Search Documents

By Murray F. Hawkins, W. J. Ainsworth

In all types of subsurface pressure gauges the extension which occurs in the pressure-sensitive element is a function of the difference between the external (well or calibration) pressure and the internal pressure within the gauge, rather than a function of the external pressure only. The internal pressure is near atmospheric and depends upon (a) the quantity of air sealed within the gauge at the time of calibration or measurement, (b) the quantity of moisture (liquid water), if any, sealed within the gauge, and (c) the temperature at which the calibration or well measurement is made. Part of this correction for the change of internal pressure with temperature is taken care of by the customary temperature coefficient of the gauge. However, part of it is not, and while this portion may be only a few psi, it is nevertheless predictable or preventable, and should be considered in precision measurements. ERROR NO. 1 If air is sealed in the gauge at the same temperature and pressure for both the calibration and the well measurements, the usual temperature correction will take care of any difference between calibration and well measurement temperatures. However, if air is sealed within the gauge at temperature T1 and pressure P1 at calibration but at temperature T2 and pressure P2 for a well measurement, because different amounts of air are sealed within the gauge in each case, the internal pressure at. or corrected to, calibration temperature Tr will he different by where all temperatures and pressures are absolute. The calibration temperature is used, and not the well measurement temperature, because the usual temperature correction reduces the well measurements to calibration temperature. The correction term as calculated by the above equation is separate from. and in addition to, the usual temperature correction. Example: T, = 540°R, sealing temperature at calibration P, = 14.7 psia, sealing pressure at calibration T2 = 460°R, sealing temperature at well P2 = 14.7 psia, sealing pressure at well Tr = 660°R, calibration temperature AP = 660 [14.7/460 — 14.7/540] = 3.1 psi While this error is small even under these somewhat maximal conditions, it nevertheless represents a practical situation which did occur, and which as a matter of fact gave rise to this note. Where AP is positive, as above, the correction is added to the measured pressure; where negative, subtracted from the measured pressure. This correction should also be considered in successive calibration runs where the gauge, for example, may be warm from a previous calibration at an elevated temperature. ERROR NO. 2 Where a small quantity of moisture (liquid water) is sealed within the gauge at atmospheric conditions, the increased vapor pressure of the water at higher well or calibration temperatures will cause an increase in internal pressure. This moisture will come presumably from condensation within the gauge following temperature changes, from moisture on the operator's hands, and from atmospheric moisture (rain, mist, fog, etc.). Calculation shows that approximately 0.2 cc of water (three to four drops) is sufficient to saturate the air within an Amerada RPG-3 Gauge at 160°F, at which temperature the vapor pressure of water is about 5 psia. As the vaporization occurs in a sealed volume, the increase in internal pressure will be in excess of this 5 psi. At higher temperatures the pressures will be higher; however more water will be required to saturate the air within the gauge. Some experimental work was carried out with an Amerada RPG-3 Gauge at 200°F fitted with a 1,000 psi element, both with a dry recording chamber and with a small amount of water added. The results directly proved the existence of the error due to the presence of moisture, and, it is felt, indirectly, due to the differences in sealing temperatures and pressures, as both effects may be ascribed simply to an increase in the moles of gas within the recording chamber. SUMMARY In precision measurements the error introduced by sealing the gauge during a well test at a different temperature and pressure from that of calibration may be corrected for by using the equation presented, or it may be prevented by taking care always to seal the gauge at near calibration conditions. The error introduced by sealing moisture in the gauge may be prevented by taking care to keep moisture out of the gauge, or by removing the moisture by either warming or evacuating the gauge. Both of these errors are independent of the range of pressure measurement and the type of gauge, and are in addition to the usual temperature correction. ACKNOWLEDGMENT Appreciation is expressed to W. B. Kendall, Geophysical Research Corp., Tulsa, Okla., who pointed out the error from differences in sealing temperatures during some winter work in Canada. ***

Jan 1, 1956

S. F. EMMONS RESEARCH FELLOWSHIP. The movement was started by a number of the friends and admirers of the late S. F. Emmons, Economic Geologist of the United States Geological Survey, to perpetuate his name through a fellowship to be known as the " S. F. Emmons Research Fellowship," and they have succeeded in raising some $13,000 for the purpose of carrying on research work in economic geology. The Committee in charge of this Memorial Fund has succeeded in obtaining the co-operation of Professors Kemp, of Columbia, Irving, of Yale, and Lindgren, of Massachusetts Institute of Technology, in the administration of this fellowship. These three gentlemen are respectively geologists of the institutions mentioned and are exceptionally qualified to determine in what direction the fund can be best administered. It is hoped that additional contributions will be forthcoming from many who have heard of this movement. Subscriptions are invited and may be sent to any one of these gentlemen, or to Benjamin B. Lawrence, Treasurer, No. 60 Wall Street, New York City.

Jan 11, 1913

Assistant Professor of Mining Engineering.-Mining engineer to teach mine surveying, mine mapping, assaying, etc., but not metallurgy. Location, Ohio. Salary, $1800 per annum. No. 379. Metallurgist.-Experienced metallurgist capable of running 25-ton blast lead furnace. Man who knows the country and speaks Spanish desired. You may know that this state is in peaceful conditions and that even during the worst time of the revolution there were several mining concerns never idle. Besides, its resources are wonderful, and once a man gets started, he will find many possibilities. Notwithstanding that Sinaloa is a mining state, our smelter will be the only lead smelter on this coast. Location, Culiscan, Sin., Mexico. No. 381. Quarry Superintendent.-Engineer experienced in limestone quarry work for position as superintendent; must be capable of producing results; must increase output of quarries from 4 to 12 cars per day. Young man with abundant energy is desired. Permanent position, chance to grow up with the company. Location, New Jersey. Salary depends upon the man. No. 382.

Jan 4, 1919

By S. J. Aparo

After surveying the beneficiation techniques in the Florida phosphate field, it is apparent that optimum beneficiation of this ore is a difficult task. Due to continually changing grade, size distribution and basic nature of the ore, there appears to be no universal technique nor a single reagent entirely satisfactory for achieving optimum metallurgy under these dynamic conditions. Although no major change in the basic flow sheet has been made in the last 20 years, there have been many refinements of the process in recent years which have helped increase production, improve recovery, lower unit cost of operation and make the beneficiation of lower grade deposits economically feasible. Among the significant changes is the use of larger plants and equipment which has helped to increase production significantly. The use of cyclones has facilitated and reduced the cost of slimes removal in these large plants. There have also been several new approaches to the flotation of coarse phosphate that are mentioned in the text of this paper. Lastly, significant improvements have also taken place in the area of flotation reagents.

Jan 1, 1970

(Members are urged to send in for this column any notes of interest concerning themselves or their fellow-members..) Members and guests who registered at institute headquarters during the period Dec. 10, 1915 to Jan. 10, 1916: A. R. Fletcher, Palo Alto, Cal. H. L. Hollis, Chicago, Ill. R. G. Hall,. St. Louis, Mo. Howland Bancroft, Denver, Colo. Walter E. Koch, Terlingua, Tex. G. D. B. Turner, Butte, Mont. George A. Macready, Searchlight, Nev. H. A. Wheeler, St. Louis, Mo. H. W. Edmondson, Concheno, Chili., Mex. George B. Rodgers, St. Francois, Mo. Arthur F. Taggart, New Haven, Conn. Paul S. King, Wilmington, Del. H. V. Winchell, Minneapolis, Minn. G. H. Clevenger, Palo Alto, Cal. Frank A. Ross, Spokane, Wash. J. W. Beard, Syracuse, N. Y. W. D. B. Motter, Jr., Benson Mines, N. Y. Albert De Deken, Louvain, Belgium. S. Le Fevre, Forest Glen, N. Y.. James H. Smith, Jr., Mount Carmel, Pa. E. H. Hamilton, formerly manager of the Virginia Smelting Co., West Norfolk, Va., has become consulting metallurgist to the Consolidated Mining and Smelting Co., of Canada, Ltd., Trail, British Columbia.

Jan 2, 1916

By H. Rumfelt

Surface excavators for mining coal and such non- metallic minerals as quarry stone, gypsum, phosphate and the like have advanced tremendously in the last 50 years, and their advancement has paralleled that of excavators used in the construction industry during the same period. Up to a certain stage, the construction industry led the way with this development and even pioneered in how the equipment was used. Afterwards, however, new mining machinery and related operating techniques progressed along a different path than their construction counterparts because of the different demands of the two industries. The word "stage" as used above quite generally connotes a transition period, possibly of several years' duration, during which mining development followed the construction industry. Later, mining branched out and responded to its own needs. Most readers are familiar with the events which led to the development of the power shovel. The first dredge was recorded as having been used in England in the latter 1700's and was no doubt developed along the lines of some notes written in the late 1400's by Leonardo da Vinci.

Jan 1, 1971

By Martin Coryell

THIS coal area, and the coal from a limited portion of it, has been known for a long time. In 1817, McClure prepared a geological map to represent the boundaries, and they are not controverted at the present date. In 1834, Richard C. Taylor made a survey and report on portions of the basin. In 1835, Prof. W. B. Rogers was appointed by the State of Virginia to make a geological survey, and made six annual reports in which this area was included; but the re¬ports and maps were not published. R. C. Taylor's Statistics of Coal, published in 1855, gave to the public the details of exploration and production, to date, very perfectly and completely. Daddow and Bannan's work, Coal, Iron, and Oil, published in 1866, repeated the details before given, and advanced some vague theories respecting the coal-field, but gave no new facts. Macfarlane's work, Coal Regions of America, published in 1873, under the head of "Triassic Coal," chapter 27, gives what is known from existing publications of the position, geology, and production of the field, making

Jan 1, 1875

By W. M. Aubrey

Lying approximately 110 miles east of Toronto, Canada, the Marmora mine produces iron ore with a content of about 40 pct Fe, primarily in the form of magnetite. Operated by the Marmoraton Mining Co., a subsidiary of Bethlehem Steel Co., the orebody is mined by open pit methods. The ore from the pit is crushed, cobbed, ground to -100 mesh, magnetically concentrated to 67 pct iron, and then pelletized in shaft furnaces. The pellets are normally shipped by rail throughout the year from Marmora to Picton on Lake Ontario where they are unloaded and stored. Subsequently, during the navigation season, the pellets are shipped to Bethlehem Steel's Lackawanna plant in Buffalo, New York, for use in the blast furnace. At Marmora, the pellet plant demand and the concentrator output are not usually equal. To counter this problem, surge capacity in the form of storage pits in combination with a 30-ft diam thick¬ener has been provided between the concentrator and the pellet plant. Two sets of controls have been installed on this thickener, one controlling the…

Jan 9, 1960

By W. N. Page

The Red-Ash colliery was the scene, March 6, 1900, of an explosion by which some fifty men were killed or wounded, and much property was injured or destroyed. On March 19th, the earliest date at which entrance was practicable, I examined the mine with the view of determining the extent, cause and point of origin of the explosion, and with the permission of Mr. F. Howald, the manager, and the owners of the property, for whom the examination was made, I present in this paper some results of that examination, comprising the essential portions of my report to them. Location and Plan of the Mine. The Red-Ash colliery, situated on the south side of New river, next below the Rush Run mine, with which the underground workings are connected, is a drift-mine, the entrance to which is on a slope, about 500 ft. above the river. (Fig. 1 is a plan of the workings, in which the points where human bodies were found are designated by numbers.)

Jan 1, 1901

By J. C. Bayles

An obstacle to the more careful and satisfactory study of metals has been the difficulty in harmonizing the results of chemical and physical tests. These give us records of observations made from different and often widely separate points of view, and while it is true that they furnish bases for more or less accurate triangulations into the realm of speculation, it is doubtful if, with only the laboratory and the testing machine, our investigations would not move in parallel lines, leaving between them an unexplored field in which must probably be sought the information which shall connect the results of chemical and physical tests, and give to both a practical value which neither has yet been found to possess. The use of the microscope in the study of metals is not a new thing, but it is only lately that it has begun to attract the attention it merits or to show results of tangible value to the metallurgist. Among recent valuable contributions to the literature of this subject, I have been especially interested in the work of Mr. A. Martens, of

Jan 1, 1883

By P. D. Merica

The remarkable phenomena exhibited by the aluminum alloy known as duralumin were discovered during the years 1903-1911 by A. Wilm1,2 and have been described by him and by others. 3 4 5 6 The unusual feature of this alloy is the fact, as was shown by Wilm, that it can be hardened quite appreciably by quenching from temperatures below its melting point followed by aging at ordinary temperatures, which consists merely f allowing the material to stand at these temperatures. The hardness is not produced by the quenching alone but increases during the period of aging, which may be from one to three days. Cohn3, 5 gives data showing the increase of hardness of duralumin during aging, after quenching in water from about 450° C. Upon annealing, the alloy so hardened by aging is softened exactly as is hardened steel. The composition of this alloy usually varies within the following limits: Copper, 3 to 4.5 per cent.; magnesium, 0.4 to 1.0 per cent.; manganese, 0 to 0.7 per cent.; aluminum, balance; iron (as impurities), 0.4 to 1 per cent.; silicon, 0.3 to 0.6 per cent. Its density is about 2.85. It is used only in the forged or rolled condition. This alloy has been produced for some years commercially and is in demand for the fabrication of parts for which both lightness and strength are required, such as for aircraft. Its tensile strength will average 50,000 to 60,000 lb. per. sq. in. (3515 to 4218, kg. per sq. cm.) after appropriate heat treatment, such as that described by Wilm.

Jan 6, 1919

By Alfred Wandke

The problem of vein formation has been of particular interest to the writer for years. As his work for a long time was confined largely to districts showing large deposits of copper ore, it was natural that the efficiency of replacement, as one if not the chief control of the emplacement of the ore, seemed a particularly attractive hypothesis. Of late years, in almost daily underground work in the Guanajuato district, he has collected evidence which makes it certain that in a number of cases the ore solutions were under sufficient pressure to force the rock walls apart and to hold them apart, thus offering an open space for the deposition of vein and ore-bearing material. This paper will concern itself with conditions frequently met with in hypogene ore deposits of the vein type, and will deal in particular with ore occurrence in precious-metal veins of the type classified by Lindgrenl as epithermal deposits, or metalliferous deposits formed near the surface by ascending thermal waters2 and in genetic connection with igneous rocks. To account for the emplacement of this type of ore deposit various writers have suggested the following agencies: 1. Shattering of the wall rocks. 2. Pressure of growing crystals. 3. Magmation, as treated at length by Spurr3. 4. Replacement. 5. Openings produced by folding. 6. Shearing due to gravity. 7. Shrinkage produced by the passage of pre-ore solutions. 8. Contraction joints produced by lateral secretion. To this list there may be added another agency, a discussion of which forms the basis of this paper: 9. Pressure of the ore-bearing solutions.

Jan 1, 1931

By C. W. Drury, E. J. Hall

The iron-nail method of assaying has been used for a number of years, but has not met with the approval of all assayers. The method possesses advantages which may be given as follows: (1) no preliminary treatment is required; (2) a lead button of proper size can be obtained; (3) it is economical. On the other hand, it has its disadvantages, which may be summed up as follows: (1) it is not applicable to ores containing large amounts of impurities other than sulphur, as practically all the base metals will contaminate the lead button ; (2) the slag is unsatisfactory in the larger number of fusions; (3) the method was known to give low silver results under certain conditions and the gold results were questionable. It was with the idea of determining the extent of this latter disadvantage that the following investigation was undertaken. It is well known that the fusion obtained in the lead assay is far more satisfactory than that in the " nails method" for gold and silver. The principal difference in the charges as a class is the presence of considerable reducing agent in the lead charge, and a limited oxidizing action in the nails charge, dud to PbO. The possibility of improving the nails fusion by simulating the lead charge was the reason for using argol in some tests, even though there were reasons for expecting this would have an objectionable effect on the results. Preparation of the Gold-Bearing Material. The materials containing gold and silver used in the following experiments were prepared rather than selected, in order to have a definite working product excluding undesirable elements. A high-

Jan 1, 1914

By Charles Morgan

AN increased demand for brown iron ore in the Birmingham district during the past 18 months has caused renewed activity both in prospecting and mining these ores. In recent years the production in Alabama has ranged from 41,559 tons in 1932 to 639,351 tons in 1928. During the last 9 years about 83 per cent of the total brown ore produced in the United States has come from Alabama (Tables 1 and 2).

Jan 1, 1937

By P. R. Kneitz, G. Yoshikado, D. Zayakov

The design and analysis of a circular, domed powerhouse for Pacific Gas and Electric (PG&E) Company's Kerckhoff 2 Project is described. Exploration, geologic stress determinations, mechanical properties, reinforcement and instrumentation are addressed briefly. The analyses of the circular, domed cavern and the comparison of predicted and field deformations are presented in somewhat more detail. The behavior of the completed powerhouse cavern has been found to be substantially as predicted by the analysis.

Jan 1, 1982

By William P. Dyrenforth

The principle of electrostatic separation is discussed and elaborated on by dividing into the three main mechanisms of electrification as applied to separation of solid substances, i.e., (1) contact electrification, (2) electrification by conductive induction, (3) electrification by ion bombardment. Types of equipment used for electrostatic processing are described and the effects of humidity mentioned. Processing of iron ore, titanium minerals, rare earths and cassiterite is discussed and some existing plants are described.

Jan 1, 1978

By Gilbert Soler

Page Introduction. By Gilbert Soler.........................657 Deoxidation of Basic Open-hearth Steel. By T. S. Washburn.............658 Slag-metal-oxygen Relationships in the Basic Open-hearth and Electric Processes. By J. S. Marsh. (With discussion)...........................672 The Total Oxygen Content of Plain Carbon Open-hearth Steel during Deoxidation and Teeming. By Michael Tenenbaum and C. C. Brown. (With discussion)......685 The Occurrence of Oxygen in Liquid Open-hearth Steel—Sampling Methods. By T. E. Brower and B. b. Larsen..........................712 Effect of Deoxidation on the Strain-sensitivity of Low-carbon Steels. By H. K. Work and G. H. Enzian. (With discussion)........................723 The Relation among Aluminum, Sulphur, and Grain Size. By C. E. Sims.......734 Some of the papers and discussions that appear on the following pages were presented at the meeting of the Iron and Steel Division in Cleveland, Ohio, on Wednesday, October 18, 1944. with L. F. Reinartz and H. K. Work as Chairmen; the remainder were scheduled for the New York Meeting of the Institute in February 1945, which was canceled.

Jan 1, 1945

R. W. NEWCOMB, New York, N. Y. (written discussion*).-0n page 1712, the middle paragraph states that, in industrial equipment, only the single-step method of automatic regulation has been applied. Quite recently, there has been developed an automatic temperature regulator, operating in conjunction with a pyrometer of the thermoelectric type, in which the control is a slow regulation, with a range capable of regulat-ing valves, dampers, rheostats, or any other rotatable member, through one or more complete revolutions. It can control two valves at the same time, with a fixed definite ratio between them. Aside from those conditions in which it is. necessary to control two valves with a definite ratio one to the other, the greatest advantage that this slow, even control will have over those controls that are either all on or all off, will be for use in connection with processes where a large temperature variation is required, extended over a considerable period of time; that is, where the temperature must be regulated along an in-creasing or decreasing time-temperature curve.

Jan 12, 1919

We are advised by Carrington Phelps, Secretary of the professional Classes War Relief of America, having offices at 33 West 42d Street, New York, that this organization is now prepared for active relief of professional men who have enlisted in military service or are assisting the Government in the civil service or in civil life, at the sacrifice of their usual sources of income. The organization has found that the main obstacle to such relief is the hesitancy of this class of persons to make known their needs. Relief cases have to be sought out; the organization has already found some but has asked the cooperation of the Institute to assist in finding as many more as may exist. It is suggested that the Institute can render useful service in this connection, first, by informing our members of this feature of war relief, by being on the alert to report those needing relief, and to make all possible inquiry after such cases. It is further desired that information as to all such cases be forwarded immediately upon their discovery.

Jan 3, 1918

By Robert S. Shoemaker

Recently we read a short article which stated that Marcona Corp. was studying the use of 25,000-hp autogenous grinding mills for an iron ore project in Alaska. As if that weren't enough, they were going to dispense with the primary crusher and feed run-of-mine ore to the grinding mills which were to be driven by wrap-around seven-cycle motors. We see also that Bougainville Copper Co. will be grinding 90,000 tpd of ore in only eight 4250- hp ball mills. At Bougainville too, their float section will be the first large one to be completely equipped with the new 350-cu ft flotation cells. After a half century of relatively peaceful growth in the minerals industry, we are now seeing almost exponential advances in both equipment and plant size. At the same time, we are seeing a constant blending of hydro and pyrometallurgical techniques and processes into minerals beneficiation until the sample grind-'em-up-and-concentrate-'em plant is becoming a rarity.

Jan 1, 1970