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By Owen R. Rice

Changes in coke hardness affect the working of the blast furnace, for soft coke is an obstacle to proper furnace operation. Soft coke is due to a low hydrogen-oxygen ratio in the coal charged; increasing this ratio increases the hardness of the coke. The best means of determining the hardness of coke is the combined tumbler and ball-mill. What is Good Coke? It is not always appreciated that the correct answer may be such a reliable forecast to the physical condition of the blast furnace, and incidentally its entire operation, that among the ordinary variations in other raw materials and also in operating conditions, it assumes a position of primary significance. Inasmuch as coke forms two-thirds of the total bulk of material charged, this assertion will not seem exaggerated, and in the subsequent discussion its applicability will be presented. Coke is the ideal blast-furnace fuel because it is strong and hard enough to resist the crushing and grinding effects of the furnace burden, and its porosity allows the ready passage of gas upward through the charge, and rapid combustion before the tuyeres. Coke deprived of its strength and with a cell structure physically frail and chemically susceptible to solution by carbon dioxide has its chief asset eliminated. When the melting zones are approached the fluid cinder trickling toward the hearth will envelope the small pieces of coke and form a sticky mass that will retard the free passage of gas. Blast pressure will then rise, driving will slow up and fragments of coke will lie inert before the tuyeres, rendered practically incombustible by their slaggy envelop. It is believed also that coke messes at cast are attributable to quantities of such coke floating unburned in the hearth. It has been correctly claimed that coke rendered small outside the oven possesses greater combustibility than that so developed in the

Jan 1, 1922

By Robert R. Boyd

The gravity discussed here is that of the clean oil produced. Gravities of fluids containing water, free or in the form of emulsion, sand, drilling mud or mineral salts of a nonbituminous nature do not represent the gravity of crude oil as considered in this paper. During recent years it has become a frequent occurrence for operators to be called upon to explain to landowners the reasons for variations in gravity on shipments of oil from wells in which they are interested as royalty owners. In regard to single well leases it has been noted that marked changes in gravity frequently have occurred for no apparent reason. Data collected on the subject and correlated with production methods reveal interesting facts. It is the purpose of this paper to present some of the highlights on the subject. These gravity changes in the natural crude oil are with a few exceptions the result of the liberation under varying conditions of the volatile hydrocarbons from the natural oil-gas solution contained within the pool. The subject of the liberation of gases from natural oil-gas solution has been investigated by Ben E. Lindsly, of the U. S. Bureau of Mines, and the observations recorded here are in the main consistent with his conclusions. Investigators have recognized two methods of liberation of gas from solution—flash and differential. In the latter method the vapors are removed from the liquid as rapidly as formed and have no opportunity to come to a condition of equilibrium with the oil. In flash liberation an equilibrium condition between the oil and the gas exists at the pressure of separation. Mr. Lindsly has found that the method of liberating the gas from the oil has a pronounced effect on the final gravity and that differential liberation results in a higher A.P.I. gravity due to the higher ratio of gasoline producing hydrocarbons left in the oil. Under actual production practices with high velocities in flow strings, it is our contention that conditions of perfect equilibrium between gas and the oil rarely exist, and that gas separation is made under varying conditions, sometimes approaching that of equilibrium and at other times departing from it.

Jan 1, 1937

By R. H. Singleton

ThE purpose of this investigation was to determine the effect of cerium upon the nonmetallic inclusions found in cast and wrought steel containing various amounts of sulfur, oxygen, and nitrogen. Interest of the Physical Metallurgy Laboratory of the Watertown Arsenal Laboratories in this type of research was stimulated by the reports from industry that rare-earth metals imparted beneficial effects upon the mechanical properties of steel, but that the mechanism was not understood. Berry and Dorvel' found that misch metal improved the impact properties of aluminum-killed cast steels. They reported that the rare earths modified the intergranular-film type nonmetallic inclusion, present with aluminum as the sole deoxidant, to a randomly distributed globular type. Lilliequist and Mickelson2 observed the improvement of ductility and toughness of quenched and tempered cast steels through rare-earth additions. They also observed the change from angular to duplex inclusions when rare earths were present. They con-

Jan 1, 1960

By R. A. Pallanch

PROBABLY one of the most perplexing problems with which a mill operator contends is the proper evaluation of his mill results. True, he accurately determines his recoveries of metals and grades of products monthly, weekly, and often daily. These figures do not of themselves directly translate to mill economics. When one figure is unusually good there may be an offsetting circumstance. The advantage of high lead or zinc concentrate grade may be offset by poorer recovery; high lead recovery may be offset by poorer zinc recovery, or vice versa; and so on. Besides, grades or recoveries may not of themselves mean more than a reflection of the grade and character of the ore during the period under study. What the operator sorely needs is some one measuring stick that tells him when he has achieved his greatest return, regardless of grades or recoveries-for if he knows his methods and practices are yielding the optimum return he need no longer concern himself with the assays of products and tailings, or the corresponding distribution of metal values. At first blush it would appear that the obvious answer to this is the actual money return to the mill. Paradoxical as it may seem, however, money return does not make a dependable yardstick any more than do grades and recoveries, as ore conditions would vary enough to bring about greater money return during periods when the actual metallurgical work is not as good. The mill operator, of course, should always aim for the greatest return on the ore, once it is in the mill bins, with proper attention always to mill treatment cost. The need of a proper yardstick becomes more imperative with the increasing complexity of the problem. In the case of a simple, single-product operation on a fairly uniform ore, in which only one metal is of significant importance, the need is not great, as grade and recovery pretty well tell their own story. At the other extreme is the operation that makes three or four separate marketable products from a complex mixture of heterogeneous ores that vary tremendously in individual metal contents and ratios, degree of oxidation, and other characteristics, and in which gold, silver, copper, lead and zinc are all significant values. ECONOMIC RECOVERY The first attempt at obtaining a proper single yardstick for a fairly complex ore with which I am familiar is the use of the "Economic Recovery" term at the leadzinc flotation mill of the Sunnyside Mining and Milling Co., Eureka, Colorado. This method had been applied there early in Sunnyside flotation-mill history (not later than 1920) and credit for the innovation I believe belongs to Messrs. Kuryla and Marquand. The term "Economic Re-

Jan 1, 1947

By Richard Henry Lee

Since the economies in the blast furnace resulting from enriching iron ores are so great, much attention has been paid during the past few years to the various methods of concentrating lean ores, and, as the concentrated ore is usually of extreme fineness, various methods of agglomeration and sintering, of more or less value, have been put into operation. The resulting agglomerated concentrates are generally obtained in the form of briquettes or nodules. The briquettes naturally divide themselves into two classes: (1) those made by the mixture of some binding agent, and then formed into briquettes under great pressure; and (2) those made by sintering the concentrates, the latter either being formed into bricks before exposure to heat or the sintered mass broken into fragments afterward. Of the first class I will not speak, as they are not used on an extensive scale in this country. The second class of briquettes, or those made by sintering, are simply masses of melted or fused silicate and oxide of iron mingled with more or less silicates of aluminum, lime, and magnesia. The fact that the material in a briquette is sintered is proof positive that there are no pores in the material. There are, however, quite a number of holes of greater or less diameter through the gubstance of the briquette. They are not pores in the common acceptance of that term as applied to ores by furnacemen, as the ides of the holes and channels are fused. In reality the material is simply mill cinder. It is practically untouched by the gases in the upper part of the furnace, and the iron has to be reduced by solid carbon in the boshes and hearth. Briquettes sometimes show a little saving in fuel in the furnace over an ore mixture of large lumps, but that saving is made simply because, owing to the numerous holes and channels through the mass, the briquette is practically composed of numerous small or fine lumps, and, as is well known, the finer the

Jan 1, 1914

By G. Richards Gwinn

Graphite is one .of the so-called minor nonmetals that have become of major importance during the present conflict. Requirements of the domestic industry for graphite are relatively small and uses have changed so greatly in the past 25 years that different types, with few exceptions, are more nearly interchangeable in use. However, the quality of the graphite required for crucibles is exacting and under present manufacturing practices only a small part of the world production can be utilized economically by this industry. Graphite, for the domestic crucible industry, was supplied almost entirely by imports from Madagascar and Ceylon before the present war. The quantity required has been increased by the war and the greatest demand is for Madagascar flake. The fall of France to Germany in 1941 and the Japanese expansion southward threatened our supply of crucible-grade graphite, therefore the domestic industry was revived to supplement imports and to act as insurance in the event of complete stoppage of imports. Two plants were constructed for the Government, one at Ashland, Alabama, called the Crucible Flake Graphite Co., operated by Haile Mines, Inc., and one near West Chester, Pennsylvania, operated by the Benjamin Franklin Flake Graphite Co. Loans were made by the Reconstruction Finance Corporation to the Alabama Flake Graphite Co. at Ashland, the Ceylon Graphite Co., at Goodwater, Ala., and the Southwestern Graphite Co., at Burnet, Texas. However, by the end of 1943 the import situation had improved and it was no longer necessary to continue Government assistance to mine and stock-pile the high-cost domestic material. Graphite is found in virtually every country of the world. Most occurrences are of no economic importance because of their poor quality, prohibitive mining and milling costs, inaccessibility, and poor location with reference to the industrial centers where graphite is used. The principal commercial deposits are found in Ceylon, Madagascar, Chosen (Korea), United States, U. S. S. R., Canada, Germany, and Mexico. Graphite is a typical international mineral in that it is utilized mainly in countries noted for industrial activities, whereas the two islands, Ceylon and Madagascar, which produce the major part of the world's high-grade graphite, are virtually devoid of any manufacturing establishments requiring its use. The industry thus is violently disturbed by wars. Types oF Graphite Used in Crucibles Graphite of various kinds and from many countries has been used for making crucibles. Passau (Bohemian) flake was first used in Europe, but by the middle of the seventeenth century crucible formulas were established largely on Ceylon graphite and German Klingenberg clay. Ceylon graphite is granular and the grains are subdivided into more or less

Jan 1, 1948

By T. A. Klinefelter, O&apos, R. G. Meara, Glenn C. Truesdell, Richard W. Smith

The investigation of domestic talcs was undertaken by the Bureau of Mines, Department of the Interior, in cooperation with the University of Alabama, at the request of the U. S. Army, on Dec. 1, 1941: "Considerable concern has been expressed by the Supply Arms and Service over maintaining continued availability of supplies of the necessary raw materials. These ceramic products are used by the Signal Corps in all army radio equipment, and to a greater degree in the new ultra-high-frequency equipment. The Air Corps has become a user of large amounts of radio-grade ceramics for' aircraft spark-plug covers required for high-altitude operations. In addition, the use of this material is essential to the proper functioning of the radio air-navigation aids of the Civil Aeronautics Board." History The use of steatite and talc in ceramic bodies goes back a great many years. If pure, talcs shrink little under heat-treatment and are very resistant to heat shock. The massive form, commonly called "steatite" by the trade, cuts and works easily, and this was naturally the first method used in obtaining articles of talc. When gas was in general use for illuminating purposes, a. large business was carried on in the manufacture of tips for gas burners.' With the development of uses for electricity, low-tension insulators were made in a similar manner; and, in fact, the forming of shapes from massive talc continues. However, as the business increased, cuttings and waste became more and more of a problem. In the twenties, one of the larger producing firms had a cooperative agreement with the Bureau of Mines at its Columbus station to work out a body using the finely powdered material. Somewhat earlier, manufacturers of spark plugs used the finely ground talc as part of the body and to some extent in wall-tile bodies. Somewhat later it came into use for kiln furniture and similar products and still more recently it has been used in some dinnerwares. With the development of the radio and the high-frequency fields generated, it was found that a dense steatite porcelain was far better than even high-tension electrical porcelain, which is a clay-flint-feldspathic type of body. Until the war increased the demand, the several pioneer steatite-porcelain manufacturers were able to furnish adequate supplies. When war began in Europe and Asia, three important foreign sources of raw material were cut off; i.e., the French, Italian, and Man-churian talcs. Domestic producers of high-grade porcelain are few, and the trade

Jan 1, 1948

By Frank H. Macpherson

When it became apparent early in 1941 that the United States might be drawn into the war, studies were made of the bauxite situation in Arkansas, principally because 9.5 pct of the known bauxite reserves of the country were located in that State. Bauxite mining was then geared for maximum production to supply ore to meet this country's war requirements and, if necessary, to supply the needs of Canada as well. In view of the comparatively small bauxite reserves, Congress appropriated funds for an extensive exploratory drilling program to be carried out by the Bureau of Mines in cooperation with the Geological Survey. An alumina plant was erected near Bauxite and an aluminum plant near Hot Springs, Ark., by the Defence Plant Corp. The Metals Reserve Co. established a schedule of prices, arranged for stockpile sites and a buying agency. Operators cooperated to step up production and new ones came into the field. Production Record Prior to 1941, the greatest annual production in Arkansas was 562,892 long tons, dry basis in 1918. During the single month of August 1943, 693,596 long tons were mined—130,704 tons more than for the entire year of 1918. In general the Arkansas bauxite deposits are relatively small, irregular in thickness, somewhat scattered and, compared to coal, iron or open-pit copper deposits, are ill-adapted to an expansion in output. Commercial deposits range in horizontal extent from less than an acre to about 40 acres and are usually very irregular in outline. The average thickness of all known workable deposits is between 12 and 15 ft. with a maximum of about 60 ft. The ore bodies are usually somewhat undulating and nearly horizontal although locally some deposits dip as much as IS°. Types of Bauxite Three physical types of bauxite may be recognized: pisolitic, granitic and amorphous. Pisolitic ore is the most common type. It consists of small pebble-like nodules, ranging from the size of a pin head up to several inches in diameter, all set in a fine grained matrix. Transported bauxite is usually- pisolitic. Most residual bauxite is granitic. It is believed not to have moved appreciably from the location where it originally was formed. This is indicated by the fact that it appears to grade into unaltered nephelite syenite, which it overlies. Amorphous ore is the least abundant. It is nonpisolitic and resembles clay, has no characteristic texture, and can be identified definitely only by chemical analysis. Uses of Bauxite Bauxite is chiefly used for, and at the present time is substantially the only

Jan 1, 1948

By H. M. Wilson

The relation of labor to the accident rate in mines is admirably epitomized by Thomas T. Read in his paper presented at the St. Louis meeting, in the sentence "Reliance for accident prevention must be upon the individual worker himself." In connection with the inspection of mines for the fixing of merit premium rates for insurance under workmen's compensation, it has been the practice of The Associated Companies to allow 60 per cent, of the credits for safeguarding of the physical hazards of the mine and 40 per cent. for the human element. By "human element" is meant that inherent tendency of the industrial worker to be careless, negligent, or disobedient, in respect to his own safety, and after that also of his fellow workman. This is a tendency not only of the laborer or of the skilled miner, but of all human beings, working or traveling anywhere. This element of mine safety, sometimes called the moral hazard, has been admirably shown by statistics, compiled from the records of the Department of Mines of the Union of South Africa, to be due in about equal measure to the carelessness of the miner and to that of the operator. These statistics show that about one-half the fatalities in mines are due to the so-called hazard of the industry, or what is sometimes called the dangers inherent to work or misadventure. Of 2497 fatalities investigated, including over 200,000 employees, for a period of over 21/2 years, it was found that 17.5 per cent. were due to faulty plant or material, fault of the foreman, or of the management—in short were due to the operator; 17.1 per cent. to disobedience of orders, carelessness or ignorance of injured persons; and 5.9 per cent. through fault of others, including fellow workmen. The fault of the operator is evidenced by failure to give proper warning, failure to inspect, failure to furnish proper equipment, and neglecting to comply with the recommendations of the inspector. That education and training of the mine operator, as well as of the mine worker,

Jan 1, 1918

By N. T. Burdine

Formulas for calculating relative permeability from pore size distribution data are derived from basic laws of fluid flow ill porous media. The tortuosity factors that appear in the equation5 are described in. terms of the physical properties of tile medium and the saturations of the contained fluids. Procedures for calculating and methods for measuring the tortuosity factors are discussed. Values of relative permeability calculated by the formulas art: compared with results obtained by experimental measurements I INTRODUCTION Recently, several investigators have derived relative permeability equations from Darey's and Poisenille's Laws in which some, physical factor or factors describing the porous system appear. The factor that has caused the greatest amount of comment, and which is probably least understood, is the tortuosity of the fluid {lath ill the porous sample. Values of the tortuosity factors appearing in the equations range from a constant for all condition- of the fluid flow system to an inverse function of the pore radii. It is the purpose of this paper to compare wine experi~i~cntslly determined relative permeability curves with those calculated by a method which utilized capillary pressure infortmation. The capillary pressure data were obtained prefer.. ably from pore size distribution information as determined by mercury injection but. in some cases, in the absence of suitable mercury injection information. data were taken from measurements made by the porous semi-permeable diaphragm method. The physical significance of certain tortuosity concepts is inferred and the determinations of the tortuosity factors from pore size distribution data and by electrical measurements are discussed. THEORETICAL BACKGROUND In previously reported studies on pore size distribution in petroleum reservoir rocks. by the author and co-workers ail equation was derived relating specific permeability. k, to pore entry radii, R, porosity. . tortuosity factor. .,, and incremental pore volume. V. The equation is where being the "effective" length of the flow path in the porous sample. and L the length of the porous sample., The constant. 0.126. is a units conversion factor. (This definition of tortuosity factor X, = L L does not conform to all such definitions found in the literature. Fly similarity, in a two-phase system. the effective permeability of the wetting-phase.

Jan 1, 1953

The Tuscarora mining district, which has been highly productive of gold and silver ores in past years, is situated about 50 miles north- west of Elko, Nevada. The town of Tuscarora lies at an altitude of about 6,000 ft on the west side of the Independence Valley. Precipitation, particularly the winter snowfall, is considerably greater than in many other parts of Nevada, and temperatures are lower. From Tuscarora can be seen-across Independence Valley in the mountains to the east, a distance of about 12 miles, the Freeport Minerals Jerritt Canyon mine, which seems to be-destined to become one of the great gold mines in the western hemisphere. Tuscarora, a gold and silver camp, was active from the early 1870s to 1903 and produced about $10 million in those 30 years. Ten major mines and several smaller ones were operated in an area of about 1.45 square kilometers (one-half squaremile). The deepest shafts were only 230 m (750 ft) but most of the ore came from about the 105 m (350 ft) levels. Mineralization above the water table, at about 30 m (100 ft), was mostly native silver and cerargerite with free gold. Below the water table the ore was rich in sulfides including argentite, stephanite, proustite, pyrargyrite, enargite, arsenopyrite, bornite, chalcopyrite, pyrite, sphalerite and galena. A number of the properties contain sizeable dumps of what was con- sidered waste rock when it was mined. These dumps aggregate over 408,000 mt (450,000 st) with one dump, the Navajo, containing over one-third of the total. A few grab samples taken in the summer of 1978 from some of the dumps indicated interesting silver values with minor gold content. AgAu Exploration Ltd., was organized to explore and develop these dumps into a heap leaching operation. In the fall of 1978 a campaign was started to lease, with front money payments on a royalty basis, three groups of claims on which were located a few hundred thousand tons of dumps. In September and October of 1978, a systematic program of sampling was started on the Navajo dump which was most favorably situated in that it was near to an area which would furnish good sites for heap leaching pads. At the time it was fully recognized that sampling of dumps was a most difficult problem. Because of the topography on which they were situated and the manner in which they were formed, each dump required its own special sampling technique.

Jan 1, 1981

By Campbell M. Hunter

Petroleum is found in almost every province in Persia. On the northern frontier, along the southern shore of the Caspian Sea, it is found near Enzelli and Shakhtesar and gas at Khoremabad. Oil is also found at Gumish Tepe, northwest of Astrabad, on the southeastern shore of the Caspian Sea. Further inland, to the south of Astrabad, oil is found at Dehahkuh-i-balae, also on the margin of the Khorasan desert at Semnan, 115 mi. (35 m.) east of Teheran. Along the western frontier, from northwest to southeast, oil is encountered at Ouschachi, north of Lake Urumieh; in the province of Azerbaijan, at Zohab, Khanikin, and other places in. the district of Kormanshah in the province of Ardelan. Further south, in the province of Luristan, oil is found east of Mendeli and in the Pusht-i-kuh districts. Considerable quantities of oil are also obtained from Schuster, Maidan-i-Naphtun, Ram-Hormuz, Beheban, which are almost on a straight line, running northwest and southeast along the foothills of the Bakhtiari Mountains. At Ahwaz, in the province of Arabistan, oil has been found along another range of hills whose axis also lies in a northwest-southeast direction. In the Fars province, boring for oil has taken place at Daliki, and indications of oil are found at Kheri, Fasa, Darab, and other places. A gas show is also recorded at Kuhi-Sung-Atush in this province, 30 mi. (48 km.) east of Darab. In the south of Persia, oil is encountered on Qishm Island, also at Ahmedi and other places north of Bunder Abbas. On the southeastern frontier, oil is found on the Sarhad range of hills. Thus, oil indications have been noted over a distance of approximately 1100 mi. along the western and 700 mi. along the northern frontiers of Persia. History The first working of oil in Persia of which there is any record took place at Kir-ab-US, Susiana, now known as Kiab, about 57 mi. northwest of Schuster. Herodotus (about B. C. 450) reported a well near Ardericca that produced three different substances; namely, asphalt, salt, and oil. The oil, which was black and had a strong smell, was called Rhadamance by the Persians.

Jan 1, 1921

Christopher R. Corning was one of the ablest mining engineers and geologists in America and one whose name was well known also in Mexico, Cuba, South America and many European countries. He was educated at Zurich, Switzerland, and at the Bergakademie, Freiberg, where he was graduated in 1883 with the degrees of Markscheider and Bergingenieur. He continued his studies at Heidelberg until 1886, chiefly in chemistry, under Bunsen, and mineralogy and petrography under Rosenbusch. Although he received a Ph.D. in chemistry, he never used the title. During holidays of 1883-86, he traveled, seeing mines and studying geology in Spain, France, England, Italy, Germany, and Austria. In 1886, he returned to America and in 1887 he was in the Lake Superior iron ore country on the staff of John F. Stevens, then building the Duluth South Shore and Atlantic Railway. In 1889, Mr. Corning was at the Bunker Hill & Sullivan mines at Wardner, Idaho, with John Hays Hammond, and there met E. E. Olcott. Although Mr. Corning was not long connected with the Bunker Hill & Sullivan mines, he left the imprint of his ability and splendid personality upon the men and the property. That his friendship was cherished was manifested by the cordiality, hospitality and frequency of letters of good counsel and cheer. In 1897, Mr. Corning, with E. E. Olcott and Prof. Robert Peele of Columbia University, formed the firm of Olcott, Corning & Peele, consulting mining engineers. Pressure of university duties compelled Professor Peele to withdraw in 1904, and later Mr. Olcott was forced to retire by reason of other important business interests, but the friendship and high mutual regard of the three men continued undiminished. About 1902, Mr. Corning and Professor Peele translated into English Riemer's book on "Shaft Sinking under Difficult Conditions." Mr. Corning's knowledge of structural geology, mineralogy and ore deposits was extensive and accurate. He was a close and intelligent observer. When he became interested in a problem, no amount of trouble was too great in endeavoring to reach a satisfactory solution. He had professional experience in the West, notably in the Coeur d'Alenes, Mexico and South America, and several times was called on to attempt to straighten up mismanaged properties. In 1912, at the request of a large number of members, Mr. Corning headed the "Committee of FiveJ' that investigated the affairs of the American Institute of Mining Engineers and brought about beneficial changes in the organization and its policies. He was one of the organizers

Jan 1, 1924

By Barnabus Bryan

THE normal statistics of supply and demand of petroleum and its products have little more than local influence on the market movements of oil securities. The two major reasons for this condition might be called the technique of production and the technique of refining. The speed of improvement in each and the complete lack of control of their, inter-relation have resulted in overproduction of both crude oil and gasoline in the face of immense in-crease in demand. The trouble with oil securities has been that of the mushroom radio companies, where too frequent changes have killed the possibility of profits. It is a case of too much efficiency. During the past ten years there has been continual talk of wasting reserves of crude oil. This has been based on "present methods of production." Yet the methods of ten years ago in the oil industry are as antiquated today as the kerosene lamp.. The fear of famine has transformed the industry. The refiner, through the cracking process, has doubled the gaso-line output from a barrel of crude oil, thus doubling reserves and changing a current undersupply into oversupply. When the automobile driver desires he can again double reserves and transform want into abundance by demanding an automobile which will deliver twice as many miles per gallon of gasoline. Entirely apart from refining and in complete dis-regard for its needs, the oil producer has forged ahead at a pace too rapid for his own good. The science of geology has developed with experience and' lavish expenditure into a constant danger to profits in the production of oil. Two and one-half per ;cent of the producing wells in the United States are yielding one-half of the oil, while their flush production is used as an excuse to force down the price of crude oil until 200,000 wells must be abandoned or produce at a loss. The fabulous yield of the new high-pres-sure fields enables the fortunate owners to make a profit regardless of the price of oil. Such a condi-tion is unhealthy from the standpoint of oil itself and as a national policy. It is manifestly absurd to suppose that such a condition can endure for a gen-eration. There will come a day when the sequence of discovery will be temporarily broken, and at that time the consumer will be forced to pay heavy interest on the foolhardy policy of today.

Jan 6, 1927

By J. Tarwater

The torsional testing of cylindrical medium-carbon steel specimens, heat treated to a high strength level, revealed a stress-strain relationship that was dependent on the direction of torsional plastic pre-strain. This Bauschinger effect was observed in prestrained specimens both with and without subsequent elevated-temperature strain aging. Yield stresses in strain-aged specimens exceeded those of simply prestrained specimens and the difference in stress was greater when the prestrain direction opposed the test direction. This behavior is discussed in terms of the classical dislocation pile-up using Cottrell's equation, A plastically prestrained strain-hardenable member, loaded in a direction opposite to the direction of prestrain, produces a stress-strain relationship differing appreciably from the curve representing reloading in the prestrain direction. This phenomenon, referred to as the Bauschinger effect, will be discussed in terms of the stress differences ob- served at a specified strain. The effect, dating back to the 1880's, was first attributed to grain boundary stresses. When later work revealed that the effect was also present in single crystals, revised theories attributed the diminished applied reverse stress to assistance from internal long-range stresses. These stresses have been associated with dislocation pile-ups or with dislocation arrays having analogous stress patterns. The stress patterns are subject to alteration by interaction with interstitial solute atoms and acceleration of the interaction may be accomplished with elevated-temperature strain aging. As discussed herein, the interaction showed a directional effect with regard to the applied stresses necessary for small plastic strains. Aside from the rigorous Bauschinger stress-strai relationship, which compares prestrained members, it is interesting to compare the stress-strain curve of a member being prestrained with that of a prestrained member being reverse loaded. For small strains which are a fraction of the prestrain deformation, the applied stresses of the reverse reloaded member are smaller. However, as the reverse strain approaches the prestrain value, the stresses approach equivalence. It has been reported1 that the stress required to return a prestrained specimen to its initial "zero" position generally exceeds the prestrain stress because of the work hardening occurring on potential slip systems during prestrain.

Jan 1, 1963

By T. A. Klinefelter, R. G. O’Meara, Glenn C. Truesdell, Richard W. Smith

THE investigation of domestic tales was undertaken by the Bureau of Mines, Department of the Interior, in cooperation with the University of Alabama, at the request of the U. S. Army, on Dec. I, 1941: "Considerable concern has been expressed by the Supply Arms and Service over maintaining continued availability of supplies of the necessary raw materials. These ceramic products are used by the Signal Corps in all army radio equipment, and to a greater degree in the new ultra-high-frequency equipment. The Air Corps has become a user of large amounts of radio-grade ceramics for aircraft spark-plug covers required for high-altitude operations. In addition, the use of this material is essential to the proper functioning of the radio air-navigation aids of the Civil Aeronautics Board." HISTORY The use of steatite and talc in ceramic bodies goes back a great many years. If pure, tales shrink little under heat-treatment and are very resistant to heat shock. The massive form, commonly called "steatite" by the trade, cuts and works easily, and this was naturally the first method used in obtaining articles of talc. When gas was in general use for illuminating purposes, a large business was carried on in the manufacture of tips for gas burners.1 With the development of uses for electricity, low-tension insulators were made in a similar manner; and, in fact, the forming of shapes from massive talc continues. However, as the business increased, cuttings and waste became more and more of a problem. In the twenties, one of the larger producing firms had a cooperative agreement with the Bureau of Mines at its Columbus station to work out a body using the finely powdered material. Somewhat earlier, manufacturers of spark plugs used the finely ground talc as part of the body and to some extent in wall-tile bodies. Somewhat later it came into use for kiln furniture and similar products and still more recently it has been used in some dinnerwares. With the development of the radio and the high-frequency fields generated, it was found that a dense steatite porcelain was far better than even high-tension electrical porcelain, which is a clay-flint-feldspathic type of body. Until the war increased the demand, the several pioneer steatite-porcelain manufacturers were able to furnish adequate supplies. When war began in Europe and Asia, three important foreign sources of raw material were cut off; i.e., the French, Italian, and Manchurian tales. Domestic producers of high-grade porcelain are few, and the trade

Jan 1, 1943

By Howard Hughes

IN drilling for water and oil to reasonable depths through the generally soft yielding clay and sand formation of the Coastal Plain of Texas, . Louisiana, and Mississippi, the rotating method of drilling was adopted, principally on account of the easy and quick penetration, and the low cost of the drilling plant. In favorable ground, free of heavy gravel and rock strata, as much as 1,000 ft. has been drilled in less than 36 hr., although such performances were of course rare. Hydraulic rotary drilling, or, as it is now called, rotary drilling, was used in the above States as early as 1880. The plant consisted of an ordinary derrick, a 25-h.p. boiler, a small hoist, a steam pump, and a water swivel with hose attachment, and an ordinary flat diamond-pointed bit. The successful drilling in of a phenomenal oil well by this process on Spindletop, near Beaumont, Texas, on Jan. 10, 1901, and the ascertained impracticability of drilling subsequent wells in the same locality by other methods (owing principally to heavy quicksand under pressure from below), brought rotary drilling into great prominence, practically to the exclusion of any other process throughout the Coastal Plain, and later on elsewhere. The method, as its name implies, involves the rotation of a pipe by means of machinery placed on the derrick floor. A drill bit attached to the lower end cuts a clearance for the drill pipe, with much the same motion and effect as an auger. Water forced through the drill pipe by means of a pump, and escaping through the bit, removes the cuttings and returns to the surface outside the drill pipe. In this manner the hole is kept open, permitting the drill stem to rotate freely. The pressure of the column of muddy water holds up the walls of the hole until it has been cased. Practically all the wells of the Gulf coast region, numbering nearly 10,000, have been drilled with this system. During the last five years its use has been extended to many other States and countries.

Jan 3, 1915

By William Clark

A bean placed at the bottom of tubing in flowing wells is not a new idea. In fact, a device which in effect was a bottom bean was patented prior to 1890 by John D. Rockefeller. Because of the limited use of the bottom bean, prior to 1922, when it was installed in a few wells in the Santa Fe Springs field, California, the knowledge of the results of its operation is very meager. Since then various oil operators have experimented with bottom beans, but most of the records of the results obtained by their use are unavailable. For the past year or two, more attention has been directed to this method of producing wells; the theory and best means of application have been studied, and accurate records maintained. In theory, the use of bottom beans in flowing or gas-lift wells should secure certain advantageous results. With the exception of flow friction of the tubing and flow lines, there is no back-pressure held on the rising column of fluid. Thus severe beaning is possible with no danger of killing the well by too heavy a fluid column, a condition that often exists when a surface bean is used. The whole energy of the gas expanding to atmospheric pressure is utilized to lift the fluid in the well. The same effect is obtained when flowing a well through open tubing or casing. In using a surface bean this energy of expanding gas is wasted into the flow lines beyond the bean, because the fluid has reached the surface by the time the restriction is reached and the work of the gas performed. The bottom bean affords an efficient use of the expanding force of gas, utilizing less gas to raise the same amount of oil, hence allowing for lower gas-oil ratios. The flow restriction being at the entrance to the flow string, a more uniform mixture of gas and oil enters the tubing and a steadier backpressure is held on the well. The uniform mixture and high velocity attained while flowing through the bean, which is above the critical velocity required to suspend a spray condition of gas and oil, prevent slippage of gas, surging and heading with its resultant strain on the casing. The advantageous conditions allow positive control of production in gas-lift wells within limits set by the bean size and amount of input gas; and probably help to prevent sanding up of a well and the coning

Jan 1, 1931

By N. O. Johnson

THE Hog Mountain mine is a pyritic-gold property in the north central part of Tallapoosa County, Alabama, at an elevation of 800 ft. in the southern Appalachian region. It is 13 miles by a good secondary road from Alexander City, a station on the Central of Georgia Railroad. Since its discovery in 1839, the mine has been worked intermittently. The records of past operations are few and are scattered over a long period of time; however, available information indicates a production of approximately 12,000 oz. of gold prior to the present company's activities, which started in 1933. Additional 7844 oz. has been produced under the direction of the present management. The ore from stopes has averaged 0.200 oz. gold per ton; the ore from development, 0.136 oz. gold per ton. Silver, copper, iron and sulphur are also present but to date are of minor importance. The grade of ore in comparatively narrow veins makes necessary extreme vigilance in the methods of mining. Geology Wall Rock.-Hog Mountain consists of a quartz-diorite intrusion approximately 5000 ft. long by 1200 ft. wide. Its resistance to weathering, as compared to the surrounding schists, has led to the formation of a conspicuous ridge rising 400 ft. above the adjacent country. All the mining operations are confined within the limits of this quartz-diorite formation. . Except where there is excessive shearing, either parallel or at flat angles to the quartz veins, all the walls of the stopes within the limits of the veins are strong enough to make timbering unnecessary. Where shearing exists, there may be a sloughing off of the walls, especially in the process of drawing the ore. When this occurs, stulls are placed in the stope, either while the stope is advancing, or while ore is being drawn from a completed stope. In general, very little timber is required. Veins.-The quartz veins have been deposited along fracture planes in the quartz diorite. There are 20 principal veins, all of which are roughly parallel and strike at right angles to the long axis of the formation.

Jan 1, 1937

By David Reger

LITTLE new oil was found in West Virginia, during 1923, but there were important discoveries of gas. Most of the large oil producers have contented themselves with pumping old wells or in drilling only enough new wells in defined territory to maintain a fairly constant production, the attitude being that no, profit is made in producing high-grade oil at a low price and that an eventual loss is sustained by draining the reserves of a limited commodity that, at some more favorable time, will be of much value. The representative of one large company said: "We have done nothing but pump old wells during 1923 and we have made no plans for 1924." Careful attention to producing wells has been the rule, there having been few abandonments; the belief is prevalent that small wells will eventually become profitable under more favorable marketing conditions. In natural gas, the opposite point of view prevails. Because of the vast capabilities of the state for producing gas, its output being ahead of all others, great systems of transportation and distribution into the markets of four adjoining states have been built and a demand has been created that no present, or apparently potential, production can satisfy. This demand has become so great that large distributing companies not only discourage new applications for service but advise old customers to install coal furnaces for auxiliary fuel; some have requested public-service commissions to grant higher 'rates against large industrial consumers than those allowed for domestic heating. The response to this known market has been a rapid increase in price, both at the well mouth and at the door of the ultimate consumer, and the industry has become so stable that the only uncertainty, or hazard, appears to be the question of the presence of gas in fair quantity in a given territory under consideration. Several oil companies have now forsaken their policy of selling gas, wells outright when drilled and ;have organized gas departments to drill for gas and to dispose of the daily output by meter to distributing corporations. With such companies and with other producers whose interest is chiefly gas, the year has been busy and profitable. Some new territory of apparently large value has been proved and deeper producing sands in old fields have been tapped.

Jan 3, 1924