Search Documents

By Ralph Sweetser

THE present state of iron blast-furnace practice is metallurgical rather than mechanical; the tend-ency is toward intensity rather than toward ex-tension. The engineers have built blast furnaces big enough and strong enough, and have furnished accessory equipment ample and accurate enough for the present state of the art, but the metallurgical side has been too much neglected; the metallurgist, rather than the engi-neer, is now the man on whom the present and future progress in iron blast-furnace practice depends. The mining engineer has produced great tonnages of iron ores, and has kept ahead of the demands for quantity; now the metallurgist is improving the chemical and physical qualities of this product by ore-dressing and other forms of beneficiation. For a generation or more, the principles of mechanics have had most influence in the advancement of iron blast-furnace practice; atten-tion now is given more to the principles of metallurgy, chemistry, and ore-dressing. This metallurgical progress is taking place inside and outside the blast furnace. The two great determining factors of the inside operation are the slag, and the rate of combustibility of the coke. Outside the fur-nace, the progress is, and will be, along the lines of more careful mixing of ores and iron-bearing materials, in the sizing and washing of limestone, and in the char-acter and structure of byproduct coke.

Jan 3, 1922

By Maurice B. Dusseault, Edo Nyland

Numerous consistent seismic signals are being generated in a pilot fireflood in a 750 m deep high permeability unconsolidated channel sand in Eastern Alberta. The pilot has a central air injection well, eight production wells on artificial lift, and two internally placed observation wells. Surface seismometers and a 12-hydrophone downhole string were deployed to detect seismics signals. Date were collected for 22 hours employing signal-triggered event detectors recording on cassette tapes. Monitoring during twelve hours of steady air injection at 625m3/s yielded a clear event frequency of about 50 events/h. The events were mostly clear compressional wave arrivals originating in the vicinity of the firefront. Stopping air injection caused a gradual drop in event frequency, and the rate was reestablished when air injection was reinitiated. Spectral frequency analysis and knowledge of material properties indicate that the events are shears of a stick-slip nature associated with the strain-weakening behavior of the over-compacted reservoir sands. The event amplitude indicates small-scale shearing, and different amplitudes suggest that planes re-shear with lower energy release levels. The triggering mechanism for shear rupture is high shear stress created by thermal expansion in the area of highest ther- mal gradient. Other enhanced recovery techniques may also produce useful signals for process control. In particular, steam flooding, hydraulic fracturing, and high-pressure injection operations likely generate mappable microseismic events which can be applied directly to production/ injection strategy.

Jan 1, 1982

By W. L. Chen

The Batac jig was first introduced in the US for fine coal cleaning in 1973 (Tackett, 1977; Hake, 1976). Since then, a total of six such jigs of various sizes have been installed in five US plants for a total capacity of 2346 t/h. The raw coal size ranges from 19 mm x 0 to 9.5 mm x 0-fraction sizes previously fed to heavy medium cyclones, Deister tables, or water only cyclones. Growing interest in the Batac jig as a replacement for the above equipment is due to the following reasons: • Unlike heavy medium cyclones, no magnetite is required. As a result, the operating cost of the plant is reduced. • The compactness of equipment is unique on a unit ton per hour basis as compared to other equipment. • Solid state electronic control of jig stroke length, frequency, and jig bed depth makes the equipment highly efficient. Installations of Batac jigs in the US as of June 1980 are shown in [Table 1]. Use of the Batac jig is even greater outside the US (Anonymous, 1980; Chen, 1980). Its use is not limited to fine coal but is applied to coarse coal as well, with 102 mm size in the feed (Zimmerman, 1975). In countries where consumption of magnetite associated with the heavy medium system of coal cleaning is considered a waste of iron ore resource, the Batac jig is regarded as the primary choice in the selection of cleaning equipment (Chen, 1980).

Jan 1, 1981

By Fred Van Covern

Before getting into a discussion of the subject of my paper, I want first to make it clear to everyone that I am speaking as an individual; and that any expressions of opinion that are contained herein, or may be expressed in any oral discussion that may follow its presentation, are entirely my own, and must not be construed to be the official opinion of the American Petroleum Institute. Demand fob Motor Fuel, 1936 During the year just closed the domestic demand for gasoline exceeded 481 million barrels. This compares with 434,810,000 bbl. consumed during 1935 and indicates an increase of 10.46 per cent. Export shipments amounted to 27,831,000 bbl. while in 1935 they totaled 30,613,000 bbl. Total demand, therefore, was 509,422,000 bbl., or 9.16 per cent above the 465,423,000 bbl. of 1935. Following are the figures for several years: Already we are supplying gasoline domestically and as foreign shipments at a rate almost 25 per cent greater than our low level of 1933. Before giving figures for 1937, I should like to spend a moment or two in discussion of gasoline inventories, from the point of view of minimum working stocks and other requirements and of probable actual levels. Inventories of Gasoline The year 1936 closed with about 62,900,000 bbl. of finished and unfinished gasoline in storage—about 6 million barrels more than was on hand

Jan 1, 1937

By Ben Gumpertz

THE important factors in any study of the screening of sand with a gravel enve-lope, as applied to use in oil wells, are: (r) sand size and shape, (2) gravel size and shape, (3) ratio of gravel size to sand size, (4) flow velocity, (5) viscosity of the fluid. Perhaps the first extensive investigation of the function of gravel in screening sand was performed by Coberly and Wagner,1 from which the following conclusion was drawn: "The diameter of the largest grains in a single classified sand suitable for gravel packing is approximately 23 times the grain size at the ten-percentile analysis of the formation sample." This applies to sands classified by Tyler screens and is for gravel grains of the maximum size that could be used to form a stable bridge. Field practice has shown that the screening effect of a given gravel for a given sand apparently varies with the flow velocity.2 Also, it has been assumed by some opera-tors that the thickness of the walls of the gravel envelope surrounding the well has little effect upon the screening process. It is thought by others that a narrow envelope of gravel might form an ineffec-tive screen. Thus the purposes of this work are: I. To investigate the effect of gravel-sand size ratio upon screening action under the condition of varying flow velocities. 2. To investigate the effect upon screen-ing action of varying the thickness of the gravel screen.

Jan 1, 1940

By J. Cervik, P. C. Thakur, S. D. Lauer

Methane drainage by cross-measure boreholes on retreat longwall faces can be a viable alternative to the vertical gob degas boreholes under favorable circumstances. The research was done in a mine working Pittsburgh coal seam in northern West Virginia under USBM Cooperative Agreement No. 14-09-0050-3252. The study was the first application of this technique to Pittsburgh coal seam. A total of 14 small diameter, inclined boreholes were drilled over a retreat longwall panel from gate roads, to intersect the overlying coal seams. All boreholes were manifolded to a pipeline and the gob gas was extracted by a surface exhaust fan. The methane capture ratio was poor at 7% to 18% at various stages of the longwall panel. A vertical gob degas borehole captured an additional 20% gas. Poor results were due to premature failures of the cross-measure boreholes leading to air leakage. For better performance, the boreholes should be drilled from a point 30 to 45 m (98 to 148 ft) from longwall pillar over the largest chain pillar. The standpipe should be grouted for at least 6 m (20 ft), and the entry containing boreholes and the pipeline must be supported to ensure access for maintenance and optimization of methane capture. Coursing the ventilation air around longwall such that it forces methane migration toward cross-measure boreholes can further improve methane capture. The optimum vertical inclination is 45º ± 10º.

Jan 1, 1986

By B. D. Cullity

AS methods for measuring fiber textures become more exact, it becomes justifiable to scrutinize an observed pole-density curve for evidence of minor texture components. These are disclosed by minor maxima or abnormally broad major maxima. One possible source of these minor components is twinning of the main component. In cubic metals and alloys, there are two kinds of twins: 1) Annealing twins in face-centered cubic metals. These are reflection twins on {Ill), and they can be expected to be present in recrystallization textures. 2) Deformation twins in body-centered cubic metals. These are shear twins on (112). Although usually formed only by impact, they might conceivably be present in the deformation texture of severely cold-drawn wire. Fortunately, both kinds of twinning lead to the same orientation relationships. It thus becomes possible to prepare a single list of angles between various planes in parent crystal and twin, which is helpful in examining pole-density curves for evidence of twinning in any cubic metal or alloy. Such a list of interplanar angles is given in Table I. This table consists of three parts, corresponding to the three major texture components—<100>, <110>, and <111>-most commonly found in the fiber textures of cubic metals. The table lists the angle between the pole of {hkl}, in either the parent crystal P or the twin T, and the fiber axis <uvu>. The crystals with <uvw> parallel to the wire axis are here

Jan 1, 1959

By Thomas S. Nye

Mineral exploration in the United States relies heavily on theoretical geologic concepts and indirect methods such as geophysics and geochemical prospecting, as there are few exposed areas of mineralization which have not already been explored. In Mexico, ore grade samples can be cut at the surface on vein, replacement, and disseminated types of deposits in many areas. The problem is not in finding a mineralized area but in deciding which mineralized area can be explored and developed at the least risk and cost, with the greatest profit potential within the framework of Mexican mineral economics and that nation&apos;s government policies. Socio-economic Posture Mexico, prior to World War II, had suffered from more than one hundred years of intermittent wars and exploitation by internal and foreign elements. Consequently, the basic facilities which today&apos;s society takes for granted were scarce or non-existent in most of the country. Travel was largely a matter of negotiating poor dirt roads, riding horseback or walking. Relatively few people were literate and medical facilities were luxuries for the wealthy. Mexico&apos;s leaders were, however, determined to improve the lot of their people, within a system of private enterprise and personal freedom. Long-range programs initiated at about the time of World War II to provide infrastructure-education, health and welfare, transportation, power, water, communication-are now established fully or in part for most of the country and are being continually expanded.

Jan 12, 1972

By W. A. Tiller, W. C. Johnston

A theoretical analysis of alloy solidification in which the effective partition coefficient, k, of the solute is allowed to vary as a function of interface position is performed. A variety of solute distm&apos;butions in the solid is predicted depending upon the functional dependence of k with interface position. Conversely, the variation of k with interface position required to produce a particular solute distributzon in the solid can be calculated. These preciictions have been tested by controlling the width of the momentum boundary layer in the liquid as a function of interface position with a rotating mugnetic field. One of the objects of controlled solidification is to utilize the freezing process for the preparation of crystals of specific materials containing a predetermined distribution of solutes. For example, a thermoelectric power generation material may exhibit a figure of merit, 2,&apos; as a function of temperature, T, and solute concentration, C, as illustrated in Fig. 1. If we wish to use this material in a device between the temperature limits T1 to T2 a significantly greater efficiency will result from the device if the thermoelectric element illustrated in Fig. 1 consists of a range of solute concentrations appropriately located with respect to the temperature distribution rather than using a sample of constant solute concentration. For this reason and many others2 we are interested in programming and controlling the solute distribution in a single crystal

Jan 1, 1962

By D. B. Dowling

(San Francisco Meeting, September, 1915) THE interest which has been aroused in prospecting for oil in the foot hills of southern Alberta, and in the oil possibilities of the known gas fields situated in the less-disturbed areas, called for a much closer examination of the structure, thickness, and composition of the underlying rocks of the region than had -hitherto been made. The areal geology of the larger part of the great plains was outlined by Dawson, McConnell, and Tyrrell, between 1881 and 1885. The foothill area was not critically examined at that time, owing to the time which would have been required for its proper study and the difficulty that was found in recognizing in the foothills the divisions which had been adopted in the mapping of the formations of the plains. This was clue in great measure to the paucity of exposures in continuous sections of the lower divisions of the Upper Cretaceous. Since the pioneer work on the plains was published, the beds which form continuations south into Montana have been critically examined. The Canadian beds arch over the end of a flat anticline which rises to the south; and two sections in Montana, one on each side of the anticline, help to explain some of the difficulties previously encountered in the mapping of the measures found in the foothills. The index map, Fig. 1, shows the area studied, and its relation to southeastern Alberta, and to Montana.

Jan 6, 1915

It has been stated, by Sir James M. Barrie, that "the man of science appears to be the only man who has something to say, just now-and the only man who does not know how to say it ". The friendly jibe of the novelist contains enough exaggeration to make it humorous to the followers of Huxley and Spencer; but could any litterateur poke similar fun at the exponents of the avowedly utilitarian branches of science-the men of technology-without suggesting an unpleasant truth? Indeed the engineer does bungle language deplorably. He makes a fetish of efficiency, yet he shows no regard for the effective use of one of his most important tools-the pen; he believes devoutly in accuracy, yet he employs an instrument of precision as carelessly as a small boy handles a gun. This inconsistency may be due to causes such as were indicated by the Academic Senate when it undertook to explain the defective writing of the students in this university.* The Senate suggested that the student is "constantly subjected by his environment to the unedifying influence of myriad examples of poor English", and that he is also affected by "a certain public prejudice against correctness of expression". With these statements most of us will agree. Our local newspapers, for instance, tend to spoil the student&apos;s taste for good English; later in life, as an engineer, his daily contact with illiterate men inclines him to careless speech and slovenly writing. As

Jan 1, 1931

By Takahide Wakamatsu, Shigeru Mukai

Fundamental investigations were made on the treatment of slime and the chrysocolla flotation, both of which are urgent problems to be solved in copper oxide mineral flotation. Unfavourable effects of slime on flotation are caused by the slime adsorption at the air/liquid Interface as well as the slime coating on the mineral surface. The adsorption of slime at the air/liquid interface was measured by using various kinds of slime particles. As a consequence, goethite, bentonite and talc tended to adsorb markedly at the interface. As a desliming method, slime flotation with a polymer flocculant such as polyethylene-oxide prior to the ordinary copper oxide flotation was found to be effective. The use of both a copper-avid organic reagent and an alkyl xanthate was examined for a selective collection of chrysocolla through xanthate adsorption tests, chrysocolla float- abllity tests and flotation tests for synthetic and natural ore. The copper-avid reagents used were salicylaldoxime, 8- hydroxyquinollne and benzoin-a-oxime. As a result, the ad- sorption of higher xanthate such as amyl xanthate on chrysocolla as well as the chrysocolla-to-air bubble attachment was increased by the presence of a copper-avid reagent under suitable reagent addition and pH of pulp. Flotation tests for synthetic and natural ores confirmed that chrysocolla could be floated sufficiently and selectively with a copper- avid reagent like 8-hydroxyquinoline or salicylaldoxime with its subsequent collection by amyl xanthate.

Jan 1, 1976

By Arthur Tauber, Horst Kedesdy

FERRITES are sintered metallic oxides of the spinel structure type1 and belong to the class of soft ferromagnetic materials. Similar to a ceramic, they can be formed and fired to a dense body, exhibiting a high electrical volume resistivity ranging from 102 to 102 ohm-cm as compared with 10-6 ohmcm for some of the metallic magnetic materials. This high resistivity, with resulting low eddy current losses, finds special application at high frequencies. The dispersive susceptibility of ferrites at microwave frequencies has also led to many applications in this field. Where high resistivity with high permeability is desirable, ferrites are used in low frequency applications. During the last few years ferrites exhibiting rectangular hysteresis loops have been developed for computer and magnetic memory systems. The general formula for ferrites is MeFe2O4 where Me is a divalent metal ion such as Ni, Zn, Mg, Mn, Cu, Cd, and Fe. Only two of these ferrites are nonferromagnetic, namely, those with Zn and Cd. Solid solutions can be formed between different ferrites, and it is of interest to note that solid solutions of a ferromagnetic ferrite with a nonferromagnetic ferrite yield much better magnetic materials than the basic ferrite body. In general, it can be said that the solid solution formation between ferrites has widened the field of ferrite synthesis and has led to methods of preparing materials with a large variety of magnetic properties.

Jan 7, 1957

By Rodolfo V. de la Cruz

The accurate assessment of the in situ deformability of rock masses is very important in the de and construction of underground openings for mining and geotechnical engineering applications. This paper presents a method and device for determining the in situ deformability of rock masses by relating the borehole jack load to the diametral displacements at a number of orientations around the borehole wall. The method called mu1tiple measurement method include the steps in which: a) diametral displacement sensors are installed at different orientations around the borehole to measure the changes in length of various diameters of the borehole; b) a uniaxial load is applied on two opposed octants of the borehole wall, and; c) using elastic theory and assuming a reasonable value for the Poisson&apos;s Ratio of the rock mass, the in situ deformability of the surrounding rock materials is determined from the measured diametral displacements and applied unidirectional load. The multiple measurement method has a significant advantage over existing methods since it provides several independent data in a single test from which to calculate the in situ deformability of the rock mass. The multiple data provide a check and counter check on the reliability and accuracy of the various measurements. The multiple data would also provide a means of quantifying the degree of fissuring on the borehole wall. Information on the degree of fissuring is very important in numerical modeling of rock masses.

Jan 1, 1984

By K. G. Davis, P. Fryzuk

WEINBERG,&apos; in an investigation of solute distributions along unidirectionally solidified rods of dilute silver in tin alloys, concluded that, for rods of 2 mm diameter or larger, a very high degree of convective mixing takes place in the melt ahead of the advancing interface. Suggested causes for this mixing were (1) thermal convection, (2) convective currents set up by changes in fluid density associated with concentration gradients, and (3) currents set up by changes in volume during freezing. Evidence was presented that causes (2) and (3) were not primarily responsible for solute mixing. Further, convective mixing took place in horizontal rods with temperature gradients as low as 6°C per cm, putting doubt on the importance of thermal convection. In the present work, convective mixing is examined in melts with known initial solute distributions. The absence of a moving solid-liquid interface eliminates convection caused by volume changes on solidification. In the first experiment, three silica tubes 2 mm in diameter and approximately 20 cm long were filled with an alloy of 100 ppm Ag in tin (99.999 pct purity), placed adjacent to one another in a horizontal furnace, and solidified from one end at 1 cm per hr. A110, a Y emitter, was used as tracer. A few centimeters at the start of the rod were left un-melted, to determine the initial concentration Go. After solidification was complete, one sample was removed. The hot furnace was then brought back to

Jan 1, 1965

By H. K. Shearer

The principal events in the oil history of south Arkansas, north Louisiana and Mississippi in 1930 have been: In Arkansas, very little activity, except for discovery of deep oil production at Urbana, and completion of the first oil well in Miller County. In Louisiana, continued development of the Zwolle area, bringing production up to about 10,000 bbl. per day; practically complete development of the Carterville oil-producing area; discovery and drilling of the rather disappointing Holly area, and discovery of Trinity gas production at Sugar Creek, Claiborne Parish and Rodessa, Caddo Parish. In Mississippi, discovery of the Jackson gas field, in Hinds and Rankin counties. Proration of oil runs was not put in effect in these areas during 1930, because the natural decline of the older fields brought production below the demands of local markets. The only effect of the oversupply and low price of oil was the curtailment of some drilling which might otherwise have been done. Drilling in Arkansas reached the lowest stage since the discovery of oil, with less than 100 completions. Louisiana showed some increase in drilling over 1928 and 1929, but almost half of the wells were drilled primarily for gas rather than oil. As no review on north Louisiana production has been prepared since 1927, and there was none on south Arkansas for 1928, the developments of the three years, 1928, 1929 and 1930 are here briefly discussed.

Jan 1, 1931

By F. E. Bash

IN recent years, there have been a number of experiments conducted to determine the rates of heating and cooling of various sizes and shapes of steel ingots. Up to date, however,-most of the published data has dealt with small sized ingots, the largest being an 18-in. (46 cm.) cube, the data on which was presented before the Iron and Steel Institute in May, 1918, by E. F. Law. It is due to thus lack of information on the rate at which large ingots absorb heat and come to temperature that the heating- practice varies so widely in different plants. One of the questions over which there is much debate is the proper rate of heating of large ingots for forging and the time actually required for the center of a mass of steel to come to forging temperature. As a continuation of experiments described by M. E. Leeds1 and at the request of Mr. G. R. Norton of the Sizer Forge Co. and Mr. R. C. Drinker of the Emergency Fleet Corpn., the test described in this paper was carried out on a 24-in. (61 cm.) round ingot and the rate of heating and cooling determined under regular production conditions. The ingot had been partly forged at one end but, on developing a flaw, had been scrapped so that it was available for test. The size and shape of the ingot and its position in the furnace are shown in Fig. 1.

Jan 9, 1919

By J. R. Finlay

Every business man who has reached the age of forty, or perhaps even thirty, must know from his own experience that there are occasional periods of "good times&apos;&apos; and others of "bad times "-booms and panics. Those who give to business some complexion of science have invented a semiscientific name for these alternations-the business cycle-indicating that it is a normal phenomenon which by its own nature repeats itself. The longer one lives and the more one enlarges his own experience by the study of history, the more of these cycles he knows and the more disposed he becomes to take their recurrence for granted. If these alternations can be put into the category of common- places, why not treat them as such? We are in a sharp depression right now, why worry about it? Is there not a certain average value for business that can be depended upon in spite of depressions? By way of rejoinder one might answer that war is the great commonplace of history, but when we get into one we generally find it worthy of attention. In the present case, many a man has lost two-thirds of his income, and he is extremely nervous about finding it again. The Southern Pacific Railroad earnings have dropped 75 per cent in the past year; Pennsylvania, 60 per cent; United States Steel Corp., about the same. The drop in current earnings is

Jan 1, 1932

Alfred C. Young† (communication to the Secretary): Before the appearance of Mr. Scott&apos;s paper in these Transactions we were not specially interested in the investigation which he has started; but at his request we have endeavored to collect from musty records and the recollection of our old friends a brief chronicle of the progress made by this house. As 3000 instruments were manufactured by us before any descriptive record was kept, and 2000 more before the record contained more than a statement whether the instrument was a transit or a level, and sometimes its size, we approach the task with timidity, trusting that the reader will bear the difficulties in mind, particularly as the writer&apos;s predecessors, from whom, no doubt, the information desired could have been obtained, have passed away. Instruments for surveying were manufactured by David Rittenhouse, of Philadelphia, as early as 1760; but it was not until late in the first quarter of this century that there was any American market for an instrument outside of the ordinary surveyor&apos;s compass. With the advent of canals and railroads, and the more extensive development of the Pennsylvania coalfields, arose a demand for surveying-instruments to meet problems in engineering beyond the limited field of the compass. On May 1, 1820, in which year the practical mining of anthracite coal in Pennsylvania began, William J. Young, who had served his apprenticeship with one Thomas Whitney,

Jan 1, 1901

By R. H. Doremus

From measurements of carbide precipitation rates in a iron it was concluded that the carbides nucleated on dislocations in both strained and unstrained samples, except for the latter at lower temperatures and higher carbon concentrations, where there were more muclei than could form on the dislocations. The equation of Cottrell and Bilby for the segregation of atoms to dislocations was found to be inapplicable to this system. No satisfactory theory for the growth process is available. A study of the rate at which a second phase separates from solid solution can frequently reveal much about the mechanism of separation. There are still many features of the precipitation of carbon from a iron that are not understood, although this system has been examined extensively. To provide more insight into the mechanism of carbide precipitation in a iron, rates of this process were measured at different temperatures, carbon concentrations, and densities of dislocations in the iron. The concentra- tion of carbon in solution was followed from the height of the internal-friction peak; this height is directly proportional to the amount of carbon in solution and is not affected by the growing carbide particles. In this paper these rates are compared with those found by earlier investigators, and the mechanism of precipitation is discussed in light of these results as well as two earlier studies1, 2 and the electron microscopic work reported in the preceding paper. EXPERIMENTAL The amount of carbon in solution was followed by

Jan 1, 1961