Search Documents

Prospecting methods used in Tennessee have gradually improved with the years, as required by depletion of the easily accessible and shallow deposits and the universal trend toward mechanization, and as necessitated by exploring deeper beds, often occurring under limestone and flinty overburden. In the early days it was a very simple matter to dig pits by hand, using a plentiful supply of local farm labor to expose relatively shallow deposits of "brown rock" under shallow clayey overburden that would stand up without timbering. Visual inspection of the exposed phosphate and expert judgment of the "grade" analysis, aided by a "biting" test to reveal presence of unwanted silica, furnished most of the information required. All this might be helped by a few samples sent to the local chemist† who supplemented his income by judicious trading or tanning a few bear skins. The extra curricula activities did not affect the accuracy of the analysis which hold up even under present day standards. Some shot and core drilling was done in Hickman County, mostly for the limestone-like blue Phosphate deposits. The next step was the use of a 4-in. posthole auger, hand operated as described by Guenther, followed by a completely mechanized rig, as described by Pickard. Both these methods are practically adapted to the prospecting of the relatively soft brown rock deposits at moderate depths of clay overburden. For prospecting in areas of deeper overburden, such as are often found in Hickman County, up to 150 or even 200-ft depths, a modified core-drilling method is described by Guenther. Johnston describes a special diamond-drilling technique, developed by TVA, to penetrate flint horizons, which was adopted by the International Minerals in chemical corporation to prospect in Hickman County where deposits had previously been prospected at considerable expense and with difficulty, by small, temporary, hand-dug shafts.

Jan 1, 1948

By John H. Hollomon

The interpretation of notched-bar impact results has been a matter of controversy since the introduction of more or less standard tests by Fremont,' Charpy2 and others at the turn of the century. Many investigators3-l1 have contributed to the understanding of the significance of such tests. Several symposiums12,13 have been held with the express purpose of discussing the significance and interpretation of the impact tests. It is not the purpose of this paper to review all these contributions to the development of the knowledge on this subject, but rather to present an interpretation of notched-bar impact tests that appears to be in agreement with the available published data. Fundamentally, the interpretation discussed in this paper of the brittle failure of some steels in notched-bar impact test is similar to the qualitative analysis presented by Ludwik3 in the I92o's. Essentially, Ludwik stated that the function of the notch was to increase the tensile stress necessary for yielding, and that brittle failure occurred when the stress necessary for yielding exceeded the normal stress required for fracture (with no plastic deformation). Ludwik, however, had no means of measuring this normal stress necessary for failure of a plastically* undeformed metal, therefore he could not extend his interpretation beyond the qualitative stage. Kuntze14 and recently Mc-Adam15 attempted to determine the effect of deformation on the stress necessary for fracture by testing, in tension, specimens notched to various depths and angles. Because of the uncertainties in Kuntze's (and McAdam's) analysis of the stresses (which have been pointed out by Sachs16) and the inherent nonuniformity in the stress distribution in notched bars, the results of such investigations are difficult to interpret. A more direct method of measuring the effect of deformation on the fracture stress was suggested in previous papers"-18 and has been utilized in the present investigation. The present paper concerns itself primarily with the behavior of notched impact specimens. The effects of strain rate, temperature, and stress distribution, which are discussed with reference to the impact specimen, apply just as well to the behavior of metal at the bases of notches in any engineering structure. All that is necessary is to determine the stress distribution in the structure at the base of the notches.

Jan 1, 1944

By John H. Hollomon

The interpretation of notched-bar impact results has been a matter of controversy since the introduction of more or less standard tests by Fremont,' Charpy2 and others at the turn of the century. Many investigators3-l1 have contributed to the understanding of the significance of such tests. Several symposiums12,13 have been held with the express purpose of discussing the significance and interpretation of the impact tests. It is not the purpose of this paper to review all these contributions to the development of the knowledge on this subject, but rather to present an interpretation of notched-bar impact tests that appears to be in agreement with the available published data. Fundamentally, the interpretation discussed in this paper of the brittle failure of some steels in notched-bar impact test is similar to the qualitative analysis presented by Ludwik3 in the I92o's. Essentially, Ludwik stated that the function of the notch was to increase the tensile stress necessary for yielding, and that brittle failure occurred when the stress necessary for yielding exceeded the normal stress required for fracture (with no plastic deformation). Ludwik, however, had no means of measuring this normal stress necessary for failure of a plastically* undeformed metal, therefore he could not extend his interpretation beyond the qualitative stage. Kuntze14 and recently Mc-Adam15 attempted to determine the effect of deformation on the stress necessary for fracture by testing, in tension, specimens notched to various depths and angles. Because of the uncertainties in Kuntze's (and McAdam's) analysis of the stresses (which have been pointed out by Sachs16) and the inherent nonuniformity in the stress distribution in notched bars, the results of such investigations are difficult to interpret. A more direct method of measuring the effect of deformation on the fracture stress was suggested in previous papers"-18 and has been utilized in the present investigation. The present paper concerns itself primarily with the behavior of notched impact specimens. The effects of strain rate, temperature, and stress distribution, which are discussed with reference to the impact specimen, apply just as well to the behavior of metal at the bases of notches in any engineering structure. All that is necessary is to determine the stress distribution in the structure at the base of the notches.

Jan 1, 1944

By C. A. Stickels, C. M. Yen

Secondary recrystallization was investigated in vacuum-melted electrolytic iron to which 70 pm N was vacuum-meltedadded. The secondary texture is "near {554}<225>" for material cold-rolled 75 to 90 pct, the sharpness of the texture increasing with increased rolling reduction and with decreased annealing temperature. At reductions of 95 and 97.5 pct the secondary texture is &apos;"near {322)(296)". Both secondary orientations also exist as major components of the primary re-crystallization texture. Development of a strong "near {554) (225)" secondary texture appears to depend on the evolution of the Primary texture to a transition texture depleted in orientations near the secondary orientation before the onset of secondary growth. A variety of qualitative experinzents have been used to show that nitrogen is important in limiling primary grain growth. The presence of nitrogen does not seem essential for the establishment of a transition texture, but a loss of nitrogen during annealing may facilitate growth of grains in the secondary orientation. Secondary grains we shown to form initially at the specimen surface. This is not thought to indicate that surface energies are important in the growth process. It is proposed that the quasi-two-dimensional character of surface grains permits discontinuous growth parallel to the surface before secondary growth of interior grains is possible. An earlier study of recrystallization textures in 90 pct cold-rolled electrolytic iron showed that secondary recrystallization occurred after annealing for several days at 700C1 This type of secondary recrystallization, which had not been reported previously, results in the formation of a strong texture, best described by the indices "near {554}(225)". The purpose of the present work was to investigate the effect of various processing variables on secondary recrystallization in this material and determine the mechanism of secondary grain growth. LITERATURE REVIEW An understanding of the mechanism of a secondary recrystallization process depends on knowing: 1) how grains in the secondary orientation come to be in the primary recrystallization texture; 2) why normal grain growth does not occur; and 3) what factors determine the strength of the secondary texture. For secondary growth of grains of a particular orientation, a certain minimum fraction of the grains must be in that orientation after primary recrystallization. This requirement is apparently satisfied "naturally" in certain systems, i.e., when the primary texture obtained by rolling and recrystallizing material initially randomly oriented contains a sufficient fraction of primaries in the secondary orientation. However, in other cases, e.g., {110}<001> and {100}<001> secondary growth in silicon iron,2 it is necessary to enhance the fraction of primary grains in the secondary orientation by rolling and recrystallizing textured material. In the present case, the "near {554}<225>" orientation is contained within the spread of orientations found in the primary recrystallization texture of iron or bbc iron-base alloys. In systems where the main driving force for secondary growth is the reduction in total grain boundary energy, secondary growth is observed only when normal grain growth is minimized. Four ways in which normal grain growth can be limited are: 1) Limitation by a strong primary texture. When a very strong primary texture consisting of a single component or twin-related components develop, most primary grains are separated from one another by relatively immobile small-angle grain boundaries. The classic instance of this is secondary growth into the primary cube texture in some fcc metals. 2) Limitation by precipitates. Precipitates present in the proper volume fraction with a suitable dispersion will limit primary grain growth. The role of MnS inclusions in impeding normal grain growth in Si-Fe is well-documented.5 3) Limitation by sheet thickness. Normal grain growth slows drastically when the mean grain diameter is of the same order as the sheet thickness. This effect has been used to obtain secondary recrystallization in thin sheets of high-purity silicon iron.&apos; 4) Limitation by solute impurities. It is well-established that certain impurity elements in solution can have a large effect on grain boundary mobility.&apos; However, there does not seem to be any secondary recrystallization process in which primary grain size stabilization has been shown to be due to the drag exerted on grain boundaries by dissolved impurities. In certain systems, e.g., secondary recrystallization in silver,&apos; the means by which normal grain growth is limited has not been identified, and solute-impurity limitation might be suspected. In order to understand the factors which determine secondary texture strength in three-dimensional growth, it is necessary to examine in more detail the current picture of general secondary recrystallization processes. Following Cahn,9 it is assumed that the primary grains have a range of sizes and that secondary growth of one of the large grains in this distribution is possible when it exceeds a critical size with respect to its neighboring grains. The critical size depends on the ratio ?S/?p, where ?s is some sort of average grain boundary energy between the potential secondary and the primary grains and ?p is some sort of average grain boundary energy between primary grains. For a constant primary grain size, the critical size for secondary growth increases as ?$/?p increases. May and Turnbull5 have incorporated the

Jan 1, 1969

By Alexander Squire

A BRIEF study of the effects of material and processing variations upon the tensile properties of steel formed from mixtures of iron and carbon was made in order to provide information regarding the .properties obtainable in iron-carbon compacts as influenced by forming pressure, sintering temperature, and graphite particle size. Sintered steels formed from mixtures of iron and graphite have been studied by Stern,1 who investigated the effect of various percentages of graphite on compacts formed from electrolytic iron that were repressed and heat-treated after sintering. A further study, by Stern and Greenberg,2 is concerned with the heat-treatment of steels formed by the carburization of iron compacts, and Margolies3 has reported work on the simultaneous sintering and carburization of iron-powder parts. Glauch4 investigated the effect of various types of graphite on the properties of iron-carbon powder alloys but did not determine the effect of different particle sizes of the same graphite alloyed with different types of powder. In the investigation reported in this paper, powders typical of those produced by electrolytic deposition and the decarburization of shotted steel scrap were used. The powders were mixed by tumbling in a jar mill with graphite powder ground to an average particle diameter of 2, 4, 6, and 16 microns (as determined by microscopic measurement). The properties of the iron and graphite powders are presented in tabular form as Table I. In order to obtain the maximum information from a minimum number of test specimens, the study was divided into two sections with one set of specimens treated identically in each section as a basis for comparison. In the first section, iron powder produced by the shotting and subsequent decarburization of scrap steel was mixed with 2-micron graphite powder, pressed at 50,000, 100,000, and 200,000 psi, and sintered in hydrogen at 1200°C for the periods of time ranging from 15 to 120 minutes. In the second section of the investigation, electrolytic iron powder was mixed with graphite of an average particle diameter of 2, 4, 6, and i6 microns, pressed at 100,000 psi, and sintered at temperatures ranging from 1000° to 1200°C. for periods of time of 30 to 180 minutes. By following this procedure an indication of the effect of the following variables upon the density and tensile properties of iron-carbon powder compacts was obtained: (I) forming pressure, (2) sintering time, (3) particle size of graphite powder, (4) sintering temperature, (4) type of iron powder.

Jan 1, 1947

By F. M. Simonds, E. Z. Burns

The Rawley property is located in the Kerber Creek mining-district, Saguache county, Colorado, at an elevation of 10,600 ft. (See sketch-map, Fig. 1.) Ore was found in this vicinity as early as 1880, and claims covering a large area were located and in many instances patented. The ores, however, being of comparatively low grade, and the nearest railway station, Villa Grove, being some 20 miles away, it is extremely doubtful whether any considerable amount of ore was ever handled at a profit. It is safe to say that several hundred thousand dollars were spent (a large part in building mills) previous to 1902-03. About that time a very capable promoter gathered together a group of these claims and interested some New York people, who had had no previous mining experience, in the purchase of these claims. Following the organization of a company, this promoter became General Manager. As often happens under such conditions, the first step was to erect a mill to treat 100 tons per day. It may not be fair to this enterprise to say that the failure which followed might have been foretold, simply on general principles, but this much is certain—the water supply fluctuates in the course of a season through a wide range and for a considerable portion of the year was inadequate to run this mill at capacity. Further, it is currently reported that some of the mill foundations were placed on ice. However true this statement may be, it is a fact that, when first inspected by us, many of the belts in the mill were held on&apos;their pulleys by means of idlers. A shut-down followed, with a material re-adjustment of interests, at which time we became consulting engineers for the company.

Jan 1, 1914

The ten-year "supply-demand relationship" tables in this chapter for various mineral and metal commodities have been adapted from Minerals in the U.S. Economy, compiled by the Bureau of Mines, U.S. Department of the Interior, published in 1975. Acknowledgment is made to the Bureau of Mines for compilation of the tables. [ ]

Jan 1, 1976

ALBERT SAUVEUR, Chairman. A. A. STEVENSON, Vice-Chairman. HERBERT M. BOYLSTON, Secretary, Abbot Bldg., Cambridge, Mass. John Birkinbine, William Kelly, J. S. Unger, William H. Blauvelt, Charles Kirchhoff, Felix A. Vogel, James Gayley, Richard Moldenke, Leonard Waldo, Henry D. Hibbard, Joseph W. Richards, William R. Walker, Henry M. Howe, C. F. W. Rys, William R. Webster, Robert W. Hunt, E. Gybbon Spilsbury, Frederick W. Wood. J. E. Johnson, Jr., The innovation of a special meeting under the auspices of the Iron and Steel Committee was well justified, if we accept as a criterion the number of papers presented at the meeting held on Oct. 16 and 17 in New York and the attendance at that meeting. Twenty-four papers were read, and most of these were widely discussed orally, while doubtless the written discussions will be even larger in extent. Discussions will be received up to Dec. 1, 1913. The attendance at the meeting of 106 members and 75 guests is an evidence of the wide anti growing interest in the Institute of men interested chiefly in iron and steel. It is especially interesting to note this large attendance at a meeting where very little of a social nature was introduced into the program. An informal dinner for the men at the Engineers&apos; Club closed the meeting. At this dinner were present about 70 members and guests. One of the Vice-Chairmen and the Secretary of the new Committee on Petroleum and Gas told of the important plans in prospect of that Committee. Brief impromptu speeches by a considerable number of the members and guests were enjoyed. Professor Marburg reiterated his previous assertion that he believed that the Institute and the American Society for Testing Materials, as well as some of the other technical societies, were all fighting for one good cause; that there was room in the field for all of these societies with their various points of view; and that they should march shoulder to shoulder. The success of this dinner was due largely to the efforts of Mr. Johnson who had the affair in charge.

Jan 11, 1913

By H. I. Aaronson, C. Wells

Configurations of ferrite crystals have been found in a plain carbon steel which appear to have resulted from the nucleation of new ferrite crystals at the interphase boundaries of previously formed crystals despite the high carbon concentrations which necessarily develop at these boundaries. This phenomenon has been termed sympathetic nucleation. An attempt has been made to reconcile the occurrence of sympathetic nu-cleation with current nucleation theory. THIS investigation is one of a series on the formation of proeutectoid ferrite from austenite. From the viewpoint of chemical composition, this reaction consists of the nucleation and diffusional growth of crystals of carbon-poor ferrite within a matrix of carbon-rich austenite. The austenite adjacent to the austenite-ferrite boundaries will be greatly enriched in carbon, approximately to the value of the y/(a + y) equilibrium curve or its metastable extrapolation at the temperature of transformation. Those areas of austenite appreciably farther removed from the growing ferrite, on the other hand, will be relatively unaltered in composition, especially at the earlier stages of transformation. Since rates of nucleation are considered to decrease exponentially with decreasing supersaturation,&apos; the frequency with which ferrite nuclei appear at austenite-ferrite boundaries should be negligible in relation to that at which they form in other regions of the austenite. During this investigation, however, many groupings of ferrite crystals have been found which appear to have resulted from the nucleation of ferrite at austenite-ferrite boundaries. This phenomenon has been given the name of sympathetic 71.1tcleation. A number of micrographs of morphological configurations caused by sympathetic nucleation will be presented, after which an explanation for this reaction will be proposed in terms of current nucleation theory. Some of the structures to be considered are composed of bainite, an aggregate of ferrite and carbide, rather than of ferrite. Since ferrite and bainite differ only in that bainite forms under conditions which result in the nucleation of carbides behind the advancing austenite-ferrite boundaries,&apos; it will usually be unnecessary, for the purpose of this paper, to distinguish between the two reaction products. All studies were performed on an electric furnace steel (obtained from the Vanadium Alloy Steel Co.) containing 0.29 pct C, 0.76 pct Mn, 0.25 pct Si, 0.005 pct P, and 0.007 pct S. The alloy was cast as a 150 Ib, 7x7 in. cross section ingot and forged into bars 2x2 in. in cross section. These bars were homogenized for 48 hr at 1250°C in an Endo-Gas atmosphere. The depth to which decarburization penetrated during this heat treatment was determined by chemical and microscopic analyses and the affected metal was removed by machining. Specimens for isothermal transformation studies were cut from the remaining material; most of these specimens were 1/2x1/4X1/16 in., though some with a thickness of 1/32 in. were prepared for use at the shorter reaction times and lower reaction temperatures. Specimens were austenitized for 30 min at 1300°C, isothermally reacted for various times at temperatures ranging from 775" to 475 "C, and then quenched in iced water. The austenite grain sizes within individual specimens ranged from ASTM Nos. 1 through —4. A commercial heat-treating salt which was continuously deoxidized by an immersed graphite crucible served to minimize the loss of carbon during austenitizing; thick covers of powdered graphite and immersed graphite rods effectively prevented decarburization in the lead pots employed for the isothermal reaction treatments. The heat-treated specimens were sectioned and mounted in Bakelite. Following the completion of standard grinding and mechanical polishing procedures, the specimens were electrolytically polished with a Buehler-Waisman apparatus and etched in 2 pct nital. Experimental Results Rules of Evidence for Sympathetic Nucleation—On the basis of observations made on a single plane of polish, one precipitate crystal may be considered to have been sympathetically nucleated at the inter-phase boundary of another precipitate crystal when the following conditions are fulfilled: 1) The sympathetically nucleated crystal is not in contact with a grain boundary or a subboundary in the matrix phase. 2) The shape, size, and location of the crystal at whose boundary sympathetic nucleation occurred (hereafter termed the base crystal) and the crystal formed by sympathetic nucleation substantially pre-clude the possibility that the plane of polish em-ployed may have concealed the fact that both crys-tals actually nucleated at a grain boundary or a sub-boundary in the matrix phase.

Jan 1, 1957

By A. F. Lucas

The discovery of oil in 1901 on the Spindletop dome, Texas, inaugurated a new industry on the Gulf Coast, an industry which has gran with the discovery of successive fields, until today it engages the services of thousands of workers and employs enormous capital. New fields are being discovered from time to time and doubtless some still remain to be found, though of late years discoveries have become more infrequent. Nowadays several hundred dry holes are drilled each year in a fruitless and blind effort to discover new fields, for as yet geologic science has developed no effectual method of locating the coastal oil deposits in advance of drilling. Moreover despite the occasional discovery of new fields, the total production of the Gulf Coast is today no greater than it was in 1906, for the added production of the new fields has been offset by the rapid decline and more or less complete exhaustion of some of the older ones. Careful geologic work within the fields has in some cases increased the production temporarily, but has developed no really new supplies. The Gulf Coast oil industry seems to have passed its period of greatest expansion and to be declining at a fairly steady rate, and this condition is naturally viewed with alarm by the more farsighted operators. In my opinion, the time has come for the adoption of radical and aggressive methods of prospecting; and a fraction of the money wasted yearly in drilling shallow wells in hopeless locations might well be devoted to this purpose. Many facts lead me to believe that all the salt-dome oil has had a common origin; that it has migrated up from considerable depth along lines of structural weakness; and that a deep well, properly located, stands an excellent chance of discovering the parent reservoir and thus of developing new and probably great supplies. This paper is presented as a discussion—necessarily hypothetical and based largely on personal opinion—of the possibility of encountering deep-seated oil deposits beneath the salt domes. Salt-dome Structure All of the oil produced in the coastal region of Texas and Louisiana is probably associated with salt domes, though in Goose Creek, Edgerly, and one or two other fields no salt has yet been actually penetrated. As

Jan 1, 1920

By G. R. Fitterer

NONMETALLIC inclusions in steel have received much attention by metallurgists during the past few years. Many investigators have been emphatic in stating their belief that these impurities are the chief causes of steel failures, while others think that their effects are negligible. One of the main reasons that definite information on the effects of these impurities is lacking is that no reliable method has been developed for the exact determination of the amounts of these different impurities in steel. Some valuable new information has been brought out by a reliable method for nonmetallic inclusions which has been developed at the Pittsburgh Experiment Station of the U. S. Bureau of Mines, in cooperation with the Carnegie Institute of Technology and the Metallurgical Advisory Board. This procedure satisfactorily extracts some of the more common inclusions from steels, thus enabling the investigator to correlate steel failures with inclusion content. Although the data given herein are the first to be published on the subject of the electrolytic extraction method, the interest in the subject is evidenced by the fact that it is already being used by some 20 to 30 steel companies for their various purposes. Some of the comments received from these laboratories indicate that the method is highly satisfactory: the unfavorable comments, when traced to their sources, have been found to be based on some small mistake made in either installation or operation. The chief discrepancy seems to have occurred in attempts to apply the method to the extraction of inclusions from alloy steels. The procedure can be used only for the plain carbon steels and for such low alloy steels as those containing the usual amount of copper (0.2 to 0.3 per cent). Steels containing the carbide-forming alloys such as chromium, tungsten, etc., present far too many difficulties for the accurate determination of inclusions. Luckily, the iron and manganese carbides do not offer any difficulties and no contamination of the oxide-sulfide residue results. It is highly probable that some modification of the following

Jan 1, 1931

By G. M. Ritcey, M. J. Slater, B. H. Lucas

The recovery of uranium from acid leach slurries by continuous ion exchange, or solvent extraction using sieve-plate pulse columns, is compared. Differences in processing costs are of prime concern and can be related to differences in the unit operations of the two methods, as well as the chemical and physical properties of the slurry. Parameters are defined for the operation of the solvent-in-pulp process and the design of the continuous ion exchange column. Pilot plant operating experience with both recovery systems is described, and an overall assessment of the relative costs is presented.

Jan 1, 1973

By E. C. Harder

AT a Meeting of the New York Section, on May 23, 1918, the sole subject of discussion was the nature and occurrence of iron ores in certain parts of the world.? Owing to the importance of this subject, it has been deemed&apos; advisable to publish the remarks made at that meeting in the form of a paper, for presentation at the Milwaukee Meeting, instead of in the usual place, under News of Local Sections. The remarks related to the following districts: Brazil, by E. C. Harder, of the U. S. Geological Survey; Scandinavia, by Waldemar Lindgren, of the U. S. Geological Survey; Cuba, by C. M. Weld, of the U. S. Bureau &apos;of Mines; Southern Europe, by A. C. Spencer, of the U. S. Geological Survey; China, by H. Foster Bain, of the U. S. Bureau of Mines; Alsace-Lorraine, by Sidney Paige, of the U. S. Geological Survey. BRAZIL By E. C. Harder During the years immediately preceding the war, the iron ores of Brazil were attracting the attention of iron operators both in Europe and in the United States. This was clue to the large quantities of practically undeveloped ore available, and to its great purity. It is reasonably safe to state that had capital not been diverted from the exploitation of these deposits to war purposes, Brazilian iron ores would probably now be offered in European and American markets. It is certain that after the war these ores will play a prominent part in the economic reconstruction of Europe and perhaps in the development of America.

Jan 9, 1918

By Edward W. Parker

Note.—The material from which this paper has been prepared was collected tor the U. S. Geological Suvey Bulletin, No. 316, Contributions to Economic Geology, 1906, and appears also, though in somewhat more extended form without illustrations, in that publication. Although the briquetting of coals and lignites has been carried on for many years in Europe, and has reached a particularly high state of development in France, Belgium, and Germany, it has made comparatively little progress in the United States. The causes for the backwardness of the United States in this regard are several, and first among them has been the abundant supply of cheap raw fuel with which the manufactured article has to compete. With our millions of acres of coal-productive territory, from which the product can in moat cases be cheaply extracted, it has appeared in many districts more economical to waste the slack or culm, which constitutes a considerable percentage of the product, than to attempt to save it at the additional expense required for briquetting. It is for this reason that the view in all sections -of the anthracite-region of Pennsylvania is marred by the unsightly culm-banks which encumber the ground, and that in some of the bituminous-districts one sees huge piles of unmarketable slack allowed to burn up in order to get rid of them. When the coal is of a coking quality, or when the slack can be used for steaming-purposes, these losses are not sustained, but many thousands of tons of what might be converted into usable fuel have been wasted every year simply because of the increased expense involved in its preparation.

Jan 1, 1908

By P. S. Miller, S. H. Ash

EXTENSIVE and diversified resources justify large populations and great industries. To carry on the business of commerce and meet the demands of large populations, the utilization of tunnels in some form for transportation purposes constitutes an important link in modern civilization. The driving of tunnels has been appropriated by the tunneling branch of the heavy-construction industry, and the progressive steps taken by modern tunnel builders were not even dreamed of 50 years ago. Great strides have been made toward more rapid progress in tunneling in the United States during the past 10 years. Tunneling consists of a definite cycle of operations developed from ideas that are crystallized and translated into action programs through various engineering phases that begin with the first preliminary survey and do not end until the job is completed. Once the line of the bore is established and a time set for the completion of the work, the face must advance according to estimates prepared before the work commences. This schedule must be followed in regular sequence from the moment the drills start against a new face of rock until they are ready again to drill the succeeding face, constituting a round.1 Mining is largely tunneling carried on under conditions often more inherently hazardous than actual tunnel construction, but for various reasons1 tunneling is more hazardous than mining in any branch of the mineral industry, On the other hand, obstacles are sometimes encountered in heavy-construction tunneling projects that when met in mining enterprises do not offer comparable tasks to avoid or overcome them. One of these is the existence of water under high pressures. In mining enterprises, various alternatives offer a solution in driving a tunnel, even to the extent of its discontinuance or the abandonment of the mine, but a "construction" tunnel usually must go forward because some important project depends largely if not entirely upon it. This paper describes an unusual method of driving a water-supply tunnel through rock carrying water under pressures and conditions that did not permit the use of ordinary tunneling methods. THE DELAWARE AQUEDUCT The new Delaware aqueduct is a Manhattan project of some magnitude; when completed, it will contain what probably will be, for some time to come, the longest tunnel in the world. Various features in its construction are currently described in the trade journals of the construction industry, and informative engineering details are given in the Delaware Water Supply News, published twice a month by the Board of Water Supply of the City of New York. Work was begun on this project on March 24, 1937. The tunnel will convey water from reservoirs at the headwaters of the Delaware River to the City of New York.

Jan 1, 1942

By R. L. Boyer, F. Morgan, M. Muskat

In the last several years a type of application of the fundamental permeability-saturation relationships has been developed which offers great promise in the interpretation of general reservoir performance.l-&apos; In these developments no attempt is made to solve the detailed flow dynamics in actual oil and gas-producing systems. That problem still remains unsolved. But the permeability-saturation phenomena are incorporated in the analysis of oil-producing reservoirs in a manner such as to reflect the true role they play in controlling the gross reservoir behavior. In particular, they are introduced in such a manner as to determine the gas-oil ratio of the production at any stage of depletion, and, when combined explicitly with the so-called material-balance principles in differential form, one can obtain a differential equation describing completely the average pressure and gas-oil-ratio history of oil-producing reservoirs. While thus far they have been applied directly only to gas-drive reservoirs, they are susceptible of extension to partial water-drive systems, and qualitatively the same principles are of value in the study Of complete water-drive reservoirs. Moreover, in addition to giving a means for computing the variation of the reservoir pressure and gas-oil ratios vs. the cumulative production, they automatically lead to predictions of the gross ultimate recovery under natural depletion—and when properly extended they provide means for predicting the ultimate recovery under gas or water injection. The data required for such applications are the initial fluid distribution in the producing section, the pressure-volume-temperature data on the gas and liquid phases, and the permeability-saturation relationship for the oil-satuiated zone. The former can be obtained with reasonable accuracy by methods that are well established and available throughout the industry. The permeability-saturation data, however, involve techniques that are not at all standardized. In fact, only

Jan 1, 1947

By M. Muskat, R. L. Boyer, F. Morgan

In the last several years a type of application of the fundamental permeability-saturation relationships has been developed which offers great promise in the interpretation of general reservoir performance.l-&apos; In these developments no attempt is made to solve the detailed flow dynamics in actual oil and gas-producing systems. That problem still remains unsolved. But the permeability-saturation phenomena are incorporated in the analysis of oil-producing reservoirs in a manner such as to reflect the true role they play in controlling the gross reservoir behavior. In particular, they are introduced in such a manner as to determine the gas-oil ratio of the production at any stage of depletion, and, when combined explicitly with the so-called material-balance principles in differential form, one can obtain a differential equation describing completely the average pressure and gas-oil-ratio history of oil-producing reservoirs. While thus far they have been applied directly only to gas-drive reservoirs, they are susceptible of extension to partial water-drive systems, and qualitatively the same principles are of value in the study Of complete water-drive reservoirs. Moreover, in addition to giving a means for computing the variation of the reservoir pressure and gas-oil ratios vs. the cumulative production, they automatically lead to predictions of the gross ultimate recovery under natural depletion—and when properly extended they provide means for predicting the ultimate recovery under gas or water injection. The data required for such applications are the initial fluid distribution in the producing section, the pressure-volume-temperature data on the gas and liquid phases, and the permeability-saturation relationship for the oil-satuiated zone. The former can be obtained with reasonable accuracy by methods that are well established and available throughout the industry. The permeability-saturation data, however, involve techniques that are not at all standardized. In fact, only

Jan 1, 1947

By A. E. Bellis

ROBERT J. ANDERSON, Cleveland, Ohio (communication to the Secretary *).-The paper by Messrs. Bellis and Hardy was interesting to me and has led me to make a few remarks concerning some of the points brought out. The question of employing correct hardening temperatures is one that is sadly neglected, particularly in many large plants that forge and treat their machine tools for private use. As is most aptly remarked in this paper, "The custom of using one, high-speed temperature for all tools is very poor practice;" still, such practice is more common than otherwise. An instance came to my attention some time ago, in connection with some work with the standardization of high-speed steels for machine tools, where there were no less than six different brands of alloy steels being used for machine tools such as lathe, shaper, planer, boring mill and cutters of like nature. All of these different steels received identical heat and forging treatment-or at least that was the aim of the tool hardener. That the results were highly unsatisfactory goes without saying. That the hardening department of many plants is conducted on a rule-of-thumb fashion is the reason for a great deal of the trouble and disappointment which seems to be the lot of many tool-steel users. Exceedingly crude execution is the rule rather than the exception, and it is no small wonder that the results are as good as they sometimes happen to be. It would seem that at the present price of alloy steels the subject should receive a closer scrutiny by purchasers than it does. One not familiar with the workings of souse plants that disdain to lend an ear to scientific heat treatment would scarcely give credence to some of the methods employed, not only in the treatment of the steel but also in its selection and purchase. Heating for hardening should be conducted under close pyrometric control only after the correct hardening temperature has been determined.

Jan 3, 1917

By Myrick N. Bolles

The concentration of gold and silver in mattes low in copper, and the subsequent separation and recovery of either or both of these metals, is a question the satisfactory solution of which has long vexed metallurgists. It covers a broad and important department of metallurgical science and brings in its train a series of attendant problems continuing from the initial operations of concentration to the final recovery of " values."

Jan 1, 1905

By Robert Glass Cleland

THE DEATH of William E. Dodge occurred at a time when, all unwittingly, the company in which he had so long been the dominant factor was about to break with its old practices, its old traditions, its old interests, and transfer its major activities three fourths of the way across the continent and engage in an enterprise that differed almost as much from the original Phelps Dodge undertakings as the rough, arid mountains of the new region differed from the green hills and valleys of New England. To understand the effect of this transformation upon the fortunes of Phelps Dodge, one must change the setting of the present narrative from the familiar locale of the Atlantic seaboard to the land of "distance, silence, and solitude," that men called Arizona. In 1880 that Territory was one of the last frontiers of the Old West. To the Spaniards it had been a land of mystery and fable, the limit of the King&apos;s settlements, the far edge of the rim of Christendom. Through it Coronado; in a vain effort to find the fabulous Cities of Cibola, had led "the most brilliant company ever assembled in the Indies to go in search of new lands." Below its southern border, Father Kino, the "steel-thewed" Jesuit described by his

Jan 1, 1952