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By W. E. Keck

THE potential iron ores of Michigan can be classified from the stand-point of the predominant impurities into siliceous, sulphurous and phos-phorous ores. Research on the flotation of each of these classes of ore was carried out in the following Planner. The flotative properties of the valuable minerals of iron and of the worthless and deleterious ones were first determined under carefully controlled conditions. This information was then applied to synthetic mixtures of these minerals, which simulated the potential ores. Finally, data obtained during the two foregoing stages of the investigation were used in the flotation beneficiation of samples of the potential ores. Hematite is the most important mineral of iron in each of the above classes of iron ores. This paper deals with a study of that mineral in the very nearly, pure state. There are two varieties of the mineral-specular hematite and massive hematite. The latter is the principal variety, but the former is an Impor-tant mineral of iron in some of the potential ores. Because of this condi-tion, flotation research was performed with both varieties. This research consisted essentially of: (1) a survey of the literature on hematite flota-tion, (2) the preparation of pure massive hematite, (3) the preparation of pure specular hematite, (4) the; development of a laboratory procedure and (5) flotation experimentation. For the purpose of this discussion, the results of previous work on the flotative properties of hematite can be summarized as follows: Specular hematite has been readily floated with terpineol and sodium oleate or heptylic acid1. Further, hematite has been likewise floated with a pro-prietary frother and oleic acid or other soluble oils 2. Finally, lead nitrate, copper sulphate, silver nitrate, chromium nitrate, mercuric chloride, ferric

Jan 1, 1937

By G. H. Clevenger

THE reagents now used in flotation consist of various acids or salts, which may be either electrolytes or non-electrolytes, dissolved in water and some substance or combination of substances which function as collecting or frothing agents. At times the only dissolved salts present are those naturally occurring in the water used. The general effect of the electrolyte is to greatly sharpen the separation between the gangue and the concentrate. Examples of this are: The use of sulphuric acid with zinc ores; and of sodium carbonate or calcium oxide (line) with silver-gold ores. Crude pyroligneous acid is also sometimes used when available. Various oxidizing agents, such as permanganates, bichromates, etc., are added in the selective flotation of lead-zinc ores. Many other reagents for performing certain specific functions, either real or imaginary, have been proposed, and a number of them have been tried upon a working scale. The wild orgy of experimentation which is now going on in flotation exceeds even that which followed the introduction of the Washoe process for the treatment of Comstock ores, when, among other things, sage-brush tea and tobacco juice were reagents added to the pans. Out of all this will, of course, eventually come a more or less standard practice for the treatment of each class of ore. Omitting a discussion of the functions of frothing and collecting agents, the reagents used in flotation for this purpose may be classified under five general heads: (1) Essential oils; (2) fixed or fatty oils;. (3) alcohols and their combinations with organic acids; (4) coal tar and its refined products; (5) petroleum and its refined products. A flotative agent of some kind is required in flotation as now practiced. A single reagent, as, for example, certain. of the essential oils, may perform the dual function of frothing and collecting agent, or a mixture of substances may be required.

Jan 9, 1916

By Dr. O’Neil Thomas J., Donald W. Gentry

Pure gold was hidden in the quartz, they said, 'Twas proved by dreams and signs, and rods divining, By chemic tests, and spirits of the dead, In fact by everything-except by mining. " from R.E. White, "The Mining Town," Alta California, August 18,1873 Textbooks in mining engineering have traditionally covered ore reserve estimation and mine valuation in a single volume. Indeed, Examination and Valuation of Mineral Property by R. D. Parks (1957), having been the standard of the profession for over 20 years, is a classic example. However, the state of knowledge in these two fields has grown tremendously. Most mining engineering curricula now cover these topics in separate courses, and in practice, these tasks are usually performed by different individuals. Thus, this trend now suggests the need for separate, specialized publications rather than a single volume for both topics. Because of the separate development of the science of ore reserve estimation, it is important to state at the beginning what this chapter does not cover. It does not address in detail the design of sampling programs, sampling methods, or the processing of samples or sample data compilation. There are a number of suitable references available on these topics, including Peters (1978), Gy (1979), as well as the previously cited book by Parks. Furthermore, this chapter does not cover in any substantial detail either the traditional methods for using sample data to calculate ore reserves or the more recently developed geostatistical methods. The traditional methods are thoroughly covered by Popoff (1966) and more concisely by Barnes (1980). Among the more useful references for statistical applications in ore reserve estimation are Barnes (1980), David (1977), and Clark (1979). A thoughtful review of the entire science and art of ore reserve estimation is provided by King, McMahon, and Bujtor (1982). In spite of the fact that expansion of knowledge now calls for separate books on ore reserve estimation and financial evaluation, neither publication can ignore the important interrelationships between the two fields. In regard to this text, the unique and crucial role of ore reserves can not be omitted entirely; however, the field is now simply too extensive to treat here in any comprehensive manner.

Jan 1, 1984

By E. G. Schempp, W. A. Morgan

The influence of modifications in the molybdenum, vanadium and, to a limited degree, carbon and boron content to a basic composition of 5 pct Cr, 0.75 pct Mo, 1 pct V hot-work tool steel composition, was studied in respect to hardenability, grpain- coarsening temperature, and tempering charactevistics. Tensile, impact, and fatigue pvoperties were studied for the most promising compositions. An alloy with a typical composition of 0.43 pct C, 4.97 pct CI-, 0.33 pct Si, 2.25 pct Mo, and 1.00 pct V uas found to offer the most favorable combination of properties in respect to high-strength applicntions when tempered at 1100°F. MANY 5 pct Cr high-strength steels are at present being manufactured in North America which fit well into the classification of the AISI-SAE system. Much interest has been shown in these materials as ultra-high-strength steels for use at elevated temperatures. The limiting temperature of use lies at the point where the steels begin to soften rapidly. Although a great deal of information has been made available in the past two years on the properties of selected alloys in this series, little information exists on the effect of systematically varying the ccntent of one or more elements in the 5 pct Cr-base alloy. This paper presents the results of an investigation of the effect of variations of the carbon, molybdenum, vanadium, and, to a limited extent, the silicon, manganese, boron, and niobium content of a 5 pct Cr steel to the AISI H-13 base analysis. EXPERIMENTAL PROCEDURE All experimental heats were melted in a 50-lb. induction furnace. The melting stock consisted of

Jan 1, 1962

By C. G. Rhodes, D. Kramer

The kinetics of precipitation of transient a phase during the transformation in U-16 wt pct Mo between 400° and 550°C were studied using quantitative metallography and electrica1 resistiuity measurements. The volume percent of a phase goes through a maximum in time, corresponding to a critical degree of progress of y' formation. prior to its re-solution after prolonged annealing. The fastest rate of a precipitation oc-cuvs at 500°C with a concomittant lowest peak of 9.5 vol pct a. At 450°C, 14 vol pct a, greatest fov any temperature, was observed after 24 hr witlz an associated slowest rate of formation. a precipitation at 400°C ceases after approximately 160 hr and the amount of a present remains unchanged after long times at temperature; no y' was observed metallographically at this temperature. IN the U-Mo system at 16 wt pct Mo, an ordering reaction takes place below 600°C, see Fig. 1, whereupon the random bcc solid solution, y, transforms to the ordered bct phase, y'."2 The new unit cell is constructed of three old unit cells somewhat distorted. While attempting to study the kinetics of this transformation it was observed that an unexpected phase was precipitating out early during the transformation anneal reaching appreciable amounts before disappearing after long times. The y' appeared in the presence of this new phase and after long times constituted the whole sample. Owing to the high optical activity of this unexpected phase under polarized light, it was suspected to be the a phase. Subsequent X-ray powder pictures confirmed this belief. The kinetics of a phase formation and disappearance is the subject of this paper. EXPERIMENTAL PROCEDURE A) Alloy Preparation. Alloys for this study were prepared by vacuum induction melting normal reactor grade uranium and 99.5 wt pct Mo pellets in thoria crucibles. Two ingots were prepared, and sections of the top and bottom of each ingot were chemically analyzed for uranium and molybdenum content. The results of the analyses appear in Table I. B) Metallography. Samples of 16M were wrapped in tantalum foil, sealed in evacuated (5 X 10"6 mm of Hg) quartz capisules, and annealed at 1110"C prior to being transferred directly to the transformation temperature. They were examined metallographically after increasing times to determine the progress of the transformation at 400°, 450°, 500°, and 550°C. The samples were prepared for metallographic examination by mechanical polishing with diamond paste and electrolytic polishing with a solution of glacial acetic acid and chromic acid. Since the y' phase is tetragonal, its presence can be detected by viewing the sample in polarized light. To increase the contrast between y' plates, the samples were electro-etched in a 10 pct oxalic acid solution. To reveal a phase in bright field (it can be seen in polarized light in the "as-polished" state), the samples were electro-etched in a solution of citric acid and nitric acid. To determine the vol pct a phase, a variation of the one dimensional systematic point count method as described by Hilliard and cahn3 was used. The

Jan 1, 1962

By AIME AIME

ON the morning of Monday, Nov. 9, 1936, two motorcycles, with sirens screeching, - escorted a procession of 70 automobiles from the Colonia Railway Station in Mexico City to the Hotel Geneve. Riding in' the cars were just over 200 visitors- members of the A.I.M.E. and their guests. They had come, via St. Louis, in two special trains from 24 different states for the 146th General Meeting of the Institute. During the morning they and 200 others, who had come from the United States by automobile or from various cities and mining camps in Mexico, duly registered with !efficient Mme. Irma Ordoiiez de Obregon and her assistants. Then started a week of strenuous but delightful activity that will never be forgotten by the participants. They were to cover more than 500 miles by automobile, always with a motor escort, and often

Jan 1, 1937

By Wiley C. Buford

Gary Works No. 1 BOP Shop is a three furnace shop which went into operation December, 1965. The heat size is over 200 tons, with a substantial percentage of the production used to feed a Continuous Slab Caster. Vessels are driven by a shaft mounted bull gear and main housing utilizing eight 35 HP flange mounted motors and primary gear reducers. Torque absorption is controlled by two spring actuated torque arms. At 1:00 p.m. on Thursday, August 6, 1970, as "E" furnace was being turned down for a preliminary test, the drive side trunnion bearing failed. The furnace dropped slightly and shifted several inches north in the direction of the drive unit. The decision was made to tap the heat which was done without incident and the vessel uprighted. No attempt was made to completely drain the slag from the vessel, so as to avoid any further damage to the trunnion shaft bearing surface. The bearing failure occurred approximately four years and eight months after start up of the shop. Unfortunately ?M? furnace had gone down for a normal reline two days prior to the bearing failure, leaving the shop with only one operating furnace.

Jan 1, 1972

By G. P. Boomslitter

In previous discussions on stresses in hoisting ropes, little has been said concerning the effect of the elasticity of the rope itself on the stresses due to acceleration. Laschinger1 has calculated acceleration stresses for several cases but he has ignored the elasticity of the rope as a factor, except as it compresses the drum and stretches itself as it winds thereon. He also deals with steam plants and he shows the effect of the "jerky" start of the engine. This effect would actually be reduced by the elasticity of the cable. With the advent of the motor-driven hoist, new conditions have arisen. The jerk mentioned by Laschinger has been eliminated and smoother starting made possible. But the elastic properties of the rope seem to introduce considerable periodic acceleration stresses in the rope. The following discussion of acceleration stresses is based on the assumption of a constant acceleration at the drum. To be exact, the mathematical work is based upon the assumption that the top is moving upward with a constant acceleration, and ignores the fact that the cable is shortening as it winds. However, the effect of the shortening would be inconsiderable during the first part of the acceleration period. Most hoisting engineers make the assumption of constant acceleration at the drum. Under the older method of calculating acceleration stresses, this would be true with a constant torque motor. But if stresses vary, as this paper attempts to show that they do, constant torque would not give constant acceleration, although the velocity-time curves obtained in the full size test herein described showed that they approach rather closely to this condition, at least as nearly as could be measured. Theoretical Discussion According to elementary physics, the force required to accelerate a Wf body of weight W at the rate of f ft. per sec.2 is wf . To raise the body Wf with acceleration of f ft. per see.2 the total force required is I + Wf, in if

Jan 1, 1927

By Frederick Laist

I AM APPRECIATIVE of the honor you have done me in electing me to membership in your Society. I value the contacts with men of imagination and ideals which this implies. I am grateful for the recognition of such small contributions as I may have made, or helped to make, to the vast fund of scientific and engineering knowledge. We like to think, as we grow older, that our lives have not been purely parasitical, and that through our efforts some forward step, however small, has been taken toward improving conditions under which we live and do our work. In these days of industrial depression, we hear much criticism of our "machine age." Modern engineering, mass production, the complexity of our lives, all come in for some share of blame. The farmer is said to have been spoiled by the tractor and the gang plow, the factory worker has become a slave of the assembly conveyor, the scientific worker is no longer free but has sacrificed much of his individuality to the research organization of which he is a part. We wonder whether our work as engineers has been worth while and whether our striving after more efficient ways of doing things has been a curse to mankind rather than the boon we thought we were conferring.

Jan 1, 1932

By W. M. Peirce, R. K. Waring

Zinc of high purity offers definite advantages in certain fields. A process by which zinc of 99.99 + per cent purity is produced by pyro-metallurgical methods is described in this paper. The process consists of a fractional distillation following the primary reduction; this fractional distillation employs the principles of rectification for the separation of lead and other high-boiling impurities and cadmium and other low-boiling impurities. Theoretical Considerations Involved in Production of High-purity Zinc by Distillation Fractional distillation, fractional condensation, and rectification are recognized methods of separating mixtures of liquids. In the field of organic liquids these methods are widely used but not commonly to effect as complete a separation of liquids as is done in the problem under consideration. Zinc boils at 905" C., cadmium at 778" C. and lead at about 1620" C. Zinc may contain from several hundredths of one per cent to over one per cent each of cadmium and lead, and the problem is to reduce these impurities to a few thousandths of one per cent. For lead and zinc, the spread in boiling points is substantial, 715° C., while for zinc and cadmium it is only 127" C. The basic limitation of any separation by distillation may be found from the relation between the equilibrium composition of the vapor and the liquid for all mixtures of the two substances involved. If a mixture of constant boiling point is found, or if a stable compound that vaporizes without dissociation occurs, there is a definite theoretical limit to the degree of separation that is possible when operating at atmospheric pressure with respect to that mixture. Otherwise, any degree of separation is theoretically possible. The equilibrium composition of vapor in contact with liquid mixtures of zinc and cadmiurn at the boiling point has been determined experi-

Jan 1, 1937

By Juanito C. Fernandez

INTRODUCTION The Philippines is endowed with mineral resources, much of which still remains unexploited. The country's known reserves, at least for the major mineral commodities, have increased every decade since the first major discoveries more than 80 years ago. Mining, therefore, naturally evolved as one of the pioneer industries and has ever since been a major factor in economic development. The Philippines has entered a new era in mineral resources development and management. One significant feature of this era is the degree to which the government is involved with the industry. In recent years, the state has increasingly encouraged the private sector to carry out detailed exploration aided by governmental contributions through extensive geological and geophysical surveys, fundamental researches and even indirect financial assistance in some specific areas. Significant changes in mineral resources development policies were brought about with the promulgation of Presidential Decree 463 or the Mineral Resources Development Decree of 1974. The Decree provides for a more rational system of administration and disposition of mineral lands to promote mineral resource exploration and exploitation. Various forms of incentives are provided. Foreign entities are allowed to participate in development through service contracts with leaseholders or with the government in the case of reserved areas. The thrust in mineral resources development has been focused on the base metals which as envisioned would provide the foundation for sound economic development. In recent years, however, major strides have been made to promote the exploitation of the non-traditionally produced commodities especially the non-metals. Development likewise point to the growing determination of the government and the private sector to expand benefits from mining. This is evident in efforts to promote downstream processing operations and to encourage investments in exploration, exploitation and mineral processing ventures. The integrated mineral resources development plan, therefore, proposes the vertical integration of mining extraction activities with the processing requirements of the metal-based manufacturing industries. While mining activities shall continue to be carved out by the private sector, the government shall influence the industry's direction by establishing legitimate goals to maximize benefits through an integrated approach giving due consideration to environmental protection and resource needs of future generations. STATUS OF MINERAL RESOURCES DEVELOPMENT Extent of Exploration Application of modem exploration tools and concepts complemented by intense infusion of foreign technology and rapid development of indigenous expertise have enabled the government jointly with the private sector to geologically explore vast grounds and to expand the country's known mineral resources. Approximately 93% of the country's total land area of 30 million hectares have been geologically mapped on at least 1:250,000 scale. Of the 93% total coverage, roughly 37.54% or 11.07 million hectares have been done on scales of 1:10,000 to 1:50,000 as shown in Figure I. Only 3.07% of the total coverage have been surveyed in detail. Land gravity surveys have been undertaken on over 45% of the total, while some 77,300 line km. of aeromagnetic surveys have been flown over 110,000 sq. km. of land area. Processing of data is almost complete. Total magnetic intensity and IGRF-corrected maps are available. Geological interpretation utilizing Landsat MSS imagery and low altitude aerial photography augmented by ground truthing have been undertaken in several large areas with very encouraging results. Beach and offshore mineral surveys were initiated in 1977 and have covered substantial areas in northwest and southeast Luzon and northeastern Mindanao. Highly promising areas for detrital magnetite, chromite, gold and some heavy minerals including ilmenite and titanium have been identified. In the petroleum sector, two offshore oilfields are currently producing from Miocene limestone reefs in Northwestern Palawan. Another field from the same area will be on stream in mid-1982.

Jan 1, 1982

By Allan T. Gwathmey, J. Bruce Wagner, Kenneth R. Lawless

Between 250°and 550°C in oxygen pressures of 10 to 760 mm Hg, the relative oxide thicknesses formed per unit time on the (100), (111), (110), and (320), decreased in this order. The predominant oxide orientation was (001)Fe3O4 and [110] Fe304 A small amount of a-Fe2O3 which exhibited a fiber pattern was observed in all oxides except those formed at 250°c in low oxygen pressures. IN order to understand the properties and behavior of thin films, particularly their role in oxidation reactions, there is needed more experimental information on their structure, composition, and kinetics of formation on clean surfaces of known geometry. The present study was undertaken to obtain such information for thin oxide films formed on single crystals of a body centered cubic metal, iron. Crystals in the form of spheres were used in order to expose all possible crystal planes to the reactant gases simultaneously. Using this procedure the relative rates of oxidation of all planes could be estimated, and those exhibiting, maximum or minimum oxidation rates could be selected for a more intensive study of composition and expitaxy. Since the three types of information were obtained from the same experiment using a single crystal substrate, any differences between rate, composition, and expitaxy on the several planes may be attributed to the influence of the substrate structure. EXPERIMENTAL The starting material for this study was Armco iron rods, 6 in. long and 3/8 or 1/2 in. in diam. The analysis was reported to be 99.8 pct Fe, with major impurities listed as carbon 0.018 pct, manganese 0.027 pct, phosphorous 0.005 pct, sulfur 0.029 pct, silicon 0.005 pct, and copper 0.11 pct. These rods were cleaned with ether and heated in an atmosphere of moist hydrogen at 950°C for three days. The purpose of this treatment was to decarburize the iron and to provide a consistent, uniform grain size for the growth of single crystals. Crystals in the form of rods, up to 1/2 in. in diam and 2 in. long, were prepared by a method similar to that reported by Leidheiser and Buck.2 Spherical crystals, 3/8 and 1/2 in. in diam and having a handle about 1/4 in. in diam by 112 in. long, were machined from the single-crystal rods. After machining, each crystal was etched in aqueous nitric acid to remove the cold-worked metal at the surface. Before each experiment, the crystal was polished mechanically with metallographic papers through number 4/0, and electropolished in a perchloric acid-acetic anhydride mixture by the method of Jacquet and Rocquet.3 The crystal was washed in running distilled water for at least 5 min. The excess water was blotted with a soft paper tissue, and the crystal was placed in an all-glass reaction vessel (See Fig. 1). The crystal was heated at 550°C in hydrogen for at least 8 hr prior to the oxidation in order to reduce any surface oxides and to help relieve any stresses in the metal. For the structure and composition studies, flat faces were cut parallel to (loo), (111), and (110) planes on the iron crystal spheres. The orientation of these faces was checked by a back-reflection X-ray diffraction technique. The faces were within 2 deg of the desired orientation. The flat faces were treated as described above except that prior to electropolishing they were given an additional polish on metallographic felt saturated with twenty-minute levigated alumina. After the crystal was heated in hydrogen for at least 8 hr, the temperature was adjusted to the desired value, and the hydrogen was evacuated. Commercial oxygen which had been purified by successively passing through tubes containing magnesium perchlorate, Ascarite and magnesium perchlorate was admitted to the desired pressure as measured by a mercury manometer. A resistance-wound furnace surrounded the oxidation chamber, and a temperature controller maintained the temperature within ±3°C. The furnace was provided with a small window for observing the crystal. The changes in thickness of the oxide films were followed by observing the interference colors. The oxidation was allowed to proceed until the desired oxide thickness was attained on a given crystal plane. The experiment was terminated by evacuating the oxidation

Jan 1, 1962

By Daniel R. Hull

In 1926 Gendersl reviewed the existing theories of this subject and stated his views in support of the gas-pressure theory. Again, in 1937, the subject was thoroughly reviewed by N. B. Vaughan3 and by Phillips and Brick,2 so that no résumé is called for here. The purpose of this paper is to describe certain observations made in the course of mill work, and to point out that they mostly tend to confirm the gas theory of Genders. Vapor Segregation There is, however, one type of inverse segregation that can be accounted for by considering the volatility of one of the constituents of an alloy. The most familiar case is ordinary brass, which is subject to a zinc enrichment of a few tenths of a per cent at the surface of a chill casting. This has been noted in 70-30 brass by Genders, and a typical example of it is given in Table 1, which represents a cylindrical billet 7 in. in diameter by 55 in. long. After lathe-turning 1/32 in. from the surface, the remaining distance to the center was sampled at six equally spaced intervals. the lead, which is essentially the same throughout, will be mentioned later. Consider a brass-mill mold, either round or rectangular in cross section, standing several feet high. It may require a minute or two for pouring. Before it is full, the metal in the lower end has partly solidified and contracted somewhat away from the mold. The initial shell of solidification follows not far behind the top of the column, even if the central portion is liquid for a long way down. There is, then, a space between metal and mold that is filled with zinc vapor. The vapor has no exit, because the liquid at the top of the rising column is not only in contact with the mold but keeps UP a fresh supply of zinc vapor, which has, perhaps, already begun to condense in the lower portion. The cycle is short. Within a minute or two after the mold is full the bar has cooled enough to condense all the zinc. Some of it may condense on the mold; it might be expected that most of it would condense there, but the mold at that time is well coated with a velvety carbon residue from the oil dressing, overlain by fluffy zinc oxide that commenced covering the inside of the mold as soon as pouring began. The clean skin of the freshly cast brass offers a preferred surface for condensation. Reabsorption is quick and inevitable. A simple experiment indicates that a surprisingly large quantity of zinc vapor is trapped in the space between mold and

Jan 1, 1941

By Daniel R. Hull

In 1926 Gendersl reviewed the existing theories of this subject and stated his views in support of the gas-pressure theory. Again, in 1937, the subject was thoroughly reviewed by N. B. Vaughan3 and by Phillips and Brick,2 so that no résumé is called for here. The purpose of this paper is to describe certain observations made in the course of mill work, and to point out that they mostly tend to confirm the gas theory of Genders. Vapor Segregation There is, however, one type of inverse segregation that can be accounted for by considering the volatility of one of the constituents of an alloy. The most familiar case is ordinary brass, which is subject to a zinc enrichment of a few tenths of a per cent at the surface of a chill casting. This has been noted in 70-30 brass by Genders, and a typical example of it is given in Table 1, which represents a cylindrical billet 7 in. in diameter by 55 in. long. After lathe-turning 1/32 in. from the surface, the remaining distance to the center was sampled at six equally spaced intervals. the lead, which is essentially the same throughout, will be mentioned later. Consider a brass-mill mold, either round or rectangular in cross section, standing several feet high. It may require a minute or two for pouring. Before it is full, the metal in the lower end has partly solidified and contracted somewhat away from the mold. The initial shell of solidification follows not far behind the top of the column, even if the central portion is liquid for a long way down. There is, then, a space between metal and mold that is filled with zinc vapor. The vapor has no exit, because the liquid at the top of the rising column is not only in contact with the mold but keeps UP a fresh supply of zinc vapor, which has, perhaps, already begun to condense in the lower portion. The cycle is short. Within a minute or two after the mold is full the bar has cooled enough to condense all the zinc. Some of it may condense on the mold; it might be expected that most of it would condense there, but the mold at that time is well coated with a velvety carbon residue from the oil dressing, overlain by fluffy zinc oxide that commenced covering the inside of the mold as soon as pouring began. The clean skin of the freshly cast brass offers a preferred surface for condensation. Reabsorption is quick and inevitable. A simple experiment indicates that a surprisingly large quantity of zinc vapor is trapped in the space between mold and

Jan 1, 1941

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

NEW YORK SECTION J. E. Johnson, Jr., Chairman Edgar Rickard, Vice Chairman. D. M. Liddell, Secretary, 7 Wall St., New York, N.Y. C. A. Bohn, Treasurer John V. N. Dorr Lewis W. Francis. The annual meeting of the New York Section was held on Wednesday, June 6, with about 40 members in attendance. The treasurer re a brief summary of-the financial statement for the year, and the secretary's report was read. These reports were ordered placed on file together with the report of the auditors for the two previous years.

Jan 8, 1917

By E. G. Leonardon, D. C. McCann

The search for oil has required, and without a doubt supplies, a tremendous amount of information on the structure, composition, physical properties, and history of sedimentary rocks. The earliest and most complete source of knowledge is the sample or core of the rock itself, the uses of which are well known. The purpose of this paper is primarily to discuss a new method for obtaining these cores, and to illustrate its use in connection with electrical logs. Most cores have been obtained through a special adaptation of rotary drilling, and the results have been remarkably good, considering the mechanical problems involved. Unfortunately, because of the time and expense, this method cannot be used for the entire length of the drill hole. Even though ingenious contrivances have been evolved in order to reduce the time spent in round trips, such as wire-line coring equipment, mechanical coring still remains too expensive to be carried out continuously. In practice, therefore, one is finally compelled to estimate the probable depths of the more interesting horizons and, allowing a wide margin of safety, to core through those sections only. It is true also that interesting results have been obtained by examining the cuttings brought to the surface by the mud circulated in the well during the process of drilling. Be that as it may, the inescapable fact remains that key horizons may be passed inadvertently, for one reason or another, while the drilling operations are being performed. The only continuous record of the formations encountered is that furnished by electrical surveys. Obviously, it would be desirable to make the electrical survey first and to take the samples from the wall of the hole according to the indications on the electrical log. In this way, it would be possible to core only the exact sections desired, eliminating the otherwise inevitable estimates as to the point at which to start coring, and thereby reducing to a minimum this expensive operation. At the same time this method would provide a maximum of useful samples. A device for taking samples of the formation from the walls of a hole therefore offers the possibility of recovering cores from zones otherwise lost as a source of this type of information. Furthermore, by coring

Jan 1, 1939

By E. G. Leonardon, D. C. McCann

The search for oil has required, and without a doubt supplies, a tremendous amount of information on the structure, composition, physical properties, and history of sedimentary rocks. The earliest and most complete source of knowledge is the sample or core of the rock itself, the uses of which are well known. The purpose of this paper is primarily to discuss a new method for obtaining these cores, and to illustrate its use in connection with electrical logs. Most cores have been obtained through a special adaptation of rotary drilling, and the results have been remarkably good, considering the mechanical problems involved. Unfortunately, because of the time and expense, this method cannot be used for the entire length of the drill hole. Even though ingenious contrivances have been evolved in order to reduce the time spent in round trips, such as wire-line coring equipment, mechanical coring still remains too expensive to be carried out continuously. In practice, therefore, one is finally compelled to estimate the probable depths of the more interesting horizons and, allowing a wide margin of safety, to core through those sections only. It is true also that interesting results have been obtained by examining the cuttings brought to the surface by the mud circulated in the well during the process of drilling. Be that as it may, the inescapable fact remains that key horizons may be passed inadvertently, for one reason or another, while the drilling operations are being performed. The only continuous record of the formations encountered is that furnished by electrical surveys. Obviously, it would be desirable to make the electrical survey first and to take the samples from the wall of the hole according to the indications on the electrical log. In this way, it would be possible to core only the exact sections desired, eliminating the otherwise inevitable estimates as to the point at which to start coring, and thereby reducing to a minimum this expensive operation. At the same time this method would provide a maximum of useful samples. A device for taking samples of the formation from the walls of a hole therefore offers the possibility of recovering cores from zones otherwise lost as a source of this type of information. Furthermore, by coring

Jan 1, 1939

By Dudley Homer

MINAS DE MATAHAMBRE, S.A. is a Cuban mining corporation with mines located in the Matahambre district about 100 miles westerly from Havana in the Province of Pinar del Rio. The port of entry is the subport of Santa Lucia on the north coast of Cuba. The mines are located six miles inland at the town of Minas de Matahambre. Minas de Matahambre and Santa Lucia are connected by a 9-mile automobile road, and a 30,000-ft. Leschen aerial tramway. At the subport of Santa Lucia the company maintains docks, concentrate bins, tugs, lighters, and miscellaneous shipping equipment. The power plant of the company is also located at Santa Lucia. Connection between the power plant and the mine is effected by a 30,000-ft. transmission line. In the town of Minas de Matahambre are located the mines, concentrator, shops, and warehouses. The con-centrates are transported to Santa Lucia by the Leschen aerial tramway. The mines are equipped with three shafts, viz., Nos. 1, 2, and 3. (Fig. 1.) No. 1 Shaft is a three-compartment vertical tim-bered shaft and has reached a depth of 1825 ft. This is the present main hoisting shaft. No. 2 Shaft is a four-compartment vertical shaft lined with steel sets and native hardwood lagging. Certain portions where the ground is heavy have been lined with re-inforced concrete. Practically all production will be hoisted eventually through this shaft. No. 3 Shaft is a three-compartment vertical timbered shaft. It has reached a depth of 1090 ft. Its purpose is for prospecting, ventilation, and handling men and sup-plies through the north section of the mine.

Jan 1, 1933

By F. S. Crawford

IRON and copper are mined in the Lake Superior district. The iron mines of the district have the best safety record for that industry in the country as a whole, while the copper mines of the district rank second in two of the four years recorded (Table 1). In Utah copper comes mainly from open-pit mines, which enables that state to lead easily in safety. All of the Michigan production comes from deep underground workings. About 60 per cent of the iron miners in St. Louis County, Minnesota, are employed at open-pit mines; this favorably affects the combined open-pit and underground accident-frequency rate, as this county provides most of the Minnesota-mined iron ore. In Michigan, however, there are few open-pit mines, the bulk of the production coming from underground mines, while all of the Wisconsin production, just across the state line from Michigan, is from underground mines. In spite of the fact that fewer mines in Michigan use the safer open-pit method, the iron-mining industry of that state maintained a consistently low record from 1931 to 1934; however, it was many points behind its nearest competitor, Minnesota, with its much greater production from open-pit mines.

Jan 1, 1939