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By D. W. Brunton

Discussion of the paper of D. W. Brunton, presented at the Spokane meeting, September, 1909, and published in Bulletin No. 33, September, 1909, pp. 837 to 855. WILLIAM' KENT, New York, N. Y.:-The Institute may congratulate itself on the opportunity of reading the splendid address of President Brunton. It is au admirable summary of the progress that has been made in the mining and metallurgical arts in recent years. The paper rightly give's the chief credit for this progress to the aid which has been rendered to these arts by the advances in mechanics, chemistry, and electricity. It is notable that most of the headings in Mr. Brunton's address refer to the work of the mechanical engineer, the electrical engineer, and the chemist, rather than to that of the specialist in mining-operations. It seems that. the most successful mining engineer of the present day is the one who makes the most intelligent application of the inventions and designs of engineers and others who are not directly engaged in mining. A tabulation' of the headings of the address, grouped as below, shows this most clearly. Work of the Mechanical Engineer-Rock-drills, hoisting-machinery, tramming, pumping, ventilation, dredging, sampling, concentration, briquetting, fume-recovery. Work of the Electrical Engineer-Electric machinery for hoisting, pumping, tramming, lighting and signaling, electric . transmission, electric smelting. Work of the Chemist and Metallurgist-Explosives, chlorination, cyanidation, roasting, lead-smelting, and copper-smelting. Work of the Geologist-Economic geology. Work of the Mining Engineer-Mine-mapping, surface-mining, timbering, tunneling; and planning and supervision of the work in general. The mining engineer of the present day, who is in responsible charge of a large plant, finds his chief work not in doing

Jan 1, 1910

By W. B. Plank

I HAVE been asked by the Chairman of the Engineering Education Committee to outline what the engineering colleges would like the mining companies to do with the young engineer just, out of college. It has been suggested that, because my own personal experience has been almost entirely within the coal industry, I handle this subject from that view- point. Many thoughtful engineering educators are today wondering what effect the present employment policies of many industrial companies are going to have on the young man just starting out in his profession. Since before the World War large industrial concerns, such as those in the electrical and mechanical industries, have gone to the colleges to interview 'likely graduates until today there has developed in most of our engineering colleges, especially in the eastern part of the country, what appears to be a lively competition on the part of these companies in bidding for the young graduate engineer. The employers of mining engineers, with one or two exceptions, have not yet begun to enter this competition. It remains to be seen how serious this situation will become, how it will affect the training of other engineers, and what effect, if any, it will have on the mind of the young man about to enter college who may be inclined to take up mining engineering, but who gains the impression from this well advertised employment service just mentioned that there is no opportunity for him in the mineral industry as com- pared with the opportunities offered in say civil, mechanical, and electrical engineering.

Jan 1, 1929

By R. W. Shoenberger, J. E. McNulty, B. R. Kuchta, William Spackman, A. A. Terchick, M. E. Hopkins, Norman Schapiro, R. J. Gray, A. F. Duzy, M. P. Corriveau

INTRODUCTION * The United States is fortunate in having abundant reserves of metallurgical-grade coals. Although these coals are better in quality and more accessible than most metallurgical-grade coals found throughout the rest of the world, the best grades of these coals are being depleted. Consequently, more efficient exploration tools and techniques, such as advanced methods of core drilling and logging, correlation by petrography, paleontology, palynology, † physical stratigraphy, and geophysical methods are being used to help assess the extent and quality of the remaining coal reserves. Exploration and assessment of new and existing coal properties become of utmost importance in determining ( 1 ) the economic justification for mining the coal, (2) the optimum design of the preparation plant, and (3) the most effective use of the coal. Recent progress has been made in relating mineral matter, especially pyrite, in coal to geologic conditions and paleogeographic trends. l * Editor's note: Because of the numerous and varied contributions of the associate authors of this chapter, the text does not differentiate between sections prepared by each individual as has been done in other chapters. † Palynology is the science concerned with plant microfossils, especially spores. pollen. and other fossils of microscopic size.

Jan 1, 1979

By George Wolff

To THE average person, the purport of the items and figures on the balance sheet of a mining company are hazy and the real financial condition of the company is cloaked in obscurity. It is also likely that the satisfaction of the stockholder in his investment, as well as the determination of the prospective investor, rests more on the reputation of the company, his confidence in the management, the stated earnings per share and the dividends paid, than on a comprehension of the information contained in the balance sheet. The balance sheet of any company at best can only closely approximate the true financial condition as of a given date. Any item of asset, except cash, can probably be altered if another's viewpoint is applied. It is difficult and expensive to drill and explore an orebody to determine the entire tonnage of ore therein. Those inherent difficulties render it practically impossible to prepare an absolutely correct balance sheet of a mining company. It is possible, however, to present the facts of a mining company more intelligently and comprehensively than is usually done. With this in mind, a balance sheet of an imaginary mining company is submitted, with supporting schedules. The same fundamental principles hold true whether we consider a large or a small company. Less complexity is involved in dealing with the affairs of a smaller company. Therefore, for this purpose, the assumed company operates but two mines and a smelting plant. It has been deemed advisable to introduce the features of the operation of a mine acquired prior to March 1, 1913 and one after that date. The presentation therefore is concerned in one mine with the appraisement as of March 1, 1913 and in the other with the appraisement by reason of discovery. A consequential factor pertains to dividends paid from depletion reserves and therefore free of surtax to the stockholders. While supporting schedules, when necessary, give details of certain items on the balance sheet, it seems desirable to give further explanations with respect to some of them. This seems to be important because some mining companies do not treat the items as indicated on the statements submitted.

Jan 1, 1928

By Bradley Stoughton

[Secretary's Note.—TO avoid repetition of foot-notes, references to authorities are made in this paper by means of figures, referring to a numbered list in the appendix.—J. S. 1 Introduction. This paper gives the results: first,, of a research into the somewhat extensive literature of titanium; and second, of a series of original tests upon the effect of titanium on iron castr ings. New investigations have also been made upon the effect of titanium on steel, but I hope to treat this subject in an independent paper at some later date, and, therefore, will not discuss the experiments in detail here. The combined results of this study, which extended over a period of more than two years, can be briefly summarized as follows : 1. Steel or cast-iron, in which the titanium is properly proportioned, and which has been properly treated, is improved in strength, toughness, and durability against wear, such 'as, for example, the wear of railroad-rails, of steel and chilled-iron rolls, car-wheels, etc. 2. These improvemerits seem to be caused, not so much by the direct effect of titanium on the metal, as by its cleansing influence in removing harmful impurities, such as oxygen and oxides, nitrogen, occluded slags, and perhaps also sulphur. It appears also to reduce segregation, which would contribute to the same end. 3. In order that its effects may be fully realized, the treatment of steel or iron with titanium must be correctly performed. There are a few simple, but essential, details to be observed; if they are neglected, the best results cannot be expected. To illustrate by an example: A series of tests on cast-iron

Jan 1, 1913

By W. D. Forgeng, D. Beregekoff

In the routine examinatlion of a wide variety of metal specimens it is sometimes necessary to have special methods of polishing in order to retain and reveal certain details in each specimen. Among such special cases is the retention of graphite in malleable and gray cast irons, the preservation of all types of non metallic inclusions in both hard and soft steels, obtaining a scratch-frec surface with soft metals, and avoiding the usual relief effects with very hard specimen. such as tool metals c3o1ltaining various carbide and nitride phases. It, is the purpose of this paper to give an account of some of these special polishing methods in use at the Union Carbide and Carbon Research Laboratories. The polishing procedures outlined have been found to give uniform results. It is obvious that only general rules and the most important working details can be given here. Following these rules, the polisher can obtain satisfactory results if he possesses the necessary patience and has a sincere desire to give as nearly perfect a finish as possible to his work. Procedure The specimen is flattened with considerablecare on a file or sharp cutting sanding belt, since the initial production of a flat surfacc greatly facilitatcs subscqucnt polishing. The polishing motors have two speed., 600 and 1200 r.p.111. ,It higher speeds specimens arc likely to he over-Ileated, therefore the high speed is used only when a saving of time is important. The following abrasive papers are used consecutively: Yo. 2, So. 1, No. 0, No. 00 and No. 000. The final wet polishing is done oil a cloth-covercd metal disk. Woolen broadcloth of the best quality and capable of resisting severe pressure is most commonly used on the last lap. . polishing felt of the type used for polishing optical glass has been found equally satisfactory and is much stronger than broadcloth. For retaining inclusions and graphite, a hard cloth with very little residence, such as

Jan 1, 1939

By D. Beregekoff, W. D. Forgeng

In the routine examinatlion of a wide variety of metal specimens it is sometimes necessary to have special methods of polishing in order to retain and reveal certain details in each specimen. Among such special cases is the retention of graphite in malleable and gray cast irons, the preservation of all types of non metallic inclusions in both hard and soft steels, obtaining a scratch-frec surface with soft metals, and avoiding the usual relief effects with very hard specimen. such as tool metals c3o1ltaining various carbide and nitride phases. It, is the purpose of this paper to give an account of some of these special polishing methods in use at the Union Carbide and Carbon Research Laboratories. The polishing procedures outlined have been found to give uniform results. It is obvious that only general rules and the most important working details can be given here. Following these rules, the polisher can obtain satisfactory results if he possesses the necessary patience and has a sincere desire to give as nearly perfect a finish as possible to his work. Procedure The specimen is flattened with considerablecare on a file or sharp cutting sanding belt, since the initial production of a flat surfacc greatly facilitatcs subscqucnt polishing. The polishing motors have two speed., 600 and 1200 r.p.111. ,It higher speeds specimens arc likely to he over-Ileated, therefore the high speed is used only when a saving of time is important. The following abrasive papers are used consecutively: Yo. 2, So. 1, No. 0, No. 00 and No. 000. The final wet polishing is done oil a cloth-covercd metal disk. Woolen broadcloth of the best quality and capable of resisting severe pressure is most commonly used on the last lap. . polishing felt of the type used for polishing optical glass has been found equally satisfactory and is much stronger than broadcloth. For retaining inclusions and graphite, a hard cloth with very little residence, such as

Jan 1, 1939

By John A. E. M. Church

THE prospector's pan was the first implement used for saving gold, and its action is so effective that it has never been equalled for thorough work. Copper plates, blankets, sluices, and amalgamators of several patented designs have thrust it aside, but in spite of all the advances made there is no dispute among experienced men as to the comparative thoroughness of the work done by it and its rivals. When its rivals are doing their best, the pan can take their discarded refuse and prove their inefficiency by producing from it not only gold, but even the mercury which has been lost from the machines themselves. The trouble with the pan has always been that it was only a tool. Man was the machine that moved it. His work was high-priced, the quantity treated small, and it was impossible to use the pan for any but the richest sands. As a consequence the best gold-saving appliance known has been discarded for years and replaced by machines of inferior excellence, but which could more than make up for their limited ability in saving gold by their capacity for treating great quantities of ore. Mr. Peck is one of the old-time amalgamators of the Comstock district, and the first idea of the new machine came to him as he used to pan below the tailrace of his mill. No matter how fine the work of the mill was, the pan invariably proved that better could be done. The tailings always contained gold, silver, and mercury. This state of things is just as true to-day, after all the improvements that have been made, as it was then, and the much-vaunted method of the " Washoe process" consists in extracting 72 per cent. of the gold and silver by one operation, and then repeating this operation half a dozen times to get out about one-third of the remainder. With all the advances of twenty years in milling, there is nothing more crude in metallurgy than the treatment of tailings in many of the large mills of the West.

Jan 1, 1880

By Nicholas J. Grant, Oliver Preston

PUBLICATION of data by Irmann' indicating outstanding thermal stability and elevated-temperature strength properties in a sintered aluminum powder product (SAP) stimulated interest in the strengthening of metals by means of a highly dispersed oxide phase. This material was produced by compacting, sintering and extruding a fine flake aluminum powder, resulting in a dense product containing 10 to 16 volume pct alumina, which arises from the thin oxide film on the starting powder, highly dispersed in a matrix of pure aluminum. The method of producing SAP, and the stable high-temperature properties obtained from it, introduced the possibility of developing superior materials for high-temperature service by powder metallurgy methods. The composition of the materials of this type which are presently under consideration is predominantly metallic, containing from less than 1 pct up to about 20 volume pct of the oxide. As a result, other properties of these materials, such as electrical and thermal conductivity, thermal shock resistance, and to a certain extent ductility, notch sensitivity, machinability and hot working properties, are also predominantly metallic. These alloys do not constitute, therefore, a completely new class of materials as do the cermets, but rather present a new means of modifying the properties of a metallic matrix. In this sense, SAP type alloys are more closely analogous to the alloy aging systems. While the strength properties realized in the oxide-pure metal systems at the lower temperatures are substantially less than the best attainable in the aging systems, the thermal instabilities in the latter make them of less value for use at temperature much above their optimum aging temperatures, as indicated in Fig. 1. While the means of obtaining an oxide dispersion are more difficult and costly than conventional aging processes, in the light of the as yet limited understanding of such systems there is considerable promise of improved high temperature properties arising from the thermal stability of these structures. Since the development of SAP in 1946, its properties and the properties of a series of similarAl,O,-A1 products containing from about 1 to 20 pct aluminum oxide have been fairly extensively studied and reported.'- "articular attention has been given to

Jan 1, 1958

By David R. Mitchell, E. A. Reilly, G. R. Gardner, F. P. Lasseter

THE methods that may be applied to the treatment of slurries and water, as these are related to practical coal-preparation problems, are concerned essentially with the movements of solids suspended in water. It is assumed that there are no fundamental differences between the principles involved in the treatment of coal slurries and the phenomena encountered in general mineral-dressing practice, and the latter are-presented in some detail. Basic principles are correlated with present practice for both the anthracite and the bituminous coal fields, and methods are discussed which are designed to utilize best all the material subjected to treatment and suggest a sound approach to the solution of problems relating to the return of clear water to process or to streams. In order to approach the practical phases of the subject with sufficient understanding of the basic principles, it is necessary to discuss two types of phenomena that are applicable. The first is flocculation and the second is sedimentation. Descriptive matter is given covering the various methods and types of equipment employed to conduct these operations, with emphasis on their application to water and coal-slurry treatment. DEFINITION OF TERMS Definitions of terms are consistent with modern developments, and conform, in general, with their usage in mineral-dressing practice. Because of variations in coal-preparation methods, it is impossible to define a rigid upper limit of particle size for a coal slurry or sludge which will apply generally. Limits vary somewhat with the particular treatment method employed at a given plant. For purposes of definition, this limit is chosen as the particle size for which preparation methods such as Chance comes and jigs are usually dispensed with, and other methods, such as the Hydro-tator, tables, and froth flotation, are employed. Generally the limit will be 10 to 6 mesh.

Jan 1, 1950

By W. H. Bassett

ABOUT twenty-five years ago the copper industry had outgrown the Lake Superior production. The electrolytic copper producers had- their process well in hand and the industry was well started in the use of electrolytic copper, both for working into wire and sheet, and for the making of alloys. The trade knew that some brands of copper made good material and that other brands did not. There came together a group of men-a refiner, a rolling-mill man, and a manufacturer of electrical machinery-each of them desiring to know why there was a difference and what .it was. Much investigation was done with wire bars and cakes which involved ' chemical analysis, metallographic examination, physical tests and electrical tests. To find the influence of different kinds of copper in making brass 200 carloads of ingots were made into ,eyelet brass under careful observation; each carload was carefully analyzed and tested before used. The alloy was made and rolled under standard conditions and the results recorded.

Jan 1, 1924

F. E. BACHMAN, Buffalo, N. Y. (Communication to the Secretary) : The investigation so fully described by Mr. Laudig was undertaken with the idea of determining if it is possible to learn by expesiment, without an actual trial in the furnace, what economical results can be expected from the use of a given ore-mixture. The research was necessarily preliminary, and the results obtained are only to be depended upon so far as they relate to the samples treated. With the exception of the ores obtained from the stock-piles of the Buffalo Furnace Company, and several samples taken at a neighboring furnace, there is no certainty that the ores represented the average shipments of any mine. For this reason the publication of the names of the ores might do producers a great injustice. The names of the ores arc therefore withheld, and their identity is further .veiled by leaving out of the analyses the phosphorus-contents. The investigation was begun with the preconceived idea that the rate of reduction would be found to be dependent upon the accessibility of the particles of the ore to the action of the reducing-gas. In other words, a spongy, brown hematite or a very fine Mesabi would be the easiest reduced. I had formed a scale with No. 21 first, No. 30 second, No. 1 third, Nos. 5, 24, 25 and the remaining Mesabis fourth, etc , which is sufficient to show how much actual results differ from a judgment based on physical characteristics. The ore expected to be most easily reduced proved to be 25th in the list, while the one placed

Jan 1, 1897

J. M. Wadsworth,' Okmulgee, Okla. (written discussion).—It seems to me that thc young man must first be absolutely sure that the work he has taken up is to his liking and then I would advise that he get into the practical end of it and learn as much about it as he can as fast as he can. For instance, in the refinery business the college man, graduated in chemical engineering, should ground himself by going through the various departments in a refinery and working in them until he is thoroughly familiar with the operating problems. In a short time he would be able to apply many things which appear in the abstract form in his college work and this would opcn up an opportunity for him to capitalize on them, promoting his own interest. I do not criticize the present-day college men as a class, but I have found that many of them come into your plant with the idea that mere possession of a diploma should insure rapid promotion; in a short time they are impatient and usually leave. We have found in employing men that the single attribute most difficult to find in them is a lot of energy and whole-hearted interest in the work at hand, and it seems to me that if a man combines these with a careful technical training he should be fairly well equipped to gamble on his future. They must learn that the biggest satisfaction to be gained in life is in their work. Procedure for Attaining Objective of Young Petroleum Engineer H. B. Fell,+ Ardmore, Okla. (written discussion).—Of course, the first thing to be ronsidered in any proposition is the ultimate objective that is desired to be attained. 1 presume that the desired objective of most of the young men graduating in petroleum engineering will be that of chief executive of one of the companies in the petroleum industry, or one of the allied industries, or to become an independent oil producer, or oil refiner, or possibly an oil distributor. The next phase then to be considered is the procedure which should most logically be followed to attain the objeckive of the indivitlual, since in these cases these young men will have been trained in a course in petroleum engineering and it would logically be presumed that the attainment of their objective should be through the operating end of the branch of the business with which they are connected. The operating end is, of course, the department of each branch of the business that develops the resources, or refines the products, or distributes the products, from which the profits are derived, and is a part of any business which is filled with enough interesting work to appease the desires of the most ambitious young men. In order to get the best possible training it would appear to me that the place for a young man to start after graduation would be at the bottom of that branch of the industry which he expects to follow. For example, if he is going in the producing end he can gct no better training than is secured by starting as a roustabout in the ficltl, where he romes in constant rontact with the character of work that is necessary

Jan 1, 1928

By P. Pollard

A method has been developed for evaluating acid treatments in fractured limestone fields by breaking down pressure drawdown into three component parts: (I) pressure differcntial across "skin" near the borehole face, (2) pressure differential due to flow resistance in the coarse communicating fissures and (3) pressure differential between the fine voids and the coarse fissures. It is apparent that in most successful acid treatments the first term, skin resistance, has been reduced or eliminated. Further, it is often possible to estimate the volume of coarse fissures associated with the second term, coarse fissure flow resistance. In cases where this volume is comparable with practical acid volumes it seems likely that this resistance also may be attacked with a suitably retarded acid. INTROD UCTION Acid treatment has been successfully applied as a general practice in the limestone wells in the Mara/ Maracaibo districts of Venezuela for some 10 years. At the same time the need has been felt for a more precise method of: (1) evaluating the effect of an acid job and (2) selecting wells which should benefit from an acid treatment. The following method, based on an analysis of build-up curves for wells producing from fractured limestone, provides a means of forecasting the effect acid will have on a well and in many cases the probable order of production rate increase which may be expected. In certain cases it is also possible to calculate the fissure volume through which the acid has to be displaced for best results. Various approximations are introduced in the method, but within the limitations of these the analysis gives an indication of how a well, whether previously acidized or not, may be expected to respond to acid treatment. Suitable build-up curves cannot be obtained on "tight" wells which do not give sustained production and the method is not applicable to such wells. Figs. 1 through 7 illustrate various types of build-up curves obtained from limestone wells in Western Venezuela. Curves are included showing (1) both skin and coarse fissure resistance, (2) skin resistance only, (3 and 4) reduction of skin resistance by acidization, (5) fissure resistance only, (6) reduction of coarse fissure resistance by acidization, and (7) acidization failure. This theory has been successfully applied for over three years during which 22 acid treatments have been carried out specifically to reduce skin resistance and three treatments to reduce coarse fissure resistance. The method has been found to be a useful aid in the selection of wells for acidization.

By Richard W. Smith

KYANITE, long known to occur in Georgia, did not excite commercial interest until about 1930. Investigations revealed two main types of deposits: (1) separate kyanite crystals embedded in mica schist; and (2) crystal aggregates of kyanite associated with quartz in small and very irregular veins. The second kind at first sight appeared to be the best source of supply. Large boulders or dornicks of kyanite with more or less quartz were found on the surface at many places throughout the Piedmont and Highland sections of the state, but prospecting failed to disclose a sizable vein. These dornicks seem to be a surface accumula-tion from small veins or lens-shaped masses not more than one or two feet thick, and with a horizontal extent of not' more than a few feet. The larger surface accumulation of kyanite dornicks, where not too badly stained by iron oxide, may prove to be marketable, but it is extremely doubtful whether a vein large enough to mine will ever be found. In 1932 deposits of the kyanite-mica schist were known to occur in two places northwest of Clarkesville, in Habersham County. In 1934, at the request of and in cooperation with the Georgia Geological Survey, the United States Geological Survey made a thorough investigation2 of the deposits and found that the two known areas of kyanite-mica schist in Habersham County were but a part of an unsymmetrical, U-shaped belt (Fig. 1) with a western limb extending into Rabun County and somewhat longer than the eastern limb. The total length of the belt is about 30 miles. The width of outcrop ranges from 100 ft. to 1/4 mile or more. Deposits of kyanite-mica schist of very doubtful commercial importance were found in several other counties. Only the deposits of this kyanite-mica schist belt in Habersham and Rabun counties will be discussed in this paper.

Jan 1, 1936

SLAG composition, slag constitution, reactions in slag, and reactions between slag and metal-in other words, the physical chemistry of slags-are matters of great importance to the open-hearth operator, whether or not he makes use of any detailed knowledge of them. Although this is a relatively young branch of the science of steel- making, much progress has been made; however, much remains to be learned, and many of the statements that can be made at present are probably--or even certainly-subject to future change. Nevertheless, the physical chemistry of slags is sufficiently developed to provide a reasonably secure basis for real understanding of steelmaking reactions. FUNDAMENTALS OF SLAG CONTROL By way of introduction, some time is spent in this chapter on effecting an easy transition from some of the more "practical" manifestations of slag to discussions couched in the more formal language of physical chemistry. This necessitates a certain amount of repetition, but it is felt that the purpose of the chapter is best served in this way. Reactions in the metal phase have products that find their way into the slag and are important components thereof; they are discussed in detail in the preceding chapter. Some substances distribute themselves Between slag and metal in definite fashion, and others are found only in the slag. Their reactions are a large reason for this chapter. Limitations of Slag Control. The open-hearth process is essentially oxidizing and cannot be otherwise operated. (Oxygen gradients in the furnace, the mechanism of oxygen inflow, and similar subjects are discussed in Chapter XIX.) As shown in the calculations of material and heat balances for the charge (see Chapter XV), from 25 to 50 lb. of oxygen will flow from air or combustion gases into the charge or molten bath during the heat for each ton of liquid steel

Jan 1, 1944

By Vasily P. Muravjev, Gennady I. Razgildeev

The theory of reliability is a powerful mathematical tool for determining optimum selection of components and application of electrical power to coal mines. In order to make this tool useful, statistical material on equipment life must be gathered and all failures carefully recorded. Statistical data can be applied to new apparatus design and can be used to determine optimum configuration of network and maintenance to reduce costs. Reference is made to underground power systems in the USSR. Technical progress in the last few years has occurred in the design and application of highly productive coal mining and transporting machinery. One of the most important problems facing mining engineers is to increase the availability of the machine to obtain higher productivity. However, machine failures and breakdowns of electrical power supply components cause serious delays in the coal-winning processes. In spite of the fact that electrical equipment and the power supply contribute only a small percentage of direct mine costs, electrical failures as well as power supply delays can result in severe indirect losses. It is necessary, therefore, to consider reliability and safety in the application of electrical equipment underground. To obtain the best results, it is necessary to investigate and evaluate the reliability of the electrical mining components (starters, breakers, motors, cables, etc.) and optimal methods for minimizing maintenance, the desired result being equipment which is efficient and safe. Electrical equipment reliability directly influences economics: the lower the reliability the more frequently failures occur, causing serious working delays and possibly huge economic losses. By the same token, while increasing the number of preventive maintenance calls per unit time might result in fewer failures, thus reducing delays, the cost of making more frequent maintenance inspections will increase; this is one aspect to be discussed in detail. Obviously, failures of identical types of electrical equipment (starters with the same current and voltage, etc.) are influenced variably by different working conditions, environments, quality of the apparatus, maintenance procedures (personnel, frequency, quality), load, and other factors. Hence, the lifetime of identical types of equipment will vary depending upon usage in terms of the foregoing factors. Thus for a given type of electrical component, these factors must be considered quantitatively; the interaction of all these factors are evaluated quantitatively by a statistical method using probability theory. Equipment reliability must be quantitatively determined from a study of equipment life, since no one laboratory test can reproduce all working conditions and environmental effects. Nevertheless, reliability theory applied to electrical mining equipment is a very powerful mathematical tool for selecting as well as evaluating certain parameters. It is necessary to select several reliability parameters so that one can obtain an expression for the total overall economic situation in terms of cost, taking into consideration damage caused by electrical equipment failure and cost of maintenance. To accomplish this result, such characteristics as apparatus lifetime, breakdown idle time, and losses (damages) can be determined quantitatively on a statistical basis. For identical electrical equipment working under similar conditions, the previously mentioned reliability factors are random variables and therefore can be characterized readily by a probability density function. Investigations carried out by the authors in the Kuznetsk Basin (Kuzbas) in West Siberia, USSR, show that the reliability factors of electrical mining equipment are well described by the exponential, normal, or Erlang's distribution in most cases. Mining electrical equipment life is well-described by the exponential law. The distribution of lifetime density is

Jan 1, 1971

The Report on the Manufacture of Coke for the year 1880 by J. D. Weeks1 includes an historical account of the early days of coke-making that is very complete and accurate, and but little can be added to it to fully cover the period prior to 1885. The few additional references that have been found follow. The earliest suggestion found about making coke in this country is in a letter from D. M. Randolph to Harry Heth, dated August 22, 1808. Heth was then operating the mines in the Richmond, Virginia coal field and had sent Randolph to England to investigate steam engines for hoisting and pumping and other conditions in the coal industry there. The letter was written in London and said: "I shall explain to you, how, by turning Deep Run fine coal in Coak, to make great profit from what has heretofore been useless. You will do well to ascertain the price and amount of demand for this article throughout the U. States among brewers and manufacturers. I know how also to make every bushel of such fine slaty coal, fetch as much as any of the best grate coal, by turning it into Coak: and that too, after paying all expenses of the process."2 His interest was to use the slack more for domestic purposes than otherwise, probably, although what the interest of brewers would be in coke as fuel does not appear. Nothing ever came of this suggestion, and so far as known, no coal from this field was coked excepting in gas-making. The Plumpsock Iron Works, mentioned by Weeks as having used coke, was advertised for sale in June 1818.3 It was stated that stone coal was the only fuel used at the works, the pit being within 100 yards of the forge. "Three men with a horse and cart are sufficient to raise coke, and haul to the forge all the coal necessary for keeping the works in full operation." The coke, of course, was made in ricks, or heaps, and not in ovens. The first real coke oven in this country was probably built in Connellsville, the coal coming from a mine nearby on Mounts Creek. L. L. Norton operated an iron foundry and was persuaded by his foreman, one Nichols, who came from Durham, England to build a coke oven. The oven was 12 feet square, and the first coke was produced in 1833. Later

Jan 1, 1942

By W. G. Frailing, W. P. Sims

The Lakeview Pool of Kern County, California, was discovered in 1910 with the drilling of Lakeview No. 1 which blew out and produced an estimated 8,250,000 bbl of oil in 544 days of uncontrolled flow. The well has since been known as the Lakeview Gusher. Full exploitation of the pool did not take place until about 25 years later. A total of 112 producing wells were completed in the Lakeview sand through April 30, 1949. As of that date, about 30 per cent of the total wells drilled were still producing, with an average pool production rate of approximately 2000 bbl per day. The cumulative oil production was about 41 million bbl of oil, or 55.3 per cent of the tank oil originally in place. The pool is bordered on its down-structure side by a body of inactive edgewater and water production where present has been principally the result of coning. Since the depletion of the greater portion of the gas energy by the Lake-view Gusher, the pool has operated under gravity drive. Relatively high angle dips, good permeabilities and favorable fluid characteristics have made gravity drainage particularly effective. Since January, 1942, the oil recovery -has been relatively constant at about 53,000 bbl per ft drop in fluid level. Correlations between the volume of reservoir space drained and the cumulative oil produced indicate that an ultimate recovery of 63.3 per cent of the tank oil originally in place is attainable. INTRODUCTION The Lakeview Pool is an outstanding example of gravity drainage. It is one of many productive reservoirs of the Midway-Sunset Field, and is located in Kern County, approximately five miles southeast of Taft and two miles north of Maricopa, California. Its position rel- ative to surrounding pools and to the Thirty-Five anticline is shown on Fig. 1. The northern portion of the pool lies in sections 32 and 33, Township 32 South, Range 24 East, Mt. Diablo Base and Meridian, while the southern portion lies in sections 25, 26, 35 and 36, Township 12 North, Range 24 West, San Bernardino Base and Meridian. As no two sections bear the same number, they will hereafter be referred to by section number alone. The purpose of this paper is to review the performance of the Lakeview Pool in an effort to evaluate the effectiveness of gravity drive as a recovery mechanism. REGIONAL STRATIGRAPHY AND STRUCTURE The oustanding structural feature is this area is the Thirty-Five anticline, the axis of which plunges South 75" East through the center of Section 35. As shown on Fig. 2, the following zones are oil and gas bearing in the Thirty-Five anticline area: Pleistocene Basal Tulare Tar Sands Pliocene San Joaquin Mya Sands Top Oil or Scalez Zone Etchegoin Kinsey Sand Wilhelm Zone Gusher Sand Calitroleum Sand Miocene Reef Ridge Lakeview Sand Sub-Lakeview Miocene Sands Monarch Sands or fractured shale equivalent Maricopa Webster Sand or fractured shale equivalent Fractured Shale-Uvigerina Zone C Obispo Sand and fractured shale equivalent Pacific Shale Zone The productive interval of the Lakeview Pool is limited to Upper Miocene and Lower Pliocene deposition. In this general area, the most prevalent type of accumulation results from stratigraphic traps or permeability pinchouts. As is the case of the Lakeview Pool, strati-graphic traps resulting from angular unconformities are present. The structure within the Miocene does not parallel that of the Etchegoin (Pliocene), as the Miocene beds were folded, and in places faulted, and subjected to erosion prior to Pliocene deposition. The Lakeview horizon consists of truncated sands which occur on the northeast flank of the Thirty-Five anticline. The direction of strike is west and northwesterly through sections 25 and 36 and continues northwesterly through sections 26 and 33, to the approximate center of section 32. At this point the strike swings to the northeast and the horizon re-enters section 33. in the northwest corner. The change in strike in section 32 affords synclinal accumulation at that point. The Lake-view sand is truncated updip by the Etchegoin overlap. To the southeast, the sand shales out, while to the northwest, the productive interval appears to be limited by a combination of stratigraphic pinchout and permeability barrier. Structurally, the Lakeview reservoir presents three areas of interest, as shown on Fig. 3. Area I in section 32 is a region in which a productive Sub-Lakeview Miocene sand is present. It occurs from 10 feet to 30 feet below the base of the Lakeview sand and attains a maximum thickness of 25 feet in Well No. 21, section 32. The producing characteristics of the Sub-Lakeview Miocene sand differ radically from those of the Lakeview sand. Water production at high structural locations and abnormally high fluid levels indicate that there was no communication with the Lakeview sand. Wells in Area I penetrated this sand and produced it in conjunction with the Lakeview sand. In Area 11, the Lakeview sand is a

Jan 1, 1950

By W. E. Hale, G. J. S. Govett

An orientation survey was conducted over a known disseminated copper deposit and a Au-Cu vein deposit and employed geological, geophysical, and geochemical methods. Geochemical techniques proved the most effective and economical means of locating and defining areas underlain by these types of mineralization. Six additional, widely separated occurrences were also investigated and mineralization was confirmed by determination of cold-extractable copper in stream sediments. The length of anomalous drainage varies from several to 16 km and depends on the type and tenor of mineralization. Despite generally marked relief and extreme physical and chemical weathering, cold-extractable copper anomalies in soils appear to reflect closely variations in the ore mineral content of immediately underlying rocks. Threshold values vary with local geological conditions and type and grade of mineralization. Significant thresholds in stream sediments are about 65 ppm and 10 ppm for cold-extractable copper in disseminated and vein copper occurrences respectively. Similar differences are encountered in soils. This necessitates the use of a scale of threshold values at progressive stages in each exploration program. Dis-seminated copper occurrences are presently the major source of mineral production m the Philippines. Much potentially productive ground remains to be investigated and applied geochemistry appears to offer the best available approach. The Institute of Applied Geology (I.A.G.), a joint project sponsored by the University of the Philippines, the Philippine Bureau of Mines and the United Nations Development Program (Special Fund) undertook during 1965-66 a number of field projects in Northern Luzon Island (Fig. 1). These field operations were of a two-fold nature and involved both orientation and exploration. During approximately six weeks, an orientation survey, involving geological mapping, geophysical surveying and geochemical prospecting, was conducted over a partly developed, disseminated copper deposit at Santo Nino (Fig. 1). This study demonstrated the economic and technical feasibility of geochemical ptospecting, relative to the other methods tested, for the location and delineation of a typical disseminated copper occurrence characteristic of those that represent the major source of metal in the Philippines.' Geochemical techniques, similar to those tested at Santo Nino, were then applied in a second orientation study of a vein occurrence at Suyoc (Fig. 1). The results of these two orientation studies suggest that, in reconnaissance work in this region, stream sediment analyses, combined with the determination of pH in the same streams, can be used to indicate areas underlain by rock containing anomalous concentrations of copper, whether it occurs in the large tonnage, low grade, disseminated deposits or in the comparatively small tonnage, higher grade, gold vein occurrences. Furthermore, the orientation surveys demonstrate that soil sampling and analysis serve effectively to outline more closely the mineralized zones within the generally anomalous areas identified from the stream reconnaissance. To further test the methods selected from the two earlier trials, six additional, widely separated prospects were investigated. The geological and geochem-

Jan 1, 1970