Search Documents

By R. D. Mollison

"For his contributions to mining which are highlighted by perseverance; successful exploration, particularly the Kidd Creek deposit; technological advancement and sound management policies; and for his lecture, "Exploration-The Diversificiation and Development of a Mining Company." Recipient of the 1983 D.C. Jackling Award

Jan 1, 1984

By Reynold Q. Shotts

Nitric acid oxidation rate analyses of three coals, previously studied microscopically by the Bureau of Mines, revealed three components. Relative quantities agree with those found for the four components given by the Bureau and results are consistent with current ideas of coal constitution. Possible multi-component composition for bright coal and a reactivity-rank relation are suggested.

Jan 5, 1953

By V. R. Garfias

EVEN before the arrival of Cortes in 1519, the history of Mexico was closely linked to that of its mineral production; the mining activities of the Aztecs being thus described by Clavigero, one of the early historians: In the mountains of Anahuac there abound in veins all kinds of metals, and infinite variety of other fossiliferous products. The Aztecs obtained gold from the countries of the Cohuijques, of the Mixtecas, of the Zapotecas and from various other places. They gathered that precious metal usually in grain, from the sands of the rivers, keeping a certain portion for the crown. They obtained silver from the mines of Taxco, of Tzumpango and others; however, this metal was not as esteemed by them as by other neighboring nations. They had two kinds of copper; one hard, which they used instead of iron to make sickles, lances and all kinds of rural and military instruments and another, soft, with which they made kettles, goblets and other receptacles. This metal abounds mainly in the province of Zacatula and in that of Cohuijques, which at present is in the kingdom of Michoacan. They obtained tin from the mines of Taxco and lead from those of Izmiquilpan, located in the country of the Otomiea. From the tin they made money, and the lead, we know they sold in the market places, but we ignore the uses to which they applied it. They also had mines of iron in Tlaxcala, in Taxco and in other places; but they either had not discovered them, or did not know how to make use of the metal they contained. In Chilapa there were mines of mercury, and in other places there were mines of sulphur, alum, vitriol, cinnabar, cohre and of a white earth which they esteemed highly. As regards mercury and vitriol, we do not know of what use they were to them; the other metals they used in paintings and dyes. There were then great abundance of amber and asphalt-bitu- men of Judea--on the coast of the seas and many cities of that territory paid tribute of one and the other to the kingdom of Mexico. They mounted the amber in gold, and it was only used as ornament and display by them. With the asphalt they made certain perfumes. The following extracts dealing with pre-Colonial gold are taken from the famous "Cartas de Relación" to Charles V, in which Cortea described the progress of the Conquest: . . . here there came two chiefs who owned lands in the valley; one four leagues down the valley and the other two leagues up the valley and they gave me some gold necklaces of little value and seven or eight girls. . . . . . . that day I left the City of Churultecal and traveled four leagues to some villages of the City of Cuasucingo where the natives received me very well and gave me women and pieces of gold. . . .

Jan 1, 1937

By B. C. Raynes

IN the early part of 1952, under the auspices of the U. S. Atomic Energy Commission, Horizons Inc. undertook an investigation dealing with the preparation of high purity thorium metal in order to develop an economically competitive production process for this metal based on a recovery of the metal by a fused salt electrolysis, since a survey of the literature of thorium chemistry indicated that electrolytic methods had not received much attention, despite the consideration that electrochemical production methods often offer attractive commercial potentialities. Thorium metal has been prepared by methods which fall into four general categories: 1) reduction of halides or double halides; 2) reduction of the oxide; 3) thermal decomposition of halides; and 4) electrolytic methods. Some of the important results obtained by various investigators since about 1900 in recorded attempts to prepare pure thorium metal are summarized in Table I. A bibliography of pertinent literature is included in this paper. Thorium is strongly electropositive and possesses a great affinity for oxygen and nitrogen. As a result the prospects for the production of high purity thorium from aqueous media or oxygen bearing compounds are remote. The most promising and profitable area of investigation for production of thorium metal lies in fused salt electrolysis. Thorium has been produced previously by this technique from halide salts in fused alkali chloride eutectic mixtures. Until recently, however, the lack of known large uses for thorium has inhibited the investigation of these methods. The basic problem in an investigation into fused salt production methods for thorium is to develop a suitable fused salt system for the economic preparation of thorium. The first portion of the work in these laboratories was a small scale investigation of the electrolysis of potassium thorium fluoride, KThF5, under a variety of conditions. High purity thorium was prepared in this manner, but the process did not appear to offer the simplest and most attractive continuous commercial operation. The work reported here relates to an all-chloride system employing thorium chloride as the cell feed. ThCL4 was produced as an anhydrous material stabilized in molten sodium chloride. This product, further diluted in NaCl, was subjected to electrolysis. The electrolytic process has been studied in cells capable of holding up to 50 lb total salt charge. Ductile, pure thorium metal has been reproducibly obtained in this operation. Considerable experimentation was carried out in the preparation of ThCL as a cell feed free from moisture, oxides, and other impurities. Thorium was cathodically deposited as a coarsely crystalline powder interspersed with residual bath salts. Aqueous procedures for separating and recovering the metal were developed. The thorium metal powder obtained has been evaluated with respect to its hardness, chemical purity, and certain other physical properties. Preparation of ThC1,—Thorium chloride, and the chlorides of some other metals (aluminum, beryllium, tantalum, zirconium, etc.) cannot be obtained from aqueous solution by direct heating and evaporation. Evaporation and heating of a solution of thorium chloride yields a hydrated salt or partially hydrated salt, and finally Tho,. Anhydrous thorium chloride is obtained by forming a hydrated ammonium chloride complex salt in acidified water solution, dehydrating this compound, and finally decomposing the double salt and subliming the ammonium chloride component. Various methods for the preparation of anhydrous thorium chloride, in accordance with this concept, were investigated as indicated in Table I1 from hydrated thorium chloride (ThCl, . 3H2O), and from thorium oxycarbonate (ThOCO,). In the method found most satisfactory for this work, thorium oxycarbonate was dissolved in an excess of concentrated HC1 to give a clear yellow solution. At least 2 mol NH,Cl were added to the solution per mol of contained thorium. Ammonium thorium chloride hydrate was crystallized from solution by cooling and saturation with HC1. The resultant complex, (NH,Cl),ThCl;xH,O, was dehydrated by evaporation at 130° to 150°C and thoroughly dried at about 250°C. The dried ammanium thorium chloride was then mixed with sodium chloride in proportions to form NaThCL or to produce a ThCL4-NaCl mixture with a given thorium content. The ammonium chloride was sublimed off at temperatures above 500°C in an inert atmosphere furnace to give an anhydrous chloride source electrolyte, essentially free of Tho, and of NKC1.

Jan 1, 1958

During the presentation of the papers, questions were deferred until after the last paper in the afternoon. At that time, the authors and co-chairmen formed a panel for discussion of any pertinent questions. The panel was as follows: Carl Gerity - Ozark Lead Company – Chairman Mike Young - Master Mechanic - Ozark Lead Company Largo Albert - Maintenance Specialist (hoisting) Mines Maintenance Dept. - International Nickel Company, with assistance from Co-author Alan Cameron - International Nickel Company Gary Beerkircher - Product Manager - Rexnord Inc., Nordberg Machinery Group Richard Schaal - Director of Maintenance - Superior Division, Magma Copper Company Rich Hodgson - Assistant Production Superintendent - FMC Corporation The remarks have been edited by the panelists for readability, the basic ideas were not changed. Additional thoughts by the panelists submitted at the time of their revision are indicated by ***.

Jan 1, 1975

By C. B. Gillson, Henry Fay

For several years past, investigations on the chemistry of tellurium have been carried on in the laboratory of this institution. The methods of preparation of pure telluriumf and the estimation of tellurium‡ have been studied, and an attempt to determine the atomic weight of tellurium is now in progress. All these problems had been investigated, however, along purely theoretical lines; and it was thought desirable to study the more practical application of the metal, which can now be had in considerable quantities as a waste product in the refining of copper-ores. In its physical and chemical properties tellurium is very similar to antimony, and it was thought

Jan 1, 1902

By Richard H. Ross

A broad definition of' "Mill Design" might cover everything from the first tentative choice of general process to the final structural details for construction. The first phases are mainly concerned with metallurgy and economics and the final stages with the mechanics of putting the selected equipment together into an integrated plant. It is the purpose of this article to discuss only data, derived from laboratory testing, that contributes directly to design of the milling plant itself, and only the plant design phases that are influenced by laboratory testing. Most ore beneficiation testing is devoted to determining recoveries, grades of products, elimination of impurities, reagent and supply requirements, etc. having little to do with physical plant design although these factors are of prime importance in the evaluation of a mining project.

Jan 3, 1964

By R. M. Leibrock, J. E. Huzarevich, R. G. Hiltz

The various factors considered in recommending the initiation of a gas injection project in the southern portion of the Cedar Lake Field are discussed. Performance history under gas injection operations is reviewed and these data are analyzed, utilizing both the material balance method and the fractional flow and frontal advance expressions. Results of the analysis of the performance data indicate that the injected gas has contacted and affected at least 60 per cent of the reservoir and a substantial increase in ultimate recovery can reasonably be expected. By holding the reservoir pressure appreciably above the bubble point, the well productive capacities have been maintained substantially above the level predicted for primary operations. The analysis of the Cedar Lake project suggests that in certain limestone reservoirs, at least, the probable success of gas injection cannot be predicted simply from ohservation of permeability distribution throughout the pay section, as indicated by core analysis data, on either one or a number of wells. Further, the performance of this particular project fails to indicate any basis for classifying carbonate reservoirs in general as being inherently unsuited to a dispersed type gas injection program, thus indicating that each reservoir should be considered on its own merits, regardless of the composition of the reservoir rock. INTRODUCTION Early in the life of the Cedar Lake Field, an extensive data gathering program was initiated to provide an accurate record of reservoir performance characteristics. From the study of these data it was apparent that there was a critical need for supplementing the natural reservoir energy in order to maintain well productivities and obtain the maximum ultimate oil recovery. Accordingly, detailed engineering studies were made of the various methods of secondary recovery which might be applicable. As a result of these investigations, the decision was made to initiate a gas injection program of sufficient intensity to maintain reservoir pressure at approximately 600 psia, or some 274 lb above the bubble point pressure of 326 psia. A full scale dispersed type gas injection program has been in operation on leases of the Stanolind Oil and Gas Co. in the southern portion of the field for nearly five years, and sufficient performance data are now available to evaluate the benefits which have been derived from this project. It is the primary purpose of this paper to analyze the performance data for the Cedar Lake gas injection project and to point out the significance of the ohserved behavior with respect to certain hypotheses which have been advanced in recent years concerning the probable success of gas injection projects in limestone reservoirs. This paper properly should be regarded more on the order of a progress report, inasmuch as some revision in interpretation will undoubtedly be required from time to time as additional performance data are obtained, although the satisfactory performance of the project to date leaves little doubt as to the ultimate success of gas injection in the Cedar Lake Field. As a result of the success of the project to date, a unit was formed in the southern part of the field, effective March 1, 1951, for the purpose of continuation of the gas injection program. Participants in this unit are the Mid-Continent Petroleum Co. and Stanolind Oil and Gas Co. GEOLOGY AND STRATIGRAPHY The Cedar Lake Field is located in the northern portion of the Midland Basin area as shown in Fig. 1. The southwest portion of the field lies within a playa, or dry salt lake, which covers an area of approximately eight square miles. As might be expected, it was this lake which furnished the inspiration for the name of the field. Except for its value as a salt water disposal pit, this lake has succeeded only in magnifying the difficulties in developing this portion of the field. Typical of this section of West Texas, the area in general is relatively flat and has a semi-arid climate. The localized structure which favored the accumulation of oil is an anticline with approximately 100 ft of closure. The major axis of the structure extends in a general southeast-northwest direction. Originally this structure was defined by seismograph data, which have been subsequently confirmed by development. In general, the geologic column is typical of that found throughout the basin. From the surface to depth of approximately 1,800 ft, surface sands and undifferentiated red beds. probably Triassic. are encountered. Below this point to the producing horizon, all formations are of the Permian age.

Jan 1, 1951

By J. E. Huzarevich, R. M. Leibrock, R. G. Hiltz

The various factors considered in recommending the initiation of a gas injection project in the southern portion of the Cedar Lake Field are discussed. Performance history under gas injection operations is reviewed and these data are analyzed, utilizing both the material balance method and the fractional flow and frontal advance expressions. Results of the analysis of the performance data indicate that the injected gas has contacted and affected at least 60 per cent of the reservoir and a substantial increase in ultimate recovery can reasonably be expected. By holding the reservoir pressure appreciably above the bubble point, the well productive capacities have been maintained substantially above the level predicted for primary operations. The analysis of the Cedar Lake project suggests that in certain limestone reservoirs, at least, the probable success of gas injection cannot be predicted simply from ohservation of permeability distribution throughout the pay section, as indicated by core analysis data, on either one or a number of wells. Further, the performance of this particular project fails to indicate any basis for classifying carbonate reservoirs in general as being inherently unsuited to a dispersed type gas injection program, thus indicating that each reservoir should be considered on its own merits, regardless of the composition of the reservoir rock. INTRODUCTION Early in the life of the Cedar Lake Field, an extensive data gathering program was initiated to provide an accurate record of reservoir performance characteristics. From the study of these data it was apparent that there was a critical need for supplementing the natural reservoir energy in order to maintain well productivities and obtain the maximum ultimate oil recovery. Accordingly, detailed engineering studies were made of the various methods of secondary recovery which might be applicable. As a result of these investigations, the decision was made to initiate a gas injection program of sufficient intensity to maintain reservoir pressure at approximately 600 psia, or some 274 lb above the bubble point pressure of 326 psia. A full scale dispersed type gas injection program has been in operation on leases of the Stanolind Oil and Gas Co. in the southern portion of the field for nearly five years, and sufficient performance data are now available to evaluate the benefits which have been derived from this project. It is the primary purpose of this paper to analyze the performance data for the Cedar Lake gas injection project and to point out the significance of the ohserved behavior with respect to certain hypotheses which have been advanced in recent years concerning the probable success of gas injection projects in limestone reservoirs. This paper properly should be regarded more on the order of a progress report, inasmuch as some revision in interpretation will undoubtedly be required from time to time as additional performance data are obtained, although the satisfactory performance of the project to date leaves little doubt as to the ultimate success of gas injection in the Cedar Lake Field. As a result of the success of the project to date, a unit was formed in the southern part of the field, effective March 1, 1951, for the purpose of continuation of the gas injection program. Participants in this unit are the Mid-Continent Petroleum Co. and Stanolind Oil and Gas Co. GEOLOGY AND STRATIGRAPHY The Cedar Lake Field is located in the northern portion of the Midland Basin area as shown in Fig. 1. The southwest portion of the field lies within a playa, or dry salt lake, which covers an area of approximately eight square miles. As might be expected, it was this lake which furnished the inspiration for the name of the field. Except for its value as a salt water disposal pit, this lake has succeeded only in magnifying the difficulties in developing this portion of the field. Typical of this section of West Texas, the area in general is relatively flat and has a semi-arid climate. The localized structure which favored the accumulation of oil is an anticline with approximately 100 ft of closure. The major axis of the structure extends in a general southeast-northwest direction. Originally this structure was defined by seismograph data, which have been subsequently confirmed by development. In general, the geologic column is typical of that found throughout the basin. From the surface to depth of approximately 1,800 ft, surface sands and undifferentiated red beds. probably Triassic. are encountered. Below this point to the producing horizon, all formations are of the Permian age.

Jan 1, 1951

By William E. Ford, Edward Salisbury Dana

IN the representation of crystals by figures it is customary to draw their edges as if they were projected upon some definite plane. Two sorts of projection are use8; the ah- graphic in which the lines of projection fell at right angles and the chirographic where they fall at oblique angles upon the plane of projection. The second of these projections is the more important, and must be tr2atcd here in some detail. Two points are to be noted in regard to it. In the first place, in the drawings of crystals the point of view is supposed to be at an infinite distance, and it follows from this that all lines which are parallel on the crystal appear parallel in the drawing. In the second place, in all ordinary cases, it is the complete ideal crystal which is represented, that is, the crystal with its full geometrical symmetry as explained on pp. 10 to 13 (cf. note on p. 13). In general, drawings of crystals are made, either by constructing the figure upon a projection of its crystal axes, using the intercepts of the different faces upon the axes in order to determine the directions of the edges or by constructing the figure from the gnomonic (or stereographic) projection of the crystal forms. Both of these methods have their advantages and disadvantages. By drawing the crystal figure by the aid of a projection of its crystal axes the symmetry of the crystal and the relations of its faces to the axes are emphasized. In many cases, however, drawing from a projection of the poles of the crystal faces is simpler and takes less time. The student should be able to use both methods and consequently both are described below.

Jan 1, 1922

By C. B. Dudley

In October, 1878, and again in February, 1881, I had the honor to make public, through the medium of the American Institute of Mining Engineers, the results of an extended study of steel rails which had been in service, and which mere taken for the purpose from the tracks of the Pennsylvania Railroad Company. These studies appeared in three papers. In the first of these papers the question. what kind of steel is least liable to fracture or disintegration in the track, was the principal one considered. In the second paper the question discussed was, does the power of steel to resist wear increase with the hardness ? In the third paper the relation between wear and the chemical and physical properties of the metal was the principal point considered. The general results arrived at, or the cooclusions reached, were, as follows: 1. That a mild steel is less liable to fracture, and if properly made, less liable to crushing or disintegration in the track than a harder steel. 2. That the wearing-power of steel in rails not only does not increase as hardness increases, but, on the contrary, diminishes; or, in other words, that a mild steel gives less loss of metal under the same service than a hard steel. These conclusions may be briefly stated in a single sentence—namely, in rails mild steel is not only less liable to fracture and disintegration in the track, but it also gives longer life, or wears more slowly under the same traffic; than harder steel. It is perhaps hardly necessary to add that by mild steel is meant steel

Jan 1, 1891

By Warnie Flint

PERSONAL INJURY ACCIDENTS According to statistics compiled by the National Safety Council, US Bureau of Mines, American Medical Association, and other agencies, accidental injuries cause more deaths than all the leading diseases. NO one is immune to an accident. Probably the best way to describe an accident is to say that it is an unexpected happening. The automobile driver is not expecting a terrifying crash, the electrician does not expect to be electrocuted, nor is the coal miner expecting the roof to fall on him. All personal injuries will not result in death. There is a multitude of victims who arc living proof of what accidents can mean to an individual-victims who are blind, paralytic, missing arms, legs, etc. In most instances the earning power of these individuals is gone, and they arc utterly dependent upon family or welfare. For many years there seemed to be an attitude that prevailed in industrial America that accidents were inevitable, and that so many fatalities and injuries should be expected. This, of course, was utter nonsense. Since the birth of such organizations as The National Safety Council, American Society of Safety Engineers, and the US Bureau of Mines, much progress has been made in reducing accidents. The enactment of compensation laws greatly contributed to the progress that has been made. Does this mean that all accidents can be prevented? Unfortunately, it does not. Human psychology indicates that men will work unsafely or perform unsafe acts for the following reasons : 1) Lack of Knowledge or skill. 2) Conflicting motivations, such as: (a) to be more conformable, (b) to save time or effort, (c) to be accepted by a group. 3) Physical or mental condition. Nearly everyone desires his own safety, hut not all individuals are willing to do what they know to do to insure their own safety.

Jan 1, 1981

By W. B. Agocs

IN August 1954 a low altitude test geophysical survey was made in the Green Pond area of Morris County, New Jersey, with a Gulf Research and Development Co. Model II total magnetic field variation magnetometer mounted in a Sikorsky S-55 helicopter. The test was made in this area to compare the results of a high precision, very low altitude magnetometer survey with an existing ground magnetic survey in this area having known magnetite concentrations, so that the method could be used in areas of difficult access for the detailing of airborne magnetometer anomalies of interest in place of ground surveys. The load capacity of the Sikorsky S-55 permitted installation of a recording scintillation counter so that a radioactivity survey would be made simultaneously with the magnetometer survey. The area surveyed is located at approximately 41°00'N and 74o28'W, just south and east of the town of Green Pond, N. J. The outstanding topographic feature of the region is Copperas Mountain, a well defined ridge, maximum elevation 1222 ft, which runs the entire length of the survey. The lowest point in the survey, 810 ft, is in the extreme eastern corner. Topography of the area is shown in Fig. 1. The three major rock units outcropping in the area are all metamorphic: the Pochuck gneiss, which has been divided into two metamorphic facies; the Byram gneiss; and the Green Pond conglomerate. The relative ages of the Pochuck and Byram formations, both pre-Cambrian, are in doubt, but it is believed that the Pochuck is the older of the two.' The Green Pond conglomerate is Silurian.' Distribution of the outcrops and mine locations is shown in Fig. 1. Two facies of the Pochuck gneiss can be distinguished locally—the Copperas Mountain and Kitchell members. The Copperas Mountain member is a hornblende gneiss, and all the mines and prospects in the area are in this unit. The Kitchell is a quartz-plagioclase feldspar gneiss. The Byram gneiss is a relatively nonresistant valley formation which is high in the potash feldspar. The Green Pond conglomerate is a well indurated quartzite-conglomerate which forms the Copperas Mountain and the Green Pond Mountain's ridge to the north. It overlies the gneisses with a strong angular discordance that may be a fault. The geologic structure of the Green Pond area is relatively uncomplicated. The foliation planes of the gneisses dip steeply to the southeast, and the Green Pond conglomerate dips steeply to the northwest. Additional faulting in the area is indicated at the contact between the Kitchell member of the Pochuck and the Byram along the base of the topographic spur extending to the southeast from Copperas Mountain. The magnetite mines of Pardee, Winter, Davenport, Green Pond, Copperas, and the Bancroft shaft are described by Bayleyl and Stampe2.' The ore is in the Copperas Mountain member of the Pochuck gneiss. The magnetite veins are 10 to 50 ft wide and up to 300 ft long, dipping to the southeast at angles ranging from 40" to 75". The locations of these mines are shown in Fig. 1. Dip Needle Survey: The dip needle survey shown in Fig. 2 was taken from a U. S. Bureau of Mines Report of Investigations." The figure numbers below the local, individual map area outlines refer to the figures in the aforementioned reports which were not contoured. The area of the dip needle survey was confined almost exclusively to the outcrops of the Pochuck gneiss. The separation between survey profiles was 100 ft and the distance between stations on the profiles was 25 ft in highly anomalous zones to 100 ft in magnetically flat areas. A total of 16 1/2 miles of traverse was surveyed over an area of approximately 1/2 sq mile with 2050 stations. The magnitude of the magnetic anomalies is difficult to determine due to the lack of information concerning the type of dip needle used and the procedure followed in making the dip needle survey. This latter would include the method of "zeroing" the dip needle and the procedure of reading at the stations, whether on the swing or statically. Calibrations made of the Gurley dip needle, Lake Superior type, show a static sensitivity of 385 gamma per degree in the range from —25" to +35o, corresponding to a variation in the total field of —9600 gamma to +13500 gamma in a total field of 57000 gamma, inclination 72". The sensitivity increases to 16 gamma per degree from a deflection of 60" to 76", and from 76" to 172" the sensitivity decreases continuously to a low of 260 gamma per degree. From the above it may be seen that it is difficult to assign an arbitrary sensitivity for the dip needle used on this survey. However, an estimated value of 100 gamma per degree may be assigned. On this basis, the majority of the magnetic anomalies, whose deviation is +20°, would be 2000 gamma. Locally, west and northwest of the Pardee mine the magnetic anomaly is +50°, or 5000 gamma; in the Green Pond mine area deviations of +75" are observed that would correspond to anomalies of 7500 gamma. The areal extent and width of the dip needle magnetic anomalies is comparable to profile and station spacing. Hence it is concluded that part of the detail may be due to control, and the probable cause of the magnetic anomalies is at or near surface exposures of magnetite concentrations in the form of veinlets and disseminations whose locations correspond to the local magnetic anomalies. On the basis of the magnetics, none of the magnetite concentra-

Jan 1, 1956

By Henry F. Heblby

HOW often has the thoughtful observer pondered the apparent contradictions experienced in the weather? One can take records of two days, one in the winter and one in the summer. The "degree days1' indicate that space heating and domestic load were present in one case and not in the other. The Business Index may be about the same, indicating that the industrial activity of the area and its concomitant use of fuel were about the same. Thus the volume of the products of combustion released to the atmosphere varied only as related to the space heating demand. Yet on one day in winter the atmosphere may be clear and bracing, while on a summer's day the air is thick and murky and the visibility sharply reduced. The situation may be reversed. What are some of the factors that contribute to the creation of these conditions? These few notes have been prepared to indicate some of the influences that are exerted on the problem. The Sources of Atmospheric PolLution The industrial area of Pittsburgh, Pa., has been a dominant center for the production of iron and steel for over one hundred years. In fact, with the growth of the numerous auxiliary processes Allegheny County which contains Pittsburgh is prob- ably the most industrialized county in the world. In addition, the type of manufacture carried out in this area is predominantly dependent on thermal energy (heat). That energy is supplied from coke and coal produced in the vicinity of Pittsburgh Indicative of the stupendous quantities of fuel that are employed in this industrial area's economy, the following (Table I) taken from the U. S. Census (1940) may be of interest. In tonnage consumed in the area, the figures are equally impressive: Annual Tons oF Coal Metallurgical Industries.... 35,000,000 to 40,000,000 Commercial Installations (Pgh.)................. 1,500,000 Domestic hand-fired) (Pgh.)................. 750,000 An influence that has never been fully appreciated by many individuals is the fact that no matter what adventures the gases of combustion experience as they pass through the various processes, uti-mately the spent gases are discharged through chimneys to the atmosphere.

Jan 1, 1949

By J. W. Evans

ONE of the most important and frequent calculations that the extractive metallurgist is called upon to make is that of the standard free energy change of a reaction (?F°). For many reactions of metallurgical interest, the lengthy arithmetical calculations have been eliminated by the use of free energy-temperature diagrams which have been constructed by Ellingham,1 Richardson and Jeffes,2 Kellogg,3 and Osborn4 (e.g., for oxides, sulphides, halides) from critical surveys of existing data. The speed and simplicity of making calculations with these graphs make them of great practical value and, this should be stressed, in the majority of cases no greater accuracy is obtained by the individual calculations from specific heat data, entropies, and heats of reaction. With the increasing industrial application of vacuum methods to the winning of metals, notably at present magnesium and the alkaline earth metals, it is necessary to calculate low metal vapor pressures above reaction mixtures. The existing free energy diagrams usually give values where the solid and liquid metals are at unit activity. To obtain the free energy change associated with the reaction Metal (solid or liquid) = Metal (gas) it is customary to calculate this from either vapor pressure equations or from the appropriate free energy functions. This paper presents graphically the free energies of vaporization of a number of metals of economic importance which can be used in conjunction with other free energy diagrams. Certain metals have been excluded on the following grounds: titanium, tungsten, molybdenum, and platinum have very high heats of vaporization and boiling points and the uncertainty of these values arising from difficulties of high temperature measurements makes free energy values of doubtful accuracy; the data for cobalt, vanadium, and zirconium are uncertain; finally, arsenic, antimony, and bismuth could not be conveniently included. because of the presence of mixtures of polyatomic and mona-tomic vapors in the temperature range considered. Free Energy Diagram In Fig. 1, the standard free energies of vaporization per mol (?F°T) have been plotted for the temperature range 0" to 2000°C for the reaction M (solid or liquid) = M (gas) The data have been obtained from the free energy functions — (F-H298)/T for the solid, liquid, and gaseous elements and the heats of vaporization at 298°K, i.e., ?H298 (vapor). The values of these functions have been taken without change from the recent critical survey by Brewer;' the bulk of this data is from Kelley7 with adjustments in the light of more recent work. Values of the function — (F-H298) /T at T = 298°, 500°, 1000°, 1500°, and 2000°K were employed. Where possible, a further independent value was obtained by using the boiling point, i.e., where ?F°T = 0. All calculations are based on the assumption that the metal vapors are monatomic and that the boiling points refer to those temperatures at which the partial pressure of the monatomic vapor above the metal is 760 mm. For the alkali metals, e.g., sodium, potassium, and lithium, diatomic gas molecules are present as minor species; details of these are discussed by Brewer." On the basis of the above values and allowing for the change in slope at the melting point, straight line graphs were constructed and extrapolated to 2000°C. The deviation from a straight line did not exceed ±500 cal, which in all cases appears less than the probable error in the ?F°T values.

Jan 1, 1954

By G. D. Tranter

The importance of ladle and teeming practice and its relationship to the yield and quality of the product has focused considerable attention on this phase of open-hearth operation. Inherently bad steel cannot be perfected by manipulation during teeming, but through the proper handling of "off heats" serious losses, which in many cases arise, can be greatly minimized. Conversely, good steel can be ruined as a result of poor workmanship in the pit, and rendered unsuitable for application to orders where exacting surface and physical requirements are essential. Sufficient evidence has been secured to warrant careful investigation of pit operations when an abnormal number of basic defects develop in the semifinished product or are found on the inspection table. This paper is written from the standpoint of the problems involved in making satisfactory ingots for sheet rolling. Furthermore, since rimming steel is almost universally used for manufacture of sheet, the data presented herein refer particularly to that type of steel. Going back some 30 years in open-hearth history, the word "pit" properly described the hole into which the ladle was lowered to receive the metal tapped from the furnace. The working space was necessarily limited, and the disposal of slag and metal overflowing the ladle or lost because of breakouts presented a serious problem. The equipment, of course, was rather crude in the light of present-day development. Often no ladle stands were provided, the ladle being hung on the crane beneath the runner. When delayed taps occurred, the ladle was often held in position for many hours, thus tying up pit operations and causing delays to adjacent furnaces. Because of crowded conditions, slag thimbles were not used and a network of cast-steel triangles and old tapping bars, placed before the heat was tapped, was the means for removing slag from the hole. Furnaces of different capacities were used

Jan 1, 1935

By G. D. Tranter

The importance of ladle and teeming practice and its relationship to the yield and quality of the product has focused considerable attention on this phase of open-hearth operation. Inherently bad steel cannot be perfected by manipulation during teeming, but through the proper handling of "off heats" serious losses, which in many cases arise, can be greatly minimized. Conversely, good steel can be ruined as a result of poor workmanship in the pit, and rendered unsuitable for application to orders where exacting surface and physical requirements are essential. Sufficient evidence has been secured to warrant careful investigation of pit operations when an abnormal number of basic defects develop in the semifinished product or are found on the inspection table. This paper is written from the standpoint of the problems involved in making satisfactory ingots for sheet rolling. Furthermore, since rimming steel is almost universally used for manufacture of sheet, the data presented herein refer particularly to that type of steel. Going back some 30 years in open-hearth history, the word "pit" properly described the hole into which the ladle was lowered to receive the metal tapped from the furnace. The working space was necessarily limited, and the disposal of slag and metal overflowing the ladle or lost because of breakouts presented a serious problem. The equipment, of course, was rather crude in the light of present-day development. Often no ladle stands were provided, the ladle being hung on the crane beneath the runner. When delayed taps occurred, the ladle was often held in position for many hours, thus tying up pit operations and causing delays to adjacent furnaces. Because of crowded conditions, slag thimbles were not used and a network of cast-steel triangles and old tapping bars, placed before the heat was tapped, was the means for removing slag from the hole. Furnaces of different capacities were used

Jan 1, 1935

By V. C. Perini

The North Central Texas district as herein defined includes the counties of Brown, Callahan, Coleman, Comanche, Coryell, Eastland, Erath, Fisher, Hamilton, Haskell, Hood, Jones, Lampasas, Mills, Nolan, Palo Pinto, Parker, San Saba, Shackelford, Stephens, Stonewall, Summer-ville, Taylor, Throckmorton and Wise. These counties as listed are the counties of District 7B, State Railroad Commission. In the new designation of districts for the Transactions, the North Central Texas district includes most, but not all, of the counties of the previously classified West Central Texas district. This district covers the south central crest and the west flank of the Bend flexure north of the Llano uplift. The west flank of the Bend flexure is on the east boundary of the Permian Basin of West Texas. The greater part of the oil and gas produced in this district has been from Pennsylvanian strata. Some oil and gas has been produced from the lower Permian (by the latest, selection of the Pennsyl-vanian-Permian boundary) and minor amounts from the Mississippian and Ordovician sediments. Increasingly important quantities of oil and gas are to be expected from the older sediments by deeper development in proven fields and by new discoveries. Most of the oil and gas in the district has accumulated in localized, well-defined structural traps in limestone and sandstone reservoirs and in traps due to stratigraphic changes in sedimentation, mainly porosity traps in limestone and sandstone lenses, both usually associated with some structural feature. These features are found by surface and subsurface geological structural mapping, by core drilling and by geophysical surveying. Geochemical methods are also the basis for some wildcatting. The demand for sweet crude oil from this district is firm for local and national consumption, but the market price for the oil remains practically the same as in 1941. The price is not adequate to meet the requirements of the average independent operator with the continued advance in production, tievelopment and wildcatting costs. Stripper wells are being plugged daily and should be jealously saved for the future local and national reserves, especially in view of the fact that new discoveries of commercially important oil and gas reserves are not keeping pace with consumption. An expected economic disruption attendant upon the national war effort has arisen and continues in the future outlook for this district. The lack and delay of securing replacement parts for almost all oil-field equipment has handicapped and delayed operations and has decreased efficiency in wildcatting, development and production. Sufficient experienced drilling, scientific and office personnel is lacking because of inductions in the armed forces and migration to war industries during the period before manpower conservation became effective. The office personnel of the average oil and gas producer continues to be swamped by the increasing demands for reports by state and federal bureaus. An average of IQ days

Jan 1, 1944

By V. C. Perini

The North Central Texas district as herein defined includes the counties of Brown, Callahan, Coleman, Comanche, Coryell, Eastland, Erath, Fisher, Hamilton, Haskell, Hood, Jones, Lampasas, Mills, Nolan, Palo Pinto, Parker, San Saba, Shackelford, Stephens, Stonewall, Summer-ville, Taylor, Throckmorton and Wise. These counties as listed are the counties of District 7B, State Railroad Commission. In the new designation of districts for the Transactions, the North Central Texas district includes most, but not all, of the counties of the previously classified West Central Texas district. This district covers the south central crest and the west flank of the Bend flexure north of the Llano uplift. The west flank of the Bend flexure is on the east boundary of the Permian Basin of West Texas. The greater part of the oil and gas produced in this district has been from Pennsylvanian strata. Some oil and gas has been produced from the lower Permian (by the latest, selection of the Pennsyl-vanian-Permian boundary) and minor amounts from the Mississippian and Ordovician sediments. Increasingly important quantities of oil and gas are to be expected from the older sediments by deeper development in proven fields and by new discoveries. Most of the oil and gas in the district has accumulated in localized, well-defined structural traps in limestone and sandstone reservoirs and in traps due to stratigraphic changes in sedimentation, mainly porosity traps in limestone and sandstone lenses, both usually associated with some structural feature. These features are found by surface and subsurface geological structural mapping, by core drilling and by geophysical surveying. Geochemical methods are also the basis for some wildcatting. The demand for sweet crude oil from this district is firm for local and national consumption, but the market price for the oil remains practically the same as in 1941. The price is not adequate to meet the requirements of the average independent operator with the continued advance in production, tievelopment and wildcatting costs. Stripper wells are being plugged daily and should be jealously saved for the future local and national reserves, especially in view of the fact that new discoveries of commercially important oil and gas reserves are not keeping pace with consumption. An expected economic disruption attendant upon the national war effort has arisen and continues in the future outlook for this district. The lack and delay of securing replacement parts for almost all oil-field equipment has handicapped and delayed operations and has decreased efficiency in wildcatting, development and production. Sufficient experienced drilling, scientific and office personnel is lacking because of inductions in the armed forces and migration to war industries during the period before manpower conservation became effective. The office personnel of the average oil and gas producer continues to be swamped by the increasing demands for reports by state and federal bureaus. An average of IQ days

Jan 1, 1944

By Guy A. Johnson

In 1976, The Bureau of Mines developed a prototype system to sense and extinguish fires in shafts and shaft stations in underground metal and nonmetal mines. Subsequent work modified this technology to include fueling areas, spontaneous combustion zones and coal mines. This paper updates IC-8783 "In-mine Fire Tests of Mine Shaft Fire and Smoke Protection Systems," which was published in 1978 and summarized the design and in-mine, actual fire testing of the first prototype mine shaft fire and smoke protection system. This paper also updates related work from IC-8775 "Spontaneous Oxidation and Combustion of Sulfide Ores in Underground Mines," (also published in 1978) and IC-8808 "In-mine Evaluation of Under- ground Fire and Smoke Detectors," (published in early 1979).

Jan 1, 1982