine of drilling. By the middle thirties the percussion drill had reached practically its highest attainable efficiency as a drilling machine. Since then improvement has been in metallurgy of component parts to increase life or lessen weight, in the development of pneumatic and automatic feeds, in the use of jumbos to more quickly and easily handle machines, and in changes in drill rods and bits. By 1937, drilling in the United States and Canada was done by relatively heavy mounted drifters with positive hand or automatic feeds. In Sweden, on the other hand, emphasis had been placed on light equipment and drifting was done with pneumatic bars and reverse-feed stopers. In 1938, one of the most prominent American drill manufacturers developed an air-leg for successfully drilling the extremely variable but relatively soft iron ores of some of the northern Michigan mines. Also in 1938, a comparative Swedish test, also in soft iron ore, of a 50-lb jackhammer mounted on an air-leg, against a 100-lb reverse-feed drifter on a pneumatic bar, showed the net drilling time was increased by the air-leg set-up from 51 to 71 pct, in drilling 6-ft rounds in a 6 1/2x6 1/2 ft drift. Miners were becoming scarce in Sweden even at that time and, since the lighter equipment made the work easier and more attractive, the airleg was then made use of in some types of soft rock. In 1940, for instance, a large tunnel for a hydroelectric plant was driven with this equipment. By 1943, when tungsten-carbide inserts came into the picture in Sweden, a great many of the kinks in percussion drilling with this hard-metal had been worked out in Germany under the stress of war conditions. However, only 10 pct of the drilling machines manufactured in Sweden were jackhammers for use on air-legs and only the one manufacturer made air-legs in the United States. American practice had largely supplanted integral forging of drill bits by the detachable steel bit. Canada and South Africa were using the one-pass throwaway bit but Sweden was still using the same old integral forged bit. After a long study of the trend toward simplicity

Jan 1, 1952

By C. S. Yust, C. S. Morgan

ThIS note reports the observation of masses of dislocation etch pits around the weld necks of small single-crystal particles of calcium fluoride sintered to a cleaved face of a larger CaFz crystal. Crystal particles in the -50 +I00 mesh size range were placed on freshly cleaved CaFz surfaces and heated at 1250°C for 30 min in a tantalum container in an argon atmosphere. The sintered specimens were then etched at room temperature for 40 to 50 min in a 2 pct sulfamic acid solution which is a selective etch for dislocations in caF2.' Figs. 1 through 3 show the masses of dislocation etch pits observed around weld necks after etching. In some cases, particles were gone after removal of the specimens from the furnace although weld necks were readily visible. In other instances, no etch pits formed around a weld neck. A possible cause of concentrations of dislocations on the crystal surface is mechanical deformation of the base crystal when particles are dropped on it. If such a deformation does occur, it would be much smaller than that caused by the light punching of a crystal with a sharp instrument which results in large concentrations of etch pits. However, crystals deformed by punching with the sharp instrument and annealed at the conditions of these experiments (1250°C for 30 min) before etching showed no concentrations of dislocation etch pits. It is obvious that dislocations from the much smaller deformations, possibly created when particles are placed on the surface, would also anneal out. Etching of large crystals which had particles placed on them in the usual manner but which were not heated showed no dislocation concentrations such as shown in Fig. 1. The magnitude of dislocation etch-pit concentrations did not vary with extensive variation of the cooling rate. The appearance of many of the etch-pit clusters is typical of a well-annealed condition, indicating that the dislocation concentrations formed before the specimen temperature was lowered. Therefore, it is evident that thermal stresses in the neck area did not create the deformation indicated by the presence of the dislocations. The possibility exists that the etch-pit concentrations at places where particles had been removed may be the result of deformation accompanying the fracture of the sintered bond. That this is not so was demonstrated by breaking off particles around which no etch pits occurred. Re-etching never resulted in the large concentrations observed at sintering sites. The stress available to effect material movement during sintering of two particles will depend on the geometry at the contact point but can easily exceed the macroscopic yield stress in CaFz systems. It appears that the plastic deformation observed results from sintering or simply from the weight of the small particles. It has been previously argued that plastic flow makes an important contribution to the initial densification of oxides having the fluorite crystal structure.2p3 If plastic deformation occurs, it would begin as soon as the temperature is sufficiently high

Jan 1, 1967

By G. R. Countryman, G. H. Thomas, I. Fatt

Miscible displacement in both thewetting and non-wetting phase has been studied in two-phase systems. Experimental data show that dispersion is a function of saturation and cannot be predicted from dispersion theory developed for single-phase miscible displacement. Some of the effect of saturation on dispersion is a result of the development of dead-end pores or a dendritic pore structure in multiphase systems. The presence of dead-end pores or dendritic structure is confirmed by pressure transient studies. INTRODUCTION Displacement by flooding with a miscible liquid is a possible means for recovering the estimated two-thirds of the oil that remains behind after primary production. The immense economic importance of a process that can recover such large quantities of oil has led to extensive laboratory studies of miscible displacement. As usual in production research, most laboratory studies of miscible displacement have not attemped to reproduce all of the conditions existing in a petroleum reservoir. In the early stages of investigation the need has been for information on the broad, basic principles of the phenomena involved in miscible displacement. The effects of overburden pressure, reservoir temperature, and wettability have been considered of secondary importance. However, one property of a petroleum reservoir which is expected to be of major importance and yet has been omitted from many laboratory studies is the presence of interstitial water. Two possible effects of interstitial water on the displacement mechanism in the hydrocarbon phase immediately come to mind. First, from the general1y accepted theory that capillarity governs the distribution of oil and water in porous rock one would expect that for water-wet rock the water will be in the small pores and oil in the large pores. A miscible displacement of oil carried out in the presence of water is operating in a pore size distribution shown in Fig. lb, whereas if the same test had been performed with only one phase present the pore size distribution is as shown in Fig. la. Although there is not yet a theory of miscible displacement which explains in detail the effect of pore size distribution, one would expect the differences between Figs. la and lb to influence the displacement efficiency. A second factor which may make a multiphase system different from a single-phase system is the presence in the multiphase system of dead-end pores or dendritic structure. Experiments of various kinds on reservoir rock have led to the belief that all pores in the network structure of a porous rock take part in conducting fluid during single phase fluid flow.1,2 There are then no dead-end pores and no fingers or dendritic structures containing stagnant fluid. In a multiphase system, however, the second phase may

By B. F. Oliver

Equilibrium and kinetic segregation coefficients for the dilute high-temperature system tantalum in iron have been experimentally determined in a levitating zone melter. The equilibrium segregation coefficient, ko, is 0.43 * 0.03. Planar interface solidification is possible up to a freezing velocity of 4 in. per hr but not at 6 in. per hr. Precise concentration control of the solid is possible over this range of freezing velocities. The momentum boundary layer thickness, and the diffusion boundary layer thickness, 6, are such that either 6, > 6 or ALTHOUGH considerable data exists in the literature concerning the stability of planar-solidification fronts, little data exists for high-temperature metallic systems. The study of fundamental aspects of solidification in high-temperature iron-base systems is complicated by the extensive solvent power of liquid iron. In order to minimize such effects a levitating zone melter was used to study the segregation of tantalum in iron.' The solute tantalum was selected because: 1) the ko value was, according to the literature, initially thought to be less than 0.1, thus increasing the precision of the method used;2,3 2) the vapor pressure and is a constant, fixed by induction stirring, 6, the diffusion boundary layer, is 5150 u. At 400 rpm and 6 in. per hr freezing velocity the cast structure exhibits circular macroporosity and banding concentric with the axis of the rotation of the interface. Electron-beam microprobe analyses indicate that the tantalum content is highest at the center of rotation (1.2/1) and decreases with increasing radius as the fine-grained bands become sharper. This entire structure exhibits microseg-regation of tantalum. of tantalum in 1 atm of H2 is small, assuring conservation of solute during redistribution; and 3) spec-troscopic analyses were available for the appropriate range of tantalum considered. Additional objectives were 1) to determine kinetic segregation coefficients for well-stirred zones with constant boundary conditions and thus quantitatively calibrate solute-segregation behavior in the levitating zone melter, and 2) to examine the range of freezing velocities over which smooth solid-liquid interfaces could be controlled in an iron-base alloy under the restrictions of the thermal gradients imposed while levitating a zone. The single-pass zone-melting method was used to calculate individual k values.'

Jan 1, 1964

By T. A. Klinefelter

Lightweight concrete aggregates are materials weighing less than the usual aggregates of sand, gravel, and crushed rock. Concretes made with sand and gravel or crushed rock weigh 145 to 150 lb per cu ft, compared with 50 to 90 lb per cu ft for concretes made with lightweight aggregate. The ultra-lightweight concretes weigh much less than 50 lb per cu ft. Lightweight aggregates may be natural or manufactured materials, or byproducts from other commercial operations. Natural materials include pumice and pumicite, tuffs, breccia, scoria, diatomite, and vegetable products, such as peat, straw, and sawdust. Manufactured materials include expanded perlite, vermiculite, slag, clay, shale, and slate. Byproducts include cinders, aircooled slags, and coke breeze. Concretes made with lightweight aggregate were used first in construction of commercial buildings, later in homes. Present usage is general in multistory and other building construction, such as bridge decks, barges, jet-plane runways, piers and other structures. The industry has grown remarkably in the last decade. General Considerations The particular use to which the concrete may be put determines the importance of the various properties of the aggregates employed. Any given type of aggregate, however, should be reasonably uniform in composition and properties. It should be suitably graded and maintain proper weights, insulation values, and adequate strength to prevent breakdowns in mixing. It should bond properly with the cement, be inert to chemical reactions with cement and steel, and resist weathering, moisture, insects, and fungi. Some properties of any given type of lightweight aggregate from different suppliers may vary considerably because of differences in the source of raw material and the method of treatment. This statement applies particularly to expanded clays, shales and slates. All lightweight concretes have higher absorption of moisture and lower thermal conductivity, lower compressive strength, as well as lower unit weight as compared with standard concretes made with sand, gravel or crushed rock. Excepting cinders, the cost of lightweight aggregates is usually higher. Grading and unit weight requirements are given in ASTM standards: C 330-53T, Lightweight Aggregates for Structural Concrete; C 331-53T, Lightweight Aggregates for Concrete Masonry Units; C 332-54T, Lightweight Aggregates for Insulating Concrete. The production of masonry units shows the growth of the use and types of lightweight aggregates. In 1947 the total number of lightweight block was 460,000,000 units in 8 by 8 by 16-in. equivalents. By 1954 this had increased to 950,000,000 units. Of the 1954 production, 27 pct was of manufactured types, 43 pct of cinders, and 30 pct of remaining types. Raw Materials Used as Lightweight Aggregates It was stated above that a variety of products both natural and manufactured are used as lightweight aggregates. It is easy to understand that a bulky material of low unit value cannot be transported far and still remain a low cost product. Hence the product used in a particular market depends upon the availability of the possible raw materials. Thus it is

Jan 1, 1960

By J. S. Billheimer, B. H. Sage, W. N. Lacey, C. G. Yundt

As a part of a general investigation of the separation of bitumen from hydrocarbon mixtures a study was made of a restricted quaternary system composed of methane, decane, tetralin, and bitumen. The work was limited to a pressure of 8000 psi, a temperature of 220 °F, and to a fixed relative proportion of decane, tetralin, and bitumen. The measurements permitted the determination of the distribution of these components in each of the fluid phases. It was not possible to distinguish a second liquid phase in the course of these measurements. Gas-liquid equilibrium "constants" of each of the components were found to vary markedly with the composition of the system while temperature and pressure remained fixed. INTRODUCTION The separation of bitumen frorn naturally occurring hydrocarbon mixtures has been of importance for a number of years in the production of petroleum, especially in the California area. The deposition of this material from crude oils was noted in earlier studies of the solubility of natural gas in crude oil.¹,²,3 Studies of the separation of bitumen from crude oils from the Greeley and Santa Fe Springs fields were carried out."." The behavior of these systems appeared complex and studies of two restricted ternary systems involving mixtures of n-pentane, tetralin, and bitumen,' and of decane, tetralin; and hitumen, confirmed this belief. Reviews of the literature pertaining to the separation of bitumen from naturally occuring and refined hydrocarbons are available." The important effect of methane in the separation of bitu- men from naturally occurring hydrocarbon mixtures was apparent from the earlier studies and for that reason it appeared desirable to investigate a restricted quarternary system involving mixtures of methane. decane, tetralin, and bitumen; data concerning the behavior of mixtures of decane. tetralin. and bitumen having already been obtained.V his study was restricted to a pressure of 8000 psi," a temperatue of 220° F, and fixed relative proportions of bitumen, decane. and tetralin. This composite constituent, hereinafter designated as the less volatile constituent, was made up of 0.0455 weight fraction bitumen. 0.0909 weight fraction decane, and 0.8636 weight fraction tetralin. The experimental method involved bringing together mixtures of methane and the less volatile constituent in varying proportions in a constant volume container at the pressure and temperature indicated above. The composition of each of the phases was determined and from this the extent of the separation of bitumen was established. MATERIALS The bitumen used in this investigation was obtained from the same stocks employed in earlier studies. The crude material from the North Coles Levee field was stored in the laboratory] in a closed drum for a period of five years. Several samples from this stock were subjected to refining operations which were described earlier,' and every effort was made to follow the same procedure in all cases. It was necessary to prepare supplies of bitumen for this investigation at two rather widely different times. These materials have been identified as samples 1 and 2. The composition of the crude bitumen after it was washed with n-pentane at room temperature

Jan 1, 1949

By M. M. Slotnick

It was once aptly said that a sign of approaching senility is ceasing work on a subject and beginning to talk about it. Perhaps that explains why, after many Years in which Part of my duties has been the training of college men in various branches of petroleum exploration geophysics, I have now begun to talk about it. In making an outline of what I believe ought to be discussed under the general heading of the title, I found it almost impossible to subdivide the ideas into an ordered set of discrete subjects. Rather, the pertinent remarks seemed to interlock almost everywhere. The consequence is that it will be necessary to start with the conclusions and then try to justify them by jumping back and forth. However, based on the types of men with whom I have had to deal, the subject naturally divides itself into two parts. In the first part, I should like to deal with the case of those undergraduates whose natural bent is toward the physical sciences and who may decide to enter the geophysical fold as a career. The other part will deal with those many men, geologists and engineers for the most part, who have drifted into exploration geophysics by one means or another, and whom it is necessary to train for geophysical work while they are occupied in their routine jobs. Here it may be in point to remark that most men in exploration geophysics at Present have been developed from precisely the latter group, and that the problem of training here is of great importance even though, in this paper, it will perforce occupy the secondary place. Training oF a Geophysicist The outstanding reason for the perplexing problem on the training of a geophysi-cist is that ideas differ on the answer to the question: "what is a geophysicistp" ln any of the scientific "specialties," like physics, for example, it is relatively simple to pigeonhole a man as being qualified to call himself a physicist. That appellation applied to an individual does not mean that he has mastered only the branches of intellectual endeavor usually associated under the broad name of "physics." we expect him also to have a more than mere acquaintance with mathematics and chemist~ and some understanding of most of the other sciences. But note this important point—we expect our physicist, whom we have chosen as an example, to be intelligently trained so that, if necessary, he can and will know how and where he can get the proper information on a subject in which he is not a specialist; he will know how to absorb that information and turn it to his uses. It seems to me that this is the outstanding characteristic of a man who can truly call himself a scientist: that he is a specialist in one of the broad branches of science in that he has enough training and discipline in the scientific approach so that, when called upon to do so, he can inteugently absorb knowledge from another bordering science (and all sciences not only border upon one another to some extent, but more often, overlap One another), and

Jan 1, 1946

By M. M. Slotnick

It was once aptly said that a sign of approaching senility is ceasing work on a subject and beginning to talk about it. Perhaps that explains why, after many Years in which Part of my duties has been the training of college men in various branches of petroleum exploration geophysics, I have now begun to talk about it. In making an outline of what I believe ought to be discussed under the general heading of the title, I found it almost impossible to subdivide the ideas into an ordered set of discrete subjects. Rather, the pertinent remarks seemed to interlock almost everywhere. The consequence is that it will be necessary to start with the conclusions and then try to justify them by jumping back and forth. However, based on the types of men with whom I have had to deal, the subject naturally divides itself into two parts. In the first part, I should like to deal with the case of those undergraduates whose natural bent is toward the physical sciences and who may decide to enter the geophysical fold as a career. The other part will deal with those many men, geologists and engineers for the most part, who have drifted into exploration geophysics by one means or another, and whom it is necessary to train for geophysical work while they are occupied in their routine jobs. Here it may be in point to remark that most men in exploration geophysics at Present have been developed from precisely the latter group, and that the problem of training here is of great importance even though, in this paper, it will perforce occupy the secondary place. Training oF a Geophysicist The outstanding reason for the perplexing problem on the training of a geophysi-cist is that ideas differ on the answer to the question: "what is a geophysicistp" ln any of the scientific "specialties," like physics, for example, it is relatively simple to pigeonhole a man as being qualified to call himself a physicist. That appellation applied to an individual does not mean that he has mastered only the branches of intellectual endeavor usually associated under the broad name of "physics." we expect him also to have a more than mere acquaintance with mathematics and chemist~ and some understanding of most of the other sciences. But note this important point—we expect our physicist, whom we have chosen as an example, to be intelligently trained so that, if necessary, he can and will know how and where he can get the proper information on a subject in which he is not a specialist; he will know how to absorb that information and turn it to his uses. It seems to me that this is the outstanding characteristic of a man who can truly call himself a scientist: that he is a specialist in one of the broad branches of science in that he has enough training and discipline in the scientific approach so that, when called upon to do so, he can inteugently absorb knowledge from another bordering science (and all sciences not only border upon one another to some extent, but more often, overlap One another), and

Jan 1, 1946

By H. J. Hager, P. H. Haskell

Fox the past 20 years Alabama has probably led all other coal-producing districts in the proportion of coal prepared by wet washing. All rail mines, with one exception, and a high percentage of truck mines now wash all coal under 3 or 4 in. Most of this coal has been cleaned by jigs, though within the past few years one or more wettable plants have been installed for cleaning some of the coal from practically all the major seams. These tables supplement either single or multicell jigs usually for one of the following purposes: (I) to wash the finer sizes of raw coal, (2) to rewash the finer sizes of washed coal after they leave the jigs, (3) to retreat jig middling products. The main purpose of this paper is to present cleaning data and operating factors involved in the preparation by tables of the finer sizes of raw coal. The specific information and data pertain to the Mary Lee seam of coal as extracted at three of the mines of the Alabama By-Products Corporation, which produces coal for both by-product coke-oven consumption and the general steam market. The Mary Lee seam has long been recognized by coal-preparation authorities as presenting a very difficult ash-reduction problem. Washing characteristics and physical structure of the seam vary widely. Its thickness ranges from 32 in. with no rock parting to l00 in. with from one to three partings. Over the entire field the bed contains bands of bone and rash. These are distributed throughout the seam cross section. A portion of this bone or bony coal occurs as definite bands 1 in. or more thick; however, some bone is interlocked as layers within the coal and consequently breaks into flakes when the coal is broken. This material is relatively high in ash and its specific gravity varies widely. It has been observed that in most cases in the washing of Mary Lee coal from 10 to 18 per cent of the raw coal is within ±0.10 specific gravity of the attempted point of separation. Therefore with the average wet jig, only with extreme difficulty can a low-ash product be obtained without loss of much marketable coal in the refuse. Without entering into the controversial question as to whether modern washing equipment can efficiently handle simultaneously all sizes up to a given maximum, suffice it to state that the comparatively old-type jigs in service at the Alabama By-Products Corporation's mines could not clean the fine sizes satisfactorily. Therefore, in 1931 that company installed six diagonal-deck tables at the Barney mine, which were installed as an addition to a complete plant cleaning all coal below minus 3 in. The primary washed product is shipped as steam coal and another portion may be prepared as washed nut for domestic trade. These tables are washing 9 tons per hour of raw coal sized to ¼ in. to 0. The washed table coal is mixed with the 3 to ¼ -in. jig product to constitute a 3 in. to o steam coal.

Jan 1, 1941

By W. N. Lacey, C. G. Yundt, B. H. Sage, J. S. Billheimer

As a part of a general investigation of the separation of bitumen from hydrocarbon mixtures a study was made of a restricted quaternary system composed of methane, decane, tetralin, and bitumen. The work was limited to a pressure of 8000 psi, a temperature of 220 °F, and to a fixed relative proportion of decane, tetralin, and bitumen. The measurements permitted the determination of the distribution of these components in each of the fluid phases. It was not possible to distinguish a second liquid phase in the course of these measurements. Gas-liquid equilibrium "constants" of each of the components were found to vary markedly with the composition of the system while temperature and pressure remained fixed. INTRODUCTION The separation of bitumen frorn naturally occurring hydrocarbon mixtures has been of importance for a number of years in the production of petroleum, especially in the California area. The deposition of this material from crude oils was noted in earlier studies of the solubility of natural gas in crude oil.¹,²,3 Studies of the separation of bitumen from crude oils from the Greeley and Santa Fe Springs fields were carried out."." The behavior of these systems appeared complex and studies of two restricted ternary systems involving mixtures of n-pentane, tetralin, and bitumen,' and of decane, tetralin; and hitumen, confirmed this belief. Reviews of the literature pertaining to the separation of bitumen from naturally occuring and refined hydrocarbons are available." The important effect of methane in the separation of bitu- men from naturally occurring hydrocarbon mixtures was apparent from the earlier studies and for that reason it appeared desirable to investigate a restricted quarternary system involving mixtures of methane. decane, tetralin, and bitumen; data concerning the behavior of mixtures of decane. tetralin. and bitumen having already been obtained.V his study was restricted to a pressure of 8000 psi," a temperatue of 220° F, and fixed relative proportions of bitumen, decane. and tetralin. This composite constituent, hereinafter designated as the less volatile constituent, was made up of 0.0455 weight fraction bitumen. 0.0909 weight fraction decane, and 0.8636 weight fraction tetralin. The experimental method involved bringing together mixtures of methane and the less volatile constituent in varying proportions in a constant volume container at the pressure and temperature indicated above. The composition of each of the phases was determined and from this the extent of the separation of bitumen was established. MATERIALS The bitumen used in this investigation was obtained from the same stocks employed in earlier studies. The crude material from the North Coles Levee field was stored in the laboratory] in a closed drum for a period of five years. Several samples from this stock were subjected to refining operations which were described earlier,' and every effort was made to follow the same procedure in all cases. It was necessary to prepare supplies of bitumen for this investigation at two rather widely different times. These materials have been identified as samples 1 and 2. The composition of the crude bitumen after it was washed with n-pentane at room temperature

Jan 1, 1949

By P. Beardmore, A. H. Holtzman, M. B. Bever

Specimens of the alloy CU3AU in the ordered and disordered states were subjected to explosive loading at shock pressures in the range from 160 to 475 kbars. The resulting changes in the resistivity, stored energy, microhardness, and microstructure were determined. By comparing the effects of explosive loading on ordered and disordered specimens a separation of structura1 and configurational changes has been made. In the pressure range from 290 to 370 kbars, representing a small increment of strain, the degree of long-range order in the ordered alloy decreased sharply. This change is attributed to the generation of shear stresses in excess of the theoretical shear strength of the alloy. Disordered CU3AU under explosive loading behaves in a manner considered to be characteristic of fee solid-solution alloys generally. The response of metals to high-velocity deformation and, in particular, to explosive loading has attracted much interest in recent years.' In general, metals are substantially strengthened by the passage of shock waves although the permanent strains are small. Explosive loading induces this strengthening by causing the metal to undergo rapidly a transient strain in a narrow region, first in the shock front and then in the rarefaction wave, which releases the pressure. The transient strain is given by e = 4/3 In V/Vo, where Vo and v are the specific volumes in the uncompressed and compressed states.2 The process produces many defects, which account for the strengthening. For the investigation reported here, an ordered alloy was chosen because it was expected to give sensitive indications of the near-neighbor effects produced by shock waves. The ordered alloy CU3AU was of special interest because of past work on the effects of conventional deformation on this alloy.314 The disordered alloy was included as a standard for comparison and as an alloy typical of a solid solution containing short-range order. The effects of explosive loading were followed by measurements of the resistivity, stored energy, and microhardness, and by metallographic examination. EXPERIMENTAL PROCEDURES Preparation of Specimens. Part of an ingot of the alloy Cu3Au prepared previously4 was cold-rolled with several intermediate anneals in vacuum to a final thickness of 0.042 in. Specimens of dimensions 2.0 by 1.0 by 0.042 in. were machined from this strip. After a recrystallization treatment of 1 hr at 565oC, half of the specimens were disordered by heating in evacuated Pyrex capsules for 1 hr at 460°C and quenching into water. Although they contained short-range order, they will be referred to as 'disordered" to indicate the absence of long-range order. The rest of the specimens were cooled slowly from 380°C to induce long-range order. The grain size of the ordered and disordered specimens was 0.012 mm. Explosive Loading. This was carried out at the Eastern Laboratory, Explosives Department, E. I. du Pont de Nemours & Co., by a driver-plate procedure described elsewhere.2 Two ordered specimens were stacked alongside two disordered speci-

Jan 1, 1964

By John M. Bostwick, James C. Bradbury

Bitumen is a general term for a group of materials composed of mixtures of hydrocarbons that are fusible and soluble in carbon disulfide. Included in the group are petroleum, asphalts, asphaltites, and mineral waxes. Asphalt is a dark-colored, cementitious solid or semisolid, which generally softens on heating and resumes a more viscous or solid state when cooled. It is found in native form in fissures and pore spaces in rocks and as lakes. It is also obtained from the residues produced in petroleum refining. Asphaltites are black, naturally occurring solid bitumens. They are generally shiny and break with a conchoidal fracture. Common asphaltites are gilsonite (uintahite), grahamite, and glance pitch. Mineral waxes are solid or semisolid, relatively nonvolatile bitumens of various colors, having an unctuous feel and waxy luster, Of the native waxes, ozokerite is the best known. Montan wax is also classed as a natural wax, although it never occurs in the pure state and must be extracted from lignite or cannel coal (Ladoo, 1920). Mineral waxes may also be obtained by pyroprocessing of petroleum, lignite, and peat. Pyrobitumens are dark-colored, solid hydrocarbons that are infusible and relatively insoluble in carbon disulfide. They are so-called because they will yield liquid and gaseous hydrocarbons only when heated. Asphaltic pyrobitumens are defined as "substantially free of oxygenated bodies" and include wurtzilite (elaterite), albertite, and impsonite (Thrush, 1968). Nonasphaltic pyrobitumens contain oxygenated bodies; examples are coal and peat. The nonasphaltic type will not be discussed further. Petroleum Asphalts Asphalts refined from crude petroleum have almost completely replaced the native types. Refineries can produce asphalts in every desirable grade more economically and in greater quantity than the native types and with a variety of properties that meet the requirements of the various manufacturers using them. For all practical purposes, it is estimated that more than 95% of the asphalts consumed in the United States are refined from crude petroleum (private communication). Native Asphalts Native asphalts are dark brown or black, semisolid or solid substances that, in theory, formed by slow, natural fractionation of crude petroleum at or near the surface of the earth (Goulston, 1938). They are colloidal systems of high molecular weight components dispersed in a medium consisting of low molecular weight components (Pracy, 1954). Native asphalts may occur as lakes, as impregnations of rock (rock asphalt) or as deposits consisting of mixtures of natural asphalt and mineral matter in various proportions (Stern, 1960). Practical use of native asphalt dates to about 3000 B.C. It was mined from surface pits or lakes and used, then as now, for masonry mortar, waterproofing aqueducts and tunnels, binders for road construction, and as an article of commerce (Miller, 1938). Generally the native asphalts find little commercial use today except where they are geographically abundant, easily mined and transported, or have specific or special application. Petroleum-refined asphalt is produced by unusually economical techniques and is much less costly to use. The largest and best known of the lake deposits is that on the Island of Trinidad, where the lake covers an area of 114 acres and is 285 ft deep at its center (Stem, 1960). The lake asphalt is refined by heating to evaporate in-

Jan 1, 1983

By Cheri Eby, William R. Eby

INTRODUCTION Pneumatic conveyance systems provide for material placement at high compaction rates in confined spaces. This method of conveyance provides proper roof support and ground stabilization important to underground mining activities. Today underground mining activities are conducted far differently than those of our ancestors, in that the reclamation process is the final step in any mining activity. Responsible mine owners are constantly seeking innovative methods to assist them in their reclamation procedures. During the last few years, particular attention has been paid to previously mined areas, as many of these abandoned areas lay open, imposing a constant threat to humans and animals. Considerable attention is being directed to applying proper methods for the filling and sealing of underground slopes, drifts, tunnels, and adits, because today we are experiencing the effects of past mining activities such as subsidence, acid mine water run-off, buring refuse piles, and underground mine fires. Furthermore humans and animals who have ventured into abandoned mine openings have died from exposure, suffocating gases, and mine collapse. This paper explains the method of pneumatically filling and sealing these openings and underground works by means of employing pneumatic equipment and proper backfill material together, thus achieving high material compaction and thereby providing the complete filling of the voids and alleviation of the mentioned dangers. NEUMATIC SYSTEMS The use of air to transport material is widely used; however, conveying abrasive material (e., rock, earth, and cement) requires certain pneumatic transport systems designed to handle the abrasiveness as well as the size of these materials. The Eby pneumatic transport sys tem, known as a Mobile Stower, in mounted on a 42-foot trailer pulled by a Kenwor th tractor. This arrangement allows for quick mobilization and project set-up. The pneumatic system, composed of several components assembled together, produces the volume and pressure of air required to transport the material. Knowledge of elevation, ambient temperature, and material composition at the locations to be backfilled play a big part in the design and useage of the pneumatic system. In this particular system design, material is placed by a front-end loader into an eight (8)-yard hopper which is located over a belt conveyor. The conveyor transports the material up to an air lock feeder, which is the metering devise used to feed the material into the Tee Injector located directly below. Air is supplied by a positive displacement blower which, in this instance, delivers up to 4400 CFM's of air at 8 to 12 PSI. Horse power requirements to drive the blower are met with the useage of either a diesel engine or an electric motor. A diesel engine enables the Mobile Stower to operate in remote areas. As the air flows through the upstream air piping, it passes through the Tee Injector and picks up the material and conveys it through the material conveyance pipe, (referred to as down-stream pipe), and out the placement nozzle. Depending upon material composition and the amount of tonnage to be moved, either mild carbon steel pipe or specially heat- treated hardened pipe is used for the material conveyance line. The entire pneumatic system is controlled from the operator's console. With the aid of instrumentation, only one person is required to operate the system. Tonnage rates vary in accordance with horse power and air supply, as well as

Jan 1, 1982

By E. S. Lenker, H. J. Van Hook

A complete swies of solid solutions has been found between the compounds InAs and GaAs Below the solidus. The melting relations determined by differential thermal and static quenching technzques, indicate that the liquidus and solidus are of the simple ascendant type. No evidence of unmixing of the homogeneous solid solutions was observed at sub-solidus temperatures. A quenching method for locnting the solidus, using X-ray diffraction techniques, is described in some detail. THE semi-conducting properties of compounds formed by various combinations of the less familiar intermetallic elements have created an increasing interest in the phase relations in systems involving these elements. The complete phase diagram of such a system, containing a compound of special interest, will often provide information as to the most favorable conditions for preparing large crystals from a melt, as well as specifying the temperature stability of the crystalline phase or phases produced. In view of the current importance of gallium arsenide in semiconductor research and of the structural similarities of indium arsenide, it was thought that the complete phase relations of the system InAs-GaAs should be investigated. Previous work on the system Ga-As by Koster and homa' and on In-As by Liu and peretti2 has shown that GaAs and InAs are the only compounds formed, having melting points of 1238° and 942°C, respectively. In a survey of various systems of elements from groups IIIb and Vb, spengler3 also re- Mines Ltd., for his continuing encouragement and for permission to publish the results of this work. ports complete miscibility of gallium, indium, and arsenic in the liquid state. In a partial investigation of the InAs-GaAs system, Woolley and smith4 found extensive solid solution throughout the alloy range. Their subsolidus work, however, was inconclusive at temperatures below 900" and they did not determine the liquidus relationships of the system. PRESENT INVESTIGATION The starting materials used were high-purity gallium, indium, and arsenic. The method of preparation of the compounds follows that devised by M. Shafer and is described in detail in a paper by Shafer and eiser.' The end-member compounds, GaAs and InAs, were first prepared by reaction of the elements in the desired proportions in evacuated silica glass vials. The vials were rotated in a furnace as the temperature was slowly raised to insure rapid and complete reaction at low temperatures. Thereafter the starting materials, GaAs and InAs, were melted by heating the sealed vials to 1300" and 1000°C, respectively; the vials in this case were filled as completely as possible to keep the vapor space small and thereby minimize the loss of arsenic to the vapor phase. Ten binary mixtures of these compounds were then prepared by reaction of the powdered material in the solid state just below solidus temperatures. At 900C preparations containing 3, 5, 8, 10, 25, 35, 50, and 75 mol pct GaAs were found to be single homogeneous phases, indicating a complete series of solid solutions between GaAs and InAs. Moreover, it was discovered that the homogeneity of any crystalline binary preparation could be very accurately checked by X-ray diffraction because of the large differences in unit cell dimensions of the end membe5s. The cubic lattice constant ofor GaAs is a = 5.652A and that of InAs is a = 6.061A

Jan 1, 1963

GENERAL GEOLOGIC DESCRIPTION The mineral deposit of this case study can be described as a "typical" porphyry copper deposit of the southwestern USA and northern Mexico mineral province. The copper mineralization is related to Laramide age intrusives of intermediate composition which have been intruded into older, mostly crystalline, host rocks. Post Laramide deformation and faulting have subjected the deposit to erosion, leaching, and enrichment processes, which have created a secondarily enriched chalcocite zone. Later basin and range faulting down dropped the ore zone, resulting in deep burial beneath late Tertiary conglomerates and gravels, thus preserving the deposit from further erosion and oxidation. Lower grade chalcopyrite mineralization constitutes the primary zone underlying the enriched blanket. MANAGEMENT OF SAMPLE DATA Sample data were obtained from exploration diamond drill holes that were collared vertically and drilled with surface rigs. Most of the holes were surveyed downhole and found to deviate significantly from the vertical. The data were keypunched from original drill hole logs to formats as described in Chapter 6. Three types of cards were prepared: 1) A heading card containing the following information: [Project Name Coordi-in_ Hole Collarnates Bear-clina-Total ID Northing Easting Elevinglion Depth] 2) Individual record cards following each heading card with the following information: [SampleMin. Zone interval Assay Fields Leached (enriched ID From-ToTotal Cu Oxide Cu primary)] 3) Where downhole survey data were available, a card was punched for each downhole survey point. The card image looked very much like the heading card, followed immediately after the heading card, and contained the following information: [Hole Sur Point Sur Point Sur Point ID Bearing Inclination Depth] The keypunched data were then processed by the drill hole survey program producing a record file which contained information as follows: [Line 1. Project Name Date Assay Field Identifiers Line 2. Hole ID Northing Easting Elevation Bearing Inclination Number of Samples Line 3 through N+ 2 (where N equals the number of samples in the hole) Top Min. of Min. Zone Zone Sample Sample Coordinates Sample Assays Leach InterLength Northing Fasting Elev Total Cu Oxide Cu (etc) face] MINERAL BOUNDARY PROBLEM AND TREATMENT According to the geologic description, at least three mineral zones are present within the ore limits, as well as fault boundaries and a buried topographic surface, each of which have to be considered. The interfaces of the various mineralogical and geological boundaries were identified as accurately as possible in each drill hole by the project geologist, the location of the interface was surveyed in the computer program in association with the nearest sample intercept to the interface (note last field of line 3). Thus, the boundary is represented as a point in 3D space at each intersecting drill hole. The linear interpolation (LINTERP) program then searched the last field of the surveyed record to find the top of each mineral zone, or geologic boundary, and read the coordinates associated with that sample point. The program then used the coordinates to compute an interpolated surface between all existing data points as described in Chapter 11. A contour map was plotted for each of the computed surfaces and reviewed by the project geologist. Where the surfaces were poorly defined due to lack of real drill hole information, the geologist, at times, inserted a "pseudo" drill hole intercept according to his best judgment and feeling for the configuration of the surface, and such points were entered into the data stream for LINTERP. When the project geologists were satisfied that they had obtained

Jan 1, 1980

By B. Lustman

IT has been known for a number of years that the addition of certain alkaline-earth and rare-earth metals to nickel-chromium base electric resistance alloys causes marked increase in their oxidation resistance as measured in an intermittent oxidation test similar to the ASTM—B 76-39 test. However, the mechanism whereby such additions confer protection is still unknown. On the basis of the experimental observation that the increase in life in intermittent tests of nickel-base alloys is proportional to the atomic radius of the added element, Hessen-bruchl has proposed that the added metal ions occupy holes in the oxide lattice which prevent diffusion of nickel ions in the oxide. Horn2 has postulated that the effect of such additions is to accelerate the rate of diffusion of chromium atoms in the metal and thus to favor the formation of Cr2O3 scales. Hickman and Gulbransen3 concluded from electron diffraction observation that the addition of the elements in question results in the formation of a barrier to the diffusion of nickel ions to the surface. In connection with some experiments conducted to develop a test for the resistance to oxidation of alloys in massive form under conditions of intermittent heating and cooling, some features of the oxidation of nickel-chromium base alloys were revealed which may serve to elucidate the mechanism of protection conferred by rare-earth and alkaline-earth elements. Specimens of cylindrical shape 0.360 in. diam x 0.37 in. long were placed in alumina thimbles and inserted into and withdrawn from a Globar-heated furnace operating at 2150°F at 7.5-min intervals. The weight of oxygen absorbed as well as the weight of oxide spalled were measured at intervals. With the particular experimental conditions used, the specimens in a 7.5-min cycle were at temperature for 2 min which corresponds to the heating time of the ASTM test. The weight changes of similar specimens under conditions of continuous heating in air at 2150°F were also measured. The specimens after oxidation were examined metal- lographically and samples of the spalled oxide collected for X-ray diffraction identification of the phases. The specimens used were from the same lot of material used by Hickman and Gulbransen3 and had the compositions shown in table 1. Included in table I are results of ASTM life tests on the materials in the form of wires. These materials, their composition and the ASTM life test data thereon were all supplied by F. E. Bash of the Driver-Harris Co. It may be noted that alloy 13246 of 80 pct nickel, 20 pct chromium nominal composition showed the shortest life in the ASTM test; alloy 12246 with the addition of small amounts of the elements zirconium, calcium, and aluminum, intermediate life; and alloy 12046 with the further addition of silicon, the longest life. In fig. 1 are shown the results of intermittent oxidation tests made on bulk specimens at 2150°F as well as continuous tests conducted at the same temperature. Duplicate tests were made on each specimen. The ordinate scale, inches of metal oxidized, was derived from the experimentally observed weight gain of oxygen by assuming the scale to be entirely Cr2O3. It may be noted that the metal-loss curves during intermittent oxidation show a constant or continuously increasing rate of weight

Jan 1, 1951

A plan which has just been approved by President Wilson, by, the Secretary of the Navy, and the Naval Consulting Board, provides for the active cooperation of the Associated Advertising Clubs of the World with the 30,000 engineers who will soon undertake the task of making a card index survey of American industry, so that it may be prepared for national defense, if need comes. Herbert S. Houston, President of the Associated Clubs of the World comments on the plan. "Through the great power of advertising we expect-to arouse manufacturers, workingmen, businessmen, in fact the whole country, to the vital need of making industry the basic line of defense so that, if necessity arises, it can supply munitions quickly and abundantly. "This is not a war measure, but a peace measure. The militarist will support it and so will the pacifist, as well as the great body of Americans in between. So the slogan `national defense and international peace, has been adopted believing that the two causes will be best served by linking them together. "While the primary thing, of course, is service to the country, it is manifest that this work of the engineers will be of the greatest service to industry in times of peace. If industry is mobilized for defense, it will be placed on a basis of efficiency to meet the keen competition that will surely follow the present war." Howard E. Coffin, one of the leaders of the American automobile industry, in outlining the far-reaching plans of his committee, the Committee of Industrial Preparedness of the Naval Consulting Board, said: "At the outset I wish to emphasize the absolutely non-partisan nature of this work. I am not even familiar with the political affiliations of the great majority of the members of the Board or of my committee. In setting out to, mobilize the industrial resources of the United States, we are concerned only with the benefit to the nation, and to that end we have called into being an organization made up of the best technical and business brains of the country, and that organization will work along business lines with strictly business methods. I think it reasonable to say that this is a movement perhaps unique in the history of national governments, and one geared up to the highest standards of twentieth century efficiency. "It is vitally necessary that American industry be made aware of the part it must play in the national defense. Our whole conception of warfare has been changed almost overnight. Our military heads at Washington are largely, of course, graduates of the very best technical schools, have been taught the profession of fighting, and are masters of that profession. As members of the Naval Consulting Board, we are unable to tell these men how to do their work. But while these departmental heads have lived with military problems all their adult years, we on the other hand have slept and eaten and lived with the industrial problems of the country. The two questions are wholly distinct, and the masters of one cannot possibly be the masters of the other. We are confronted then with the necessity of interlocking these two vast elements of our national life into a great working organization for the national defense. It is that which we are about to do.

Jan 5, 1916

By C. E. Lesher

THE Disco* process for the production of low temperature coke and its immediate predecessor, the Wisner or Carbocite process have been described in the voluminous literature of low temperature carbonization.1 This paper will describe the development of the process from the first attempt at commercial operation by the American Gas and Electric Co. at Philo, Ohio, Yn the 1920's to the successful operation in 1949 by the Disco Co., a division of the Pittsburgh Consolidation Coal Co., of the 1000-ton per day Disco plant near Pittsburgh, see Figs. 1-2. In the 1924 coal industry depression following the hectic post World War I expansion, the northern Appalachian, unionized bituminous coal fields were affected first and foremost, and Western Pennsylvania as hard as any. Competitive market pressure was heaviest on the lower grades of steam coals, notably the from the Panhandle district where ash and sulphur are inherently higher than in the same Pittsburgh coal bed to the east along the rivers. The firm structure of Panhandle coal while favoring the prepared sizes, depressed the usefulness and value of the finer sizes. Panhandle slack and nut slack were marketed with difficulty at consistent, and at times considerable, loss. Many solutions were suggested, and the Pittsburgh Coal Co. investigated all. Lower delivered prices through lower mine costs and more advantageous freight rates were obvious goals, but equally obvious were the difficulties of self attainment of either in any substantial measure. Selling Btu's in pipes was abandoned as an idea after a thorough study of the economics of distribution of what was then, and is even now, the only developed continuous process of complete gasification of bituminous coal-producer gas. Although the coal company purchased huge blocks of electric power, it sold not a car of coal to the central power stations. Public utilities controlled the markets for electric current, and it was found that no matter at how low a cost current might be put on the bus bars by the coal company, distribution to its widely scattered coal mines made such an enterprise practically impossible. Consolidation of underground operations and a huge modernization program of mining operations in the 1920's were but preparation for the introduction of mechanical cleaning of the coal for market, particularly the smaller sizes of steam, gas, and by-

Jan 1, 1953

By C. E. Lesher

THE Disco* process for the production of low temperature coke and its immediate predecessor, the Wisner or Carbocite process have been described in the voluminous literature of low temperature carbonization.1 This paper will describe the development of the process from the first attempt at commercial operation by the American Gas and Electric Co. at Philo, Ohio, Yn the 1920's to the successful operation in 1949 by the Disco Co., a division of the Pittsburgh Consolidation Coal Co., of the 1000-ton per day Disco plant near Pittsburgh, see Figs. 1-2. In the 1924 coal industry depression following the hectic post World War I expansion, the northern Appalachian, unionized bituminous coal fields were affected first and foremost, and Western Pennsylvania as hard as any. Competitive market pressure was heaviest on the lower grades of steam coals, notably the from the Panhandle district where ash and sulphur are inherently higher than in the same Pittsburgh coal bed to the east along the rivers. The firm structure of Panhandle coal while favoring the prepared sizes, depressed the usefulness and value of the finer sizes. Panhandle slack and nut slack were marketed with difficulty at consistent, and at times considerable, loss. Many solutions were suggested, and the Pittsburgh Coal Co. investigated all. Lower delivered prices through lower mine costs and more advantageous freight rates were obvious goals, but equally obvious were the difficulties of self attainment of either in any substantial measure. Selling Btu's in pipes was abandoned as an idea after a thorough study of the economics of distribution of what was then, and is even now, the only developed continuous process of complete gasification of bituminous coal-producer gas. Although the coal company purchased huge blocks of electric power, it sold not a car of coal to the central power stations. Public utilities controlled the markets for electric current, and it was found that no matter at how low a cost current might be put on the bus bars by the coal company, distribution to its widely scattered coal mines made such an enterprise practically impossible. Consolidation of underground operations and a huge modernization program of mining operations in the 1920's were but preparation for the introduction of mechanical cleaning of the coal for market, particularly the smaller sizes of steam, gas, and by-

Jan 1, 1953

By Howard A. Meyerhoff

In western Argentina, in the Province of Mendoza and the Territory of Neuquen, there is a series of solid bitumen deposits which are claimed to be the most extensive in the world. In a linear belt 500 km (311 miles) long, roughly paralleling the axis of the Andes but occupying a variety of positions with respect to the orogenic structures, more than 100 outcrops have been reported. Approximately 70 of these have been prospected, and some mining has been planned or attempted for about half this number. Limited tonnage, high sulphur content, inaccessibility, labor shortages, and disastrous fires have taken a heavy toll among these operations, and in 1947, only 4 deposits were being actively mined, but 8 more were being explored and developed with a view to placing them in production. Inasmuch as these deposits are currently yielding a substantial fraction of Argentina's limited domestic supply of solid fuels, a brief account of the deposits and of the small industry based upon them will provide a commentary on Argentina's fuel problem. Character of Solid Bitumens The solid bitumens of Mendoza and Neuquen are petroleum derivatives, as is indicated by the following ultimate analysis : Constituents Per Cent Hydrogen.................... 6.8 Carbon...................... 82.4 Nitrogen..................... 1.6 Oxygen...................... 2.7 Sulphur...................... 2.2 Ash.......................... 4.3 100. 0 In physical appearance they bear a close resemblance to coal and are commonly called carbon. Their specific gravity has an extreme range of 1.10 to 1.777 in 36 samples weighed, but the average is between 1.14 and 1.24. The material is black, lustrous to dull, with blocky to sub-con-choidal fracture. Though brittle, the purest material is softer than anthracite and exhibits slightly more cohesion. This bituminous material is generally known as asfaltita or asphaltite, but definitive chemical studies indicate that the term asphaltite or grahamite can be applied correctly only to the exceptionally pure material of the Auca Mahuida district in Neuquen. Some other name should be used for the chemically variable bitumens found in all other districts, and the designation "asphaltitic pyrobitumen" has been proposed by Carlos A. S. Piscione.1 At the present time these bitumens are finding favor as solid fuel and as a gas-producing medium. They yield heat values of 8650 to 9750 cal,2 or 14,500 to 16,750 Btu per pound, and in consequence of their excellent heating qualities and the scarcity of imported coal, they are marketed as far away as Buenos Aires at a price of go to 95 pesos, or approximately $22 to 23, per metric ton. In burning, the material swells and decomposes into solid, fluid, and gaseous fractions which burn violently though nonexplosively. Its combustibility has been responsible for disasters and virtually complete destruction at Mina La Es-peranza and Mina Santa Marta, and for minor mishaps elsewhere, as at Mina Escondida in August 1947.

Jan 1, 1949