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By Howard E. Parkinson, John N. Murphy

The past five years have seen communications techniques and hardware developed by the Bureau of Mines and its contractors increasingly brought into use in U.S. mines. The Bureau philosophy has been to help develop and introduce new hardware that goes as far as possible toward meeting the mining industry's needs. The Bureau programs are also designed to provide continuous fallout of new communications capabilities which are introduced to the mine operators as they occur. As more progress is made in meeting mine communications needs, it is hoped that the mining industry will readily adopt the equipment and techniques that it finds most useful in meeting its individual needs. This paper reports on recent advances achieved in the development of improved mine communications systems. In May 1975 the U.S. Bureau of Mines (USBM) conducted a mine communications technology meeting to provide a brief overview of the USBM communications technology developments in the past 5 yr. This meeting lasted for 1 1/2 days. Therefore, I have elected to narrow this paper to a brief review of recent underground mine communication developments. The following will be discussed: 1) Ultra-high frequency (UHF) radio for fan hole drill operators;

Jan 1, 1978

NEW MEMBERS The following list comprises the names of those persons who became members during the month of December, 1913: Members ADAMS, CHARLES W., JR., Smelting, American Smelting & Refining Co., Murray, Utah. ARMSTRONG, FRANK H., Mechanical Engineer Vulcan, Mich. ARNOLD, JOHN B., Attorney-at-Law Room 840,200 5th Ave., New York, N. Y. BOYS, HARRY R., Mining Paso Robles, Cal. CAVANAGH, JOHN L., Min. Engr., Nova Scotia Steel & Coal Co.; Wabana, Newfoundland. CHOW, KAI CHI, Student 1120 Amsterdam Ave., New York, N. Y. CLARK, ARTHUR B., Mining Engineer 72 Harbour Bldg., Butte, Mont. CURLEY, JOHN R., State Mine Inspector P. 0. Box 633, Leadville, Colo. DAVIS, ANGUS W., Mining Engineer, Consolidated Mining & Smelting Company of Canada, Trail, B. C., Canada.

Jan 1, 1914

Carlisle: This is April 19, 1961. My good friend Dave Irwin is sitting on the other side of the tape recorder. We are at Rose Dhu Island, Savannah, Ga. Now, let's begin with your first job, where and what was that? Irwin: I started out to Arizona, looking for a job and wound up in Morenci. The next morning I applied at the mine office and was put on as a sampler. I worked as a sampler and as an assistant to Frank Pelton, the geologist, for a year, after which I went back to New Haven to take my last year of postgraduate work. After getting my degree, I went back to the Southwest with W. Rowland Cox and Staff, supposedly as a geologist. Q: But that was not when he was with Spurr? Irwin: That was after he had left Spurr. Henry Smith was with the Spurr end of the outfit and I happened to drop into the W. Rowland Cox end. My first job with him was to do some work on a prospect above Metcalf, Ariz., and from there I would go out on short reconnaissance trips in Arizona, New Mexico and old Mexico.

Jan 6, 1964

NEW MEMBERS The following list comprises the names of those persons who became members during the period Mar. 10 to Apr. 10, 1914. Members ADAMS, DANIEL T., Mining 1416 Westminster Bldg., Chicago, Ill. BLICKENSDERFER, FRANK CLEVELAND, Sampler Morenci, Ariz. CAVERS, THOMAS WILLARD, Met Copperhill, Tenn. CLAPP, CHARLES H., Geol Univ. of Arizona, Tucson, Ariz. CLARK, PATRICK T., Pres Bullwhacker Mine, Spokane, Wash. COMSTOCK, HARRY, Mining Mineville, Essex Co., New York. COOKE, JOSEPH H., Gen. Mgr Mono Dev. Co., Gisborn, Tooele Co., Utah. COOPER, DEXTER P., Civ. and Hyd. Engr 101 Park Ave., New York, N. Y. DEGOLYER, E. L., Geol Apartado 269, Tampico, Mexico. DESHAYES, ERNEST F., Mine Foreman Baldy, N. M. DOUGLASS, WILLIAM CRAWFORD, Min. Engr 107 Leonard Hotel, Butte, Mont.

Jan 5, 1914

(There are 67 Student Chapters in the United States, 2 in Canada ) University of Alabama-University, Alabama, Mining & Metallurgical Society, James W Stewart University of Alaska-College, Alaska, Mining Society of the University of Alaska, Guinn Metzger University of Arizona-Tucson, Arizona, Miners' Society, A E Gorum Birmingham-Southern College-Birmingham, Alabama, Pick & Hammer Club, Daniel D Arden University of British Columbia-Vancouver, British Columbia, G M Dawson Club, A Gunning University of California-Berkeley, California, Mineral Technology Association, Bernard York Carnegie Institute of Technology-Pittsburgh, Pennsylvania, The Metals Club, Gerhard Derge Case Institute of Technology-Cleveland, Ohio, Pick and Shovel Club, Gerald M Cover City College of New York-New York, New York, CCNY Student Chapter AIME, Daniel T O'Connell

Jan 1, 1954

By C. G. Dunn

IDENTIFICATION Of the kinds of orientation relationships that may exist among crystals is an important problem in the metallurgical field. As an aid to its solution standard orientations of several orders of twins would be very useful for rapid analyses to discover high-order as well as low-order twin relationships. Although data have been published that give orientations for three generations of twins, these data are not readily useful in the form presented; i.e., in a stereographic projection with one pole per orientation.1 However, accurate data based on calculations of the positions of all {100} planes for such groups would be very useful when presented in tabular form. Therefore, calculations have been made for a group of four orders of twins and the data are listed in Table 3. Illustrative applications are considered briefly, with the idea of pointing out what may be done with large groups of orientations. METHOD OF COMPUTING ORIENTATION OF A TWIN It is common practice to describe the orientation of a crystal in terms of the positions on a stereographic net of the poles of certain planes of the crystal. A single position on a net may be given it terms of two angle variables, two sets of which appear in the following equations: [Polar NetWalff Net x=rsinOocos4pyx=rcos0. y=rsinB,sin4,ny-rsin0.cos¢,, z=rcos0,,z=rsin0.sin4,,] The three numbers x, y and z determine a length r as well as a direction [(0, 0)] in an X, Y, Z coordinate system. In the present case, r will be set equal to (h2 + k2 +12)1/3, where h, k and 1 are the usual Miller indices for a crystallographic plane, a restriction that facilitates determination of the positions of poles of new planes from those of old or known ones,2 as will become evident later. Furthermore, since twinned lattices have certain planes in common, it is an easy matter to determine the orientation of a twin of a crystal if the orientation of the crystal itself is known. We start therefore with a crystal of known orientation (positions of three {100} poles given) and determine where the cube poles occur in first, second, third and fourth-order twins. Methods for identifying twinned lattices and for making the calculations to find the orientation of a twin have been published.3 4 Reference 4 will be illustrated in the calculation of the orientation of a twin, even though this method differs from the one used by the writer in obtaining the following data on four orders of twins. Consider a crystal S and its twin A1, A1 being one of the four {112} or {III}

Jan 1, 1945

By Walter Wood

The specifications for cast-iron pipe that have been submitted at this meeting are practically the outgrowth of those which were originally adopted, about 1860, by Mr. Kirkwood of Brooklyn, N. Y. They have been changed but little since that time, the mode of testing pipe in the hydraulic press, as well as the method of coating, not having departed from the original practice. The chief addition to the specifications has been in the adoption of a test-bar 2 in. by 1 in. in crosa-section, broken between 24-in. supports by a transverse strain applied on the flat side. Test-bars were first introduced into pipe-specifications about 1870. At that time a satisfactory test-piece had to stand a tensile strain of 16,000 lb. per square inch. The present test-bar was adopted in order to give some idea of the deflection of the iron that was being used. These deflection-tests have been so satisfactory to both engineers and manufacturers, and have met the requirements of the pipe-trade so accurately, that it is considered best to hold to the . 2-in. by 1-in. bar instead of adopting the short " Arbitration Bar," which yields but little information from the stand-point of deflection. The new feature in these specifications is the effort to reach standards to which pipe shall be cast in the future, thus permitting the manufacturer to make up stock and the purchaser to find material on hand when he asks for deliveries. Heretofore there has never been ally standard weight for pipes? although in some sizes certain weights are more frequently asked for than others. The fixing of standards for pipes permits the adoption of definite standards for fittings. It has been aimed to secure such uniformity for fittings as will permit the same class of fittings to cover two or more classes of pipe. In order to accomplish

Jan 1, 1905

By R. Adair, W. R. Hudspeth, W. T. McDaniel

ANEW method for concentrating the flake mica either from present washing plant tailings or from new feed has been developed. In this paper, flake mica refers to that which occurs in weathered granites, alaskites, pegmatites, and schists in a form too fine to be considered sheet mica. It ranges in size from 1 in. or more down to 200-mesh or finer and occurs with kaolin, quartz, and partially kaolinized feldspar. Scrap mica, a term often used indiscriminately to describe everything other than sheet mica, will be used to denote the waste product from sheet mica mines and fabricating plants. Both flake and scrap mica are used in the mica grinding plants to produce wet-ground or dry-ground mica, although some flake mica recovered from clay mining operations is fine enough to be marketed without grinding. Until 1930, ground mica was made almost entirely from scrap. From 1930 until 1935 a gradually increasing amount of flake mica was mined, and most of this was sold without grinding. A large percentage of this mica was recovered from clay washing plants. In this type of operation the recovery of any sheet mica was .of secondary importance and was considered a byproduct. North Carolina produces more flake mica than any other state, accounting for 73 pct of the total domestic production.' In the following review of current practice in jig plants, there is no intention to disparage these operations. Within the limitations under which they were built, they are examples of mechanical ingenuity. The term jig plant is a carryover from early practice since there are no jigs in operation at the present time. Current practice, as shown in Fig. 1, is based on successive stages of differential crushing with rolls followed by trommel screens to remove the more easily crushed gangue minerals. The oversize mica product then is usually dried, and passed through another set of dry rolls and a final screen to remove the remainder of the grit. This process is effective in recovering up to 50 pct of the mica in the original ore, the balance being lost in the screen undersize, usually —% in. Jigs and tables were at one time used to treat this screen undersize and were capable of recovering a part of the mica larger than about 60-mesh.V ine mica lost in these plants is normally washed away in streams and can be considered irrecoverable. There are ten or more washing plants in the North Carolina area that are losing approximately 50 pct of the mica in the feed. Since the three cooperating agencies, the Asheville Minerals Research Laboratory of North Carolina State College, the North Carolina Dept. of Conservation and Development, and the Tennessee Valley Authority, are concerned with conservation of minerals, they have investigated means for improving the efficiency of these mica plants. The mica industry has been cooperating fully with the laboratory to establish a more efficient method of recovery for flake mica. Choice of Methods The initial investigation was concentrated on finding a means of reducing the losses from plants now using the conventional flowsheet shown in Fig. 1. To accomplish this it would be necessary to collect the screen undersize products through the plant and remove from them the mica from Vs in. down to

Jan 1, 1952

By Dr. T

THE application of electricity in the extraction of metals has hithcrto been chiefly confined to the electrolysis of dissolved or fused compounds of these by varios methods. The power of electric currents to generate intense heat in their passage through a resisting medium has, however, long been known, and the late W. Siemens thereby succeeded in fusing considerable quantities of steel. But it was reserved to Messrs. Eugene 11. and Alfred H. CoWles, of Cleveland, Ohio, to take a new step in the metallurgic art by maKing the heat thus produced a means of reducing in the presence of carbon the oxides not only of the alkaline metals, but of calcium, magnesium, manganese, aluminium, silicon, and boron, with an ease that permits the production of these elements and their alloys with copper and other metals 011 a commercial scale. In the apparatus devised and now employed by the Messrs. Cowles, a column of fragments of well-calcined charcoal, so prepared and arranged as to present the requisite electrical resistance, is imbedded horizontally in finely pulverized charcoal, and covered by a layer of the same material coarsely broken, the whole being arranged in a box of fire-brick, covered with perforated tiles and opened at the ends to admit two carbon electrodes an inch and a half in diameter.

Jan 1, 1886

By N. Marusov, D. K. Lowe, J. C. Karp

This paper considers, from an engineering viewpoint, several factors involved in creating, designing and locating horizontal barriers for controlling water coning. This is an effort to consolidate new concepts with previous information so that a reasonable selection of barrier materials, dimensions and vertical position can be made. Coning theories previously developed are briefly reviewed and an effort i,s made to reduce the results of coning-theory calculations to a point where routine calculations can be made with a desk calculator. It is expected that these simplified calculations will give usable predictions of the amounts of improvement attainable with barriers of various dimensions. Apparatus and procedures used for testing the suitability of commercial cements are described and test results are presented. INTRODUCTION Just about as soon as the phenomenon of water coning was recognized as an oilfield problem, there were suggestions that the production of water coning could be controlled or completely suppressed by means of horizontal barriers. It was also suggested that natural barriers such as shale streaks were helpful in restricting bottom-water production. The implication was that wells not having the benefit of continuous shale streaks to suppress bottom waters should, in some way, be supplied with an artificial barrier. With regard to the selection of barrier materials, there are many references which give the merits of liquid barriers.',' These liquids include surface-active agents," recipitates' and emu1sions. There is no real need to review the merits of these materials again. This paper deals with the use of solid barriers which could be made from various cements. The two major restrictions placed on these barrier cements are that (1) they must be commercially available in large quantities, and (2) they must be applicable by means of standard tools and equipment with techniques that have been fully developed and are in general use at the present time. A schematic drawing of a horizontal barrier in a reservoir is shown in Fig. 1. Two maximum stable water cones are illustrated-—-one for the wellbore diameter and the other for a barrier. A maximum stable cone is one that has attained its maximum volume at the critical production rate and is on the threshold of producing water. The volume displaced by each water cone and the rise in water table are indications of the amount of water-free oil produced. Corrections for porosity, connate water and residual oil, of course, must be applied. The water-oil interface which defines a maximum stable cone is called a free surface. It is a surface over which the pressure is constant. This free surface has the shape of a limiting streamline at and below which there is no movement or transport. The shape of the water cone describes the pressure drop in the reservoir. The effect of a completely impermeable barrier on the cone shape is essentially the same as extending the wellbore out to the barrier radius. The placement of a horizontal barrier requires that a horizontal fracture be created using a single-point entry technique. Two methods may be employed for filling this fracture. One method consists of propping the fracture before filling with cement. The other consists of fracturing with fracture fluid, then immediately following with cement

By Charles Fulton

EXPERIMENTAL work on the process was begun on a laboratory scale at Cleveland, Ohio, in 1914, and transferred to East St. Louis, Ill. in 1916, where a commercial sized furnace was in technical operation until January, 1918. The essential steps of the process are as follows: Oxidized zinc ore or roasted zinc concentrate is mixed with crushed coke and coal-tar pitch and formed into briquets 9.25 in. (23.5 cm.) in diameter and 21 in. (53 cm.) long in a manner similar to that used in the manufacture of graphite or carbon electrodes, except that much less care and time are required. The composition varies with the nature of the ore; in one case, the composition was 100 parts ore, 70 parts coke, and 18 to 20 parts pitch. These briquets maintain their form and volume during and after the distillation of the zinc. This object is gained by using coke as the matrix and coal-tar pitch as the binder; this pitch becomes coke on heating and unites the ore particle and the original coke particle into a continuous mass. The briquet is an electrical conductor but only to such, a degree that it can be used as a resistor. The size of the ore, as in the present practice of zinc metallurgy, ranges from fine material, such as flotation concentrate, to coarse table and fine jig concentrate. The process is not restricted to any particular kind of ore, but is applicable to pure high-grade ores, ores high in iron, and complex zinc lead ores, since the residue from the distillation is held immovably in place within the briquet. In the case of complex zinc-lead ores, the distillation is conducted with a carefully regulated temperature so that a high percentage of lead is retained in the distilled briquet, which may then be smelted for its lead content. In present zinc smelting practice, the reduction fuel is from 40 to 50 per cent. of the weight of the ore. In the briquet, it is from 60 to 85 per cent. of the ore; but unless the ore is exceptionally high in residue, the distilled briquet

Jan 9, 1919

By C. M. Fellman

AVAILABLE data for the first nine months of the Year indicate that accident occurrence in metal mining was well on its way to an all-time low for 1939. However, the relatively rapid pickup in mining production in the fall will be likely to boost both accident occurrence and also accident rates. Results of the National Safety Competition for 1938, the fourteenth of its kind conducted by the U. S. Bureau of Mines, were published in August, 1939. W. W. Adams, statistician of the bureau, states that "with 345 mines and quarries competing, more than in any previous year except 1931, the contest revealed low accident rates at many of the enrolled plants and, which is even more remarkable, it revealed 113 mines and quarries at which no lost- time accidents occurred during the con- test year." The National Safety Competition provides a means whereby mines and quarries may engage in active competition to stimulate their safety programs. Companies in the contest can compare their records with those of similar plants operating elsewhere and thereby determine to what extent their safety programs are successful. The Joseph A. Holmes Safety Association gave over 150 awards for safety performance in the mineral industries in 1939 and a remarkable phase of these awards was the considerable number given to individual miners who had worked fifty or more years without sustaining a lost-time accident.

Jan 1, 1940

SECTION I Page Page New York Section War Meeting on Employment xxxii Sulphur and Pyrite v Local Section News xxxiv War Minerals Committee xviii Forthcoming Meetings xxxvi St. Louis Meeting xx Library xxxvii Minutes, of Meeting, Executive Membership xli Committee xxvi Institute Committees Iv Members in Military Service xxvi Officers and Directors lxii Personal xxx

Jan 10, 1917

By R. L. Slobod, H. A. Blum

A semiquantitative method for measuring the wettability of reservoir rocks has been developed. These data are needed for reservoir analysis and for interpretation of laboratory displacement studies. The wettability of a core sample is measured by the contact angle for the system oil-water-solid. These contact angles are calculated from the displacement pressure (threshold pressure) obtained by use of the centrifuge, using first oil-water and second air-oil in the same core sample. This method is based on the assumption that the air-oil and oil-water interfaces occupy similar positions in the porous medium when desaturation of the wetting phase is initiated. The assumption is also made that the Contact angle for the air-oil-solid system which is close to zero in value does not change appreciably even when the contact angle for the oil-water-solid system experiences marked changes. "Apparent contact angles'' for five different solids ranging from 31" to 82" have been determined, and changes irr the "apparent contact angle" of a given sample with laboratory use from 33" to 53' {lave been observed. INTRODUCTION Reservoir rocks vary in their wettability, 1,2,3,4 some being preferentially water wet while other are apparently preferentially oil wet. The degree of wettability, in theory, is measured quantitatively by the contact angle for the system solid-oil-water, hut in 1)practice this quantity is extremely difficult to determine." The need for obtaining some measure of this quantity has become obvious in recent years as a result of both laboratory. and field observations. Several reservoir.: such as the Bradford Sand in Pennsylvania and the Wilcox' at Oklahoma City are reported to be oil wet. If these report:: correctly reflect the true nature of the surface of the rock in the ground, then these reservoirs probably will not perform as predicted on the basis of a water wet rock. In the laboratory many core samples have been Observed to be oil wet. These samples, while perhaps not correctly representing the reservoir, have markedly different properties from water wet rock. The location of the phases is different (oil is in contact with rock instead of water), and other quantities such as the connate water, the capillary pressure curve; residual oil. relative permeabilities. and the recovery of oil by water flooding are markedly affected by the value of the contact -4 A further complication observed in the laboratory is the chang-ing of the wettability of a rock specimen with use. such changes mean that repeat runs on the same core are not the duplicate tests desired, but represent new experiments on a more oil wet material. The changes in surface characteristics are sometimes so rapid that by the time an experiment requiring several days is completed, the results may not be representative of the core as originally described, The, rock material itself (Silica. carbonates. etc.), whell Clean and uncontaminated, is water wet. There seems b( : little evidence of the presence of oil wet minerals such as heavy metal sulfides. The oil wetness of reservoir samples, therefore, is believed to be caused by the accumulation of an adsorbed film in which the polar group of a large organic. molecule is adsorbed on the surface leaving the organic or hydrocarbon part of the molecule projecting out from the solid. Such a surface is much more readily wet 17" oil than by water. These considerations indicate the need for a method which will provide some measure of tile wettalbility (Contact(angle if possible) for reservoir rock ..samples) The method should be capable of (1.1 distinguishing between tile wettalility of dif. ferent formation,.. (2) detecting (change. ill wettalbility of a core with use. and (3) measuring the changes in Wettability which may be accomplished with cleaning operations. such as the use of sodium silicate for increasing water wrettalbility." A preliminary report on such a method is preseted below. not with the idea that this procedure alone will Solve the wettabil-ity problem. but rather that it may provide encouragement to

Jan 1, 1952

By G. E. Perry, J. F. Bruskotter, D. G. Russell, J. H. Goodrich

The depletion performance of gas wells has been investigated by mathematical simulation techniques. The gas well model which was studied consisted of a single well located in the center of a bounded, cylindrical, homogeneous reservoir. Dependency of gas compressibility and viscosity on pressure was considered in studies of well performance at both constant mass flow rate and constant flowing pressure conditions. To carry out the investigation, the nonlinear, second-order, partial differential equation which describes Darcy flow of a nonideal gas through porous media was solved numerically. Some of the previous investigations of gas well performance have been of limited general use, because assumptions were introduced to simplify either the gas properties or the basic differential equation. Other studies have been rigorous in these respects but have presented a very limited set of calculated results. The present study was attempted to present a rigorous theoretical model and sufficient numerical results to permit meaningful conclusions to be drawn. It was found that all terms must be retained in the partial differential equation to make accurate predictions. The neglect of higher-order terms, e.g., terms of the order of the "gradient squared", leads to serious material balance errors at large times and to conservative estimates of gas well performance. The higher the gas flow rate and/or the lower the permeability-thickness product of the formation, the more pronounced are these deviations. For example, in a well draining 640 acres in a 25-md-ft formation (8,120 MMcf gas in place) at a constant rate of 993 Mcf/D, the rigorous solution predicts a bottom-hole pressure decline from 4,000 to 1,000 psia in 8.7 years. If higher-order terms are neglected in the differential equation, this decline in pressure is predicted to occur in 5.3 years. With the results of the numerical solution of the differential equation as a basis, simple, easy-to-use approximations for predicting gas well performance for Darcy flow conditions have been developed. These simple approximations are based on the familiar equations for flow of a single, slightly compressible fluid. The approximate methods possess a high degree of accuracy and enable the prediction of long-term gas well performance to be made quickly and accurately without the use of a digital computer. Both transient and stable flow period approximations were developed. INTRODUCTION In recent years income from the sale of natural gas and associated products has represented an ever-incre as ing fraction of the industry's total revenue from operations. To meet the surge in demand for natural gas, the industry has depended heavily upon established reserves and has actively pursued development of new reserves. The search has progressively led to reservoirs which yesterday were too tight and/or deep to yield the desired return on invested capital. More than ever before, evaluation accuracy is now required to forecast the criteria upon which engineering recommendations and management decisions are based. Considerable effort has been expended by both research and operations personnel on the development and application of methods for analyzing and predicting the performance of gas wells. Fundamentally, the problem is the familiar one of extracting data during the drilling, testing and early production life of a well and applying these data within an accurate simulation model to predict long-term behavior. During the past 30 or more years a voluminous literature dealing specifically with gas field problems has been generated. A recent book' lists a comprehensive bibliography of published material through 1959. Over 1,200 references are cited. Since then 39 additional articles on natural gas technology have been published in Transactions volumes of the Society of Petroleum Engineers of AIME. Most existing theory for predicting gas well performance requires that one or more idealizations (e.g., steady-state flow, ideal gas of constant viscosity, small and constant compressibility and constant-viscosity fluid) be applied. Although existing theory may apply directly or be adapted by various artifices to describe specific gas well and reservoir behavior, no widely applicable method is available, and existing methods appear to be subject to appreciable error unless better limits of applicability are defined. The objectives of this paper are (1) to present numerical solutions to the partial differential equation describing gas flow under conditions of general interest in gas well performance prediction work, (2) to present solutions which possess a high order of accuracy for both transient and stabilized flow periods of a well producing at constant rate or constant pressure, and (3) to develop and present simplified relationships which can be used as high-order approximations to the exact numerical results for fast and accurate predictions of gas well performance at the operating level. Combined, these objectives are designed gen-

Jan 1, 1967

By John H. G. Monypenny

The range of chromium content of stainless steel is, in most cases, included in the limits 11 to 14 per cent., or the middle part of the range, 9 to 16 per cent., specified by the discoverer. For some time after the steel was produced commercially, the carbon content was about 0.3 to 0.4 per cent. and occasionally higher; only rarely was material with 0.25 per cent. carbon or less produced. The reason for this is obvious from the nature of the alloys of chromium available for making such steels; as the lowest carbon content generally available was about 1 per cent., and this in conjunction with a chromium content of about 60 per cent., the production of a 12-per cent. chromium steel with less than 0.25 to 0.30 per cent. carbon was impossible. The advent, on a reasonable commercial scale, of carbonless ferrochromium has modified this condition, however, so that for the last three years stainless material containing 0.1 per cent. or less carbon and the normal amount of chromium has been on the market. As far as the author is aware, the material was first made on a commercial scale by the firm with which he is associated in June, 1920, when a 5- or 6-ton cast of material containing 0.07 per cent. carbon and 11.7 per cent. chromium was made and cast into 12-in. ingots. The necessity for using a totally different raw material, carbonless ferrochromium, instead of the ordinary low-carbon ferro (0.6 to 1.0 per cent. carbon) has led to the idea that stainless iron is a quite distinct product and quite different from stainless steel. While this may be true from a commercial aspect, it is wrong metallurgically. The name stainless iron is unfortunate as the material is a very mild stainless steel and forms the lowest carbon member of a series of steels of continuously varying content which are, in many respccts, the counterpart of the series of ordinary carbon steels ranging from "dead soft" to tool steels. In an article on stainless steel in the Journal of the Society of Chemical Industry, November, 1920, the author said "Just as in the far-off days 'steel' was regarded as a hard product of iron, and little or no attempt was made to grade it into harder or softer varieties, so at present stainless

Jan 1, 1924

By John H. G. Monypenny

The range of chromium content of stainless steel is, in most cases, included in the limits 11 to 14 per cent., or the middle part of the range, 9 to 16 per cent., specified by the discoverer. For some time after the steel was produced commercially, the carbon content was about 0.3 to 0.4 per cent. and occasionally higher; only rarely was material with 0.25 per cent. carbon or less produced. The reason for this is obvious from the nature of the alloys of chromium available for making such steels; as the lowest carbon content generally available was about 1 per cent., and this in conjunction with a chromium content of about 60 per cent., the production of a 12-per cent. chromium steel with less than 0.25 to 0.30 per cent. carbon was impossible. The advent, on a reasonable commercial scale, of carbonless ferrochromium has modified this condition, however, so that for the last three years stainless material containing 0.1 per cent. or less carbon and the normal amount of chromium has been on the market. As far as the author is aware, the material was first made on a commercial scale by the firm with which he is associated in June, 1920, when a 5- or 6-ton cast of material containing 0.07 per cent. carbon and 11.7 per cent. chromium was made and cast into 12-in. ingots. The necessity for using a totally different raw material, carbonless ferrochromium, instead of the ordinary low-carbon ferro (0.6 to 1.0 per cent. carbon) has led to the idea that stainless iron is a quite distinct product and quite different from stainless steel. While this may be true from a commercial aspect, it is wrong metallurgically. The name stainless iron is unfortunate as the material is a very mild stainless steel and forms the lowest carbon member of a series of steels of continuously varying content which are, in many respccts, the counterpart of the series of ordinary carbon steels ranging from "dead soft" to tool steels. In an article on stainless steel in the Journal of the Society of Chemical Industry, November, 1920, the author said "Just as in the far-off days 'steel' was regarded as a hard product of iron, and little or no attempt was made to grade it into harder or softer varieties, so at present stainless

Jan 1, 1924

By Sir Robert Hadfield

(New York Meeting, February, 1913.) THE Hadfield method of producing sound steel ingots has been the subject of a paper 1 read before the Iron and Steel Institute, so that it will be unnecessary to describe it fully here. The object of the method is to make possible the production of steel ingots in which the pipe is almost entirely obliterated, and it is applicable particularly to the production of sound ingots, from which good rails could be rolled. The method in brief consists in casting the ingots on cars, usually with the small end down. Each ingot mold is provided with a sand top, rammed up in the well-known manner. After the mold is filled to the desired height with steel, a layer of slag about 0.5 in. thick is placed upon it and the balance of the mold is then filled with charcoal. Then, through suitable piping, an air blast is directed in numerous jets upon the charcoal, which is burned thereby, the combustion supplying additional beat to the top of the ingot, which helps to keep the top fluid and to retard its solidification, while the lower parts are rapidly losing heat by its transfer to the mold. By-one plan the ingots are cast in molds placed upon bogies, movable trucks, or platforms, in the position A, Fig. 1. The ingots are cast vertically on bogies, say four or more ingots on each bogie, as may be found most convenient, and the upper surface of the steel is maintained in a molted condition during the transit of the ingots from the casting pit to the stripper. This is effected by a series of air pipes, for example, three in number, with jets or holes on the under surface of such pipes, placed preferably horizontally, arranged in such a manner as to cause jets of air to impinge on the upper surface of the ingots. These holes or jets are made throughout the entire length of the overhead pipes, the length of such pipes being

Jan 4, 1913

By D. C. Seidel, E. F. Fitzhugh

The Colorado School of Mines Research Foundation has developed a hydrometallurgical process for recovering nickel from oxidized ores, including both the iron-rich laterites and magnesium-rich, soft silicates. Known as the HSO-HTCP (Hydrothermal Sulfidization Oxidation-High Temperature Cementation in Pulp) Process, the system consists of feed preparation, sulfidization, oxidation, precipitation (cementation), and calcination and melting. This paper deals primarily with the sulfidization and oxidation phases of the process. Nickel sulfide ores lend themselves readily to concentration before smelting or pressure leaching, but neither of the major oxidized ore types — the iron-rich laterites and magnesium-rich, soft silicates-has been directly concentrated. Upgrading of crude ore in current practice is limited to cobbing lumps of the harder, lower grade rock (protore) from the softer, enriched silicate ore, because only a small percentage of the nickel in these ores occurs in discrete, contrasting mineral particles. There is no apparent mineralogical contrast in the superficial, iron-rich lateritic ores and, in fact, there is no firm assurance that the nickel atoms are within the lattices of the limonite minerals, or else irregularly adsorbed on the limonite. Within underlying, "rotten rock" silicates, occasional veinlets of gamierite and related nickeliferous silicates are found.' The gamierite veinlets, however, are only incidental, and the majority of the nickel atoms occur as erratic replacements of magnesium atoms in the micaceous chlorites of the ore mass. Pyrometallurgical processes account for nearly all the nickel currently being recovered from oxidized ores. Plants in New Caledonia, Oregon, Japan, Brazil and Greece smelt the ores to make ferronickels or a sulfide matte,2 and the ammoniacal leaching3 at Nicaro, Cuba, is preceded by a reducing roasL4 The only fully hydrometallurgical installation has been the politically ill-fated Freeport Nickel Co. enterprise, and this process was limited to lateritic ores.5p6 A hydrometallurgical technique which might handle both laterite and the typically richer silicate ores has been an enticing goal. The technique described here was developed at the Colorado School of Mines Research Foundation, Inc. on behalf of the Republic Steel Corp. It uses sulfur, heat, air and metallic iron to recover nickel from these ores. Inasmuch as the ores are treated as aqueous slurries, the cost of drying a plant feed that normally carried 30% or more moisture is eliminated, and there are no dust problems. Patent applications have been filed by Republic Steel Corp. on the procedures used for getting the metal into solution and on the subsequent recovery without liquids-so l ids separation of the slurry. It is referred to as the HSO-HTCP Process (Hydrothermal Sulfidization Oxidation — High Temperature Cementation in Pulp). THE PROCESS FLOWSHEET The results of various experimental studies have been combined to form the continuous flowsheet illustrated in Fig. 1. This flowsheet serves as a general pattern showing the sequence of the operations which include: (1) feed preparation; (2) sulfidization; (3) oxidation; (4) precipitation (cementation); and (5) calcination and melting. This paper deals primarily with the sulfidization and oxidation phases of the process. Feed preparation: In general, the silicate ores can be considered as earthy rather than hard, and preparation might be carried out before the addition of water in a trommel, or with water in a scrubber or log washer. This breaks up the earthy particles, allowing the hard lumps to be separated by screening. The oversize material from most ores is relatively barren and may be discarded. If there is occasion to control the iron-magnesium ratio in the plant feed, laterite, which normally breaks up readily into fine sized particles, and silicates are mixed in suitable proportions. The fine product slurry from the initial steps is mixed with elemental sulfur and fed to a conventional ball mill, although the amount of actual grinding that takes place is relatively small. The object of milling is to complete the disintegration to natural particle size and to produce an intimate mixture of the ore and elemental sulfur. This pulp, which is almost entirely -200 mesh, has a pH of about 7.0 and normally can

Jan 1, 1969

By E. P. Palmatier

RECENTLY a cooling system has been in process of installation on the 3400 and 3600-ft. levels of the Magma copper mine at Superior, Ariz. The general system of ventilation employed at this inclined-vein mine is as follows: Ventilating air enters the shafts on the western side of the mine. Booster fans at each level each deliver approximately 38,000 cu. ft. per 'min. to the drifts. This air passes diagonally upward to the upper levels of the mine on the eastern side, where it passes up the shafts to large exhaust fans on the surface. Owing to the dip of the vein, all operations on the eastern side of the mine are above the 2500-ft. level, and those on the western side below the 2500-ft. level. At present, 2500 lineal feet of new drifts are being driven-on each of the 3400 and 3600 levels. The rock temperature is about 135°F. Until the new installation is completed, ventilating air for the two levels is supplied through Flexoid tubing from small booster fans -on the 3200-ft. level. The air picked up by these booster fans has a dry-bulb temperature of approximately 85°F. and a wet-bulb temperature of 82°F. By the time this air reaches the end of the Flexoid tubing at the 3600-ft. level, the dry-bulb rises to 101°F. and the wet-bulb to 86°F. The conditions at the head of the new drift were 102' dry-bulb and 93' wet-bulb.

Jan 1, 1937