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By R. E. H. Pomeroy

Early in 1917, it became evident, owing to existing and pending market conditions, that a substitute for crude petroleum must be found for firing the smelter furnaces. After a review of the plants then existing, it was deemed advisable to depart from their practice and to adopt the following described system of distributing pulverized coal to the furnaces. The principal advantages of the proposed system, which influenced this decision, were: (I) Equal safety; no pulverized coal is stored at the furnaces; (2) greater ease of operation, furnace fires being controlled by regulating valves in burner branches, as in gas firing; (3) better organization; all machinery, including pulverized coal feed, is under one roof, and the organization is separate from the furnace department; (4) greater cleanliness; all machinery is under vacuum; (5) greater flexibility of application, the coal and air mixture can be piped where needcd. The design of the plant is the result of the combined efforts of the local engineering staff and of the machinery manufacturers. Many new features were embodied in this design to insure greater safety, cleanliness, and efficiency of handling. After 14 months of continuous operation, the plant has proved entirely satisfactory. The building is of structural steel, covered with corrugated steel, with many windows and is painted light gray inside and out. The building floor is of concrete with ample drains to the sewer, and the building is equipped with fire and service water piping. Fig. 1 shows the east side of the building and the incline conveyor from the raw-coal bins. The plant is operated entirely by electric power. All alternating current is 550 volts, 3-phase, 60 cycles. The pulverized-coal feeding niotors and control mechanism are operated by 220-volt direct current supplied by motor-generator sets in the building. Autamatic push-

Jan 1, 1921

By J. R. Linney

A HISTORY of the ore-mining and iron-smelting industry of the Adirondacks comprises a century and a half of pioneering by rugged individualists, both men and women. By geographical location, the climate is most severe-long, cold winters with heavy snowfall, and short seasons of vegetation growth; this, together with its remote location from large centers of population, adds considerably to the difficulties of conducting mining operations in this area.

Jan 1, 1943

By H. A. Guess

Introduction. History and Production Statements. Southeast Missouri is the oldest of the large producing districts of the United States. The first recorded production from disseminated ores was in 1869, although for many years prior to that time lead had been milled from shallow pockets, and steady growth in production has been shown ever since, the greatest increases being during the past five years. The production by years for each of the operating companies from 1869 to 1907, inclusive, is given in Table I. In Table 11. is given the production by years from 1908 to 1912, inclusive, for the district as a whole, showing the tonnage of crude ore mined, yield in concentrates, average assay of concentrates; yield in metallic lead both per ton of crude ore and in total; also approximate value of the yearly production. It is interesting to note that the production for the 5-yr. period 1908 to 1912, inclusive, is practically equal to the total previous production, viz., the 39-yr. period 1869 to 1907, the summary being as follows:

Jan 1, 1915

[Note.—The paper of Mr. Hoffman on " Practical Results in the Magnetic Concentration of Iron-Ore " (page 602); that of Mr. Langdon on "The Use of Magnetic Concentrates in the Port Henry Blast-Furnaaces" (page 599); and those of Mr. Landis on "The Determination of Iron in the Tails from Magnetic Concentration " (page 609) and "Note on Sampling Iron-Ore" (page 611), were all prepared as contributions to this discussion.] The papers of Mr. Langdon and Mr. Hoffman were presented. W. H. Hoffman, Croton Mines, N. Y.: I will add a few remarks, by way of answer to inquiries for further details. The Croton Mines are particularly well located for cheap mining. The ore-bed is very large, and so lies in relation to the railway tracks of the Harlem and other railroads that a very large proportion of our mining for several years to come can be done above these tracks. The concentrating-mill is now 400 feet from where we are working in the quarry. In blasting we never remove less than 2500 tons at a blast,

Jan 1, 1892

By L. T. Leyson, U. C. Tainton

Some time ago, at ameeting of the Institute Prof. J. W. Richards1 said, "I take exception to the statement that all the factors in the production of electrolytic zinc were known long ago.... There is possible in my opinion an improvement of perhaps 50 per cent. in the new electrolytic processes." An examination of the literature of the subject will show the justness of Professor Richards' contention. The work of the earlier investigators was carried on in the shadow of difficulties that, today, are hardly more than memories. We seldom hear now of zinc sponge, that bête noir of the electrolytic-zinc pioneers. Zinc sponge was the name given to a peculiar, soft, black, non-adherent form of zinc deposit that was utterly useless for melting into ingot form. At the big plant at Cockle Creek, New South Wales, in 1897, Edgar Ashcroft2 said that the solution in the plant would suddenly, and without ascertainable cause, go' "bad" and begin to deposit spongy zinc. The most delicate, even spectroscopic, methods of analysis were unable to detect any difference between "good" solution and "bad" solution; either form might change to the other on being kept for a while. When it is added that an outbreak of this insidious disease (which appeared to be infectious, or at least contagious) could be dealt with only by discarding the solution and washing out all tanks and pipe lines, some idea may be gathered of the troubles of the zinc electrometallurgist in what may be spoken of as the "sponge age" of electrolytic zinc. Thanks to the efforts of a number of investigators, we are today able to diagnose with considerable certitude the nature of the malady that puzzled Ashcroft and his co-workers. The researches of Mylius and

Jan 1, 1924

By B. D. Cullity, A. Freda

It is well known that deformation by cold drawing or swaging produces a kind of preferred orientation called fiber texture in metal wires. Such textures have been extensively studied by means of X-ray diffraction, chiefly by techniques in which the diffracted X-rays are recorded photographically. This paper describes some results obtained with a new method, involving the use of a diffractometer. X-RAY METHOD Since the pole figure of a material having a fiber texture is symmetrical about the fiber axis, there is no need to present the entire pole figure. Instead, texture data can be summarized by means of a curve showing the variation of pole density along any meridian of the pole figure, if the north-south axis of the latter is made parallel to the fiber axis. The position of a pole on the meridian is specified by the angle 9 between the pole and the fiber axis (wire axis). The X-ray method1 used here to measure pole density as a function of 9 actually consists of two methods, referred to as A and B. In method a, X-rays are reflected from the wire surface. Pole densities can be measured by this method from O = 90 deg down to a limiting value which is dependent on the Bragg angle 8 and is typically of the order of 30 to 40 deg. Method B involves diffraction from the wire cross section and covers a range of 0 values from 0 up to an angle sufficient to overlap the measurements made by method A. By a combination of the two methods, a complete pole-density curve can be obtained. However, method A alone, which requires no specimen preparation other than etching, can often reveal enough of the pole-density curve to provide complete information about texture components. Both methods require that the measured diffracted intensities be corrected for changes in absorption and diffracting volume with changes in 9. A11 intensities I reported in this paper are corrected diffracted intensities; they are propor-

Jan 1, 1960

?AARONSON, ALFRED E , Vice-Pres , Mid-Co Petroleum Co, Mid-Co Bldg, Tulsa, Okla '18 ABADIE, EMILE R, Min Engr Address wanted '76 || ABADILLA, QUIRICO A, Geol Dept, Cia Mexicana de Petroleo "El Aguila," S A, Edifico "El Aguila," Esq, Calles Aurora y Comercio, Tampico, Tamaulipas, Mexico '20 ABBOTT, CLARENCE E, Gen'l Supt, Iron Mines Div, Tenn Coal, Iron & R R Co, 1405 Minnesota Ave, Bessemer, Ala '04 ABBOTT, LOUIS BENJAMIN, Chief Engr, Consolidation Coal Co, Elkhorn Div, Jenkins, Ky '15 ABBOTT, ROBERT R Met Engr, Peerless Motor Car Co, Cleveland, Ohio '12 ABE, ASAKA Fujita Min Co, Dojima, Osaka, Japan '14 ABEEL, GEORGE H, JR, Cons Min Engr, 635 St Paul Ave, Los Angeles, Cal '18 ABEL, ALBERT E, Asst to Pres, Valley Mould & Iron Corpn, Sharpsville, Pea '19 ABEL, W D, Min Engr Forum Bldg, Sacramento, Cal '19 ABELL, O J, Pres & Treas, Abell-Howe Co, 332 South Michigan Ave, Chicago, Ill '19 ABERNATHY G E Willow Springs, Mo '20

Jan 1, 1923

By R. N. Upadhyay, M. Maleki, I. Fatt

Conventional laboratory core analysis tests on samples of two limestone reservoir rocks indicate that about 20 per cent of PV is in dead-end pores. These tests (electric logging formation factor, mercury injection capillary pressure and miscible displacement) were carried out on 1/4-in. diameter test plugs. Test results show a clear dilference between these samples and sandstone or homogeneous limestone reservoir rock. Although the amount of dead-end pore space can be only roughly estimated, the presence of such pore space seems clearly indicated. Pressure transient studies also show presence of deadend PV. Although they do not give quantitative results, pressure transient data yield a reasonable estimate of the size of the neck connecting dead-end pores to the main flow channels. INTRODUCTION Equations conventionally used to describe reservoir flow behavior contain the implicit assumption that all connected pore spaces contributed to both porosity and permeability. Several authors3-7 have pointed out the changes in pressure transient behavior and in electric log interpretation that may result if this assumption is incorrect and, instead, dead-end or cul-de-sac pores are present. There is a need for laboratory tests that can detect presence of dead-end pores in core samples. With such information on hand the petroleum engineer can make more rational use of the mathematical tools now available for analysis of reservoir flow behavior. This paper describes laboratory studies designed to detect and, if possible, give a quantitative measure of dead-end PV in laboratory-size core plugs. Three reservoir rocks were used, two of which were limestones suspected of having deadend pore spaces and a well-known sandstone, used as a comparison standard, in which there is believed to be little or no dead-end pore space. All the studies were designed to measure the natural dead-end PV; i.e., the pore space which is dead-ended because of rock structure. During multiphase flow in a rock without dead-end pores, some parts of one of the phases can become surrounded by the other, thereby giving (for certain flow behavior) an effective dead-end pV8,9. Such behavior will not be described here.

Jan 1, 1967

By Richard I. Petritz

A brief review of today's processing of integvated circuits is given. The major trends in the development of advanced integvated electronics are identified as 1) the broadening of the integvated circuit concept to a large class of circuit function, 2) the processing of more complex circuits within relatively small chips of silicon, and 3) the processing of very large electronic functions on complete slices of silicon. This latter trend, called array technology, is then developed in detail. Emphasis is given to defining the key tech-nological problems. Current progress being made is illustrated. THIS paper will endeavor to identify the major trends in advanced integrated electronics technology. One of these, array technology, will be developed in some detail. The array technology discussion will identify the key problem areas. Since it is the scope of the entire meeting' to present specific progress in the science and technology of integrated electronics, we shall indicate general directions being explored rather than discuss comprehensively solutions to the problems. In order to set the stage for the discussion of future trends in integrated-electronics technology, let us briefly compare the processes by which circuits are fabricated through discrete-device technology with that of integrated circuits technology. The reader is referred to the December 1964 issue of Proceedings of IEEE2 for a comprehensive review of integrated electronics. The article3 by Jay Lathrop is an excellent discussion of integrated-circuits technology. A discussion of the history of semiconductor technology is contained in Ref. 4. A) Current Status of Integrated Electronics. Fig. 1 (top) shows the process by which circuits are constructed from discrete devices. Key points are: 1) Slices containing large numbers of transistors or diodes are processed separately. 2) The slices are scribed into small chips (on the order of 15 mils on a side is about as small as can be conveniently handled) each chip containing one transistor. 3) Each device is specified separately—circuit -function specs are derived largely from device specs. 4) Circuits are formed by connecting together the discrete devices. 5) The number of circuit connections required is approximately equal to the number of devices. 6) There are potentially many more discrete devices per inch2 of semiconductor—only our lack of ability to handle them in discrete form prevents us from going to several orders of magnitude higher density iin Fig. 1, 400,000 transistors are discussed at 1.5 mils on a side). The bottom part of Fig. 1 illustrates the integrated circuit process. Key points are: 1) On the same slice of silicon, transistors, diodes, and resistors are processed grouped to do a complete circuit function. 2) While still in slice form, the components are interconnected into circuit functions by an evaporation process, eliminating the need for separate interconnection steps later. Dramatic improvements in cost and reliability are realized. With a simple flash of metalization thousands of interconnections are reliably made. 3) The slices are scribed into chips which contain complete circuit functions. 4) The circuit functions are specified-not each component in the circuit. This important point was missed by some of the early opponents to integrated circuitry. They argued that, with device yields at x pct, integrated circuit yields would be pct, where n is the required number of devices to make a circuit. This argument leads to extremely low yields for integrated circuits. The fallacy of the argument is that in integrated circuits each device is not specified separately. Furthermore, since a device is forever integrated into a specific circuit function, it need meet only the requirements for that particular function. Discrete devices, on the other hand, are tightly specified so that they can be applied to a variety of circuit functions. 5) Extremely high packing densities are achievable because one need only make the basic devices as large as the circuit demands. Their size is not dictated by handling requirements. A current example

Jan 1, 1967

By Yeatman, Pope

FOR many years geologists have felt that mining companies should adopt a more liberal policy in the publication of their reports. The increasing usefulness of the geologist to the mining profession in recent years demands that consideration be given to this question. Prior to 1900, the call for geologists of high reputation by mining companies was probably mainly in connection with lawsuits arising from the interpretation of rights or ownership as defined by the "Law of the Apex," and from problems such as finding the continuation of the vein or whether the vein followed was the main one or a branch. Later, outside of legal questions, the most intensive and general use of their services arose from the search for oil. Geologists to determine the position of the formations

Jan 1, 1938

By J. B. Fisken

(Butte Meeting, August, 1913.) BEFORE touching upon the immediate subject of this paper a few facts of a historical nature as to the general application of electricity to mining might be of interest. As to what was actually the first application of electricity to mining, opinions will no doubt always differ. My experience does not go back far enough, nor are the records to which I have had access of any value as covering this point. Sydney F. Walker, a man whose pioneer experience in the application of electricity to mining purposes dates back as far as 1876, ,gave an interesting resume of the subject in an address before the South Wales branch of the Association of Mining Electrical Engineers at its 1.913 session, and, unless his statements are shown to be wrong, they should be accepted as facts. According to Mr. Walker, the ignition of charges of blasting powder was the first operation in mining to be accomplished with the aid of electricity. Very frequently this energy was furnished by a static machine and occasionally by a magneto generator. Later, this was followed by the application of electricity to bell signals, and we are told that this application was looked upon skeptically and regarded as an expensive experiment by the mining managers of those early days. At the Paris Exposition of 1878, there was exhibited an electric lamp, which suggested future possibilities to the mining engineers of those days. The first successful application of electric lighting to underground excavations that I have been able to find any record of is that of M. Blavier. In the year 1879' he installed two Serrin lamps and successfully illuminated one of the large underground chambers in the Angers slate quarries. Another early application of electricity to the lighting of mines is that in the large chambers in the salt mines of Maros-Ujvár, in Hungary; these have been regularly and successfully lighted elec-

Jan 6, 1913

By M. C. Fuerstenau, D. N. Collins, R. B. Bhappu, D. N. Moir

D. N. Moir (Senior Scientific Officer, Warren Spring Laboratory, D.S.I.R. Stevenage) and D. N. Collins (Scientific Officer, Warren Spring Laboratory, D.S.I.R., Stevenage, England) — During work on the petroleum sulphonate flotation of beryl in 1959 at Harwell, and subsequently at Warren Spring Laboratory, effects similar to those mentioned by the authors were noticed. Brief details of some of this work were given to the 6th International Mineral Processing Congress at Cannes.' It is interesting to note that the authors experienced strong activation effects with Fe+++ ions on beryl when using petroleum sulphonate collectors. This phenomenon was of interest in our work when

Jan 1, 1963

By Paul R. La Pointe

GEOTECHNICAL OBJECTIVES OF UCG PROGRAM Underground coal gasification (UCG) is one of several in situ extraction technologies for utilizing deep, otherwise unmineable coal. This technology involves the injection of air or oxygen into the target coal seam, ignition of the coal and recovery of product gases. Geotechnical characteristics of the coal and enclosing rock strata strongly influence the success of this Process. The flame front follows the coal cleats (Hill, 1979), and cleating and bedding control the manner in which coal collapses into the cavity, thereby affecting recovery efficiency (Ramirez and others, 1982). Moreover, coal seams typically behave as fracture dominated aquifers in which cleat orientations govern subsequent contaminant dispersal. For these reasons, the Anaconda Minerals Co. undertook a detailed study of fracturing within the Wyodak-Anderson Coal in the eastern Powder River Basin (PRB) near its Rocky Hill UCG test site (Fig. 1). STRESS HISTORY AND FRACTURING IN THE POWDER RIVER BASIN Vertical jointing, or cleating, in coals may arise from shrinkage shortly after deposition under low confining pressures, or later in time, soon after burial but after the coalification process is well advanced (Ting, 1977). There is much evidence to support the formation of cleating after coalification (e.g. Hawkes and Mellor, 1970; McCulloch and others, 1974), which suggests that the stress state existing at that time strongly influences cleat formation. McCulloch and others (1974) argue that the typically better developed face cleat forms parallel to the plane containing [ol] and [o2]. Where the relation between cleats and stess has been studied (McCulloch and others, 1974; Stone and Snoeberger, 1977; Ward, 1977; Kulander and Dean, 1978), the highly systematic face cleat strongly parallels the [o1] direction. Stone and Snoeberger (1977) report face and butt cleat measurements of N70E and N29W for the Felix Coals 220 m stratigraphically above the Wyodak at the Hoe Creek UCG site (Fig. 1). Structural trends also indicate the past state of stress in the PRB. Glaze and Keller (1963) suggest that the NE-SW regional compression during the late Permian formed major N-S fold lines and basement magnetic anomalies. Mapel (1959) describes folds having N60W and N30W rends in the northern PRB, as well as a large normal fault trending northeast. Glass (1976) also describes normal faults trending northeast. Similarly, Olive (1957) mapped normal faults

Jan 1, 1984

By C. O. Brawner

FACTORS THAT INFLUENCE STABILITY AND STABILIZATION METHOD The most effective stabilization method and design can only be developed if the cause(s) and mechanics of the slide are known. Therefore, it is important that the stability be evaluated by an engineer who has had extensive rock stability experience. The most important factors that influence stability are structural geology, ground water, blasting and the mining method or methods. Structural Geology - The majority of failures in rock slopes occur along discontinuities in the rock (joints, bedding planes, shear or fault zones, etc.). Therefore, on all surface mining projects, the development and maintenance of a comprehensive structural geologic mapping program should be a first priority program that is considered a part of the operations function. This program should include mapping all major features - faults, shear zones and through going joints. All structural features which could influence stability should be mapped and presented in a structural domain format for the entire mine (Canmet, 1977). Where planes, wedges or blocks will be undercut by the mining excavation, shear strength and strain to failure tests should be performed on the joints, fault gouge and gouge-rock contact surfaces. These tests must be performed on the samples in the direction of potential slide movement and must determine the range of peak and residual shear strength values. A preliminary assessment of friction angle can be obtained from measurements of failed surfaces in the field (Figure 1) or from core sliding tests (Barton, 1981). An assessment must be made of the past geologic history of

Jan 1, 1983

By AIME AIME

AN outstanding session of the Annual February Meeting was one held under the joint auspices of several groups on Tuesday afternoon, Feb. 22, as a symposium on the question of preserving peace in the postwar era through the control of the supply of sundry minerals vital to the Axis nations. D. H. McLaughlin and R. C. Allen were associate chairmen. And C.K. Leith led the discussion.

Jan 1, 1944

By J. Chipman

There is no better way of paying tribute to the memory of a scientist than by developing and carrying forward those ideas which he has contributed to science and which are for us the very essence of his immortality. For a lecturer who has not had the great privilege of stdying under Professor Howe or 'ven of knowing him in person, these ideas must be transmitted through the printed word. It is our great good fortune that Professor Howe left to us a rich heritage of publication, not only in his classic monograph on the "Metallography of Steel and Cast Iron" but in a wealth of earlier hooks and papers in the transactions of this Institute arid of other scientific and engineering bodies. An outstanding characteristic of this published record is the great breadth of interest and of vision which it portrays. His was riot a narrow specialization in only the scientific aspects of ferrous metallographg. On the contra1y many of his important contributions had to do with a far broader field of metallurgicial endeavor. He insisted that his students be well grounded in 1 he fundamentals underlying the whole field and not led into the narrow groove of specific applications. Among his first major publications we find papers on copper smelting, extraction of nickel, the efficiency of fans and blowers, thermic curves of blast furnaces, the cost, of coke, and the manufacture of steel. These are the papers of a metalhurgical engineer and it was among engineers that Henry Marion Howe made his early and well-merited reputation. These early engineering contributions display very clearly the strongly sctientific inclination of their author. The classic work on "The Metallurgy of Steel" published in 1890 contains a thorough and critical discussion of all that was known at the time concerning the alloys of iron and of what we would now call the physical metallurgy of steel. In addition it describes steel-making processes in use and some that had become obsolete, and points out in critical fashion the reasons for success and failure. Steel mill design and layout were included as well as some pertinent discussion of refractories. The book is indeed an embodiment of one of Howe's outstanding characteristics—breadth. It is both the science and the engineering of steel production as known in that day. One of Howe's earliest technical papers was entitled "What is Steel?" That was nearly seventy-five years ago when many new processes and new kinds of steel were being developed. The time was ripe for such a question and the answers which Howe was able to give were helpful in understanding the phenomena of heat treatment. Twenty-five years ago Professor Sauveur repeated the question as the title of the first Henry Marion Howe Memorial Lecture. It seemed to him that this question, "What is Steel?," had served as Howe's motto throughout the remainder of his life. Today I shall present for your consideration a question of another sort: "What is Sletallurgy?" Perhaps it is not too much to hope that in the answer we may obtain a clearer and possibly broader view of the nature of our science and our profession. The time is ripe for giving careful consideration to what we mean by metallurgy. If our Metals Branch is to become in fact an American institute of Metallurgical Engineers, it is essential that we understand what is meant by metallurgical engineering. I am convinced that the best interests of the profession have not been served by a narrow interpretation of these terms. We must now place emphasis on the breadth of metallurgy as a science and as an engineering profession. With its usual brevity and wit. Webster's dictionary definesmetallurgy as "the science and art of extracting metals from their ores, refining them and preparing them for use." I shall riot assume that the words "science" and "art" and "metal" are so well understood as to require no defining but others among our contemporaries are better qualified than either your lecturer or the dictionary to present the broad meanings of these terms. When we say that metallurgy is among the oldest of the arts we are not classing it with painting or sculpture or music but rather with the making of tools or weapons or the building of bridges or chariots or cathedrals. In short we are saying that metallurgy is among the oldest of the engineering professions. The question " What is metallurg ? " has been one of rather more than ordinary concern to those of us who have the task of developing a curriculum for the education of students in this field. This development has been going on in a number of universities over a period of some years. but there seems to be as yet no unanimity as to what such a curriculum should contain. I believe there is fairly complete agreement that it must be founded upon sound

Jan 1, 1950

By C. W. Davis

THE name fuller's earth, which was derived from its early use in "fulling" or removing grease from woolen goods, is a term that is generally considered to designate mineral matter, containing hydrous aluminum silicates of the clay group, which has a high capacity for removing colors from oils, whether of animal, vegetable, or mineral origin. Fuller's earths are usually dried and may be "tempered" by heating or may be treated with water or reagents to improve their efficiency. For our purpose the term "acid-treated earths" will include those products from the partial decomposition of mineral water by acid which are equal to or more efficient than an untreated fuller's earth from Quincy, Fla., when used in bleaching mineral oil by the "contact" process. In general, the contact process for treating oils consists of heating and agitating a mixture of oil and finely divided adsorbent, the latter being subsequently removed by filtration. The term "adsorbent" is used because, although there has been a great deal of controversy over the mechanism of removal of impurities from oils by mineral matter, there is no doubt that adsorption, which involves the surface of the solid, plays a major part.1 The properties that make fuller's earth useful in the treatment of petroleum products by "percolation" and in the purification of edible oils by the contact process have long been studied, but the comparatively recent adaptation of the contact process to the bleaching of petroleum products has made desirable the further investigation of fuller's earth and other adsorbent earths.

Jan 1, 1929

By Walter Nummela

INTRODUCTION By the end of 1979 pellet productive capacity from the processing of low grade iron ores in the Lake Superior-District will total 86 million tons per year. Of that tonnage, 72 million result from the processing of magnetic ores such as taconite, about 6 million tons from the flotation processing of relatively coarse grained specular hematite, and 8 million tons from the processing of fine grained non- magnetic ores at Tilden. The Tilden flowsheet represents a break- through in the processing of this type of crude ore and hence is unique in the Lake Superior District (1). Operations at Tilden started in late 1974 with Algoma Steel, J&L Steel Corp., The Cleve- land-Cliffs Iron Company, The Steel Company of Canada, Ltd., Wheeling- Pittsburgh Steel Corp., and Sharon Steel Corp. as participants. Cleveland-Cliffs operates and manages the operation. Other companies have conducted extensive pilot plant tests or are in commercial production in the processing of fine grained non-magnetic ore materials (2). Flowsheets and reagent schedules may be different for each particular application, but some of the problem areas in the processing of Tilden ores have also been experienced at operations such as the IOC Plant at Sept-Isles, at Lamco and at Bong in Liberia, and in pilot testing of Fabrica ores of Ferteco Mineracao in Brazil. With a grind of about 80-85% -500 mesh resulting in 50% of the particles in the concentrate being less than 15 microns, a discussion of the pro- cessing of Tilden type ores fits the topic of this workshop. There are very large tonnages of fine grained non-magnetic crude ores which exist throughout the Lake Superior District and other iron ore producing regions. These fine grained non-magnetic materials constitute an important source of iron minerals. Before going into specifics of the flowsheet, it is important to

Jan 1, 1979

By Hjalmar W. Johnson

IT has long been accepted that blast-furnace practice varies to some degree with the coke used. While the qualities desirable in iron have been known for some time, the qualities in coke that produce such iron have not been established. There are no objective standards for blast-furnace coke, which is usually described in general terms, as good or bad. Many experienced operators believe that coke cannot be measured objectively except by using it in the furnace, noting the result, and labeling the coke according to furnace operations. This is admittedly unscientific, and besides is useless for the two main purposes for which a measure of coke quality is needed: (I) to produce the best possible coke from the coals and equipment on hand; (2) to test new coals and determine their value for blast-furnace coke. In seeking such an objective measure, much work has been done on tumbler tests, shatter tests, sizes of coke, porosity, specific gravity, reactivity or combustibility and other tests, but as yet very little has been published in which conclusive correlations have been established between such objective measures and furnace operation. In our study of the problem during the past 8 years we have developed no new measures of coke quality, but we have collected data that are presented here in the hope that they may assist in further work, so that at some future time there may be developed such positive measures. The purpose of this paper is to show that there are variations in coke and that such variations do influence the operation of blast furnaces. At the same time we must remember that there are variations in blast-furnace operation and it may be the blast furnace that is at fault. This correlation of coke properties with blast-furnace operation will be worked out in the following steps: I. Discussion of a period when a change in the coke resulted in an increase in efficiency on one furnace and a decrease in efficiency on another. 2. Adaptation of the inefficient furnace to the available coke so that normal efficiency was restored. 3. The use of radial distribution: a discussion of the effect of size of ore layer in adapting blast-furnace operation to the coke. 4. An example of a change in size of coke and the detrimental influence on the production of one furnace. 5. An example of a change in size of coke, together with manufacturing data, to show why it changed, the conclusion being that coke is a product with an optimum value. 6. Illustration of the fact that coke has different optimum values on two furnaces, with discussion on adaptation of operation so the optimum values will be the same. 7. Limitations of the use of screen tests as an objective measure of coke quality. 8. Importance of uniformity in coke. FUNCTIONS OF COKE AND QUALITIES REQUIRED TO PERFORM THESE FUNCTIONS Coke has three important functions in a blast furnace: (I) to furnish most of the

Jan 1, 1941

By John Johnston

ONLY two of the Institute's 26 Local Sections were unrepresented at the delegates' three sessions, held on Monday morning and afternoon and Thursday afternoon of the annual meeting. The Philadelphia and Wyoming Sections alone sent no delegates. In all, seven hours were spent most profitably in reviewing the work done by the Institute at headquarters and in the field, comparing ideas and practices in varied activities, and in establishing personal contacts. Cordiality and the co¬operative spirit marked the meeting and apparently no one had any serious grievances to air. Four motions were introduced and unanimously passed. The first, which was introduced by B. L. Sackett, was a recommendation by the delegates that a national committee be appointed to cooperate with Local Sections in the matter of student activities, to promote Institute welfare. It was agreed that this recommendation be made simultaneously to the Board of Directors and to the Mineral Industry Education Division. A subsequent resolution by A. M. Smith was passed asking that a part of the duties of this committee be to secure the opinions of Local Sections as to the most desirable methods of interesting students in the preparation of technical papers, by giving prizes or otherwise, and to report their findings at the Section Delegates' meeting next year.

Jan 1, 1933