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By G. F. LOUCHLIN

A FEATURE of the International Geological Congress to be held at Pretoria, South Africa, in the summer of 1929,. will be a symposium on the gold resources of the world. In this connection the U. S. Geological Survey and Bureau of Mines have been asked to prepare a report, showing production in the United States, describing the geology of its principal gold- producing districts, and estimating reserves (a) assuming a continuation of presen6economic conditions, and (b) assuming lower costs. This report will not be completed before April 1, but data thus far assembled are here presented with the hope of profiting by discussion and by information from those well informed on any of the important gold-producing districts. Gold production in the United States rose to a maximum exceeding $100,000,000 in 1915 and then rapidly declined to about $52,000,000 in 1920. Since then it has fluctuated, but on the whole slightly declined. Reviews of the eight leading states afford the following tentative conclusions :

Jan 1, 1929

Prof. H. S. Munroe, New York City : In his reference to cop per-dressing at Lake Superior, p. 325, Mr. Douglas says that " the .. concentration .. . has been carried out with greatest financial economy,... I do not say with the greatest economy of min eral." And again, on p. 344, referring to the same, " it would not pay to reduce the quantity treated, and increase hand-labor, in order to save a few hundredths of one per cent. of copper." Mr. Douglas probably has in mind the fact that the copper lost is all included copper, locked op in grains of sand. To save this, the rock must be crushed finer. If the mesh of the stamp-screens be reduced, the stamps will crush less; and thus we shall have to reduce the quantity treated in the mill per day, while the labor re mains the same per day, or is increased per ton, as he says. Submitting to the loss of copper, however, is not the only solution of the difficulty. A large quantity of rich sand is now collected by the jigs, and it would be easy to save so much of this material that the escaping sands would be quite poor. What is wanted at Lake Superior, and at many dressing-works in this country, is an efficient crushing-machine to treat the sands thus collected. Abroad, we have the Heberle machine and the Schranz mill for this purpose, the latter being the more successful. The Heberle grinder was tried at the Calumet and Hecla mill for crush ing these rich sands, with what success I do not know. I should like to ask Mr. Douglas if we have no American crushing-machine that will reduce jig-sands to a fine state of division

Jan 1, 1894

By Van Dyne Howbert, Fred E. Gray

The Presidio mine of The American Metal Co. of Texas is situated 45 miles south of Marfa, Texas, a town on the Southern Pacific R. R., and lies approximately 20 miles north of the Mexican border. Communication with the railroad is maintained over a state highway. All supplies for mine and mill are hauled in by truck from Marfa and precipitates and concentrates are freighted to the railroad by the same means and shipped to Selby and El Paso, respectively. The mill is at the town of Shafter, 1 mile from the mine and at approximately 350 ft. lower elevation. The ore is conveyed to it by an aerial tramway which requires practically no power on account of the difference in elevation. The mill is a countercurrent decantation cyanide and gravity concentrating plant of 200 tons daily capacity. Coarse and fine crushing are done at the mill. Two neal-by shallow wells in the bed of Cibolo Creek furnish an abundance of water. Power is generated for the mill and town by a Diesel engine plant. Ore Treated The ore is oxidized and siliceous. The greater part contains approximately 16 oz. of silver per ton, but mixed with this are many particles of ore of much higher grade, assaying in many instances 100 oz. or more. In the 16-oz. material there is an almost constant amount of silver which is difficult to recover by cyanidation. The high-grade material contains a much greater proportion of silver which is easily amenable to cyanide treatment. Thus, as the grade of ore becomes higher, the percentage of recovery of silver increases rapidly, under equal milling conditions. The silver minerals contained in the ore are principally argentite and cerargyrite, the former predominating The lead minerals, all of which are argentiferous, are chiefly cerussite and galena, with occasionally a little anglesite. The gold is free; most of the ore contains merely a trace

Jan 1, 1935

By A. C. Rubel

WHAT does management expect of W and from an engineer? First and foremost, it expects that he should become, and therefore should fit himself in every way to be, a part of management so that he may assume as much and as many of the responsibilities of management as his ability and the opportunities of the job permit. Let me make clear at the start that the profession of pure, technical engineering offers but limited opportunities at the top levels because of the inherent organization of engineering work. The line of succession to top jobs may be likened to a cone with a broad base and an extremely sharp point. Consider any oil company, large or small, or any operating function of that company, and you will find few top engineering jobs in the organization. This is true by the nature of the work handled. There will be a few district engineers depending on the spread of operations, a chief petroleum and production engineer, perhaps a few research engineers, possibly some technical executive assistants, and that is usually all. The road to these jobs is a long one and the competition is tough. The larger the organization the greater the opportunity, but always the ratio of engineers to top engineering jobs is only a small one.

Jan 1, 1947

By Kenneth Seaver

It is rather gratifying that in the field of the manufacture of refractories, in which, as a whole, foreign practice has surpassed us, the United States stands pre-eminent in the making of silica brick. In some instances European manufacturers have refused point-blank to credit the possibility of making to such specifications as are Common with us, until the actual completed shapes were shipped for inspection. But both the manufacturer and consumer in foreign lands are now frankly learning from us, and benefiting by our advanced practice in this field, as is evidenced by the orders placed here and the efforts put forth abroad to come up to the standard of American-made material. In no metallurgical operation has the employment of silica brick spread with such leaps and bounds as in the building of plants for the carbonization of coal, particularly in the byproduct coke oven. Today, in practically all types of oven, the structure above the floor level (except the facings) is of silica, while in the recuperative and in some regenerative types, its use is extended to that portion of the oven below the floor as well. By reason of the fact that there are a number of classes of refractories of higher silica content than the usual so-called fire-clay brick, there is sometimes a misunderstanding as to the class of material referred to as "silica" brick. We here refer only to a brick having a silica content of 94 per cent. or more and made usually from quartzite rock with a small percentage of lime as a binder. The term "silica" brick is sometimes rather loosely applied to brick from highly siliceous clays, or to a quartzite refractory of mingled fire-clay and quartz rock; but such products are not considered in this discussion. : Materials The rock from which practically all high-grade silica brick are made is a true quartzite or metamorphosed sandstone, variously known as

Jan 1, 1916

By H. Le Chatelier

An evident connection exists between chemical and calorific phenomena: the most important, of our sources of heat, the combustion of coal, is nothing else than a chemical reaction. Not satisfied with this indefinite statement, investigators have attempted to establish a more precise correlation between these two orders of phenomena, and have questioned whether there be not a necessary connection between the possibility of a chemical reaction and the algebraic sign of the quantity of heat which it would call into play (i.e., liberate or absorb). This question possesses the highest interest for metallurgical chemists. But the study of it by experimental methods only could not completely elucidate it. To arrive at a definite solution, it was necessary to appeal to a science much more general than chemistry,—namely, that of energetics, which embraces all the physical sciences. We can place absolute confidence in its conclusions, because they rest upon a proposition which can scarcely be denied, namely, the impossibility of The main facts in the history of the development o‡ this field of Triassic coals have been already set before the Institute in the papers of Mr. Oswald J. Heinrich, a former member of the Institute and the superintendent of the mines at Midlothian. † From these and other references to the field, it appears that coal was known to exist here as early as 1701; for on the 10th of May that year Colonel Byrd reported to the Colonial Council of Virginia the discovery of coal. Coal was mined from 1770 to 1780; but the amount shipped is unknown. It was much used in Richmond at this early date for gratefires. In 1789 shipments were made to northern ports. During the first half of the century just passed, mining operations attained in this field their greatest development, the number and extent of the collieries and the tonnage of coal raised per annum being greater for that period than for any similar period since. The maximum annual output exceeded 100,000 tons, while in two years only since the Civil War has the amount of coal raised exceeded 50,000 tons. This field covers about 150 sq. in. Its outline and the position of the strata in which the coal-outcrops occur are shown on the accompanying map, reproduced from the latest survey by the U. S. Geological Survey. Mining has been carried on along the margins of the area, often in the primitive manner in vogue at the beginning of operations, by means of shafts and slopes, usually too small in cross-section to permit the proper working of the beds. Most of the output has been won from

Jan 1, 1902

By H. W. Morse

THE CHAIRMAN (H. W. MORSE).-Gentlemen, for the first time in the history of the American Institute of Mining Engineers, we have a full session on the subject of leaching-especially on the leaching of copper ores.. This branch of metallurgy is rather in its infancy. We have had one big plant running for a year or more, and pretty successfully; and another one which will be started in February or March, the New Cornelia. We have another one at Garfield for the Utah company, which is just designed and construction begun; and from several other points come reports of interesting test work. The first paper on the program this evening is one of some of the test work on the New Cornelia ore by myself and Mr. H. A. Tobelmann. LAWRENCE ADDICKS, New York, N. Y. (written discussion).-The Ajo proposition has had, as I understand it, two great advantages: it has not been obliged to measure leaching against flotation or some other metallurgical process, and it deals with a copper content high enough

Jan 12, 1916

By D. Moskowitz

IN the course of a general investigation of boride systems, sponsored by the Office of Naval Research, various vanadium boride powders of relatively good purity were prepared which could be used for a determination of the phases present. The X-ray pattern of one of these lots showed, in addition to the known VB1 and VB22 phases, an additional phase, almost certainly of composition V3B4, isomorphous with Cr3B4, Cb3B4, Ta3B4, and Mn3B,. Its pattern fitted in well with the indices worked out by Kiessling for Mr3B4.3 The unit cell for this new compound is orthorhombic, with the dimensions a = 3.030A, b = 13.18A, c = 2.986A7 V=119.2A.' Table I lists the X-ray diffraction data for V.3,.

Jan 1, 1957

By Robert G. Woolery, S. Ramachandran, James A. Weber, Donald J. Hansen

Union Carbide began looking seriously at heap leaching in 1971. At that time some 1.6 million tons of mineral averaging 0.40 kg U3O8 /t) (0.80 lb U3O8) were stockpiled at various sites around the Gas Hills, Wyoming, uranium facility. Several alternatives for economically exploiting these reserves were considered and heap leaching seemed the most attractive. At the time, Western Nuclear Inc. was operating a heap leaching project nearby in which the low-grade ore was leached with sulfuric acid, the product liquor treated in an on site solvent extraction circuit, and the stripped product liquor re-acidified and recycled. The operators were most generous in allowing us to visit their site and in answering our questions. They were also helpful in discussing the problems associated with heap leaching. Their experience confirmed our belief that it was possible to operate a heap leach profitably on material too low grade for conventional milling. Based largely on what we had learned from Western Nuclear's experience, we undertook a program involving a laboratory study to determine the characteristics of the mineral stockpiles, as related to heap leaching, and to conduct a pilot heap leach adjoining our Gas Hill mill. Basically the pilot heap construction and leach procedure were similar to those described in the literature l, 2 with certain modifications to permit detailed monitoring of the operation. In May 1972, the decision was made to construct a test heap. The UCC plant at Gas Hills, Wyoming was selected as the most appropriate site for the following reasons: (1) The necessary equipment for heap construction was readily available. (2) Stockpiles of mineral from the various mining sites were on hand: (3) Construction of the heap could be made on an abandoned tailings pile minimizing problems associated with environmental approval. (4) Proximity of the mill would allow product streams to be absorbed into existing circuits. (5) Necessary utilities were available. (6) Tailings water from the existing circuit could be used for leaching. A program for the pilot heap leach was developed with the following primary objectives. (1) To confirm the data obtained in bench-scale tests particularly on uranium recovery, acid usage, and ore permeability. (2) To evaluate plastic liners used for base preparation. (3) To investigate heap configuration variables. (4) To determine heap leach amenability of the different mineral sources. (5) To establish the economics of heap leaching low-grade ores.

Jan 1, 1979

By F. G. Cottrell

AS previously announced, Van. H. Manning has resigned as director of the Bureau of Mines, effective June 1, to become director of research with the newly organized American Petroleum Institute. Doctor Manning has been connected with the Department of the Interior for 34 years, having been civil engineer with the Geological Survey, from 1885 to 1910, previous to his connection with the Bureau of Mines which was organized in the latter year. Doctor Manning was appointed to an administrative position in the new Bureau under Joseph A. Holmes, its first director, and on Jan. 1, 1911, was made assistant director. On Jan. 1, 1914, when Doctor Holmes had to relinquish active

Jan 1, 1920

By Rollin E. Hook, Attwell M. Adair

The response of CrzO3 and C~304 to various heat treatments was studied in are-melted iodide chromizim over the temperature range 1000" to 1750°C. These oxides, which are present as impurity phases in this material, were identified by X-ray diffraction teclzniques which were supplemented by optical metallop-aphy. As a function of increasing temperature, Crs04 is first observable in samples annealed at 1300°C and coexists with Cr2O3 (the low-temperature oxide) over a temperature range exceeding 200°C. As the temperature decreases, Cr3O4 dissolves with the concomitant precipttation of Cr2Y2. Both oxides precipitate predominantly at pain boundaries. The reactions which occur are involved with at least ternary equilibria, possibly due to iron which is present as an impurity in arc-melted iodide chromium. HILTY, Forgeng, and Folkman' reported in their investigation of the Fe-Cr-0 system that Cr3O4 (with about 8 pct Fe substituted for chromium) is a primary phase found in alloys with 9 or more pct Cr. They reported that this phase is stable only at high temperatures and that below the liquidus Cr3O4 is disproportionated into Cr2O3 and chromium-rich metal for both Fe-Cr-O alloys and in oxygen saturated pure chromium. Further, they proposed that CrsO4 forms by a peritectic reaction between Cr2O3 and the liquid. On the other hand, Hook, Garrett, and Adair2 found in their investigation of impurity phases formed in "pure" chromium (material consolidated from iodide chromium crystals) that Cr3O4 forms intergranularly and is stable as low as 1500°C which is 375OC below the melting point of chromium. The purpose of the research described herein is to determine the temperature range of stability of Cr3O4, and to show the nature of its decomposition. This further investigation indicates that Cr3O4 undoubtedly occurs in this material as low as 1300°C. The chromium studied was consolidated and fabricated from iodide chromium crystals (ICr-5) and contained Fe r 135 ppm, Si = 20 to 100 ppm, and 0 = 35 to 137 ppm. A complete chemical analysis is given elsewhere.' Annealing was conducted in 1 atm of purified helium and all samples were rapidly cooled (-200°C per sec) by withdrawing them from the furnace hot zone under a high flow rate of helium. The details of the electrolytic-etching technique and electrolytic-digestion techniques for preparation of insoluble residues for X-ray examination are given elsewhere also.' EXPERIMENTAL RESULTS The Starting Material. The as-swaged rod (final swaging done at 900°C) had a wrought grain structure and contained a dispersion of CrzO3 inclusions of maximum particle size of about 2 or 3 p, Fig. 1. The microstructure also contained a dispersed

Jan 1, 1964

By Leroy A. Palmer

All the domestic production of magnesite during 1925 came from two states, California and Washington. Of a total of 120,660 tons of crude ore, 64,600 tons, or 54 per cent., were produced in California.' Of this quantity California produced about 99 per cent. of the caustic calcined, but only 10 per cent. of the dead-burned. The largest producer was C. S. Maltby, of San Francisco, who operated the Red Mountain mine, in Santa Clara County, and the Sampson mine, in San Benito County, under lease. These two mines have been studied by the author, and offer interesting comparisons as to mining and treatment methods and final products. Geology The general geology of the magnesite deposits of California has been described by Hess,2 Bain3 and others4 and although a detailed discussion is not necessary here, a brief summary will assist in understanding mining conditions. California magnesite, when comparatively pure, is usually a white, fine-grained rock, with a conchoidal fracture, occurring in veins and lense-like masses in serpentine. The veins vary considerably in width, and usually occur in a series of more or less parallel veins intersected by other series or systems of veins, probably following original or secondary fissures in the enclosing serpentine. The most generally accepted theory of origin is that the magnesite was formed by the action of surface waters charged with CO2 percolating downward through fissures and changing the magnesium silicates of the serpentine into magnesium carbonate.

Jan 1, 1927

Edward Payson Mathewson EDWARD PAYSON MATHEWSON, President of the American Institute of Mining and Metallurgi-cal Engineers, was born in Montreal, Canada, Oct. 16, 1864, of Scotch-Irish ancestors. After preparation in private and public schools, he graduated from McGill University with the degree of Bachelor of Applied Science, in 1885, having specialized in mining engineer-ing and metallurgy. He spent the succeeding summer as a surveyor with the Canadian Geological Survey, being employed in the lake region of Ontario. The following spring he left Canada for Colorado, where he immediately obtained a position as assayer with the Pueblo Smelting & Refining Co. Within three years he became superintendent of the plant, and his success in this position brought him to the attention of the Guggenheim family, whose employ he entered in 1897. He was first in charge of their Pueblo plant, but was soon transferred to their refinery at Perth Amboy, N. J. During the succeeding five years he was in charge of important smelting operations conducted by the firm in Mexico and South America. In June, 1902, Mr. Mathewson accepted a position at the Washoe reduction works at Anaconda, soon thereafter becoming manager of the property. It is unnecessary to recount the improvements and enlarge-ments instituted at that plant under his management, until it became the Mecca of all metallurgists visiting the United States. The esteem in which Mr. Mathew-son was held, not only by the men directly under him, but by all his fellow citizens, was expressed in a send-off such as probably no other plant manager has ever received, when he left Anaconda in October, 1916, to accept the general managership of the British America Nickel Corporation, at Nickelton, Ont., Canada. Soon thereafter Mr. Mathewson accepted an appoint-ment as director of the American Smelting and Refining Co., acting as consulting metallurgist for the company and its subsidiaries. In November, 1919, he resigned this position and opened an office in New York City as a consulting metallurgist.

Jan 3, 1923

By K. N. Weaver

In the early 1950's the cement industry began putting a new emphasis on geology. This article points up some of the industry's raw materials problems that geologists are uniquely qualified to handle. Portland cement can be made from relatively abundant industrial minerals and rocks, and this may explain why cement producers placed little emphasis on geology during the early days of the industry. After World War 11, however, the industry began to recognize the need for geological exploration and some of the larger companies began to build a permanent geological staff. This development has its roots in: 1) The rapid expansion of the industry. After World War II and continuing into the early 1950's the demand for cement far exceeded the production capacity. This placed a great deal of pressure on the producers to enlarge capacity at their plants and to develop new sites. 2) The closing of many cement plants due to inadequate raw materials. Producers feared lack of raw materials due to inadequate exploration and evaluation. 3) An ever increasing pressure for upgrading of the quality of portland cement, necessitated upgrading the quality of raw materials. 4) The increasingly large capital investment needed to build new cement plants required a higher degree of accuracy in reserve calculation. These reasons are more or less self explanatory and will not be elaborated on. They are outlined to illustrate the probable evolution of thought among cement management to justify the development of a geological staff. In the author's personal experience the geologist must continually readjust to changing conditions within the industry. For example, cement production capacity grew so rapidly that today production is only about 70% to 75% of rated capacity (73.8% in 1963). Therefore, whereas the geologist's function during the active expansion of capacity was primarily one of exploration, one of his major functions today is the development of existing reserves. This assumes of course that reserves at existing plants have been proven to be adequate in terms of the company's reserve policy. Through the proper development of raw materials, the geologist can markedly influence quality control, production and long range planning. Examples of several of the operations of Medusa Portland Cement Co. will illustrate how proper attention to geologic detail pays off in the above areas. Because limestone is the major raw material of port-land cement, the examples will be concerned with it. DEVELOPMENT OF GEOLOGIC DETAIL One of the prime objectives of an exploration or development project should be the establishment of the stratigraphy and structure of the deposit. The basic tool for exploration and development is still the core drill, and the geologist must gain a maximum amount of information from a minimum amount of drilling. In order to obtain this objective the following is essential: 1) Adequate detailed geologic logging of cores. The core is first logged and separated into lithologically distinct units. In order to make the lithologic breaks as meaningful as possible, representative pieces of core (not all) are etched in dilute HCI. This removes the "drill polish", brings out the structure of the rock and indicates the proportion of dolomite and argillaceous material because dolomite and argillaceous material etch in relief. In this way the lithologic breaks become clearer and one gains a general idea of the chemical makeup before analysis. This method of logging lessens the probability of including two types of stone, e.g. limestone and dolomite into the same sample for chemical analysis. 2) Representative sampling for chemical analysis. After logging, the lithologic units are sampled for chemical analysis. A representative analysis can be obtained by extracting a 1-in. sample for every foot of core. For example, a lithologic interval of 10 ft to 20 ft would yield ten 1-in. samples taken at 11 ft, 12 ft, 13 ft... and 20 ft. These samples are then crushed, pulverized and split into a sample for chemical analysis. This sampling method represents a significant saving of time over splitting the entire core. 3) Preparing the core as a record. Because of the expense of storage and the difficulty of handling large amounts of core, only representative samples of each lithologic unit are saved for reference. An

Jan 1, 1965

By W. J. Reagan

THE problem of increasing output and decreasing percentage of rejections is a vital one in the manufacture of steel of any kind. The making of basic open-hearth steel for use in rolled steel wheels, tires for locomotive and car wheels, and forgings of various kinds, is a highly specialized industry. The increase in weight of railway rolling stock of all kinds, and the high speed that the public demands of transportation facilities, make it imperative that steel for use in this class of material shall be of the highest quality obtainable. During the past few years it has been the writer's good fortune to have opportunity-to study the defects in basic open-hearth steel, and also the results obtained by various changes in open-hearth practice, on such defects. The opportunity for study and the details available are rarely found in the manufacture of steel of any kind. It seems reasonable to assume that many of the results determined here can be applied to the production of steel of other types with a decided improvement in quality, a decrease in the percentage of rejections and an increase in output. All of the material described is basic open-hearth steel with the following range of analysis: carbon, 0.50 to 0.85 per cent.; phosphorus and sulfur, 0.04 coax.; silicon, 0.15 to 0.35; manganese, 0.50 to 0.75. All of this material is bottom-cast, therefore tapping and pouring temperatures are higher than in top-cast production. Ingots used in this type of work are of standard length with varying diameters. The ingot is known as duodecagonal, or twelve-sided. The standard body length is 88 in. and the hot top length, 14 in. Fig. 1 shows a typical ingot of this type. The diameter varies from 13 to 30 in. Ingots for special forgings, which cannot be made in molds of standard size, are made in molds of various sizes and designs. These ingots are sliced cold, into blocks of various lengths, depending upon the weight of the forging to be made. Fig. 2 shows the ingot-after coming from the slicing lathe. Just sufficient metal remains between blocks to hold the ingot in one piece while it is being removed from the lathe; then steel wedges are inserted between the blocks and the blocks are broken apart. This affords abundant opportunity for inspection, as the interior of the

Jan 1, 1930

By Grover R. Castle

INTRODUCTION "Project Financing" or "Project Loans" have become increasingly popular in recent years, and commercial banks are being asked to consider more and more of such financing. However, the analysis of this type of loan is quite different from the analysis of a loan to a financially sound corporation based on the company's balance sheet. For this reason Chemical Bank did a study of project loans in an attempt to be more sophisticated in our approach to them. As part of this study, we examined 29 project financings for which information was available. In this article I shall describe project loans and set forth the guidelines we developed, as an aid to credit officers who might have occasion to analyse this type of financing. DEFINITION OF "PROJECT FINANCING" OR "PROJECT LOAN" The terms "project financing" and "project loan" commonly describe the various methods that banks and institutional lenders use to finance the construction of new projects on a basis whereby payout is anticipated from the revenue stream generated by the project. A project financing often involves a loan to a new entity formed specifically to own the project. The analysis of a project loan proposal is quite different from the analysis of other term-loan proposals since it involves a credit decision based on the review of a projection or forecast rather than of historical earnings and/or it involves the reliance on contractual obligations of third parties. Lenders are asked to assume the added risks associated with project loans because: 1. Project financing may permit a company to obtain additional leverage. It is possible for companies to arrange financing on a project basis that could not be arranged as a direct borrowing. For example, a company may not be permitted to borrow more money directly, due to a limitation in a bond indenture. However, a project financing can sometimes be negotiated on a basis not prohibited by the indenture. 2. Often the sponsors of, or the stockholders in, the project are seeking an off-balance-sheet financing. For example, 11 of the 29 projects in our study were arranged on an off-balance-sheet basis and one showed on the balance sheet as a deferred income item. An off-balance-sheet financing, for the purpose of this article, is a financing which does not show as a direct liability on the balance sheet of the sponsors of or stockholders in a project. 3. Projects are often located in a foreign country. The financing is arranged so that the lenders assume the political risk on the loan because many companies rightly believe that this arrangement affords a degree of insulation from political risk not otherwise obtainable. 4. Many projects are jointly owned by several sponsors. This form of financing lends itself well to a situation where a new entity is formed to own a project and do the borrowing. Project loans can be used to finance a variety of activities including development of iron-ore deposits and associated pelletizing plants; development of coal reserves; construction of pipelines, alumina plants, fertilizer plants and refineries; etc. The specific areas of analysis can be quite different, depending upon the type of project being financed. It is important, therefore, to classify the proposal according to the type of project, and also by the nature of the financing - nonrecourse financing, financing covered by a guarantee of completion and financing supported by an undertaking lasting for the life of the financing. I will discuss each of these types in more detail later, but first, I should like to make some

Jan 1, 1985

By C. O. Burgess, W. D. Forgeng

DESPITE the increasing interest in and the technical importance of iron-chromium-manganese alloys, very little published information is available regarding their constitution. F. M. Becket's paper1 in 1930 represents the first correlated effort in the field of these alloys. The paper served particularly to draw attention to the commercial possibilities of iron-rich alloys containing chromium and manganese in balanced proportions. The duplex structure of alloys within the commercial range was briefly discussed, but exposition of their structural constitution was necessarily limited because the physical properties and corrosion resistance of the alloys were the main subjects of the paper. Both prior to and following the publication of F. M. Becket's paper, and at his instigation, an extensive investigation of the constitution of iron-chromium-manganese alloys of commercial purity was in progress at the Union Carbide and Carbon Research Laboratories, Inc. The present paper is based on the results of that investigation. In the last few years, investigations covering various portions of this alloy system have also been made in Europe. W. Koester briefly mentioned the effect of annealing on chromium-manganese steel2 and later3 constructed approximate sections of the iron-chromium-manganese equilibrium diagram. M. Schmidt and H. Legat14 even more recently studied this system, and their article and conclusions are of interest as representing an entirely independent study of a number of iron-chromium-manganese alloys. Koester's sections are shown in Fig. 1. The figures summarize the effect of manganese additions to iron alloys containing 5, 10, 15 and 20 per cent Cr as well as the effect of increasing chromium content on iron alloys containing 3, 8, 20 and 30 per cent Mn. These diagrams, within their composition limits, substantiated in some measure the results of our investigation. However, in our work some differences as regards the position of the mixed alpha-gamma fields were found as compared to Koester's work, and we were able to detect the presence of

Jan 1, 1938

By Rodney Lawrence, Tim Hackett

INTRODUCTION The western USA contains significant coal reserves in seams 10 feet or more in thickness which lie too deep for surface mining. As part of a demonstration of the use of two legged shield supports in the United States, Kaiser Steel Corporation, under contract to the US government used the longwall method to mine a ten foot thick coal seam in New Mexico. Caliper type shield supports and double drum shearers were used in three longwall panels. During the test, technical, production, and safety data were collected to objectively evaluate the performance of the shields in mining the thick coal seam. This paper presents discussions of practical operating experience and summary statistics to aid the mining industry in planning longwall mines in similar conditions.

Jan 1, 1981

By Robert Glass Cleland

IN gathering material for this book, I have made extensive use of the archives of Phelps Dodge, contemporary news- papers, and a wide range of secondary sources. Two manuscripts-one on the history of Phelps Dodge by Arthur Train, Jr., and John L. Lawler, the other a biography of William E. Dodge by Richard Lowitt-have been of the greatest value. I owe a particular debt to the authors whose names I have just mentioned. I have also gathered important information and obtained revealing points of view from conversations with many people. Personal visits to the company's mines and plants added knowledge and understanding that nothing else was able to supply. I am greatly obligated to the officers of the company, especially to Mr. Louis S. Cates, chairman of the board of directors, Mr. Robert G. Page, president, Mr. George R. Drysdale, vice-president of Phelps Dodge Corporation, and Mr. Walter C. Bennett, president of Phelps Dodge Refining Corporation, for their co-operation and assistance. Mr. Wylie Brown, former president of Phelps Dodge Copper Products Corporation, also supplied valuable data and deeply appreciated hospitality. In my visits to the Phelps Dodge properties, company representatives extended every hospitality and placed at

Jan 1, 1952

By AIME AIME

THE 129th meeting of the American Institute of Mining and Metallurgical Engineers convened at New York City, in the Engineering Societies Building, Feb. 18-20, 1924. On February 21 an excursion was made to the Bethlehem Steel Co., at Bethlehem, where about 200 members and guests were splendidly entertained. An illustrated description of the Bethlehem Plant will be published next month. The meeting and excursion were largely attended; the registration at New York totalled 1276 versus 1201 in 1923. William Kelly, long identified with the iron-mining industry of the Lake Superior district, was elected President of the A. I. M. E. for the coming year, at ,the annual business meeting, Feb. 19, succeeding E. P. Mathewson. The following Directors were also elected (the date signifies year of termination of office; the final figure indicates the "District" the Director represents).

Jan 1, 1924