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A BLAST can be "full of sound and fury," signifying nothing but a poorly confined charge, or it can be a muffled, well controlled explosion which moves the rock efficiently and places it in the desired location with the least amount of fuss and bother. Why one method will do the job and another proves to be almost useless is shown by the machine-gun camera studies of quarry blasting made by the Atlas Powder Co. staff. The sequence, or machine-gun, camera is the latest scientific device for the study of cause and effect factors in blasting. Movie cameras, previously used, although of some use, were limited because slow shutter speeds and small negatives failed to give clear, sharp prints. During World War II, the AAF developed the sequence camera, which figuratively stops the blast at regular intervals, making study and evaluation feasible. The camera is simple and inexpensive and offers material for accurate examination of blasting techniques. The machine-gun camera takes three 5x5 in. exposures per sec at a 1/450 sec shutter speed, four times faster than a movie camera. Negatives are 30 times larger than those of movie cameras, giving large, sharp prints. The rock movement is frozen on the picture as the sequence of the blast takes place. Pictures on this page show the advantage of individual machine gun photographs. But the sequences made possible by this camera give graphic, dramatic and conclusive support to recently developed detonation theories.

Jan 1, 1952

By Thomas Cox

The following compilations are made from a series of investigations and are used to present the subject in an unbiased manner, as the writer does not represent any company or financial interest. The present situation is complex. The producers are hard pressed by reason of the low price of crude, while the independent refiner is little better off, because of the corresponding cut in price of refined products, except on occasional contracts. If the real costs are analyzed, it will be seen that the land speculators and the lessors—royalty owners—make the larger profits and not the struggling legitimate operator or independent refiner. The present-day (October, 1922) posted prices per barrel for crudes are Kansas, Oklahoma, Mexia, Gulf Coast, and Louisiana..... $1.25 Healdton............................................. 0.75 Northern Texas and Central Texas...................... 1 . 50 Pennsylvania......................................... 3.00 Wyoming, Elk Basin.................................. 1.25 Wyoming, Salt Creek................................ 0.70 California Base..................................... 0.60 These prices are at the well. In addition, crudes must be gathered and transported to refinery (by pipe line or tank cars), refined, and the refined products marketed. These crudes are of various gravities, ranging within a narrow margin for each field or district, so that averages are not difficult to deduce, and it is these averages that really determine the average operating conditions. In order to show the present realizations, the prices and costs now obtaining are listed against the average yields; the figures are also adjusted VOL. urn.----71

Jan 1, 1923

For the use of future students the following notes on the times of completion of various railroads and canals supplying transportation to coal fields are set down. These dates are widely scattered and sometimes difficult to find. A statement showing the mileage of railroad building from 1830 to 1879 by each railroad in the United States is given in the 10th U. S. Census, 1880, vol. 4, pp. 318-365. [Date of Opening Various Bituminous Districts by Railroad Transportation1 Blossburg, Pa. district in1840 Georges Creek, Md. district in1842 Broadtop, Pa. district in1856 Clearfield, Pa. district in1866 Meyersdale, Pa. district in1872 C. & 0., W. Va. district in1873 Elk Garden, W. Va. district in1881 Pocahontas, Va. & W. Va. district in1883 Beech Creek, Pa. district in1884 Hocking Valley, 0. district in 1869.-by Canal 1840] See also Paullin's Atlas of the Historical Geography of the U. S., published by the Carnegie Institution of Washington, 1932, for small-scale maps showing railroad development by decades. [OHIO CANALS Date Date CompletedName of CanalFromToAbandoned 1827, July 4Akron Cleveland 1827, Nov. 28Cincinnati Middleton 1828, Dec. 31 Cincinnati Sandusky 1830, July 10 Cleveland Newark 1832, Dec. 31 Akron Portsmouth 1838Penna. & Ohio Akron Pa. Canals 1853 north of Pgh. 1840, Sept. Hocking Valley Columbus Nelsonville 1844 Sandusky Dayton 1846 Sandy & Beaver Bolivar Smith's Ferry 1852 1846 Cincinnati Springfield]

Jan 1, 1942

By V. G. Mooradian, John T. Norton

THE diffusion of metal atoms into the crystal lattice of another metal and the assumption of regular positions to form a homogeneous alloy are some of the most fundamental phenomena of structural. metallurgy. The mechanism of this process has been the subject of a great deal of study from many viewpoints, but the picture is still far from complete. It is generally believed that if one metal is to diffuse into another, the first must have some solubility in the second1. This means that the solvent must be able to accommodate the stranger atoms, either on points of its own lattice or in the interstices between, without losing its own crystallographic identity. It is also a general observation that cold-working is a distinct aid in the diffusion process, causing it to take place with greater rapidity at the same temperature or with the same speed at a lower temperature. There is considerable doubt, however, as to the real significance of the deformation in its effect on the diffusion mechanism. Several factors associated with the cold-working. may be responsible for the increased diffusion rate. The plastic deformation causes a distortion of the solvent lattice, which may be an aid in the assimulation of atoms of another kind. There are many references2 in the literature that suggest that some distortion or "loosening" of the lattice is necessary for atomic migration and that diffusion cannot take place in the undis-

Jan 1, 1935

By Thomas Cox

The following compilations are made from a series of investigations and are used to present the subject in an unbiased manner, as the writer does not represent any company or financial interest. The present situation is complex. The producers are hard pressed by reason of the low price of crude, while the independent refiner is little better off, because of the corresponding cut in price of refined products, except on occasional contracts. If the real costs are analyzed, it will be seen that the land speculators and the lessors—royalty owners—make the larger profits and not the struggling legitimate operator or independent refiner. The present-day (October, 1922) posted prices per barrel for crudes are Kansas, Oklahoma, Mexia, Gulf Coast, and Louisiana..... $1.25 Healdton............................................. 0.75 Northern Texas and Central Texas...................... 1 . 50 Pennsylvania......................................... 3.00 Wyoming, Elk Basin.................................. 1.25 Wyoming, Salt Creek................................ 0.70 California Base..................................... 0.60 These prices are at the well. In addition, crudes must be gathered and transported to refinery (by pipe line or tank cars), refined, and the refined products marketed. These crudes are of various gravities, ranging within a narrow margin for each field or district, so that averages are not difficult to deduce, and it is these averages that really determine the average operating conditions. In order to show the present realizations, the prices and costs now obtaining are listed against the average yields; the figures are also adjusted VOL. urn.----71

Jan 1, 1923

By L.W. Eastwood, Arthur E. Bousu, C. T. Eddy

The recrystallization and grain-growth phenomena of cold-worked metals have considerable industrial importance because of their role in the fabrication of metals. For this reason, and because of the general academic interest in the subject, these processes have received considerable attention since the time of J. E. Stead's paper1 on The Crystalline Structure of Iron and Steel. There are considerable differences of opinion regarding the theory of recrystallization and grain growth and also differences in the observation of the modus operandi of the processes themselves. The value of many of the existing quantitative data on grain growth is decreased by the failure to distinguish between the grain sizes just after complete recrystallization and those resulting from coalescence. For this reason also, the value of the diagrams of stable grain sizes, like those produced by Bass and Glocker2 and Czochralski3, is lessened in so far as an interpretation of the facts of recrystallization is concerned. It is hoped that the data presentcd in this paper will help to clarify and to simplify the facts relating to recrystallization, and at the same time will show that some of the present-day conceptions are untenable. A paper on the theory of recrystallization, with additional data, will be completed in the near future by the writers. Since the literature on the subject has been adequately and frequently reviewed, the only referenccs to it in this paper will be those necessary in the discussion of the data presented.

Jan 1, 1935

By A. M. Talbot, John T. Norton

TheRe is still considerable controversy as to the exact nature of the mechanism of the age-hardening process, in spite of the many experiments already performed. For this reason, a considerable number of typical systems should be examined in detail and their results correlated. Furthermore, the methods of studying the changes that take place during the progress of this phenomenon should be carefully scrutinized and the different methods applied to the same samples, preferably at the same time. The experiments described in this paper are presented to supply information on one age-hardening system and to show how the various methods of investigation compare in their indication of what has happened. In brief, the progress of aging in magnesium alloys containing about 10 per cent by weight of aluminum at different temperatures was followed by measurements of hardness, electrical resistivity, dilation and lattice parameter, and by microscopic observation. Previous Work Meissnerl,$ Archer?, and Gann3 have investigated the changes in mechanical properties of magnesium-aluminum alloys during aging and have shown the optimum condition for the age-hardening treatment. Meissner's results are particularly interesting because when replotted so that they represent hardness as a function of aging time, the curves of 125" and 150" C. show two hardness peaks. This result was not confirmed in the present work. Schmid and Siebe14 have reported an investigation that is similar to the present one but it was not published until the present work had

Jan 1, 1936

By Arthur E. Bousu, C. T. Eddy, L. W. Eastwood

The recrystallization and grain-growth phenomena of cold-worked metals have considerable industrial importance because of their role in the fabrication of metals. For this reason, and because of the general academic interest in the subject, these processes have received considerable attention since the time of J. E. Stead's paper1 on The Crystalline Structure of Iron and Steel. There are considerable differences of opinion regarding the theory of recrystallization and grain growth and also differences in the observation of the modus operandi of the processes themselves. The value of many of the existing quantitative data on grain growth is decreased by the failure to distinguish between the grain sizes just after complete recrystallization and those resulting from coalescence. For this reason also, the value of the diagrams of stable grain sizes, like those produced by Bass and Glocker2 and Czochralski3, is lessened in so far as an interpretation of the facts of recrystallization is concerned. It is hoped that the data presentcd in this paper will help to clarify and to simplify the facts relating to recrystallization, and at the same time will show that some of the present-day conceptions are untenable. A paper on the theory of recrystallization, with additional data, will be completed in the near future by the writers. Since the literature on the subject has been adequately and frequently reviewed, the only referenccs to it in this paper will be those necessary in the discussion of the data presented.

Jan 1, 1935

By R. Stefanko, Y. J. Wang, H. R. Hardy, R. Y. Kim

Since 1964, the Dept. of Mining at The Pennsylvania State University has been carrying out extensive studies associated with the phenomena of microseismic activity and inelastic behavior in geologic materials. Briefly, the program to date has involved the following stages 1) Study of the microseismic noise and energy rates for selected geologic materials under incremental, uniaxial tension.1,2 2) Investigation of the frequency spectra of microseismic activity of selected geologic materials under incremental, uniaxial tension.3,4 3) Investigation of the time-dependent inelastic deformation of geologic materials and the analysis of such deformation in terms of mechanical models.5, 6 4) Simultaneous study of microseismic activity and time-dependent inelastic deformation in geologic materials under incremental, uniaxial compression.7,8 Details of the research involved in stage 4 of the program constitute the subject of this chapter. It should be noted that the majority of the experimental data quoted in this chapter forms part of a thesis to be presented by one of the authors (Kim) in partial fulfillment of the requirements for the Ph.D. degree in mining engineering at The Pennsylvania State University. During the last two or three years, a number of important papers have been published which deal primarily with the fundamental structure and mechanical behavior of geologic materials. Recent papers 9,10 have provided research workers in the rock mechanics field with a meaningful overall picture of rock as a structural material. The concept that many

Jan 1, 1970

By John J. Gilman

F many years it has been suspected that a correlation existed between pits produced by etching and the density of dislocations in crystals. In 1953, the interest in this correlation was greatly stimulated when Vogel et al' demonstrated a 1:l correlation between etch pits and dislocations in low angle grain boundaries of germanium. About two years ago, the author began attempts to produce etch pits at dislocation sites in zinc mono-crystals. These attempts met with success a year or so ago,' and since that time a survey has been made of the etch pit patterns that are associated with various modes of deformation in zinc monocrystals. Unfortunately, the etching technique that will be described is too delicate for use as an accurate quantitative tool. Nevertheless, it has been of considerable assistance in clarifying the structure of plastically deformed crystals. Technique Many attempts were made to produce etch pits in high purity zinc crystals. It was found that several techniques would produce surface grooves at grain boundaries that had misorientation angles greater than about l°, but no technique was successful for boundaries with smaller angles. Among the things that were tried were: electrolytic CrO, (both etching and polishing concentrations), HNO, in various water and alcohol solutions, dilute HC1, many 0-0,-Na,SO, solutions, Cr0,-HC1 solutions, picral, electrolytic Na,S,O,, and electrolytic NaOH and KOH. A few attempts to use cathodic sputtering and thermal etching were also made.

Jan 1, 1957

By John V. Beall

Tsumeb has added a chapter to its absorbing history with the beginning of copper smelting operations this month. This development will be followed shortly by another one when lead smelting and refining plants go on the line next year. In our own milieu these events would be common- place enough (although a new lead smelter certainly would be cause for wonder), but in the sparsely settled remote regions of northern South West Africa they are a dramatic industrial expansion. They are also, however, a sound businesslike extension of policies which have marked the tenure of Tsumeb Corp. Ltd. The historical data given in Table I are a drab listing of factual bones without the corporeal splendor which should surround the denouement of the Tsumeb bonanza. When Sir Francis Galton traversed the country, his was an expedition which was in keeping with the then blooming era of heroic explorations. The Otavi highlands in the interior were unexplored and the reception of the natives uncertain. While the exploratory work was in progress during the turn of the century the Hottentots and Hereros were successively in open bloody rebellion. The suppression of these uprisings, particularly the Hereros, by German soldiers so decimated the tribes that a labor shortage ensued for many years, hampering the development of the colony. To these troubles may be added difficulties In obtaining mining supplies. However, there should have been no shortage of meat from wild game judging by conditions prevailing even today.

Jan 12, 1962

By V. G. Mooradian

THE diffusion of metal atoms into the crystal lattice of another metal and the assumption of regular positions to form a homogeneous alloy are some of the most fundamental phenomena of structural metallurgy. The mechanism of this process has been the subject of a great deal of study from many viewpoints, but the picture is still far from complete. It is generally believed that if one metal is to diffuse into another, the first must have some solubility in the second1. This means that the solvent must be able to accommodate the stranger atoms, either on points of its own lattice or in the interstices between, without losing its own crystal-lographic identity. It is also a general observation that cold-working is a distinct aid in the diffusion process, causing it to take place with greater rapidity at the same temperature or with the same speed at a lower temperature. There is considerable doubt, however, as to the real significance of the deformation in its effect on the diffusion mechanism. Several factors associated with the cold-working may be responsible for the increased diffusion rate. The plastic deformation causes a distor-tion of the solvent lattice, which may be an aid in the assimulation of atoms of another kind. There are many references2 in the literature that suggest that some distortion or "loosening" of the lattice is necessary for atomic migration and that diffusion cannot take place in the undis-

Jan 1, 1935

By J. J. Demo

The effect of aluminum additions on the coating vale and corrosion resistance of Cr-Fe diffusiou coalings on a mild steel substvate has been studied. Aluminum additions up to 2 wt pct increase the chromium penetration rate while further additions retard it. The apparent cor$lict between these data and metallogyapkic ineasurements, which show a continuially increasing coaling thickness with aluminum addition, is discrissed. Compavisorz of corrosion resistance on the basis of equal thickness of tlre entire coating measured mnetal- ALTHOUGH ferrous metal articles are cheap and widely used, they are often quickly degraded by corrosion. To prevent or slow down the corrosion process, lographically is misleading; equal thickness of the cor-rosion-resistant portion of the coating is a bette.v basis of conzpavison. Inter difision coefFicients for Cr-Al-Fe coatings of different aluminum content have been detevmined and found to dary logarithmically when plotted againnst chromium concentvation. A general method of calculating diffusion profiles for different lrealment limes and surfuce coucentralions IS described. many types of coating are applied to steel.' Among these are diffusion coatings, formed by high-temperature diffusion of selected elements into the surface, which then becomes the coating Diffusion coatings are metallurgically bonded to the substrate and show a continuously varying concentration gradient from surface to substrate. Generally, these coatings have the advantage of adhering to the substrate upon deformation of the composite. Moreover, when chromium is one of the diffusion elements, a mild steel substrate

Jan 1, 1968

By L. C. Graton

Civilization did not begin until metals became the material of tools, implements and machines. - RICKARD, Man and Metals. HISTORY is no more an end in itself than is a backsight the sum total of a survey. This Institute may view with satisfaction the remarkable development of the mineral industry since its founding three score and fifteen years ago, its own enlarging service to that industry, and the contribution thus made toward the enhanced welfare, opportunity and mutual understanding now in greater or less degree reaching and benefiting all peoples of the globe. But neither this professional society nor the dynamic mining industry as a whole wishes on this anniversary to direct its gaze chiefly toward the past. The foremost purpose of historical review should be to throw into clear perspective the strong points and the defects in the forward march thus far, primarily as the basis for conceiving and designing a still sounder progress henceonward. At various times since the Institute's founding, the theories of ore deposition have been considered from the historical view point.l-7 For the present occasion it seems fitting to lay prime emphasis on the practice and utilization of geology in its varied relations to the problems of the mining industry. It is hoped that the reader will understand and accept the degree to which the whole is sampled by parts familiar to the present writer, and the disproportionate attention to thought and achievement within the United

Jan 1, 1947

By H. W. Montz

THE problem of surface support in coal mining is naturally divided into three branches: 1. Surface covered with improvements of such value as compared with the value of the underlying coal, or with such elements of danger to mining, that absolute support is essential. 2. Surface with improvements of less value than the underlying coal such that moderate settlement may be permitted, but destructive settlement must be avoided, either by reason of danger to human life or unwarranted property damage. 3. Surface of relatively small value as compared with the underlying coal where destructive settlement may be permitted. First Problem In the first case it is evident that the original support must be maintained either (a) by leaving ample pillars and confining the coal recovery to a very conservative first mining, (b) by so supporting less conservative first mining by filling or flushing that the gradual deterioration of the pillars may be prevented and subsidence avoided, or (c) by incompressible support as masonry either as an adjunct to insufficient pillars or in place of the original coal support. a. From tests made by the Scranton Engineers Club, it appears safe to figure on 2000 lb. per sq. in. as the safe squeezing strength of coal pillars in place, provided that these are, as usual, not higher than their least horizontal dimension; and from this figure the percentage of pillar to be left for various depths may be easily calculated. For safety in this

Jan 1, 1928

By Robert T. Hill

The successful completion, January 10,1901, by Capt. A. F. Lucas, of a well, near Beaumont, Texas, whereby an enormous flow, estimated at '75,000 barrels a day, was obtained, opened a new oil-field in the United States, kindled a frenzy of exploitation and speculation, revolutionized the fuel industry of a large region, and brought gain to thousands of people. Even to-day, it is impossible to cast up the present results or to prognosticate the future influence of this event. It has caused the revival of attention in other localities where oil had been suspected, and exploration for oil throughout the Texas region. It has attracted notice to the mineral resources of the Texas region, and created an interest in the geological conditions of that great State. This State, which has increased in population and wealth, as recorded by every succeeding census, with leaps and bounds such as are exhibited by no other part of the Union, now stands fifth in population and first in productive wealth per capita. Its fields, pastures, forests and mines teem with raw material. The whole economic evolution of the State has gravitated toward a focal point where these products were available for the coming of the kiln, the machine and the factory. The only drawback to the prosperity of the State was the lack of an economic fuel, inferior coal costing an average of $5.00 per ton at the time of the Beaumont discovery. This

Jan 1, 1903

The problem of surface support in coal mining is naturally divided into three branches: 1. Surface covered with improvements of such value as compared with the value of the underlying coal, or with such elements of danger to mining, that absolute support is essential. 2. Surface with improvements of less value than the underlying coal such that moderate settlement may be permitted, but destructive settlement must be avoided, either by reason of danger to human life or unwarranted property damage. 3. Surface of relatively small value as compared with the underlying coal where destructive settlement may be permitted. First Problem In the first case it is evident that the original support must be maintained either (a) by leaving ample pillars and confining the coal recovery to a very conservative first mining, (b) by so supporting less conservative first mining by filling or flushing that the gradual deterioration of the pillars may be prevented and subsidence avoided, or (c) by incompressible support as masonry either as an adjunct to insufficient pillars or in place of the original coal support. a. From tests made by the Scranton Engineers Club, it appears safe to figure on 2000 Ib. per sq, in. as the safe squeezing strength of coal pillars in place, provided that these are, as usual, not higher than their least horizontal dimension; and from this figure the percentage of pillar to be left for various depths may be easily calculated. For safety in this

Jan 1, 1930

By J. L. Craig, C. L. Edwards, M. D. Harper, J. M. Ray

The Los Alamos National Laboratory executed 19 intermediate scale cratering experiments in oil shale at the Colony Mine in Garfield County, Colorado. These experiments have led to a better under- standing of fracture characteristics and fragmentation of & - oil shale by use of a conventional high explosive. Geologic site characterization included detailed mapping, coring, and sample analyses. Site-specific geology was observed to be a major influence on the resulting crater geometry. The joint patterns at the experimental site frequently defined the final crater symmetry. Secondary influences included vugs, lithology changes, and grade fluctuations in the local stratigraphy. Most experiments, in both the rib and floor, were conducted to obtain data to investigate the fragmentation results within the craters. The rubble was screened for fragment- size distributions. Geologic features in proximity to the explosive charge had minimal effect on the rubble due to the overpowering effect of the detonation. However, these same features became more influential on the fracture and rubble characteristics with greater distances from the shothole. Postshot cores revealed a direct relationship between the grade of the oil shale and its susceptibility to fracturing. The Colony Mine experiments have demonstrated the significant role of geology in high explosive/oil shale interaction. It is probable that this role will have to be considered for larger applications to blast patterns and potential problems in retort stability in the future of oil shale development.

Jan 1, 1983

By J. W. Rutter, K. T. Aust

The motion of individual grain boundaries under a constant driving force was investi,qated for zone-refined lead, with and without solute tin additions. The rate of boundary migration was found to depend strongly on tin content and on the orientation relationship between the adjacent grains. The results are compared with the theory of impurity-controlled grain boundary miqration developed by Lucke and Detert. Evidence was found that grain boundaries separating grains which have the Kronberg-U&apos;ilson orientation relationships of 38 and 22 deg about <Ill> and 28 deg about <100>, correspond to boundaries of high mobility. The results are discussed in relation to the formation of annealing textures in metals and the structure of high-angle boundaries. It is generally known that small amounts of impurities in solid solution greatly influence the re-crystallization behavior of metals. For example, the addition of 0.005 at. pct of tellurium to copper,&apos; or 0.005 at. pct of silver to lead,2or 0.01 at. pct of manganese or nickel to aluminum3 greatly decreases the rate of recrystallization of these metals. However, this effect may be the combined result of a decrease in the rates of both nucleation and growth; recrystallization experiments do not separate these two factors. Bolling and winegard4 determined the effects of small quantities of tin, silver, and gold on grain growth in polycrystalline zone-refined lead.

Jan 1, 1960

By Charles Fettke

IN THE present day manufacture of glass nearly pure quartz sands are used almost exclusively as the source of the silica, which is the major constituent of all common varieties of glass. Ordinary soda-lime, such as bottle, common tableware, plate, and window glasses, contain from 65 to 75 per cent. of silica. OCCURRENCE Glass sands occur in nature either in the form of loose, unconsolidated sediments or in deposits in which the individual grains have been more or less thoroughly bound together by some cementing agent so as to form sandstones. While deposits of sand and sandstones occur both widely and abundantly distributed, deposits that are sufficiently free from other constituents than quartz grains, so that they can be employed in the manufacture of the better grades of glass, are, comparatively speaking, of rare occurrence. The major portion of the glass sand produced in the United States comes from sandstones. In order to be suitable for glass sand, they should be rather friable. The rock should break down readily along the cementing material between the grains and should not break across the grains rather than along the bond. Some of the sandstones used are so friable that only light shots of slow-burning dynamite are necessary to disintegrate them sufficiently for hydraulic mining, while others have to be passed through crushers in order to disintegrate the rock into its individual grains.

Jan 2, 1926