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By George Smith

The Australian Broken Hill Consols mine is situated within a third of a mile eastwards of the famous Broken Rill Proprietory mine; but, so far as has yet been proved, the respective lodes have no connection whatever. The Proprietory line of lode, striking N.E. and S.W., is coincident with the bedding-planes of the inclosing gneiss, and, according to Mr. E. F. Pittman, A.R.S.M., government geologist, is undonbtedly a saddle-formation. This opinion, which met with much opposition at the time it was advanced, is now, I understand, being generally confirmed as the work of development opens out fresh areas for observation along the line of lode. The lode is of immense thickness—in places over 300 feet and though it has been found to contain sufficient quantities of secondary silver compounds to yield phenomenal outputs of silver, its principal constituents are various lead and other ores, and it would appear more correct to regard it as an argentiferous lead-deposit than as a silver-lode proper. The Consols lode differs from its gigantic neighbor in every respect. With an average thickness of not more than 18 inches, it has been worked along its course for upwards of 1300 feet, and at every point yet explored has been found remarkably well-defined and persistent. With a strike E. and W., it cuts obliquely across the bedding of gneiss and schist, continuing uninterruptedly through various bands of eruptive amphibolite. The dip, which is to the south, ranges from 24 near the surface to nearly vertical in the lower levels; but the alteration is not regular, as in places the lode is almost flat, and this at a vertical depth of over 300 feet. These changes of inclination have had no effect on the ore-deposits, which, as I shall endeavor to show, have been governed entirely by " cross-

Jan 1, 1897

By Robert C. Paddock

INTRODUCTION A way of producing 3,000 tpd from the El Mochito Mine was needed. Of this production, 2,000 tpd must come from the San Juan orebody. The original sub-level stoping method did not give satisfactory results due to ground instability, and the highly irregular ore/waste contacts encountered . The experience gained from the initial system helped guide research into the ground instability problem. Results from this work, combined with knowledge gained about the orebcdy configuration, defined constraints that were previously not fully appreciated. These constraints, and others, combined with objectives, were considered together to develop a new mining method. No single technique was found to be suitable, so a hybrid mining system was developed. A combination of ramping, cut and fill, and vertical crater retreat, with an option to use top heading and benching was developed. To complement the mining system, the type of equipment needed was decided upoun. Also, to support the mining system at this expanded rate of product ion, major modifications of existing infrastructure were required. THE EL MOCHITO MINE The El Mochito Mine, of Rosario Resources Corporation, has been in continuous product ion since 198. The mine began operations in April of that yeas at a rate of 100 tpd. The reserves in 198 were 100,000 tons of silver ore assayed at 1,250 grams per tonne. As of the end of 1979, the El Mochito orebodies have produced over 5.6 million tonnes of ore averaging 516 grams per tonne silver, 6.8 lead, and 7.8% zinc. Present ore reserves are about 7.9 million tonnes, averaging 138 grams per tonne silver, 4.6% lead, and 8.7% zinc, with minor quantities of copper, cadmium and gold. An expansion plan to increase mill production two fold to 2,500 tonnes per day is underway. This expansion will require the mine to produce 3,000 tpd. The mine consists of numerous orebodies, all of which have been mined to a certain extent. Of all the orebodies, the San Juan contains 8% of known reserves. This amounts to about 6.7 million tonnes. The significance of the San Juan orebody to the future life of the El Mochito Mine is obvious. If the required mine production of 3,000 tpd is to be sustained, the San Juan must be the source of the majority of that production. Due to the mineability and overall logistics concerned with the other orebodies, the San Juan must be able to reach and maintain a production rate of 2,000 tpd by 1982. GEOLOGY OF THE SAN JUAN OREBODY The El Mochito Mine is a classic example of a chimney replacement deposit in limestone. Similar deposits axe found in Mexico, at the Naica, Providencia, and Santa Eulia Mines. The El Mochito Mine is located at the south- western end of the Sula Valley on the western edge of the Honduras Depression in the Central Cordillera and Central Highlands of Honduras in a setting of Mesozoic sediments. The orebodies occur in a structural basin developed between NNE trending normal faults and apparently hinged on the south end. Topographically, the Mochito Basin lies between the uplifted Santa Barbara mountain in the west and the Palmer Ridge on the east. The San Juan orebody occurs near the intersection of the NE trending San Juan fault and the ENE trending Porvenir fault. The downward continuation of the orebody is controlled by the westward rake of these NW and N dipping structures. The discovery of the San Juan orebody is attributed to analysis of structural evidence of known ore deposits by in-company geologists. The composition of the San Juan orebody is primarily garnet skarn, with local concentrations of hedenbergite and magnetite. The economically important sulfide mineralization consists of (in decreasing abundance), sphalerite , galena, pyrrhotite , and chalcopyrite. There is some indication that a Cu-Ag mineral such as tetrahedrite may also be present. The skarns were formed by replacement of the original limestone by hydrothermal water migrating upward roughly along the intersection between the Porvenir fault system and the San Juan fault system. Textural evidence suggests that the orebody is a composite of several pulses of hydrothermal activity which would explain, in pat, the great irregularity of the contacts and the large horizontal variation in mineralogy. A general pattern of skarn types can be seen in the orebody, partially accounting for the observed lateral variation in grades. This zonation is very generalized, and one or more zones may be missing in any given locality. The orebody is almost invaxiably surrounded by a 2 cm to 25 cm zone of bustamite skaxn with low values. The border skarn is usually

Jan 1, 1981

By J. R. Thoenen

If asked whether limestone production was a mining problem I would not hesitate to answer emphatically in the affirmative. The question, "When is a quarry a mine?" is familiar. The immediate mental picture induced by the thought of limestone production is that of an open quarry. All are familiar with the open pit in the iron-producing districts of Minnesota and Michigan and the open cuts of the so-called "porphyry" coppers of the West. If these are mines, they differ little from limestone quarries in general mode of operation; if quarries, why do they need the attention of mining engineers? During 1923, the United States produced in round numbers 70,000,000 tons of iron ore. The limestone production of the United States for the same period was something over 100,000,000 tons. In tons, it about equals the oil production of the United States. The uses of limestone are legion. A paper read by a prominent engineer of Chicago, at the meeting of the National Crushed Stone Association held last February in St. Louis says: "There is no industry in the United States today that is more basic in its operation or by itself controls more industries. There is hardly a chemical operation, hardly a metallurgical operation or building operation that a crushed-stone man does not control if he will jump in and make the full utilization of it." Some of the many uses are for road metal, concrete, railway ballast, building stone: riprap, and rubble, the manufacture of iron and steel, alkalies, calcium carbide, magnesia, carbolic and carbonic acids, asphalt filler, mineral wool, poultry grit, sulfuric acid, phosphates, nitrates, soap, baking powder, the purification of copper and prevention of coal-mine explosions, to say nothing of the quantities used in the making of lime and cement. It has been said that without iron we would revert to the Stone Age; how much iron would we have without limestone? From the point of view of the mining engineer, using the term in its broad sense to include geologists and metallurgists, the production of limestone is important because of its occurrence, volume, commercial importance, and the problems presented by its recovery and treatment.

Jan 1, 1925

By L. C. Morganroth

From a geological standpoint, but scant attention has been paid to fire-clay beds. Only within the last few years have they been the subject of individual investigation, prior to this time having been considered only in their relation to coal seams. While the relative importance of coal and fire clay is still immeasurably in favor of coal, yet an industry as large as that of fire clay is entitled to a measure of attention. A discussion of the Carboniferous clays is practically a discussion of the clay beds in the Appalachian basin, since more than 90 per cent. of these clays mined are from this region. The clays are confined to the northern end of the basin, or the States of Pennsylvania, Ohio, Kentucky, Maryland and West Virginia, ranking in importance about in the order named. The clay deposits of the Carboniferous period have been divided into two classes; those found in the Pottsville conglomerate series of rocks, ' and all those that are found in the formations above, for the reason that the clay beds above the Pottsville series all resemble each other in properties, composition and appearance, and all are distinctly different from the bed found in the Pottsville formation. The bed of clay found in the latter formation is unique in that flint clay is practically restricted to it. (A variety of flint clay is occasionally found in these upper deposits but this is in such small amounts as to be negligible.) Carboniferous clays occur between stratified rocks; sandstones, limestones, etc., in the same manner as coal veins. They are often accompanied by a coal vein although where the clay is of a workable thickness, the coal is generally too thin to work. The clay beds are sometimes known by the name of the coal seam at which horizon they occur. Clay beds may be from a few inches up to 20 ft. in thickness. They may consist of all soft clay, all flint or both soft and flint. The Carboniferous clay beds of Pennsylvania are the most important of any of the clay beds found in the country, and are among the oldest ones worked. We know more about this clay geologically for the reason

Jan 1, 1916

By Samuel S. Wyer

The art of natural-gas compressing is now over 25 years old, and has grown at practically the same rate as the increase in domestic natural-gas consumers. There are now over 200 natural-gas compressing stations in North America, aggregating more than 320,000 hp. of compressor capacity and representing a property value of more than $22,000,000, and compressing more than 85 per cent. of all the gas used. The age and magnitude of the art make it evident that the use of gas compressors is a recognized integral part and universal custom of the natural-gas business. The public also is not without its rights and vital interests in this problem. Approximately 1,700,000 domestic natural-gas consumers in North America are dependent upon gas compressors for their natural-gas service. That is, if the use of compressors were to be prohibited, the majority of these consumers would be unable to secure adequate natural-gas service. Each consumer represents between four and five persons, and it therefore follows that the comfort and well-being—as far as natural-gas service is concerned—of at least 8,000,000 persons would be affected if the use of natural-gas compressors should be prohibited. These 1,700,000 consumers have invested, in services, house piping, fixtures, and appliances, an average of about $90 each, or an aggregate of $153,000,000, which is much more than the companies' investment in gas compressors. Furthermore, in all cases where the rate paid by the consumers is fair to the gas company—considering the value of the service rendered by the gas company—the consumers are entitled to continued service and protection of the investment they have made on the faith that the gas service would be continued in the future. Since "Customs adopted and acquiesced in, if not in conflict with federal or State legislation, have the force of positive law,"l and ('Courts will take notice of whatever ought to be generally known withxn the limits of their jurisdiction,"2 there ought to be no question as to the un-

Jan 1, 1916

By W. B. Gogarty

With flow of non-Newtonian fluids in porous media, effective viscosities are needed for use in the Darcy equation. These viscosities depend on the rock parameters and flowing conditions. In this investigation, rheological and flow results were correlated to develop an expression for calculating effective viscosities. Surfactant-stabilized dispersions of water in hydrocarbon were used with consolidated sandstone cores of different permeabilities. The average shear rate in a core was related to the permeability and porosity of the core and the frontal velocity through the core. By using the correlation obtained for determining effective viscosity, experimental and theoretical values were compared for each fluid system by determining average and maximum errors. For the fluid system showing the largest average error, the correlation fit 38 experimental points with an average and maximum percentage error of 4.3 and 14.8, respectively. For the fluid system showing the least error, average and maximum percentage errors of 1.8 and 4.3, respectively, were calculated using 29 experimental points. INTRODUCTION Use of non-Newtonian fluids in the petroleum industry is not new. Fluids of this type have been used for many years as fracturing agents and drilling muds. Recently, attention has focused on the use of high molecular weight polymer solutions for secondary recovery. Results have been reported on studies relating to the flow behavior of polymer solutions in porous media.1-4 Each study gives the viscosity in the Darcy equation as a function of the rheological properties of the fluid, the characteristics of the porous medium and the pressure gradient. The functional forms of the reported expressions differ somewhat in each study. The first three studies used unconsolidated porous media while the fourth used a single consolidated core. Because of the limited information available on the flow of non-Newtonian fluids in porous media, further investigation was undertaken in this area. We selected non-Newtonian fluids that did not contain high molecular weight polymers in order to minimize core plugging. The over-all objective was to gain a better understanding of the flow behavior of non-Newtonian fluids in consolidated porous media. Specifically, our goal was to determine the relationship between the average shear rate in a core and the frontal velocity. Because of this goal, it was necessary to determine the effect of permeability on the shear rate-frontal velocity relationship. We wanted to replace the viscosity in the Darcy equation with an expression relating to the average shear rate in the core and the rheological properties of the non-Newtonian fluid. THEORY For a time-independent, non-Newtonian fluid, the apparent viscosity is a function of the shear rate. This relationship is given by µ = F(v')...........(1) With Eq. 1, a single value of shear rate determines the apparent viscosity at that shear rate. With flow in porous media, a spectrum of shear rates occurs at any average throughput. An average shear rate v' can be used to represent the spectrum of shear rates that exists within the core. By using v' and the rheological data given by Eq. 1, an effective viscosity is determined for the flowing fluid. If v' is the correct average, µe becomes the appropriate viscosity for use in the Darcy equation. Under these conditions, flow rate-pressure drop relationships can be determined for non-Newtonian fluids. HOW the correct average shear rate might be related to the frontal velocity through the core and the characteristics of the porous media will now be considered. Later, the experimental data are presented that indicate the validity of these

By N. A. Zeigler

The present publication is a continuation of the work on gas analysis described in a paper presented before the Institute of Metals Division year ago.' While that paper was largely descriptive in character dealing with the various parts of the apparatus and method of operations the present one gives numerical data obtained as a result of a series c experiments with iron-carbon alloys. The apparatus and the method applied are essentially the same as previously described, changes bein only in minor details. Attention should be called to the fact that in the present work we ar dealing with the gaseous mixtures obtained as a result of vacuum meltin of various ferrous alloys. It should be understood that when the term "degasified sample" and "products of degasification" are used, the refer to the sample remaining after the vacuum fusion of the alloy an the gaseous products removed therefrom, respectively. The write does not wish to create the impression that the metallic products of thj process are absolutely free from any gaseous elements, nor that the gase obtained are present as such in the original sample. These two point are not yet definitely known and are subjects for future investigatior The point, however, which has been established beyond doubt, i that all the gases dealt with come from the metallic charge and ar present either in the charge as such, or are produced as a result of chemic: reactions going on within the charge. The suggestion that the gases an due to the reactions between the metallic charge and the refractor materials has no valid basis. General Procedure A series of iron-carbon alloys was prepared in a magnesia-line graphite crucible placed in a high frequency laboratory furnace open t the atmosphere. The materials used were Westinghouse electrolyti iron and Acheson graphite. Each alloy, after it was completely molter was kept in the liquid state for 10 min., cast into a small iron mold, an

Jan 1, 1929

By Francis Foley

FROM the point of view of the metallographist, the adaptation of x-rays to the study of the crystal structure of metals is of the greatest importance. While one may hardly consider the findings resulting from x-ray study as revolutionary, their positive nature, compared with the deductions we have been forced to accept from the work that had gone before, gives firmer ground on which to build and furnishes new fields for speculation. Prior to the advent of the crystallogram, the best work on the crystal structure of steel was that of Osmond and Cartaud.1 They concluded, from their investigation with percussion figures formed at various temperatures, that alpha, beta, and gamma irons belonged to the cubic system and that they showed well-marked specific characteristics and could not have the same internal structure. What the internal structures were, they had no direct method of determining; but from a consideration. of the fact that the 001 plane (that parallel to the cube face) is a plane of perfect cleavage and minimum hardness in alpha iron and that the 111 (octahedral) plane is by far the most important in the crystallography of gamma iron, they were led to suggest the simple cubic arrangement as that of alpha and the face-centered cubic arrangement as that of gamma iron. They suggested the body-centered cubic arrangement as that of beta iron. The atomic arrangement of the various crystal forms of iron has been quite definitely determined in recent years by means of x-rays and the work of Westgren2 and Westgren and Phragmèn3 has been rather conclusive. They not only determined the atomic arrangement of alpha, beta, and gamma iron but also that of the high-temperature modification delta.

Jan 10, 1925

By H. O. Hofman

The sudden decease, April 1, 1910, in Chicago, of Dr. Franklin R. Carpenter was a shock to his many friends. He died in his sixty-second year, of heart paralysis. To most fellow-members of the Institute who have followed the progress of the last twenty-five years in the mining and treatment of non-ferrous ores, the work of Dr. Carpenter in that line is familiar; but very few, even of those who knew hinl well in the later years, are acquainted with his earlier struggles to satisfy an inborn hunger for knowledge. The story of his life resembles that of the pioneer who opens up new country; overcoming hardships with indomitable courage, meeting doubts and difficulties with an alert and open mind, and exercising in the face of reverses an unconquerable perseverance. It seems appropriate to place on record in the Transactions a brief outline of the life and work of this eminent engineer. During the past 15 years of his life Dr. Carpenter was much interested in genealogy. In the pursuit of this study as an avocation, he traced his own ancestry to the time when ((Hugh," called "le Charpentier" on account of the dexterity with which he had swung his battle-axe as a crusader, settled in Sussex on lands received from William the Conqueror. The Carpenters came to this country with William Penn. A prominent member of the family was Joshua Carpenter, the founder of Christ Church, Philadelphia. Dr. Carpenter's branch of the family moved from Pennsylvania into that part of Virginia which is now West Virginia, where his grandfather settled in Harrison county, while the grand-uncle went further west, and built the first iron-furnace at Hanging Rock, Lawrence county, Ohio. In fact, since early times, the Carpenters appear to have been iron-masters. Franklin R. Carpenter mas born, Nov. 5, 1848, in Parkers-

Jan 1, 1911

By Leon McCulloch

WIIen clean iron and metallic zinc dust, protected from the air, arc heated below the melting point of zinc, the iron takes on a coating that has excellent protective value. This coating is a brittle alloy of zinc and iron, and the process is called sherardizing. Although the zinc particlcs are covered with oxide and cannot touch the iron, an extremcly small amount of the zinc vaporizes and the vapor, reaching the iron, alloys with it. Other zinc then vaporizes to replace that which has been removed from the atmosphere. This process continues indefinitely at a decreasing rate, for the coating already formed permits zinc to diffuse through it to combine with the iron beneath. In this way, the coating grows outward from the surface of the iron, as the bark grows from a tree. The method of growth was clcarly seen while sherardizing small cubes of cast iron, at about 450" C., in a srnall glass-stoppcrcd bottle enclosed in a rotating drum. The dust contained about 3 per cent. iron, which prevented caking, and coatings % in. thick were grown in a few hours. After a heavy layer had been formed, the cubes mere again treated for a shorter time. The layer last formed was seen to lie next to the iron, instead of at the outer surface, showing that the growth was from the surface of the iron outward. The coatings split at the edges and corners, leaving the iron exposed there. Flakes of graphite from the iron were lifted upward and embedded in the coatings. The composition of sherardized coatings varies from the outer surface inward, as would be expected from the mode of growth. That is, the iron content increases slowly at first, then more rapidly as the iron is approached. At the surface the least amount of iron possible is 6 per cent., as the experiments described below have shown. A study was made of the effect of iron in zinc dust on the proccss and on the resulting coatings. Glass bulbs, holding the small pieces to be sherardized, together with enough zinc dust to make them two-thirds full, were heated in a small, rotating electrically heated and controlled furnacc. The bulbs had 6-in. (15 cm.) necks, of 96-in. (9.Fj mm.) tubing, plugged

Jan 1, 1923

By Leon McCulloch

WIIen clean iron and metallic zinc dust, protected from the air, arc heated below the melting point of zinc, the iron takes on a coating that has excellent protective value. This coating is a brittle alloy of zinc and iron, and the process is called sherardizing. Although the zinc particlcs are covered with oxide and cannot touch the iron, an extremcly small amount of the zinc vaporizes and the vapor, reaching the iron, alloys with it. Other zinc then vaporizes to replace that which has been removed from the atmosphere. This process continues indefinitely at a decreasing rate, for the coating already formed permits zinc to diffuse through it to combine with the iron beneath. In this way, the coating grows outward from the surface of the iron, as the bark grows from a tree. The method of growth was clcarly seen while sherardizing small cubes of cast iron, at about 450" C., in a srnall glass-stoppcrcd bottle enclosed in a rotating drum. The dust contained about 3 per cent. iron, which prevented caking, and coatings % in. thick were grown in a few hours. After a heavy layer had been formed, the cubes mere again treated for a shorter time. The layer last formed was seen to lie next to the iron, instead of at the outer surface, showing that the growth was from the surface of the iron outward. The coatings split at the edges and corners, leaving the iron exposed there. Flakes of graphite from the iron were lifted upward and embedded in the coatings. The composition of sherardized coatings varies from the outer surface inward, as would be expected from the mode of growth. That is, the iron content increases slowly at first, then more rapidly as the iron is approached. At the surface the least amount of iron possible is 6 per cent., as the experiments described below have shown. A study was made of the effect of iron in zinc dust on the proccss and on the resulting coatings. Glass bulbs, holding the small pieces to be sherardized, together with enough zinc dust to make them two-thirds full, were heated in a small, rotating electrically heated and controlled furnacc. The bulbs had 6-in. (15 cm.) necks, of 96-in. (9.Fj mm.) tubing, plugged

Jan 1, 1923

By H. M. Chance

Recent research work has shown that coal can be produced, at reasonable cost, from almost all coal-mining districts containing not more than 3 to 8 per cent. of ash. From coal so produced, an abundant supply of coke, suitable for blast-furnace operation, can be made containing from 12 down to 6 per cent. or less of ash. These statements apply broadly to the Appalachian coal belt, including most of the mining districts in Pennsylvania, Ohio, West Virginia, Kentucky, Tennessee, and Alabama. The exceptions will generally be found among those coals carrying a prohibitive percentage of sulfur. Any gravimetric heavy fluid method of separation will effect a reduction in the percentage of sulfur, but this reduction may not be sufficient to produce, from coal unfit for metallurgic use, a product that can be so used. When a large part of the sulfur is in the form known as "organic sulfur, "or is present as very finely disseminated and homogeneously distributed pyrite, possibly it cannot be eliminated from the low-ash coal produced. When the sulfur exists as pyrite in distinct layers, bands, or nodules, or when it is finely disseminated but is irregularly distributed, often a low-ash coal low enough in sulfur to make good metallurgic coke can be produced from relatively impure coals. It has generally been assumed that the quality of coke on which blast furnaces must be operated depends on the geographic location of the furnace, and that the grade of coke on which a blast furnace must operate is that produced from the best coal obtainable by careful mining; or if the coal is prepared by washing, hand picking, or other means by which the foreign impurities are removed, that the grade of coke on which the furnace must operate depends on what has been termed the "inherent ash" of the particular coal. The term "inherent ash " is generally understood to mean the percentage of ash present after all removable (free) impurities, slate, fireclay, high-ash bony coal, and pyrite have been removed, and is usually applied to the percentage of ash present in run-of-mine coal from any mine after these impurities have been removed. Perfect washing, or perfect preparation, is understood to be attained when the percentage of ash in the washed coal is reduced to the percentage of inherent ash; that is, of ash that cannot be removed by the washing processes in common use. Wash-

Jan 1, 1924

By Wilford S. Wright

FOR the past four years the management of the Black Hawk Consolidated Mines plant at Mogollon has conscientiously kept accurate records pertaining to cost of operation and the performance of certain equipment. These records have been valuable in coordinating the work in the mine, mill and power plant. Also, as to quantity and kind of equipment and supplies most suitable from the standpoint of economy and dependable operation, they have served as a guide. Through comparison with records at other mines, where the same things are being done in a different way, they have pointed out mistakes to be avoided. No outstanding accomplishments, either in costs or performances, are revealed; in fact, some of the results are perhaps quite inferior to those obtained at similar plants, but it is with the thought that more records should be published for the benefit of the mining profession that the author presents these data. To other operators and to mining engineers who are called upon to make estimates for prospective operations, the information herein should be helpful. GENERAL CONDITIONS Mogollon is in the southern part of Catron County, southwestern New Mexico. It lies near the western border of the Mogollon Range, 14 miles east of the Arizona line. Silver City, 80 miles to the southeast, is the nearest railroad point. The connecting road, over which supplies are hauled into camp by trucks, is an improved highway for about 50 miles; the remainder consists of graveled roads and unimproved steep mountain grades. One general supply truck and one tank truck make daily round trips. Hauling of supplies to the mine has cost at the rate of $0.08 per ton-mile; or, on the basis of ore production, $0.30 per ton mined. Lumber, hauled in from local mills, has cost an average of $30.00 per 1000 board feet, $8.50 of which has been for hauling. The annual consumption averages 108,000 board feet. Lime, hauled from a plant in Arizona, is about the only other item not brought out from Silver City. Fuel oil for the generation of power is the item of greatest hauling expense, the f.o.b. Mogollon cost of approximately $0.06 per gal. being nearly twice the f.o.b. refinery price. Water for power plant, mill and camp use flows to camp storage tanks through a 4-in. pipe line from a spring and intake 3 miles up Silver Creek Canyon. A few times, particularly in the month of June, mill operations have been suspended for two or three days because of water shortage. MINING CONDITIONS During the years 1938, 1939, 1940 and 1941, the mine produced 230,059 dry tons

Jan 1, 1943

By B. H. Caudle, A. B. Dyes, R. A. Erickson

The study of the influence of fluid mobilities on the sweepout pattern resulting from the injection of gas or water has been extended to cover the production period which follows breakthrough of the injected material. Mobility ratios over the range common in field operations (0.1 to 17) were studied for several pattern floods (five-spot, staggered, and direct line drive). The experimental data required for these studies were obtained by the use of the x-ray shadowgraph technique using miscible oil phases of different viscosities in porous plate mode1s of a reservoir element. From the shadowgraph pictures obtained before and after breakthrough of the injected fluid, flowing ratios at the producing well and cumulative volumes injected were calculated. The method for applying such data in predicting field behavior is illustrated for a water flood of a five-spot. For this case a range of mobility ratios of 0.5 to 5.0 results in: (I) nearly complete (95 to 100 per cent) sweepout pattern efficiencies at abandonment conditions, (2) production after breakthrough being responsible for as much as one-third of the total recovery at the lower mobility ratios, and (3) a twofold variation in the operating life of the reservoir. In determining the merits of a secondary recovery operation, the fraction of the reservoir which is ultimately to be swept by the injected fluid is of major importance. Because of its significance a large amount of research has been applied to the study of areal sweepout efficiency. Muskat, Wyckoff and Botset1,2 have presented the classic analysis of the pattern efficiency at breakthrough for several injection patterns in which the mobility of the fluids ahead of the injected phase front was equal to the mobility of the fluids behind the front. Aronofsky3 as extended this analysis of recovery at breakthrough through numerical computations and by the stepwise use of the potentiometric model to include the effect of different fluid mobilities ahead of and behind the invasion front on the line drive performance. Fay and Prats' have also employed numerical computations to show the influence of one other condition of fluid mobilities on the five spot flood. In a previous paper' a new method of attack on this problem which employed x-ray and porous plates was described. At that time experimental results were also presented which described the effect of fluid mobilities on the reservoir area contacted by the injected fluid at breakthrough for the five spot and direct line drive patterns. Most of the literature pertaining to sweepout pattern efficiency has emphasized the pattern which is obtained at breakthrough of the injected phase. The increase in the sweepout pattern which occurs after breakthrough

Jan 1, 1955

By Robert Y. Grant

This study outlines the history of metal mining in Japan and the characteristics of the industry as they existed from 1925 to 1945. Mining and milling operations are described together with the role of the Japanese Government. A description of post-hostilities conditions and the present state of the industry is included. MANY of Japan's larger and better known mines date back to the early centuries of the Christian Era. The first stimulus to mining in Japan came through the growth of Buddhism, A. D. 600 to 700, and the attendant need for copper and other metals for temple ornaments and statues. During the Feudal period, 1333 to 1568, mine operations were expanded to meet the demand for ornament metal and for financing of campaigns. After removal of the seat of government from Kyoto to Tokyo, about 1600, the Tokugawa Shogunate placed great emphasis on mining, and many new mines were opened, some of which are still operating. Toward the end of the Tokugawa period, mining had declined sharply from its earlier peak. The easily worked, high grade portions of the orebodies had been exhausted, and the mining techniques then available could not exploit the deeper, lower grade ores. Similarly, extraction of metal from the sulphide ores presented a major problem. With the Meiji Restoration in 1868 and the rapid opening of the country to western ideas came a rejuvenation of the mining industry. Mining, milling, and smelting processes were greatly improved, resulting in the extension of development work into hitherto inaccessible portions of orebodies. The demand for metal during World War I stimulated activity throughout the industry; copper mining, particularly, expanded to a point where Japan ranked second among world producers.* During the depression following the war, mining underwent a severe contraction in activity, recovering slowly during the late 1920's only to undergo a further setback in the worldwide depression which started in 1929. Mineral output declined in 1930, but the beginning of Japanese expansion, 1931 to 1932, brought about an increase in the output of mine products starting between 1932 to 1934. Production continued to rise, the peak output being attained 1939 to 1943 in virtually all commodities. The greatest production of iron ore, chromite, and manganese was not experienced until 1944 when blocked imports, coupled with strong demands for steel, provided the needed incentive. Through necessity, Japan produced much of her mineral needs from her own mines at high cost during World War 11. Taking the 1932 to 1936 period as an average, however, Japanese mines produced only 16 pct of the iron available to industry, 8 pct of the lead, 33 pct of the zinc, and 68 pct of the copper. Nearly all of Japan's output of gold, silver, copper, lead, and zinc between 1925 and 1945 came from 30 to 49 pct of the mines for which production data are available; for example, 66 of 174 gold-silver mines accounted for 98 pct of the output of this group. Further analysis of mine output indicates that a large part of Japan's metal output was derived from a few large mines; about 10 gold-silver, 15 copper, 3 lead-zinc, 5 manganese, and 2 iron mines account for most of the production. Many of these mines have been operated for 200 to 400 years. With the

Jan 1, 1952

By George J. Bancroft

It is unnecessary to repeat here the contents of many valuable contributions to this subject which have appeared in the Dansactions and in the publications of the U. S. Geological Survey. As a basis for the further suggestions of this paper, the following are the most important: 1. The investigation of J. R. Don,' showing the gold of certain Australasian veins to have been deposited by ascending solutions, and not by lateral secretion. 2. The theory of Prof. Posepny? distinguishing the vadose from the deep circulation, and ascribing the origin of certain classes of ore-deposits to ascending solutions of the latter class. 3. The theory of Prof. Van Hise,3 as to the underground circulation and the primary enrichment of veins thereby. 4. The paper of Prof. J. F. Kemp,4 showing that ore-deposits are largely the products of " expiring vulcanism." Many. of Prof. Kemp's ideas have been widely adopted by mining men. 5. The theory of secondary enrichment, so lucidly expounded by Mr. S. F. Emmons.V his theory, dealing with the rearrangement of ore-bodies after primary mineralization, has been generally adopted, and seems to me to have been as completely proved as the nature of the case permits. There are two facts which I think should be constantly borne in mind in formulating a theory of the genesis of ore-

Jan 1, 1908

By Howard I. Smith

The mineral trona was discovered on Government land in 1938, about 18 miles west of the town of Green River, Wyo., in the core of the John Hay, Jr., well, a test well drilled for oil by the Mountain Fuel Supply Co. in sec. 2, T. 18 N., R. IIO W., sixth principal meridian. Although no oil or gas was reported, the drilling led to a discovery of great potential economic importance and exceptional scientific interest. Trona is a relatively rare mineral found at various places in playa deposits but not previously found at any great depth. It is composed of hydrous sodium carbonate and sodium bicarbonate (Na2CO3 NaHCo3.2H2O). Pure trona con-tains the equivalent of 70.35 per cent of sodium carbonate. Total sodium computed to carbonate times 1.42 equals the percentage of trona in the absence of other sodium carbonate minerals in the sample. Analyses Two short pieces of core sent to the author a few days after the completion of the Hay well were analyzed by R. C. Wells† and found to be exceptionally Pure trona. A brief article on this discovery has already been published.1 Arrangements were then made through W. T. Nighten-gale‡ for the author to inspect and sample the core. The company log of the well included notations of sodium salt crystals from a depth of 1190 to 1820 ft. Not being able to identify all the minerals present, the author selected several specimens of the core for petrographic examinations and sampled the sections of trona for analysis. J. J. Fahey, of the Geological Survey, examined the specimens and reported most of the crystals to be a new anhydrous sodium carbonate and calcium carbonate mineral (Na2CO 3.2 CaCO3), which he named shortite,² after Maxwell N. Short." He analyzed the samples of trona, with the results shown in Table I. In addition to the 10 ft. 1 in. of trona in the first section, it is reasonable to assume that the 9 ft. 8 in. for which no core was available for sampling is either i mostly trona or some other soluble salt, but it should not be included in calculating | reserves. In the part of the core between i 1590 ft. 3 in. and 1600 ft. 4 in. the material insoluble in cold water, amounting to about 5 per cent, was estimated petrographically I to contain 70 per cent clay, 25 per cent shortite, and 5 per cent pyrite. Accompanying Minerals Fahey later secured about 600 ft, of the core for a detailed examination and study

Jan 1, 1942

By Howard I. Smith

The mineral trona was discovered on Government land in 1938, about 18 miles west of the town of Green River, Wyo., in the core of the John Hay, Jr., well, a test well drilled for oil by the Mountain Fuel Supply Co. in sec. 2, T. 18 N., R. IIO W., sixth principal meridian. Although no oil or gas was reported, the drilling led to a discovery of great potential economic importance and exceptional scientific interest. Trona is a relatively rare mineral found at various places in playa deposits but not previously found at any great depth. It is composed of hydrous sodium carbonate and sodium bicarbonate (Na2CO3 NaHCo3.2H2O). Pure trona con-tains the equivalent of 70.35 per cent of sodium carbonate. Total sodium computed to carbonate times 1.42 equals the percentage of trona in the absence of other sodium carbonate minerals in the sample. Analyses Two short pieces of core sent to the author a few days after the completion of the Hay well were analyzed by R. C. Wells† and found to be exceptionally Pure trona. A brief article on this discovery has already been published.1 Arrangements were then made through W. T. Nighten-gale‡ for the author to inspect and sample the core. The company log of the well included notations of sodium salt crystals from a depth of 1190 to 1820 ft. Not being able to identify all the minerals present, the author selected several specimens of the core for petrographic examinations and sampled the sections of trona for analysis. J. J. Fahey, of the Geological Survey, examined the specimens and reported most of the crystals to be a new anhydrous sodium carbonate and calcium carbonate mineral (Na2CO 3.2 CaCO3), which he named shortite,² after Maxwell N. Short." He analyzed the samples of trona, with the results shown in Table I. In addition to the 10 ft. 1 in. of trona in the first section, it is reasonable to assume that the 9 ft. 8 in. for which no core was available for sampling is either i mostly trona or some other soluble salt, but it should not be included in calculating | reserves. In the part of the core between i 1590 ft. 3 in. and 1600 ft. 4 in. the material insoluble in cold water, amounting to about 5 per cent, was estimated petrographically I to contain 70 per cent clay, 25 per cent shortite, and 5 per cent pyrite. Accompanying Minerals Fahey later secured about 600 ft, of the core for a detailed examination and study

Jan 1, 1942

By Howard I. Smith

THE mineral trona was discovered on Government land in 1938, about 18 miles west of the town of Green River, Wyo., in the core of the John Hay, Jr., well, a test well drilled for oil by the Mountain Fuel Supply Co. in sec. 2, T. 18 N., R. 110 W., sixth principal meridian. Although no oil or gas was reported, the drilling led to a discovery of great potential economic importance and exceptional scientific interest. Trona is a relatively rare mineral found at various places in playa deposits but not previously found at any great depth. It is composed of hydrous sodium carbonate and sodium bicarbonate (Na2CO3.NaHCO3.2H20). Pure trona contains the equivalent of 70.35 per cent of sodium carbonate. Total sodium computed to carbonate times 1.42 equals the percentage of trona in the absence of other sodium carbonate minerals in the sample. ANALYSES Two short pieces of core sent to the author a few days after the completion of the Hay well were analyzed by R. C. Wells[t] and found to be exceptionally pure trona. A brief article on this discovery has already been published.1 Arrangements were then made through W. T. Nightengale[$] for the author to inspect and sample the core. The company log of the well included notations of sodium salt crystals from a depth of 1190 to 1820 ft. Not being able to identify all the minerals present, the author selected several specimens of the core for petrographic examinations and sampled the sections of trona for analysis. J. J. Fahey, of the Geological Survey, examined the specimens and reported most of the crystals to be a new anhydrous sodium carbonate and calcium carbonate mineral (Na2CO3.2CaCO3), which he named shortite,2 after Maxwell N. Short.* He analyzed the samples of trona, with the results shown in Table I. [ ] In addition to the 10 ft. I in. of trona in the first section, it is reasonable to assume that the 9 ft. 8 in. for which no core was available for sampling is either mostly trona or some other soluble salt, but it should not be included in calculating reserves. In the part of the core between 1590 ft. 3 in. and I600 ft. 4 in. the material insoluble in cold water, amounting to about 5 per cent, was estimated petrographically to contain 70 per cent clay, 25 per cent shortite, and 5 per cent pyrite. ACCOMPANYING MINERALS Fahey later secured about 600 ft. of the core for a detailed examination and study

Jan 1, 1942

By A. C. Dittrick

THE Simon-Carves washer, originally known as the Baum jig washer, was first built in Europe about 1892. It was probably the first washer to use intermittent pressure of air on water in one part of the wash box to obtain water pulsations in another part. This type of washer was also the first to successfully clean various sizes in the same unit. Previous practice was to size closely before washing. Today there are several large firms abroad, and a few in the United States, that are constructing the Baum type washer. The design of all is practically the same, their differences being only in details. In 1928, the Hanna Coal Co. first gave consideration to the question of coal cleaning. It was believed at that time that by efficient removal of so-called noncombustibles appearing in the Pittsburgh No. 8 seam, certain markets that had been lost due to poor preparation might be recovered. Mechanical cleaning and mechanical loading were under consideration. This type of cleaning was considered the most practical means of removing impurities in the sizes below 4 in. It was decided to adopt mechanical cleaning and develop a system of mechanical loading that would be successful on No. 8 coal.

Jan 1, 1935