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By Robert L. Thoms, Joseph D. Martinez

The development of Gulf Coast salt domes thus far, although enormously successful and productive, has proceeded in an unscheduled fashion governed by events rather than by a comprehensive plan. Motivation for the sequential progress of exploitation has included mineral discoveries, inventions, technological improvements, new needs, and a dynamic economy. Although it is too late to implement a plan for the entire cycle of exploitation of this resource, it would seem advisable to introduce now a system concept for further development. Viewed from this perspective, general determinative parameters should include economic, environmental, logistical, technical, and resource considerations, and more fundamentally, basic societal goals. Experience gained from planning in the Gulf Coast should provide guidelines for use elsewhere in the world.

Jan 1, 1981

A piece of arid, strip-mined land in southeastern Washington recently yielded over 22 bushels of winter wheat per acre-without irrigation. The surprising crop yield is the product of an innovative reclamation technique-one of several methods now being developed as alternatives to traditional reclamation. Conventional reclamation methods are not always successful on strip-mined acreage in the arid West. Replanting native vegetation usually requires fertilizer and irrigation-both energy-intensive commodities in arid regions. Now, promising alternatives which rely solely on rainfall for irrigation are being offered by two research teams.

Jan 12, 1978

By Andy B. Wallace

Veins in the Pyramid district of northwestern Nevada occur along steep fractures in Oligocene and Miocene quartz latite tuffs. The vein mineralization is zoned from a central enargite-pyrite zone outward through a complex polymetallic pyrite-tetrahedrite-sphalerite-galena-chalcopyrite-bornite-chalcocite zone, and finally to an outer zone of pyrite and galena. Wall rock alteration includes advanced argillic and sericitic envelopes along veins superimposed on district-wide propylitization. The ore distribution and alteration patterns were probably produced by an increase in pH, a decrease in sulfur fugacity, along with cooling of the migrating hydrothermal fluid.

Jan 1, 1981

By David R. Maneval, Ralph A. Lambert, H. B. Charmbury

Subsidence, although it may or may not be apparent on the surface, is an inevitable consequence of deep coal mining and a frequent cause of damage to surface structures. Efforts to prevent subsidence go back many years, but there is still only one known antidote that is both technically feasible and predictable. This is the hydraulic or pneumatic stowing of solids-or flushing. In coal mines, however, flushing has been rarely used because it is considered the most expensive method of filling such mines, even though the reverse is true for ore mines. It is thus significant that the method has found favor in a comprehensive program the Commonwealth of Pennsylvania has undertaken to eliminate the hazards of abandoned coal mines within its jurisdiction. In "Operation Backfill," as the program is known, the Commonwealth has successfully used hydraulic flushing and fully justified the method economically.

Jan 4, 1967

By W. H. Smith

IN the course of an investigation on chromium containing minor amounts of alloying elements, the information herein has been obtained on the crys-tallographic orientations resulting from arc melting, rolling, and annealing. The chromium used in this investigation was electrolytic flake obtained from the Electro Metallurgical Co. This material was heated for 20 hr at 1600°C in hydrogen with a dew point of about — 100°C. The oxygen and nitrogen content of the chromium after this treatment was 0.0003 pct 0 and 0.005 pct N. Five pounds of this chromium were arc melted in a water-cooled copper crucible. After arc melting, the oxygen and nitrogen contents were 0.002 and 0.025 pet, respectively. A section of this ingot is shown in Fig. 1. By means of a back-reflection Laue technique, the crystal habit of the cast ingot was determined. As expected, it was found that the [loo] was approximately the axis of the columnar grains. In this respect, chromium behaves like other body-centered-cubic metals in that a cubic axis is normal to the cold surface of the mold. A slab cut from this ingot was rolled at 600°C as follows: four 30 pct reductions were made with intermediate anneals at 1200°C for 15 min. Rolling was done with the [loo] of the columnar grains in the rolling direction. Following the final anneal, an 80 pct reduction was taken at 600 °C. The final sheet thickness was ten mils. By polishing and etching, the thickness was reduced to four mils and the grain orientation determined by the transmission Laue method using molybdenum radiation with a zirconium filter. Fig. 2 is the (110) pole figure for this material with the ideal (100) [011] and (111) [112] orientations indicated. The orientation is typical of most cold rolled body-centered-cubic metals having the [llO] of the grains approximately in the rolling direction and the (100) planes approximately in the plane of the rolled sheet. There is also evidence of some 10) [1 orientation. The grain orientation of sheet rolled 40 and 80 pct in the same direction as before at 600°C followed by recrystallization at 12000 C for 15 min was determined by a back-reflection Laue technique. A random texture was found in both cases. This 1200°C 15 min anneal was found to give complete recrystallization and some grain growth.

Jan 1, 1956

By G. H. Lovell, W. J. Parton, J. J. Crane

IN 1949 Lehigh Navigation Coal began a study to improve its mining methods. At this time the company mines were using conventional breast and pillar and slant chute methods to mine the. steeply pitching coal (40º to 90º). Mining costs were high, the miners' productivity low. There were many hazards typical of the methods employed. Coal seams in the Panther Creek Valley area of the southern anthracite field form a syncline dipping 40" to the south and 75º to 80º to the north, the lowest point 1500 ft from surface. Several contiguous veins 7 to 50 ft thick are mined. Characteristic folding is shown in Fig. 1.

Jan 3, 1957

INTRODUCTION TO PROBABILITY THEORY The mathematical theory of probability provides the foundation for the interpretations and inferences that can be made from statistical techniques. Probability theory is a broad field of study in itself, and can only be touched on here in order to provide the necessary back- ground for a more complete understanding of statistical analysis. Probability is concerned with the outcome of random events. It had its beginnings in the theory of games of chance which were of great interest to European mathematicians during the last half of the 17th century. The outcome of a random process or experiment is defined as an event. The collection of all mathematical points associated with each event is called the sample space for an experiment. Consider a random experiment having a finite number, n, of possible outcomes, some of which have a characteristic A. What is the probability that A will result from a single

Jan 1, 1980

By O. C. Wheeler

Production in Colombia attained a new high during 1940 when it reached a total of 25,607,976 bbl. Of this amount, the Tropical Oil Co. produced 21;426,492 bbl., including 268,586 bbl. of petroleum condensate, and the Cololmbian Petroleum Co. produced 4,181,484 bbl. from its Barco property. The wildcatting program of different companies in the Magdalena Valley that was initiated during the previous year was continued but with results that were decidedly disappointing. Ten wells were drilled in the Magdalena Valley between the approximate latitudes of Puerto Wilches and Puerto Berrio and nine of these were dry; the tenth was a small producer of no commercial importance. The prospects of finding new fields in the Magdalena Valley thus received a serious setback, since some of the tests drilled were on well developed surface structures. The prospects of the Valley, however, have by no means been exhausted and drilling operations are being continued on other prospects. One additional wildcat was drilled outside the Magdalena Valley on the Colombian Petroleum Company's Barco Concession, which brought to 11 the total number of wildcats drilled in Colom-bia during the year. This well, known as

Jan 1, 1941

By Raymond Mancha

WHEN calculating the pressure-volume characteristics of projected mine-ventilat-ing circuits by orthodox methods, certain basic assumptions are required in order to employ the various available empirical data. It is assumed, for example, that the mine air is an incompressible fluid subjected to isothermal flow, an assumption suffi-ciently accurate for practical purposes since pressure and temperature differentials are small throughout the average circuit. A more erroneous assumption, however, is that all air is accounted for as it travels throughout the mine. No attempt is usually made to evaluate stopping leakage as it occurs; instead, the air volume required at the last crosscuts is assumed to enter the mine, travel the vari-ous intake air courses intact, sweep the workings and travel out by the return air courses to the point or points of exit from the mine. Actually, there is a leakage of air from intake to return at every stopping, the quantity of this leakage depending upon the tightness of the stopping and the pres-sure difference across the stopping. Unfortunately, a lack of empirical data and knowledge of the condition of individ-ual stoppings makes an exact analysis of underground stopping leakage impossible. Generally, leakage is most severe through the old stoppings outbye the circuit. These are also subjected to higher pressure differ-ences than the newer inbye stoppings. Therefore the circuit air volume diminishes at a decreasing rate progressing from out-bye to inbye the circuit.

Jan 1, 1940

By O. C. Wheeler

Production in Colombia attained a new high during 1940 when it reached a total of 25,607,976 bbl. Of this amount, the Tropical Oil Co. produced 21;426,492 bbl., including 268,586 bbl. of petroleum condensate, and the Cololmbian Petroleum Co. produced 4,181,484 bbl. from its Barco property. The wildcatting program of different companies in the Magdalena Valley that was initiated during the previous year was continued but with results that were decidedly disappointing. Ten wells were drilled in the Magdalena Valley between the approximate latitudes of Puerto Wilches and Puerto Berrio and nine of these were dry; the tenth was a small producer of no commercial importance. The prospects of finding new fields in the Magdalena Valley thus received a serious setback, since some of the tests drilled were on well developed surface structures. The prospects of the Valley, however, have by no means been exhausted and drilling operations are being continued on other prospects. One additional wildcat was drilled outside the Magdalena Valley on the Colombian Petroleum Company's Barco Concession, which brought to 11 the total number of wildcats drilled in Colom-bia during the year. This well, known as

Jan 1, 1941

By R. Walker, R. J. Anslow

Today at Tampa we see the end results of a team effort: A vital link in an intermodal transportation system, the link that enables the unit-train concept to be employed with full effectiveness and the link that improves the economics of water transportation systems. Two new phosphate transfer complexes with a multi- million ton annual capacity are in operation in Tampa, Fla. Revolutionary in concept, these companion installations represent a total investment in the Tampa Bay area of $18.5 million.

Jan 1, 1970

By D. T. Novick, M. B. Bever, B. Roessler

Ordered and disordered specimens of the alloy CusAu were cold worked and then annealed at 2880, 310°, and 340°C, together with disordered unworked specimens. me resistivity decreased during annealing mainly as a result of ordering; the resistivity measurements suggest that in cold-worked specimens the growth of antiphase domains is impeded. The strength properties increased during annealing at 288 "C; in cold-worked specimens this increase was lo a level above that for cold-worked specimens which had not been annealed. X-ray diffraction showed that after annealing for a few hours at 288ºC, the long-range order increased to a constant value; additional annealing at 288ºC resulted in the growth of antiphase domains in which the degree of order was constant. Changes in peak breadth and particle size confirmed that in cold-worked specimens the major effects of cold work were not eliminated during annealing at 288 "C, although a slight recovery process occurred. When a specimen of the alloy Cu3Au is heated to a temperature below the critical temperature (388ºC), long-range ordering tends to occur in a specimen containing less than the equilibrium amount of order characteristic of that temperature Ideally, a specimen of Cu3Au contains no long-range order if it has been quenched from above the critical temperature. Long-range order is reduced by cold work. If cold-worked specimens are heated, restoration processes such as recovery and recrystallization may occur,

Jan 1, 1963

By Erwin S. Sperry

Brass or bronze chips, grindings, buftings, washings, and miscellaneous scrap metal sooner or later find their way into the hands of the so-called metal-smelter or " refiner," whose refining or smelting operation consists simply in melting the material, adding the requisite amounts of other metals, and then casting it in the form of ingots, which are afterwards sold

Jan 1, 1899

By G. L. Oldright

DURING 1919, in the face of high cost for labor and supplies and a rapidly dropping copper market, the management of the Ohio Copper Co. of Utah was left with an orebody that had been shown to be very low grade, and a mill that could not make a satisfactory recovery, even by flotation, because a considerable proportion of the copper minerals was oxidized. About seven million tons had been mined by the use of a caving system, the best of the broken ore extracted and milled, and the nature and copper content of the rest of the orebody fairly well determined. The rock of the whole mine was shown to run between 0.3 and 1.3 per cent. in. copper. As, the Ohio Copper orebody lies at the contact of the original sandstone (now altered to quartzite) with the quartz monzonite intru-sion that was the source of the mineralization at Bingham Canon, the rock was thoroughly shattered. It was shown further that the rock was mostly quart-zite, with a few quartz-monzonite "fingers" projecting into it. Although some of the old cleavage planes had been healed by resilicification so as to leave some of the copper minerals disseminated in the rock, a large proportion of these minerals was distributed along the cleavage planes.

Jan 10, 1923

By D. L. Katz

In the management of oil properties, it is always desirable to know the future behavior of oil wells and oil reservoirs. Some estimation of the quantity of oil and gas that will be produced must be made as a basis for decisions on possible returns on investments in lifting equipment, drilling of additional wells, and other operating expenditures. In new or wildcat areas, operating expenditures are considered highly speculative, but in the completion of partly drilled and the operation of producing fields it is good business to remove as much speculation as possible. An accurate knowledge of oil and gas reserves in such cases would solve many management problems. The term "oil reserves" usually signifies the future ultimate recovery without specifying the method of production. Thus with changing methods and innovations in the production industry, reserves of any definite reservoir may be increased by increasing the portion of oil recovered. The usual reserve estimates are made by comparisons of well and formation characteristics, by using a percentage recovery on the oil content of the formation volume using porosity data, by extending production curves on non-prorated wells, or by extending bottom-hole pressure-production curves. The most reliable method would appear to be one that would estimate the initial quantity of oil and gas present and then obtain percentage recovery values for various productive methods and formations from experience. It is the purpose of this paper to describe a method of estimating the initial quantity of oil and gas present in a reservoir. The method is based on field operating data and the properties of crude oil-gas mixtures. The principles involved, the data required, the assumptions necessary, and an example of the method will be given. The method is entirely independent of sand volumes and formation porosities. Principles of Method The method of estimating the initial quantity of oil and gas present is based upon the premise that the volume occupied by oil and gas in the reservoir is constant and that a mixture of crude oil and gas will behave in

Jan 1, 1936

By D. L. Katz

In the management of oil properties, it is always desirable to know the future behavior of oil wells and oil reservoirs. Some estimation of the quantity of oil and gas that will be produced must be made as a basis for decisions on possible returns on investments in lifting equipment, drilling of additional wells, and other operating expenditures. In new or wildcat areas, operating expenditures are considered highly speculative, but in the completion of partly drilled and the operation of producing fields it is good business to remove as much speculation as possible. An accurate knowledge of oil and gas reserves in such cases would solve many management problems. The term "oil reserves" usually signifies the future ultimate recovery without specifying the method of production. Thus with changing methods and innovations in the production industry, reserves of any definite reservoir may be increased by increasing the portion of oil recovered. The usual reserve estimates are made by comparisons of well and formation characteristics, by using a percentage recovery on the oil content of the formation volume using porosity data, by extending production curves on non-prorated wells, or by extending bottom-hole pressure-production curves. The most reliable method would appear to be one that would estimate the initial quantity of oil and gas present and then obtain percentage recovery values for various productive methods and formations from experience. It is the purpose of this paper to describe a method of estimating the initial quantity of oil and gas present in a reservoir. The method is based on field operating data and the properties of crude oil-gas mixtures. The principles involved, the data required, the assumptions necessary, and an example of the method will be given. The method is entirely independent of sand volumes and formation porosities. Principles of Method The method of estimating the initial quantity of oil and gas present is based upon the premise that the volume occupied by oil and gas in the reservoir is constant and that a mixture of crude oil and gas will behave in

Jan 1, 1936

By Dale Dixon, A. R. MacPherson

The present comminution process in principle has remained more or less the same for the last 50 years. The majority of the changes have been in the fields of equipment improvements and size increases of prevailing systems. The development and utilization of completely new systems has virtually been non-existent. As energy and steeel costs increase and lower grade ores are mined, the comminution costs per ton of ore treated must improve accordingly or the operations will not be profitable. The chapter examines further developments in existing systems and touches on relatively unexplored methods of comminution appropriate for future needs.

Jan 1, 1982

By Research Staff ? Verde Copper Mines

FLOTATION is now commonly practiced in alkaline ore pulps, yet little is known regarding the action of the alkaline solutions on the ore particles beyond the fact that films of oxidized material form. We wish to chronicle our discovery of the presence of soluble reducing agents in alkaline ore pulps of the United Verde, and present some data on lime consumption. During the grinding and flotation of a pyritic ore containing small amounts of ferrous sulfate and other soluble salts, an excess of lime was added to precipitate the salts, and filtered samples of the solution were titrated with standard permanganate solution. Even in pulps of high causticity an appreciable permanganate titration was always obtained, in spite of the fact that the solutions were shown to contain little iron. Investigation of the cause brought about the discovery of several previously unsuspected compounds in flotation pulps made from pyritic ore. Not only the reducing agents present had to be identified, but also the amount of dissolved oxygen, and a survey was finally made of the free oxygen content and reducing agents of the mill pulp in the concentrating mill at Clarkdale. A great many compounds might form, caused by oxidation of pyrite or other metal sulfides or by reaction between a lime solution and pyrite. The most probable compounds considered were calcium sulfides; polysul-fides, thiosulfates, and polythionates. Later it was discovered in the literature that in alkaline pulp polythionates do not exist and if introduced. are decomposed into sulfites and thiosulfates.1 Any precipitated sulfur is changed by alkali into thiosulfate and polysulfide. Sulfites and sulfides react to form thiosulfate, so that in the end it is possible to have in an alkaline solution only thiosulfate and an excess either of sulfide or sulfite. Confirmatory tests were made and it was finally established that the alkaline mill pulps made from the United Verde ore contained

Jan 1, 1929

By Gerhard Derge

A SERIES of studies of the corrosion of tin is under way in the Metals Research Laboratory at the Carnegie Institute of Technology. The complete program includes examination of the corrosion properties of high-purity tin and the changes produced in these properties by the addition of varying amounts of alloying elements. Other studies of this subject have been made recently under the sponsorship of the International Tin Research and Development Council, but these researches have been confined largely to the weakly acid environments commonly encountered in the canning industry.1 There is little information available regarding the corrosion of tin under alkaline conditions, but such data would be of value, for a large amount of the metal is used under such conditions. The potential measurements to be described were made because they seemed to offer the most rapid method for obtaining a general view of the conditions to be encountered in such service. These experiments will also serve to establish a technique that will be of value in further studies. It must be emphasized that the results reported are those of controlled laboratory experiments and that the conclusions drawn cannot yet be applied to service conditions; rather, they point to the directions in which more exhaustive experimental work may be done to best advantage. EXPERIMENTAL PROCEDURE The first work was devoted entirely to the problem of obtaining reproducible results from a series of potential measurements. Only the methods finally adopted as standard will be described here, except when the variations from these have furnished results of interest. The cell used is shown schematically in Fig. 1. The electrolyte is contained in the vessel A (an inverted bell jar), whose ground top is fitted to the transite-board lid B. The controlled atmosphere can be admitted

Jan 1, 1938

By John D. Kalasky

The success in providing adequate ventilation to the active faces of a coal mine for all methods of mining depends upon good face control and the air distribution and control system. A good system provides overcasts, air locks, regulators and bleeders so that an adequate flow of air will be confined to the working places with least opportunity for interruption, and that a flow of air is maintained, however small, across the worked out area to the bleeder and away from men and equipment at all times. In gaseous mines, it is just as important to satisfy effective bleeding as it is to satisfy the air volume requirements in the operating splits. The two requirements go hand in hand. Although not complicated, ventilation and methane drainage in longwall mining in a gaseous mine require careful forethought and adequate facilities to make them safe.

Jan 8, 1966