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This paper is an outline of the developmental practices now in use at North Broken Hill Limited, N.S.W. The description will be given under the following headings.I. General.......opening up of a new level.II. Driving.III. Winzing.IV. Rising.V. Auxiliary Ventilation.VI. Notes on the Introduction of Mechanical Appliances.VII. Office Records and Routine.I. GENERALThe lode, for purposes of description, may be said to be divided into two portions which are usually referred to as the Southern and Northern Orebodies.The southern ore-body is the larger and in places attains a width of 200 feet. The northern ore-body is, generally speaking, comparatively narrow. These ore-bodies have a northerly pitch of approximately 45' and a westerly dip of 60. In the southern ore-body a grid of ore chutes is provided at 31 ft. 8 in. (5 square set) intervals and this necessitates an elaborate arrangement of cross-cuts, portion of which have to be driven through the foot-wall. Crushed country rock adjacent to the foot-wall makes it necessary for drives to be placed at least 60 feet from the lode.In the northern ore-body the ore chutes are arranged along a longitudinal drive, thus making a much simpler layout. These layouts were described in detail by A. R. West (Proceedings A.I.M.M. No. 117). In opening up a new level from the shaft plat, a heading is extended in a westerly direction until a point approximately 60 feet from the footwall of the lode is reached.At this point the direction of the cross-cut is altered to a bearing approximately 90 to the general strike of the ore-body, and the cross-cut continued until the hanging-wall is intersected. From the information obtained together with that from diamond drilling, the outline of the ore-body is plotted as closely as possible, and this serves as a basis for the layout of the level. Drives south and north from the main cross-cut are made in order to determine the southern and northern extremity of the southern ore-body. The former is usually driven in the centre of the ore-body and serves as a permanent gangway and ventilation drive for the new level.From the northern extremity of the southern ore-body, the drive north is...

Jan 1, 1944

By J. J. Bezuidenhout

The waste-heat boiler is used within the Sulphide flash smelting process as the main dust and energy recovery unit. The large volume of off-gas discharged from the flash smelter is at a very high temperature (1350°C) and contains a significant dust load that subjects the downstream waste-heat boiler to tough and demanding conditions. The boiler cavity is especially prone to dust accretions, fouling, and corrosion caused by accumulation of molten particles and precipitation of sulphuric acid. Computational fluid dynamics (CFD) is applied within a qualitative study to model the flow and heat transfer distribution throughout the waste-heat boiler. The commercial CFD package, Fluent 6.2.16, was applied to a modified waste-heat boiler (23 m ×11 m ×5.4 m) within the Outokumpu flash smelting process. This investigation focuses on the geometric modifications to the typical boiler design, which includes elevation of the ceiling, placement of flow-obstructing baffles and radiation plates parallel within the flow path. Also investigated were various boiler operating conditions such as the circulation of process off-gas, air leakage from the dust discharging hoppers and variation in inlet gas composition. The geometric modifications had the desired effect of increasing the volumetric utilization and therefore enhancing heat transfer between the boiler surface and the gas stream and dust segregation. Introducing circulated off-gas at a rate of 20 m/s and at a 45° angle to the front of the waste boiler further enhanced cooling while reducing the high impact of the furnace-uptake gas-stream on the boiler ceiling. The placement of radiation plates was found to be very effective in enhancing the heat transfer surface and distributing gas flow within the boiler. These results present recommendations towards an improved waste-heat boiler design. Keywords: flash smelting, waste-heat boiler, CFD simulation, off-gas cooling.

Jan 1, 2008

By Rodney J. Hundermark, Sharif Jahanshahi, Shouyi Sun

"The major platinum producers in South Africa make use of electric furnaces for the melting of platinum group metal (PGM) bearing nickel – copper concentrates. To gain better understanding of the furnace operation, research was conducted at CSIRO Minerals in Melbourne, Australia. One aspect of the research project was the investigation of the factors affecting the electrical conductivity of melter type slags.Electrical conduction in slags can occur through two mechanisms: ionic and electronic. There is good understanding of the ionic mechanism. In slags containing high levels of iron, the dominant mechanism is electronic as a result of charge hopping (electrons or holes) between ferric and ferrous ions. There is limited understanding of the electronic mechanism and one of the aims of the research was to investigate this mechanism further.Experimental work was carried out at 1450 °C on Al2O3–CaO–FeOx–MgO–SiO2 slags similar in composition to the melter slags (typical composition range (wt%): Al2O3: 5, CaO: 5-15, FeOx: 10-30, MgO: 15-25, SiO2: 40-60). The approach was to vary the oxidation state of three different basicity slags and measure the conductivity response. The slags had molar (CaO+MgO)/(Al2O3+SiO2) ratios of 0.43, 0.64 and 0.94 and FeOx contents of up to 40wt%. A twoelectrode technique was employed with a shallow layer of slag contained in a magnesia crucible. The small amount of slag facilitated relatively quick equilibration (up to one hour) with the gas atmosphere. Experiments were typically started in air and sequentially reduced using different ratios of CO and CO2 gases.Conductivity increased with increasing basicity and increased significantly with iron oxide content. Above 20wt% FeOx, electronic conduction was significant and the conductivity varied with the oxidation state of the slag. The typical response of the conductivity to the change in oxidation state was the following: starting in air, as the slags became more reduced, the electrical conductivity increased to a maximum at around pO2 = 10-7 to 10-4 atm and then decreased with further reduction. The value of the pO2 at which the maximum occurred was dependent on the total iron oxide content and basicity of the slag. The magnitude of the conductivity of the slags increased with increasing FeOx content in a range of 20 to 170 S/m for 20 to 40wt% FeOx. For a given FeOx content in the slags, the oxidation state dependence of the conductivity varied with slag basicity. The trend observed was that the maximum in the conductivity occurred at higher oxygen partial pressures for the lower basicity slags."

Jan 1, 2003

By V. Brabie, S. Jansson, L. Bohlin

The rate of dissolution of solid MgO-C and doloma into liquid in CaO-Al2O3-SiO2-MgO slag at different temperatures was studied under conditions of forced convection by rotating cylindrical refractory specimens in a stationary crucible containing the molten slag. The corrosion rate was calculated from the change in diameter of the cylindrical specimens. Refractory specimens were 13 mm in diameter and 70 mm long. The specimens were rotated for15 to 120 minutes at speeds of 100 to 400 rpm in the molten slag. The rate of corrosion increased with temperature and with the rotating speed of the rod, and decreased when the slag was nearly saturated with MgO. The experimental results confirm the assumption that the diffusion of magnesium oxide through the slag phase boundary layer controls the corrosion process. The corrosion mechanism seems to be the dissolution of the refractory materials into the slag, followed by penetration of pores and grain boundaries and dispersion of the grains in the slag. Keywords: MgO-C refractory, doloma refractory, molten slag, corrosion rate, corrosion mechanism

Jan 1, 2004

This work shall consist of furnishing and driving foundation piles of the type and dimensions designated on the plans or in the special provisions including cutting off or building up foundation piles when required. This specification also covers providing test piles and performing loading tests. Piling shall conform to and be installed in accordance with these specifications, and at the location, and to the elevation, penetration and bearing capacity shown on the plans or as directed by the Engineer. Except when test piles are required, the Contractor shall furnish the piles in accordance with the dimensions shown on the plans or special provisions. When test piles are required, the pile lengths shown on the plans are for estimating purposes only and the actual lengths to be furnished for production piles will be determined by the Engineer after the test piles have been driven. The lengths given in the Engineer's order list will include only the lengths anticipated for use in the completed structure. The Contractor shall, with-out added compensation, increase the lengths shown or ordered to provide for fresh heading and for such additional length as may be necessary to suit his method of operation.

Jan 1, 1989

By M. M. Neale

The pottery department has been aptly described as the "heart of the zinc plant," md every operator of a horizontal-retort plant is acquainted with the fact that good retort practice is the keystone of the smelting process. Since retorts and condensers are clay products, it is obvious that improvements in other branches of the ceramic industry should be observed for possible adoption in the pottery process for zinc smelting. Deaeration of clay bodies is one of the improvements that have become fully, established in many brick and pottery plants. Our investigation of a number of these installations always yielded the same answer—improved practice. Improvement in workability, elimination of laminations, less porosity, greater wet and dry strength, were among the claims put forth for this process. All of these features are exceedingly desirable characteristics in the manufacture of a zinc retort. A preliminary test, which involved truck transportation of deaired slugs over a relatively long distance, did show the value of many of these characteristics in forming the retort. Results from the standpoint of , longer retort life in the smelting furnace were not outstanding. The idea lay dormant for several years but was revived again in 1940, when it was decided to make whatever changes were necessary in the equipment for pottery manufacture to fully demonstrate the process. A number of the manu- facturers of machinery for clay work were asked to submit proposals, and the plan finally adopted was extremely simple and economical. Machine FOR DeaeRRATING Selection of the ''Straight-line'' principle for conversion of the "Wettengel" pug mill to a ''vacuum-extrusion" machine preserved some usable parts of the original equipment, such as the drive mechanism, and main shaft. The converted machine consists of a feed hopper, a compression and shredding zone, a vacuum chamber, and an extrusion barrel, as shown in Fig. I. In operation the clay mix travels from the feed hopper into the compression zone, where it is compressed and finally forced around the tapered cone into the vacuum chamber. As it enters this chamber the clay body is shredded into thin plates, for exFosure to the vacuum. The shredder consists of a hub mounted on the main shaft, to which are bolted segmental sections, each of which carries shredder knives. The compression zone and extrusion barrel function as seals for the vacuum chamber and the shredded clay mix is agitated thoroughly during its exposure to the vacuum. A vacuum pump, equipped with a 3-hp. motor, is attached to this chamber, and maintains 25 to 26 in. vacuum during operation of the mill. Changes in Practice Prior to the adoption of the deaeration process, our standard pottery practice called for double mixing in the combination 7

Jan 1, 1944

By E. R. Brownscombe, Francis Collins

The pressure distribution in a reservoir producing an incompressible fluid by radial flow in a horizontal structure is a simple logarithmic function' used daily by reservoir engineers. The assumption of an incompressible liquid is equivalent to assuming that pressure is maintained constant at the well radius and at some external "radius of drainage," or, in other words, that the entire flow into the well passes across the external radius. In most cases a well is surrounded by other wells draining adjoining areas so that the "radius of drainage" is not a line of constant pressure with flow equal to the flow into the well but rather a contour of zero pressure gradient across which no flow occurs, production being due to the expansion of the liquid within the area. The radial flow steady state pressure distribution for this case does not seem to be extensively used despite the fact that the mathematical analysis has been given in detail' and the results are simple and generally applicable. 'The object of this discussion is to develop this result from a physical rather than a mathematical viewpoint, thereby aiding intuition in judging circumstances to which it may be applicable. If the production rate at a well in an unsaturated reservoir is maintained constant while no flow occurs across the outer radius a steady state will soon be reached in which the flow rate or pressure gradient is constant with time at all points in the reservoir. To preserve such a condition it is necessary that the pressure decline at the same rate at all points in the reservoir, that is, the curves of pressure versus radial distance at successive times are all parallel. Then each unit volume of oil is expanding at the same rate and contributing an equal share to the production. The rate of flow q across any circle r is thus proportional to the volume of the reservoir between r and the external radius re, or q = qw (I-r2/r2e) ......(1) where q, is the production from the well and it is assumed that rw is very small compared with re. This equation can be combined with the differential form of Darcy's law for radial flow, 2phkr dp q =—— ........(2) aµß dr ( where q is not a constant as in the incompressible flow case but is a function of r given by Equation (1). If Equation (1) is substituted in Equation (2) the variables p and r can be separated and the result integrated to obtain the pressure distribution p = pw +--------In------------- 2pkh[ rw 2re2] ......(3) This equation differs from the incompressible case only in the addition of the term proportional to the square of the radius

Jan 1, 1950

[Consider the situation where we wish to estimate the value of a block of ore W from the values of n samples wt (i = 1, 2.... n). The samples can be located anywhere inside or outside W. The blocks and the samples can have any size or shape (Fig. 8.1). We define ws as the set of all the samples wi: WS = Iw1; W2; W3.. . wn and we wish to estimate the block W using the samples ws. Let xi be the value of the ith sample and µw the unknown average value of the block. We can estimate µw from the average value of all the samples. Let µw be the estimator of µw. As the samples need not be of equal size, the sample average is: µw = wi xi/~ wi. (8.1) The mean squared error made when estimating µw by µw is known as the variance of estimation of W by ws. It is the error made when giving the value of the sample set ws to the block W and is written o2E (WS to W). By definition: o2E (ws to W) = E [(µw - µw)2]. (8.2) If n = 1, this error is known as the extension variance. Since the sum of the weights given to the sample values is equal to 1,0, the estimator µw is unbiased (the question of the absence of bias is studied in more detail in Chapter 9): E [( µw - µw)1 = 0. (8.3) The error (µw - µw) has zero mean and a variance o2E = E (W8 to W). If we assume that this error is normally distributed, we can define confidence limits for µw. Let tP be the value of the standardized normal variance t such that the probability that t is less than tP is p: (t,) = .\/27T f exp (- t2/2) dt = p (8.4) The probability that µw is larger than µw + t1-P oE is p. The probability that µw is smaller than µw- t1-P oE is p. The following approximation formulae are often used to calculate 2p central confidence limits for the block value: 68% central confidence limits (p = 16%): µw - o2E, and µw + o2E. 95 % central confidence limits (p = 2,5 %): µw - 2 oE, and µw + 2 oE. Tables of the function 0 can be found in any textbook on statistics (for example, Fraser, 1958, p. 388) (see Table 7.2). [ ] The last line of Table 2.2, corresponding to f = 00, also contains the value of tP for p = 80, 90, 95 and 97,5 %.]

Jan 1, 1978

We the undersigned, being all persons of full age and citizens of the United States and a majority residents of the State of New York, desiring to form a corporation pursuant to the provisions of the Membership Corporations Law for the purpose of incorporating, as provided in Section 5 of Article I. of said law, the existing unincorporated association known as American Institute of Mining and Metallurgical Engineers, Incorporated, do hereby make, acknowledge and file this Certificate for that purpose, and do Certify as follows: I. That the American Institute of Mining Engineers is an unincorporated association organized and existing with the object of promoting the arts and sciences, connected with the economic production of the useful minerals and metals and the welfare of those employed in these industries by means of meetings for social intercourse and the reading and discussion of professional papers, and to circulate by means of publications among its members and associates the information thus obtained. II. That the persons duly appointed or designated to manage the affairs of said association are designated by the rules thereof Members of its Council; that the undersigned are all members of said Council as the same was constituted on the 29th day of December, 1904. III. That on said last-mentioned date a regularly called meeting of said association was held at its office in the Borough of Manhattan, City of New York; that thirty days before such meeting notice of the intention to incorporate said association was given by mail to each member thereof whose residence or post-office address is known; that at said meeting the following resolutions were offered, seconded and duly adopted by the unanimous vote of all its members then present, to wit: "Resolved, That it is the sense of the members and associates of the American Institute of Mining Engineers in general meeting assembled that it is desirable and necessary for the well being of said association and its members and for the furtherance of the objects for which the same has been formed, that said association incorporate under the Membership Corporations Law of the State of New York; "And Further Resolved, That the Members of the Council of this Association, or a majority thereof, be and they hereby are authorized, in accordance with the provisions of Section 5 of Article I. of the Membership Corporations Law, to incorporate this association for the same purposes for which it has been organized and conducted, in the manner provided in Article II. of said law;, "And Further Resolved, That the name of said corporation as hereby adopted by this meeting shall be American Institute of Mining Engineers; "And Further Resolved, That the said incorporators shall be named in the Certifi¬cate of Incorporation as directors of such corporation until its first annual meeting,

Jan 1, 1940

By E. E. McGinley, L. D. Woodworth

DURING the past several years has occurred what, in the light of future events, may aptly be called the rebirth of the acid Bessemer process. The increased attention given to the technical and metallurgical details involved in the production of Bessemer steels has been exceedingly fruitful, and indicates the value of further research and plant development. In times like these, when the steelmaking capacity of the country is operating at a maximum rate to supply materials for the national defense program, it behooves the Bessemer operator not only to strive to increase production but also to maintain a high standard of quality. The opportunity is ripe, it seems, to recapture fields of application once considered the birthright of Bessemer steels, but supplanted in recent years by open-hearth grades. This involves cooperation all along the line, from the blast-furnace operator to the metallurgical contact man and salesman. The metallurgist's part in this program involves the study of the many steelmaking variables and the measures necessary to ensure constancy in the finished product. It is equally important that the knowledge gained be disseminated widely to ensure the wise application of Bessemer steels in new fields. The merits of Bessemer steels for certain work are well understood. The combined properties of good weldability, machinability and stiffness are unique and fully explain the strong entrenchment of Bessemer steels in certain fields; e.g., skelp for small butt-weld conduit, screw steels machined in automatics, and certain tinplate applications. It is the purpose of this paper to review briefly the physical properties of Bessemer steels as contrasted with those of open-hearth steels, to discuss control measures now employed in the making of Bessemer steel, and to consider the advantages derived from the use of these control measures. PHYSICAL PROPERTIES OF BESSEMER VS. OPEN-HEARTH STEELS A number of Bessemer blows and open-hearth heats were tested for tensile strength, ductility and impact strength. The steels selected were confined to sections from ¾ to 1 ¼ -in. diameter, inclusive, and the carbon content covered was sufficient to yield parallel ranges in ultimate strength for the comparison. Other factors, such as the extent of deoxidation of the steel and variations in chemistry, were kept as comparable as possible. Machined test pieces of 0.505-in. diameter with an 8-in. gauge length were pulled. The data obtained are shown in Fig. 1, ultimate strength being plotted against carbon content. This graph shows that for equivalent carbon content Bessemer steel has on the average 15,000 lb. per sq. in. greater tensile strength and, conversely, for the same tensile strength Bessemer steel requires on the average 0.14 per cent less carbon. The average phosphorus content for the Bessemer steel was 0.090 per cent,

Jan 1, 1941

By D. W. McGlashan, K. N. Mcleod

IN the use of free bubbles with precise temperature control and continuous pH measurement, the contact angle apparatus differs from all previous equipment. Experimental procedures differ sharply from the captive bubble method1,2 of introducing the gaseous phase in the three-phase system. When freed from the tube and captured by a solid surface, a bubble more closely conforms to the spherical ideal set up by the usual mathematical analysis of surface free energy or surface tensional relationships of the forces involved. The assembled equipment, Fig. 1, departs from the usual contact angle apparatus in providing: 1) water circulation for fixing temperature, 2) instruments to measure and record pH during testing, and 3) a system for producing and using free bubbles. The apparatus allows testing over a broad range of closely controlled conditions, and the use of free bubbles gives contact angles independent of operator manipulation, which was unavoidable in the older captive bubble method. A bubble released below the specimen rises through the liquid and contacts the mineral. If the mineral is gas-avid the bubble adheres, developing a finite contact angle. Reaction cells (1), 2x33/8x5 3/16 in. ID, are of pyrex glass 5 mm thick. To prevent optical distortion, the sides are optical flats and are planed parallel to within five wave lengths of light over the entire surface. Special cement is required to withstand chemical attack and thermal shock. The cell is placed in a thermal jacket (2) made of welded aluminum. A water seal for the optical ports is made by using O-rings tightened against the flats of the cell by fine-threaded and adjustable ports, Fig. 2. In-flow water is discharged downward from a manifold located near the bottom of the cell jacket. Water overflows the weirs at each end of the cell jacket, discharging from both sides to a collecting manifold (24). A hose (26) leads the overflow water to the thermal-conditioner well (4), which is recessed to accommodate a reaction cell and two beakers (150 ml). Both the thermal jacket and the thermal-conditioner well are insulated to minimize the effects of temperature differentials. Water, discharging from the thermal-conditioner well, returns to a thermostat bath and pump (3), from which it is pumped to the thermal jacket. The thermostat bath permits temperatures to be adjusted from 1" or 2°C to 80°C and will maintain the selected temperature within 0.2ºC. An electrode support (22) groups the four electrodes (8) so that they fit conveniently into the reaction cell, Fig. 2. This assembly holds the glass electrode, the calomel electrode, the temperature-

Jan 1, 1957

By R. Scot Clark

The reactively sputtered silicon dioxide capacitor -was developed for use in the monolithic integrated circuit, thereby requiring the capacitor to be fabricated on an oxidized silicon slice. The silicon dioxide film is formed by reactively sputtering silicon in a 50 pct Ar-50 pct 0, atmosphere and the physical properties are indistinguishable from silica. A practical upper limit of capacitance per unit area of 0.25 pf per sq mil is reached with the capacitors fabricated from the Si0, film. Methods shown to enhance this value are double stacking the thin-film capacitors and addition of aluminum to the silicon cathode during sputtering to form an aluminosilicate dielectric. A major contribution to the field of diffused integrated circuits would be the addition of auxiliary passive devices for replacement of diffused passive devices which are currently being fabricated for many integrated circuits. This accomplishment would increase the flexibility of the diffusion process in order to concentrate more on transistor parameters rather than on fabricating diffused resistors and capacitors. To pursue this technique, a thin-film SiOz capacitor was developed which has _ proven applicable to many integrated circuits. Although the SiOl capacitor has an application, the major deterrent from extending the integrated circuit into many useful areas such as low-frequency linear application is the low dielectric constant of SiO, and the low usable capacitance in an integrated circuit. This paper will cover the sputtering techniques used for forming the SiO, film, the physical and electrical properties of sputtered SiO,, and yield information concerning the application of these capacitors to integrated circuits. REACTIVE SPUTTERING Reactive sputtering is simply the sputtering of a metal or semiconductor in glow discharge in the presence of a reactive gas. The material to be sputtered is seen in Fig. 1 as the cathode of the system and is bombarded with positively charged ions of the ambient gas. In this investigation, the ambient gas is composed of 50 pct Ar and 50 pct O2 at a pressure of approximately 2.5 X l0-' Torr. The ions are accelerated toward the cathode in the cathode dark space by the electric field and upon striking the cathode effect a momentum energy transfer to the surface atoms. The transferred energy is sufficient to dislodge a surface atom or atoms and these particles diffuse through the glow discharge to the collector or anode. Several mechanisms of oxidation in the reaction chamber can be considered during reactive sputtering. 1) The surface of the cathode is oxidized and the oxide is subsequently sputtered. 2) Oxidation and sputtering occur simultaneously. 3) Sputtering of the cathode material is followed

Jan 1, 1965

By Walter Miller

Hundred-octane aviation gasoiine, toluene for T.N.T. production, high-quality lubricating oils for the needs of aviation and the armed forces, and synthetic chemicals for rubber manufacture again commanded the top priorities of the petroleum refining industry in 1944, the third year of America's active participation in the war. The objective continued to be to produce more and more of these materials—to keep up with increasingly greater requirements. By the end of the year all of the new installations projected before 1944, with the exception of possibly two or three that will tail over into January or February of 1945, had been completed and put into operation. And with the completion and putting into operation of these various units and the consequent lessening of construction responsibilities and problems, the industry was put into position to concentrate on the new operations and devote much more of its time and effort looking toward maximum output, both as to quantity and quality from the new facilities. Aviation Gasoline Making high-octane aviation gasoline continued to be the prime requisite of refining activities during 1944 as it was in the two previous war years, with the sights at the end of the year set to still higher figures than those which had been previously projected. About July I the daily output had been raised to 400,000 bbl., with some few large plant installations still to be completed and put into operation. Indications were that by December production would be up to all requirements, with good inventories. However, although by the end of the year the industry was turning out something over 500,000 bbl. a day, the estimated requirements of the armed services had been raised by a considerable figure, owing to the greatly increased aerial activities both in the European and Far Eastern combat areas. By the end of the year, therefore, the picture had changed, with the prospect for a much longer continuation of the European war, so that even with the completion and putting into operation in the United States by January 1945 of the last two or three 100-octane units authorized prior to 1944, it was evident it would be necessary to make still greater efforts to increase output of existing facilities to keep safely ahead of the game. Efforts of the industry and the Petroleum Administration for War as well as the Technical Advisory Committee and other research and development groups are concentrated therefore on methods and means of further augmenting the produc. tion of all existing refinery facilities engaged in making 100-octane aviation gasoline and components entering into it. The goal will be reached.

Jan 1, 1945

By L. D. Woodworth, E. E. McGinley

During the past several years has occurred what, in the light of future events, may aptly be called the rebirth of the acid Bessemer process. The increased attention given to the technical and metallurgical details involved in the production of Bessemer steels has been exceedingly fruitful, and indicates the value of further research and p1ant development. In times like these, when the steelmaking capacity of the country is operating at a maximum rate to supply materials for the national defense program, it behooves the Bessemer operator not only to strive to increase production but also to maintain a high standard of quality. The opportunity is ripe, it seems, to recapture fields of application once considered the birthright of Bessemer steels, but supplanted in recent years by open-hearth grades. This involves cooperation all along the line, from the blast-furnace operator to the metallurgical contact man and salesman. The metallurgist's part in this program involves the study of the many steelmaking variables and the measures necessary to ensure constancy in the finished product. It is equally important that the knowledge gained be disseminated widely to ensure the wise application of Bessemer steels in new fields. The merits of Bessemer steels for certain work are well understood. The combined properties of good weldability, machinabil-ity and stiffness are unique and fully explain the strong entrenchment of Bessemer steels in certain fields; e.g., skelp for small butt-weld conduit, screw steels machined in automatics, and certain tin-plate applications. It is the purpose of this paper to review briefly the physical properties of Bessemer steels as contrasted with those of open-hearth steels, to discuss control measures now employed in the making of Bessemer steel, and to consider the advantages derived from the use of these control measures. Physical Properties oF Bessemer vs. Open-hearth Steels A number of Bessemer blows and open-hearth heats were tested for tensile strength, ductility and impact strength. The steels selected were confined to sections from 3/4 to 1 1/4-in. diameter, inclusive, and the carbon content covered was sufficient to yield parallel ranges in ultimate strength for the comparison. Other factors, such as the extent of deoxidation of the steel and variations in chemistry, were kept as comparable as possible. Machined test pieces of 0.505-in. diameter with an 8-in. gauge length were pulled. The data obtained are shown in Fig. I, ultimate strength being plotted against carbon content. This graph shows that for equivalent carbon content Bessemer steel has on the average 15,000 lb. per sq. in. greater tensile strength and, conversely, for the same tensile strength Bessemer steel requires on the average 0.14 per cent less carbon. The average phosphorus content for the Bessemer steel was 0.090 per cent,

Jan 1, 1941

By R. H. Smith, A. C. Polk

The physical properties of the materials are listed, together with a short explanation of how this material binds the sand grains together without materially reducing the effective permeability of the sand. The chemical can be used in wells with bottom-hole temperatures ranging from 105°F to more than 350°F A description of the equipment required and the techniques used for applying these plastics to the wells is included. Introduction Recovering oil and gas from unconsoli-dated sand formations offers one of the most troublesome of all production problems. These sands generally present no particular trouble while drilling is in progress, but after the well has been completed and a pressure differential has been established across the face of the producing zone, the formation begins to L'slough," resulting in "sanding up" of the well. The term "sanding up" means that sufficient volumes of sand have moved into the well bore or casing to cause a serious reduction or complete halt of all flow of oil, water or gas. In rare cases a well may produce only a small amount of sand and still continue to flow or pump, the sand being carried to the surface in the fluid stream. However, in such instances, the result may be a costly repair bill due to the effect of the sand on surface and pumping equipment. The difficulty of producing petroleum from sands that are loosely cemented has long been recognized by petroleum engineers but only within the last few years has any new approach to the problem been undertaken. This involves the use of plastics that are capable of bonding the individual sand grains in place without materially reducing the effective permeability of a formation. The successful application of plastics for the consolidation of poorly cemented sands is relatively recent but now it is widely used in many of the more difficult areas on the Gulf Coast of Texas and Louisiana. This relatively new use of plastics1 in the oil fields has been preceded by much laboratory and field research on the use of various chemicals2,3 for solving numerous well-completion and work-over problems. Plastics now are being used successfully to control gas-oil and water-oil ratios,4'6 in zone isolation, the repair of casing leaks, the elimination of caving in cable-tool drilling wells6'7 and in the setting of linerss and casing.9 Sand-consolidating plastics, however, are basically different from all others in that they must not form an impervious seal. Field Practices The approach to the sanding-up problem usually has been the mechanical obstruction of the movement of the sand grains.

Jan 1, 1947

By A. C. Polk, R. H. Smith

The physical properties of the materials are listed, together with a short explanation of how this material binds the sand grains together without materially reducing the effective permeability of the sand. The chemical can be used in wells with bottom-hole temperatures ranging from 105°F to more than 350°F A description of the equipment required and the techniques used for applying these plastics to the wells is included. Introduction Recovering oil and gas from unconsoli-dated sand formations offers one of the most troublesome of all production problems. These sands generally present no particular trouble while drilling is in progress, but after the well has been completed and a pressure differential has been established across the face of the producing zone, the formation begins to L'slough," resulting in "sanding up" of the well. The term "sanding up" means that sufficient volumes of sand have moved into the well bore or casing to cause a serious reduction or complete halt of all flow of oil, water or gas. In rare cases a well may produce only a small amount of sand and still continue to flow or pump, the sand being carried to the surface in the fluid stream. However, in such instances, the result may be a costly repair bill due to the effect of the sand on surface and pumping equipment. The difficulty of producing petroleum from sands that are loosely cemented has long been recognized by petroleum engineers but only within the last few years has any new approach to the problem been undertaken. This involves the use of plastics that are capable of bonding the individual sand grains in place without materially reducing the effective permeability of a formation. The successful application of plastics for the consolidation of poorly cemented sands is relatively recent but now it is widely used in many of the more difficult areas on the Gulf Coast of Texas and Louisiana. This relatively new use of plastics1 in the oil fields has been preceded by much laboratory and field research on the use of various chemicals2,3 for solving numerous well-completion and work-over problems. Plastics now are being used successfully to control gas-oil and water-oil ratios,4'6 in zone isolation, the repair of casing leaks, the elimination of caving in cable-tool drilling wells6'7 and in the setting of linerss and casing.9 Sand-consolidating plastics, however, are basically different from all others in that they must not form an impervious seal. Field Practices The approach to the sanding-up problem usually has been the mechanical obstruction of the movement of the sand grains.

Jan 1, 1947

By E. E. McGinley, L. D. Woodworth

During the past several years has occurred what, in the light of future events, may aptly be called the rebirth of the acid Bessemer process. The increased attention given to the technical and metallurgical details involved in the production of Bessemer steels has been exceedingly fruitful, and indicates the value of further research and p1ant development. In times like these, when the steelmaking capacity of the country is operating at a maximum rate to supply materials for the national defense program, it behooves the Bessemer operator not only to strive to increase production but also to maintain a high standard of quality. The opportunity is ripe, it seems, to recapture fields of application once considered the birthright of Bessemer steels, but supplanted in recent years by open-hearth grades. This involves cooperation all along the line, from the blast-furnace operator to the metallurgical contact man and salesman. The metallurgist's part in this program involves the study of the many steelmaking variables and the measures necessary to ensure constancy in the finished product. It is equally important that the knowledge gained be disseminated widely to ensure the wise application of Bessemer steels in new fields. The merits of Bessemer steels for certain work are well understood. The combined properties of good weldability, machinabil-ity and stiffness are unique and fully explain the strong entrenchment of Bessemer steels in certain fields; e.g., skelp for small butt-weld conduit, screw steels machined in automatics, and certain tin-plate applications. It is the purpose of this paper to review briefly the physical properties of Bessemer steels as contrasted with those of open-hearth steels, to discuss control measures now employed in the making of Bessemer steel, and to consider the advantages derived from the use of these control measures. Physical Properties oF Bessemer vs. Open-hearth Steels A number of Bessemer blows and open-hearth heats were tested for tensile strength, ductility and impact strength. The steels selected were confined to sections from 3/4 to 1 1/4-in. diameter, inclusive, and the carbon content covered was sufficient to yield parallel ranges in ultimate strength for the comparison. Other factors, such as the extent of deoxidation of the steel and variations in chemistry, were kept as comparable as possible. Machined test pieces of 0.505-in. diameter with an 8-in. gauge length were pulled. The data obtained are shown in Fig. I, ultimate strength being plotted against carbon content. This graph shows that for equivalent carbon content Bessemer steel has on the average 15,000 lb. per sq. in. greater tensile strength and, conversely, for the same tensile strength Bessemer steel requires on the average 0.14 per cent less carbon. The average phosphorus content for the Bessemer steel was 0.090 per cent,

Jan 1, 1941

By J. E. Smith, P. B. Crawford, B. L. Laudrum

A method is presented by which the displacement efficiency of a steam-injection process may be determined. The method consists of a determination of the position of the steam front at a particular time and the application of the Buckley-Leverett theory to the hot and cold regions of the reservoir with the appropriate hot or cold fluid properties. A uniform, linear flow system is assumed for this study. The method is applied to a number of reservoir conditions. The primary properties which affect the results of a steam-injection process are the oil viscosities at steam and reservoir temperatures, injection rate, pay thickness and oil saturation. The efficiency of steam injection is compared with that of water injection for a 10-acre, linearly flooded reservoir. In reservoirs where the oil viscosity is about 35 times the water viscosity, the steam process yields recoveries about 20 per cent higher than the water flood. Where the oil viscosity is near 500 cp, the steam process may recover from three to four times as much oil as a water flood. INTRODUCTION In a previous paper,' a method was suggested for evaluating a steam-injection process. Emphasis was placed upon the determination of the steam-front position in the reservoir at various times. In the present paper, the displacement process is studied in more detail. The approach is essentially that employed by Jordan, Rayne and Marshall3 in their study of hot-water injection. The steam-injection process is quite complex, and an exact description of the process has not been found; however, a qualitative description can be made. When a quantity of steam is injected into a relatively cold reservoir, the leading edge of the steam front continaally flows into cool sand, and some steam condenses. As more and more steam condenses, a bank of condensed water will form which is augmented by displaced connate water. The reservoir may be divided in three regions—(1) a region containing displaced fluids at reservoir temperatures, (2) a region contain- ing water at reservoir temperature and (3) a region occupied by steam. The reasons for the lack of a region of hot water or oil of any appreciable size have been discussed.' A method has been presented by which the location of the steam front can be determined even when heat losses to the regions surrounding the reservoir are sizable compared with the amount of heat injected. It remains to show the effectiveness of steam injection in increasing the ultimate oil recovery. To illustrate the technique for determining the increase in displacement efficiency and, hence, the increase in ultimate production, two sets of hypothetical reservoir conditions will be studied in detail.

By Richard Paul Seelig

The following review covers published information on pressing of metal powders at room temperature. Only those operations are considered which occur between the time the powder is filled into the cavity and the compact is ejected from the die. Thus, this review does not concern hot pressing, coining or sizing feed or flow problems, commercial presses nor designs. It was also necessary to disregard to a large extent the effect of pressing on subsequent operations and on properties after sintering. 'The pressing operation is considered independently in its function to compact loose metal powder into useful shapes which can subsequently be handled. There are some comments by the writer in connection with a few of the findings quoted in the literature in order to stimulate thought and discussion. The selection of references quoted in the text is in some cases arbitrary although an attempt was made to favor papers containing novel ideas, techniques or results which mag stimulate future research. In order to enable the reader to check further into the subjects mentioned, the original, rather extensive, bibliography is appended even though not all the references are touched on in the printed version of this review. The equipment used by various workers, for example a die design created by Bridgman,22 is very interesting. 'The die insert has a conical external surface. The vertical pressure exerted on the punch transmits itself to the die which in turn is pushed harder into its tapered retainer. Thus, the higher the pressure exerted on the punch, the higher also the pressure exerted inwards on the die inserts. Inasmuch as this pressure counteracts the internal pressure from the compact the two stresses balance each other so that it is possible to obtain tremendous pressures without breaking the die. The die collar was made from an oil hardening tool steel, heat treated to a tensile strength of some 300,000 psi. The die was closed at the bottom by a plug made from special tool steels. Bridgman found that there is no steel which will withstand a com-pressive stress of 700,000 psi without continuous slow flow or immediate fracture. Therefore, the only material suitable for use in the pressing punch was sintered carbide. In view of the ingenious design it was possible to use special tool steel as die material. Jones22 raises the question whether this method of pressing has practical application in powder metallurgy. Although these tremendous pressures cannot readily be utilized without many special precautions, the tapered die and retainer idea is believed to be useful even for lower pressures. Bridgman, himself," alls attention to the fact that the properties

Jan 1, 1947

By Richard Paul Seelig

The following review covers published information on pressing of metal powders at room temperature. Only those operations are considered which occur between the time the powder is filled into the cavity and the compact is ejected from the die. Thus, this review does not concern hot pressing, coining or sizing feed or flow problems, commercial presses nor designs. It was also necessary to disregard to a large extent the effect of pressing on subsequent operations and on properties after sintering. 'The pressing operation is considered independently in its function to compact loose metal powder into useful shapes which can subsequently be handled. There are some comments by the writer in connection with a few of the findings quoted in the literature in order to stimulate thought and discussion. The selection of references quoted in the text is in some cases arbitrary although an attempt was made to favor papers containing novel ideas, techniques or results which mag stimulate future research. In order to enable the reader to check further into the subjects mentioned, the original, rather extensive, bibliography is appended even though not all the references are touched on in the printed version of this review. The equipment used by various workers, for example a die design created by Bridgman,22 is very interesting. 'The die insert has a conical external surface. The vertical pressure exerted on the punch transmits itself to the die which in turn is pushed harder into its tapered retainer. Thus, the higher the pressure exerted on the punch, the higher also the pressure exerted inwards on the die inserts. Inasmuch as this pressure counteracts the internal pressure from the compact the two stresses balance each other so that it is possible to obtain tremendous pressures without breaking the die. The die collar was made from an oil hardening tool steel, heat treated to a tensile strength of some 300,000 psi. The die was closed at the bottom by a plug made from special tool steels. Bridgman found that there is no steel which will withstand a com-pressive stress of 700,000 psi without continuous slow flow or immediate fracture. Therefore, the only material suitable for use in the pressing punch was sintered carbide. In view of the ingenious design it was possible to use special tool steel as die material. Jones22 raises the question whether this method of pressing has practical application in powder metallurgy. Although these tremendous pressures cannot readily be utilized without many special precautions, the tapered die and retainer idea is believed to be useful even for lower pressures. Bridgman, himself," alls attention to the fact that the properties

Jan 1, 1947