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By E. A. Anderson

THE copper-zinc phase equilibrium diagram has been the sub-ject of many investigations. Until recently, however, the boundary of the terminal solid solution of copper in zinc (eta) has not been thoroughly investigated. This paper reports determinations of the solid solubility of copper in zinc at temperatures from 100° to 400° C., the course of the liquidus and solidus for the eta solid solution and determinations of the peritectic temperature and peritectic point for the reaction between epsilon and the melt to form eta. The liquidus of the eta phase was determined by thermal analysis and the solidus by the microscopical examination of specimens quenched from temperatures above and below the solidus. The temperature of the peritectic horizontal was obtained by thermal analysis and the com-position at the peritectic point was determined by extrapolation of the solid solubility boundary of the eta phase to the peritectic horizontal. The solid solubility boundary of the eta solid solution was investigated very carefully. Particular care was used to achieve equilibrium in the alloys at each temperature selected. The X-ray, electrical con-ductivity and microscopical methods were used in determining the solid solubility limits. The X-ray method measures the changes in the solvent lattice with increasing solute content and in this manner locates the composition of the alloy at which no further change in the solvent lattice takes place, the limit of solid solubility. The method of electrical conductivity measures the conductivity of the alloys of a graded series of compositions, whereby the solubility limit is indicated by a discontinuity in the conductivity-

Jan 1, 1934

JOHN H. NELSON, Worcester, Mass.-At our plant we have done considerable work on notch-bar testing and are farther at sea now than when we started. So far, we have been unable to get the notch-bar test to be consistent with any other known test. Lately, I have been investi-gating the effect of the position of the notch-bar specimen in a, bar. To do this I took a 3, ½ in. square bar and quartered it, then heat treated the four quarters. Each of these pieces was again quartered and a specimen machined and notched. "In this way we would have notch-bar tests from the exterior to the interior of the bar. These were made of such lengths that it was possible to make four impact tests on each speci-men. Extreme care was taken in marking the position of these test speci-mens in the original bar. The notches were then cut with relation to position of the specimen in the original bar. The second notch was cut 90° from the first, and so on around the specimen. In this way, we have found that, with a 3 ½ in. bar of 0.4 or 0.5. per cent. carbon steel when properly heat treated, we could get impact values ranging from 15 to 100 ft.-lb. Just why this is the case we are unable to state; but it does appear to be a fact that along the outside of the original bar the notch-bar test seems to be low and increases toward the center, but it is not always consistent. For instance, we may have, on a single specimen; one notch-bar test giving us 15 ft.-lb. and another 100 ft.-lb. We have not found such inconsistencies in alloy steels. Alloy steel is consistently good or consistently bad. If it. is good, you cannot readily destroy the impact value, no matter what you do; if it is bad-that is, if it is a poor notch-bar steel-and you have sufficient latitude in your draw, you may correct it. In other words, if the hardness you are working to will allow you to draw to about 1050° F.(561° C.) or over and then quench this steel from the draw heat, you. can raise the im-pact value of the steel from about 4 or 10 ft.-lb. up to-40-or 50 ft.-lb: Just what occurs I do not know. There is evidently a critical-point in steels that have poor impact value, in the neighborhood of 1000 F. to 1050° F. (536° to 561° C.).

Jan 12, 1919

By C. K. Leith

OTHERS here are far better qualified than I to discuss some of the specific proposals for government regulation of the oil industry. I shall make no attempt to carry oil to Oklahoma. The question of public control, however, is inherent in other branches of the mineral industry in varying degrees, and my comments will be directed mainly toward some of the trends affecting the mineral industry as a whole, as a background for your more specific consideration of oil legislation. A proud American tradition has been the insistence on freedom of competition, on equality of economic opportunity, on a policy of laissez faire. Nowhere has this principle been given wider application than in the mineral industry. The mineral field has been open to all comers, and the job of mineral exploitation has naturally attracted daring and independent spirits. The laws governing conditions of discovery and development, as well as the anti- trust laws, have been devised to foster the spirit of private initiative. The result has been the building of a mineral industry on a scale never before approximated anywhere in the world. The impetus thus gained, the methods, the technique, the financial resources, have been projected be- yond our boundaries and have made the American mineral industry the purveyor to the world for many essential commodities and first in the exploitation of the world's minerals. Our habits of individual self-reliance and success are deeply ingrained, and there is hardly an individual in the entire mineral field who does not instinctively recoil fro111 the extension of collective control, whether public or private.

Jan 1, 1932

Henry Louis, Newcastle-upon-Tyne, England (communication to the Secretary): I think very highly of the novel and ingenious device of Prof. Richards for analyzing the movement of the various elements of the jig; it is a method that certainly seems to promise valuable results, if we could only make certain that these various indicator-appliances have no effect upon the action of the jig. I would like, however, to suggest that in future experiments the connection between the plunger indicator-rod and the pencil should be made by means of parallel motions, so as better to reproduce the rectilinear motion of the piston. I should expect, if this were done, that the " curve " of the plunger in the Harz jig, at any rate, would be represented either by straight lines or else by quite regular curves, according to the method by which the plunger is set in motion; the apparent combinatioil of straight line and curve seems difficult to explain. With respect to the water-curve, I am afraid I am completely at fault, but no doubt Prof. Richards can explain my difficulty. In Fig. 2, the areas of the screen-side and the plunger-side of the jig are equal. If the piston be a fair fit and the bottom of

Jan 1, 1897

By R. M. Bird

Few persons outside of the foundry trade have any conception of the great variety of sands now regularly specified and furnished, nor of the differences in foundry practice frequently resulting from apparently minor changes in sands. Conditions in each locality where the sands are mined and prepared necessitate special equipment designed to perform the work efficiently. The description that follows of the foundry-sand producing operations is typical of the areas in New York and New Jersey, and particularly refers to the operations of the George F. Pettinos Co. A few years ago the so-called Albany sands were dug by simple methods and hauled by horsecart to railroad. Depletion of sand near railroad sidings and extended use of automotive power have appreciably extended the area from which sand is now being dug. It is not unusual to haul 5 miles to the railroad. As stripping is quite shallow, 6 to 18 in., and the banks of usable sand generally run from 12 in. to 4 ft., it is economical to work the bank by benches so narrow that the overburden can be thrown by hand shovel to the exposed bottoms. In effect the top soil goes back to where it was, but on a lower level. Consequently the general surface appearance of a mined acreage is the same as before. This condition is in fact cutomarily required when a farm owner sells his sand in the ground. After such replacement, in the course of 3 to 5 years the soil is no less fertile than it was before mining. The sand itself varies as to grain and bond vertically and also along the breast. No mechanical equipment has been developed to compete with hand shovels and no machine has as yet been devised that grades the sand as required. Uniformity of sand, as shipped, depends first, last and all the time on the man on the job. Mixing equipment can change the appearance of the sand and mask its lack of uniformity, but it will never correct wrongly graded sand, dug from the bank. Modern methods of testing are helpful in setting up standards against which the man in the bank can compare his sands, but a good bank foreman is the only assurance that the sand, as dug, matches the required sample.

Jan 1, 1926

Adams, John H., Pres. & Mgr., Alabama Lime & Stone Corpn., 1302-4-8 First Ave., Birmingham, Ala. '14 Adams, L. W., Otis Steel Co., Riverside Plant Cleveland, Ohio. '15 Adams, Leland D., Min. Engr., Mgr., Signal Mines Co., Goldbanks Quicksilver Co., 485 California St., San Francisco, Cal. '14 Adams, R. L., Min. Engr., Old Ben Coal Corpn., Mine 12 Christopher, III. `19 Adams, Robert M., Robert M. Adams Co 1201 Fidelity Bldg., Duluth, Minn. '20

Jan 1, 1925

[Aamot, Olav Crone, (M'29) Chem. Engr., Elektrokemisk, Raadhusgt. 23, Oslo, Norway. Abadilla, Quirico A., (M'38) Min. Engr., Dir. Bureau of Mines, Manila, P. 1. Abbott, Agatin, (J'40) Asst. Geol., Trench Mine, Patagonia, Ariz. Abbott, Clarence E., (M'04) Civil Engr., V.P., Tennessee Coal Iron & R.R. Co., 1642 Brown Marx Bldg., Birmingham, Ala. Abel, Raymond L., (M'28) Prof., Chem. Engrg., Univ. of Pittsburgh, Pittsburgh, Pa. Abel. Walter D., (M'32) Min. Engr., Div. of Corporations, State of Calif., 403 California State Bldg., Los Angeles, Calif. Abele, Louis T., (M'31) 4800 Patterson Ave.. Richmond, Va. Abell, Leo M., (M'31) Research Met., Mount Morgan Ltd., Mount Morgan, Queens., Australia. Abenius, Hakan V., (M'37) c/o Falu Gruva, Falun, Sweden.]

Jan 1, 1940

CONTENTS [The Nature of Strain Markings in Alpha Brass (paper by J. E. BURKE and C. S. BARRETT, Met. Tech. Feb. 1948. TP 2327). ......................... 2 X Ray Studies of Twinning and Untwinning in Magnesium Alloys (paper by J. B. HESS and R. L. DIETRICH, Met. Tech. Feb. 1948. TP 2328) ................ 11 ]

Jan 1, 1948

IF you do not make the disc at the same time as the core and as part of it, it is necessary to make it by itself. This is done by spreading on a board or other flat surface a layer of clay as thick and wide as [88] the disc that you made at the feeding head of the first pattern of the gun. When it is dry, mark it exactly with compasses and then, cutting with a chisel or rasp, make it fit exactly into the empty space at the head. Likewise, make a hole just as wide as the thickness of the core exactly in the middle of this clay disc. When you have put the disc in its place in the mould and then pass the core through this hole, it passes exactly through the center of the mould in such a way that it meets the iron ring that you put at the foot of the mould for this purpose. As I said above, if' you do not make it as part of the core, it is necessary to proceed in the aforesaid way. But if' you wish to make it attached to the core (which I like better because it can be done more accurately) make a

Jan 1, 1942

By M. B. Hopkins

FOR years the expression "except rubber, tin, and manganese" has appeared in practically every discussion of the natural resources of the United States. Knowledge that natural rubber is not produced in the United States has now spread from the relatively few who have reason to be interested in the country's basic raw material supplies to all those who ride in automobiles, which means everybody. This "everybody" reads in the daily papers that we have a stock pile of natural rubber and that plenty of synthetic rubber is just around the corner. Statistics as to the United States' rubber requirements and sources of supply are of interest to him only to arrive at an answer to the question : "After taking care of rubber requirements for military purposes, will there be rubber for my automobile and the many other rubber articles I want?" More than 30,000 different rubber articles are manufactured in addition to the tires and tubes which use up about 70 per cent of the rubber supply.

Jan 1, 1942

By J. A. Retty

IN the Labrador iron fields two concessions, totaling nearly 24,000 square miles, have been staked out and commercial-grade deposits delineated. The Newfoundland-Labrador concession, owned by the Labrador Mining and Exploration Co. Ltd., is a 20,000-square-mile tract in the upper basins of the Hamilton and N askaupi Rivers which drain into Lake Melville. The New Quebec licensed area is 3900 square miles, owned by the Hollinger North Shore Exploration Co. Ltd., lying to the northwest of the northwestern part of the Labrador concession. It includes the upper basin of the Swampy Bay River and part of the upper basin of the Whale River, both of which drain into Ungava Bay. Both of the above-named companies are controlled by Hollinger Consolidated Gold Mines Ltd. with The M. A. Hanna Co., of Cleveland, holding a minority interest. When exploration was first undertaken in 1936, the only published map of the area was that prepared by A. P. Low in 1895. It showed only the main watercourses and gave only a rough, general idea of the geology. The numerous lakes of this vast area had to be first sketched and then mapped. Since then, extensive geological and topographical surveys have been conducted by the Labrador company, work which is normally done by Government branches. The object of the work was to examine the area and gradually eliminate unfavorable or less favorable prospecting ground. With this object in view, geological

Jan 1, 1948

By R. H. Sweetser

THERE are SO many conditions affecting blast-furnace results that it is hard to get satisfactory comparative data on the working of two furnaces, and much more difficult to get comparable results from the use of two entirely different fuels. The several advantages of charcoal over coke as a blast-furnace fuel have doubtless been apparent to many managers; but probably the conditions for comparative tests of the two were never so favorable as during the year 1905, at the works of the Algoma Steel Co., Sault Ste. Marie, Ontario, which comprise two modern blast-furnaces, well equipped, though of comparatively small capacity. For four consecutive months one of these furnaces was run with charcoal and the other with coke. Then the charcoal-furnace ran for a while with part charcoal and part coke; and, still later, with coke only. The ore-mixtures were about the same in the two furnaces, and, of course, all the climatic conditions were identical. The dimensions of the two furnaces, and their work with the different fuels, are given in Table I.

Jan 5, 1908

By E. F. Bradley, R. I. Jaffee, H. R. Ogden, E. S. Bartlett, D. N. Williams

The mechanical properties of solid-solution-strengthened columbium alloys have been assessed as a function of alloying additions. Studies included the effects of tungsten, tantalum, molybdenum, and vanadium. Elevated temperature fabrication was required at alloying levels above about 15 pct W or 10 pct Mo. Tungsten, molybdenum, and vanadium additions increase tensile strength at room temperature and 2200°F, but tantalum additions exert little strengthening. Similarly, tungsten, molybdenum, and probably vanadium additions increase the ductile-to-brittle transition temperature, and tantalum additions decrease this parameter. The 2200°F stress-rupture strength is increased by tungsten and molybdenum additions; with 20 to 25 at. pct additions, 100-hr rupture strengths of 30,000 psi are obtainable. Small vanadium additions exhibit mild stress-rupture strengthening, and tantalum additions are innocuous. At 2500°F, tungsten additions retain stress-rutpure strengthening capability, but molybdenum additions are much less effective. Tantalum additions augment the stress-rupture strengthening of tungsten plus molybdenum additions at 2500°F. Of the refractory metals, columbium possesses specific potential for structural use in the temperature range from 2000" to about 2500°F. Desirable features of columbium are its good low-temperature ductility, ease of fabrication, oxidation mechanics (lack of a volatile oxide at moderate temperatures), good availability and reserves, and relatively low density. However, alloying is required to provide attractive strength at elevated temperatures. Published information concerning alloying be- havior of columbium relative to mechanical properties is sketchy, particularly in consideration for long-time applications at temperatures in excess of 2000°F. Only a few stress-rupture data at temperatures from 2000" to 2500°F have been reported;'-' these are too meager to allow rationalization of the effects of various alloying additions on creep or stress-rupture properties. Additional published data do, however, give some insight toward understanding of systematic alloying behavior for columbium relative to low-temperature strength4-' and ductility,' and elevated temperature tensile behavior.4,6 This paper is intended to augment previous knowledge, and to promote understanding of the alloying behavior of columbium for long-time structural service at elevated temperature. BASIC CONSIDERATIONS Solid-solution strengthening is recognized to be of prime importance in improving strength in columbium-base alloys. Other strengthening mechanisms may be (and are, in current alloys) used to augment solid-solution strengthening. As strengthening results primarily from lattice distortion, the strengthening effectiveness per atom depends upon atomic size mismatch between solvent and solute. Another factor in this regard is conformance to ideal solution behavior in the solid solution. Thus, for example, despite appreciable differences in the degree of mismatch between tungsten (5 pct), molybdenum (5 1/2 pct), and vanadium (7 1/2 pct) in solution in columbium, all are about equally effective in straining the columbium lattice at room temperature.'-' Similarly, tantalum additions do not strain the columbium lattice, and little strengthening is expected. Size effects being equal, maximum solution strengthening at high temperatures is anticipated to result from the addition of elements that increase the melting temperature of columbium. This expectation is based on an increase in the electronic bonding forces exhibited in the transition metal series as electronic structures approach those of the Group Vl metals. Of the metals that exhibit ex-

Jan 1, 1963

By K. E. Gray, M. S. Seth

Equations of elasticity for transversely isotropic, axisymmetric, homogeneous, porous media exhibiting pore fluid pressure were formulated. Using an analogy between thermal and porous body stresses, it was shown that the solution for a transversely isotropic porous body may be obtained by incorporating body forces and the stresses due to a boundary load into the corresponding solution for the thermal stress problem. Equations of elasticity ad the thermal analogy method were used to determine transient horizontal, tangential, and vertical stresses and radial displacement in a semi-infinite cylindrical region when either a constant pressure or a constant rate of flow is maintained at the wellbore. The vertical and tangential displacements are zero from the conditions of the problem. A numerical analysis was made of the solutions obtained by using a digital computer to determine the relative influence of each system variable. Considering rock as a porous body with internal fluid pressure generally gives results significantly different than considering the rock to be nonporous; the directional character of rocks leads to significant differences as compared to results based upon the common assumption of isotropy. Stress gradients are high near the wellbore but die out away from the well. Radial stresses are compressive or neutral, whereas tangential stresses are tensile, neutral or compressive, depending upon the boundary conditions and physical properties of the system Vertical stresses are compressive for an unbounded system. For constant wellbore injection rate, the vertical stress is proportional to the rate of fluid injection and decreases with time, whereas the radial and tangential stresses increase with time. At a given location, the radial displacement generally is very dependent upon time. INTRODUCTION A realistic appraisal of the state of stress in subsurface rock formations would be of considerable interest and use to the petroleum industry. For example, knowing the state of stress in proximity to a wellbore would be of fundamental importance in designing a fracturing operation or, more important, of clearly understanding the conditions necessary to produce rock failure of desired dimensions and geometry. Understanding conditions necessary for rock failure at the wellbore would also be of utility in a preventive sense. For example, borehole stability is an important consideration for many rock formations, and knowledge of the stress state at and near the wellbore under conditions of substantial pressure gradient due to fluid flow would be of great value. When fluid flows through a porous body which is initially at some uniform stress level, the following forces generate stresses at any point in the body. (1) Forces due to nonuniform pressure distribution. With increasing pressure the elements of a body are compressed. Such compression cannot proceed freely in a continuum when the pressure is not uniform throughout, and thus, stresses due to flow of fluid are set up. (2) Pore fluid pressure. This gives rise to normal stresses whose value at any point is the product of areal porosity and the fluid pressure. Although the fluid exerts uniform pressure, the stresses it creates in an anisotropic body may not be the same in all directions since the areal porosity in an anisotropic porous body is a direction-dependent quantity. This consideration leads to the concept of directional porosity. (3) Body Forces. The flow of the moving fluid imparts a force to the rock matrix, the magnitude of which depends upon the pressure

Jan 1, 1969

By William G. Pariseau, H. Douglas Dahl

Recent subsidence legislation indicates that mining engineers would be welt advised to be able to predict and control surface damage caused by mine subsidence. To date, such an ability is practically nonexistent. Model analysis is suggested as one of the alternative paths available which might yield fruitful results. Similitude requirements developed for a self-loaded body in static or quasi-static equilibrium indicate that complete similitude without centrifuging is an impracticability. However, a pilot experimental study which used a simplifying assumption to correctly model mine subsidence has produced results in qualitative agreement with field observations. The purpose of this paper is to present a discussion of the various approaches that can be taken in the study of mine subsidence phenomena. Particular attention is focused upon the rational selection and use of laboratory models. Broadly interpreted, mine subsidence is the deformation of the rock mass enclosing a mine. Depending upon a number of factors, the movement of the subsiding rock mass may disrupt gas and water lines or other buried utilities, damage surface structures such as buildings and bridges, dislocate streams, roads, and rail lines, aggravate acid mine drainage and fire problems, and generally mar the landscape. It is clearly a problem that no mine manager can safely ignore. It is also a problem that will grow with the general population increase. In the following discussion, a summary review of past and present approaches to subsidence studies is given. The possibilities of duplicating subsidence phenomena in laboratory models are examined, and an analysis of a particular type of model is presented. Some preliminary results obtained from a model of the particular type analyzed are then discussed. REVIEW OF PREVIOUS WORK Historically, subsidence investigations have been empirical studies in the field and laboratory or theoretical analyses of mathematically idealized media. Empirical and theoretical work in the United States has generally lagged behind investigations abroad. In the United States, field studies are mostly pre-World War 11. These are summarized in the Mining Engineer's Handbook. ' Field studies in Europe are more recent and more extensive. Those made in Great Britain are summarized in the Subsidence Engineers Handbook2 and represent observations made at 157 different collieries. Such studies by themselves are of limited usefulness as are all empirical studies. One can never be certain that conditions at one mine will be similar enough to those at another to warrant the drawing of like conclusions. European subsidence formulas rely heavily upon the "angle of draw" and "critical area" concepts. The angle of draw is defined as the angle between a vertical line through the face, and another line extending from the face to the surface at the point where movement is zero. The critical area is defined in relation to the least extraction necessary to produce maximum subsidence. Fig. 1 illustrates the angle of draw and critical area concepts. First and second "limits of influence" are also shown. The angle of draw and associated critical area concept are obviously not well defined, being dependent upon the accuracy of the surface survey. In Great Britain, the angle of draw has increased through the years from about 26 to 35°. In the United States, zero and negative angles of draw have been reported. In the authors' opinion, these purely geometrical concepts represent an oversimplification of subsidence phenomena and their use, in the United States at least, should be discouraged. Empirical observations of laboratory models containing layers of earth, sand, clay, and plaster were made by Fayol (cited by Peele) as early as 1885. An outgrowth of his work was the "dome theory," a verbal description of what is assumed to occur in subsiding rock masses. The dome theory has since fallen into disrepute. Theoretical analyses worthy of the name treat a subsiding rock mass as a deformable body. In these analyses, the actual rock mass is replaced by an idealized material that deforms according to a simple stress-strain relationship. The stress equations of equilibrium expressing the Newtonian laws of mechanical action and the geometry of strain furnish additional equations that must be satisfied. A loading criterion-generally understood, and in some cases stated explicitly-completes the theory.

Jan 1, 1969

By Pei-Yung Huang, Carle R. Hayward

IN order to understand more fully the actual state of copper lost in copper reverberatory slags, a systematic study on the various reactions between certain metallurgically important copper compounds and synthetic copper reverberatory slags was undertaken by the authors in the Massachusetts Institute of Technology from 1942 to 1945.1 This paper, being only a part of the work completed, is published first because it furnishes the first experimental evidence of the formation of copper ferrite from reactions between cuprous oxide and copper reverberatory slags. CHOICE OF SLAG COMPOSITION The choice of the composition of the synthetic reverberatory slags to be used was much deliberated. Commercial copper reverberatory slags, neglecting minor constituents, average:2.3 45 to 47 pct FeO; 38 to 42 pct Si02; 5 to 6 pct CaO; 5 to 6 pct A1203. Since the ternary system CaO-FeO-SiO2 has been much more thoroughly studied4 and is much simpler than the quaternary system CaO-FeO-Si02-A1203, it was decided to use calcium oxide only instead of calcium oxide and alumina in the synthesis of the slags. Fortunately the composition of the average copper reverberatory slag with calcium oxide substituted for alumina lies in the region of the phase diagram clarified by the investigators. A survey of the phase diagram (Fig I) suggested two compositions: (I) the com¬position near the invariant point S, which is made up of 46 pct ferrous oxide, 37 pct silica and 17 pct calcium oxide; (2) the composition near the invariant point K with 45.5 pct ferrous oxide, 43 pct silica and 11.5 pct calcium oxide. Composition S has the advantage that the percentages of ferrous oxide and of silica almost exactly coincide with those of the average reverberatory slags, and that of the lowest melting point (1093° ± 3°C) in the whole ternary system. The calcium oxide content, however, obviously is high. Since we have already substituted calcium oxide for alumina, and since calcium oxide is more basic than alumina, the resulting slag is decidedly too basic. Composition K has a slightly higher melting point (1105° ± 3°C) and a higher silica content, but this is preferred because the slag is saturated with respect to tridymite and thus should not corrode siliceous refractories. Besides, it is less basic than composition S. The final slag composition, therefore, was chosen to

Jan 1, 1947

By A. F. Meger

Coal treatment by oil spraying receives special attention at the Georgetown plant for the dividends it pays in satisfying present customers and attracting new markets. Customer satisfaction requires care, quality control, and use of suitable oils. REPRESENTED here are the ideas and varied experiences of many people in the Hanna Coal CO. who have helped develop, over a number of years, an efficient and flexible method for spraying controlled amounts of oil on coal. Since the Georgetown preparation plant began operations early in 1951, oil treatment of coal has received special attention. It is believed that oil treating will satisfy present customers and also attract new markets. The first step in developing the new method of oil spraying was the construction of a dust cabinet for testing 50-lb samples of treated coal with the available oil sprays on the market. Tests results were tabulated for both indoor and outdoor storage. The graph, Fig. 1, shows results of the original tests made with a 700-sec residual blend and a 500-sec lubricating oil on Georgetown stoker coal of 1¼x3/8-in. size.* The advantages of better price, improperly blended can raise havoc. Some.,pale oils also, although odorless when delivered, give off a sweet sickening odor when atomized under pressure. It is recommended that all products be tested before they are used. There is a specific place for all spraying oils. For example, at a power plant a severe dust condition exists around the stockpile area and in parts of the plant. The cheapest spraying oil made, regardless of odor, will do an excellent job in this case and will save the company 3 to 5c per gal or more. Domestic trade, on the other hand, must be carefully handled to prevent complaints about odor, and the only way to do this is to stay with the proved products after the odor tests have been made. The preparation plant at Georgetown has facilities to handle either tank car or tank truck deliveries. Steam is available at the unloading point if the weather is severe, and there is an indicator at the unloading point to prevent overflowing the 20,000-gal underground storage tank. Systematic test samples are removed from each delivery and sent to the lubrication engineer to insure quality control. Fig. 3 illustrates the chutes in which smaller sizes of coal are treated. Fig. 4 shows the entire spraying system. Buried in the ground is a 20,000-gal tank with immersion heaters grouped around the feeder line to insure adequate gravity flow to the pump under all conditions of weather. Oil flows to a 500-gal preheating tank where the temperature is kept about 150°F by six 1½-kw immersion heaters thermostatically controlled. Hot oil is fed through a self-cleaning disc-type filter to the hydraulic pump. Valves and piping make it possible to transfer oil from one tank to another or to drain the lines for maintenance purposes. All this equipment is below ground level in a covered pump room,

Jan 1, 1955

By Arcy A., J. G. Davis, D&apos Shock

Results of a pilot operation in the Carlsbad Basin are discussed. After hydrafracing between wells, a block of potash was removed by solution techniques. The distance between frac wells was about 200 ft, the thickness of potash mineralization, 5 ft. By proper manipulation, a feed of concentrate brine was obtained. The ex-periment showed that the thin-bedded potash could be removed by the solution techniques. The details of well construction, method of operation, and removal rates are discussed. Continental Oil Co.'s laboratory research on the fundamentals of potash solution mining has been expanded by means of a series of field tests, and subjects such as well completion and hydraulic fracturing were added to the investigation. Both single-well and multi-well systems were studied in the field work. Discussion Background: The current paper discusses one field test in which potash was solution mined by a two-well system from a thin sylvinite zone. The potential economic value of solution mining evolves from (1) the use of drilled holes and solution techniques instead of excavated shafts and caverns and (2) the ability to mine both land and marine deposits through any type of overburden geology and below conventional mining depths. Recent interest has been focused on potash' and other soluble minerals, such as trona. Solution extraction minerals, such as copper and uranium, are also worthy of important consideration. In addition, many of the techniques are directly applicable to the construction of horizontal underground storage carverns in salt. There are two general approaches to potash solution mining. The first is to mine on a single-well basis, in which the same well bore is used for both injection and production. This method is slow, and the areal extent may be quite limited in other than very thick ore zones. The second, and the preferred approach, is to mine on a multi-well basis in which the solvent is circulated between wells. This technique, if applied in a manner which allows the ore zone to be mined from the bottom upward, results in nearly all the solution taking place from the cavern roof. Salt removal rates, therefore, are very much higher than from a single-well system.l Wells can be interconnected into a multi-well pattern by several means. One is to join single-well caverns in the lower part of an ore zone. Another is to use the hydraulic fracturing techniques developed in the oil fields.' We preferred the fracture approach because of its potential for creating the greatest area of salt exposure. Test Site Description: The field tests were conducted in New Mexico's Carlsbad Basin, where the potash deposits are flat and uniform over reasonable distances. Here, 12 potash zones are present in the massive Salado Salt section. The specific target was the Third Ore Zone which is about 4 ft thick at our location and about 1150 ft deep. The test pattern was designed in the shape of an equilateral triangle with a fourth well located in the center, 200 ft from each of the vertex wells. This configuration allowed the ore zone to be hydraulically fractured from the center well with good assurance that the fracture would intersect the bore of at least one outside well. Several multi-well test patterns would be available if the fracture connected all wells. Well Completion: Surface casing was set in the top of the Salado Salt at 600 ft to shut off water flows from the surface sands, and the salt section was drilled and diamond-cored to a point below the Third Ore Zone. A drilling fluid made of diesel oil with a small amount of emulsified water was used to drill and core the salt. This fluid was highly successful in preventing enlargement of the drilled hole and in promoting good core recovery. The three outside wells were completed by setting 51/2-in. casing at the base of a streak of anhydrite about 20 ft above the ore zone. Pipe was set high so that the intersection point of the fracture could be detected even if the fracture migrated above the ore zone as it progressed outward from the center well. The center well itself was completed by cementing 51/2-in. casing through the Third Ore Zone. Cement bond logs run on the center well have shown excellent bonding. Fracturing Practice: A mechanical tool was used to cut a notch through the casing and into the salt at a point about 1 ft below the ore zone in the center well. The purpose of this notch was to fix the point of fracture entry into the salt. The fracturing was done with water at injection rtaes as high as 30 bbl per min. The salt parted at 1450 psi; and it required only 5 min for the fracture to reach the well which was 200 ft to the south. It took about 5 min more to reach the other two wells. Caliper surveys were run to locate the point of fracture entry in the three outside wells. The fracture appears to have drifted downward slightly, entering the outside wells at the top of a streak of carnallite 8 or 9 ft below the ore zone. A cross section of the wells selected for the multi-well test is shown in Fig. 1. The figure includes KC1 values based on core analysis and the trace of the fracture plane between the wells.

Jan 1, 1971

By H. DeWitt Smith, W. H. Sirdevan

The mine operated by the United Verde Copper Co. is situated near Jerome, Ariz., on the eastern flank of the Black Hills, at an elevation of approximately 5500 ft. (1676 m.) above sea level. The mine and the town of Jerome are located on a steep hillside, which slopes rapidly to the valley of the Verde River. The smelter town of Clarkdale is situated in the Verde valley 4.1 mi. (6.5 km.) distant in an air line from Jerome, and at an elevation of 3560 ft. The two towns are connected by the standard-gage railroad of the Verde Tunnel & Smelter R. R., a subsidiary of the United Verde Copper Co. This road is 11 mi. long and has a compensated 4 per cent. grade. At Clarkdale, it connects with the Verde Valley branch of the Santa Fe R. R. The narrow-gage (36-in.) line of the United Verde & Pacific Ry. was, until 1919, Jerome's only rail connection with a main trunk line. This road connects with a branch line of the Santa Fe system at Jerome Junction, after traversing 26 mi. of mountainous country. From the time of its location, in 1876, until its purchase by Senator W. A. Clark, of Montana, in 1889, the United Verde mine was worked on a small scale and shipments of high-grade gold-silver ore were made from the surface workings. Until 1894, when the narrow-gage railroad to Jerome Junction was completed, all supplies for the mine and smelter

Jan 1, 1922

By H. E. Criner, M. G. Driessen

Maurice Rey—The influence of cyclone diameter upon the fineness of separation is an important point which, however, cannot be discussed adequately if the injection pressure or the rate of flow are not specified. Perhaps some light can be thrown on the matter by using the formulas derived by Dahlstrom. Let us consider several geometrically similar cyclones where the apertures e and b are equal and proportional to the diameter D and which are operated with the same pressure drop. Eq 8 of Dahlstrom's paper can be written: Q Q = K D'. " or. if F is constant: Q = K D18 K is a constant of proportionality. Introducing this value of Q in eq 13 gives elimination efficiency = K D ,41 Elimination efficiency, in the terminology of Dahl-strom, means the diameter of particles, in microns, which divide equally between the underflow and the overflow. This denomination is regrettable and it would be preferable to call it diameter of separation or characteristic size or any other name connoting a size rather than an efficiency. Whatever the name used, the above equation shows a slow increase in the fineness of separation when the diameter of the cyclone decreases. For example, if a 14-in. cyclone gives a 400-mesh separation (37 microns), geometrically similar cyclones, having the same pressure drop will give separations at the sizes shown below.

Jan 1, 1951