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By H. Kenneth Sacks

The Bureau of Mines has developed hardware for electromagnetic (EM) detection and location of miners trapped in underground coal mines. This report describes a technique for using the developed equipment for locating uncased boreholes underground. Results of several field and laboratory experiments are described.

Jan 1, 1978

By G. R. Laurer, J. W. Neton, C. Pomroy, N. Cohen, M. Eisenbud

INTRODUCTION In uranium miners, a causal relationship between exposure of the lung to high levels of alpha radiation and the consequential induction of bronchial carcinoma is now well-established (Wagoner, et al., 1965). Quantitation of this cause-effect association presents considerable difficulty, however, as the result of various confounding factors such as the contributing effects of smoking and/or arsenic exposure (Archer, Gillam, and Wagoner, 1976), normal metabolic variability and, perhaps most important of all, the absence of accurate radon/radon daughter exposure data. Estimates of cumulative lung exposures suffer from inaccuracy due to critical factors such as 1) unknown ventilation rates; 2) difficulties in obtaining representative mine air samples; 3) the variable character and magnitudes of the exposure sources; and 4) specific differences in metabolism and job histories that exist among miners. It was with considerable enthusiasm, therefore, that investigators readily embraced the idea of using skeletal burdens of the relatively longlived descendants of radon and its short-lived daughters, i.e., 210 Pb and 210Po (Archer, et al., 1968), to provide a measure of cumulative past exposure wherein the body acts as an integrating dosimeter. Early studies considered excretion rates of 210Pb and 210Po in urine, blood and hair (Sultzer and Hursh, 1954; Black, et al., 1968; Jaworowski, 1965; Bell and Gilliland, 1964) as well as their concentrations in bone samples, if and when they became available (Blanchard, Archer, and Saccomanno, 1969). These methods were ultimately complemented by in vivo, whole-body counting techniques using low background, NaI-Csl(T1) detectors (Eisenbud, et al., 1969). By this latter method, it would be possible to measure the skeletal burden of 210Pb directly, thereby avoiding the many difficulties associated with the relation between nuclide excretion rates and body burden. The rationale was simple; by knowing the skeletal burden of 210Pb it should be possible, by the judicious use of an applicable metabolic model, to estimate the cumulative lung exposure to alpha-emitting radon daughters (Fig. 1). Various models that were consequently constructed, however (Fisher, 1969), all suffered from the same limitation, i.e., the assumption that the source of 210 Pb in the skeleton and the source of lung exposure to the short-lived radon daughters were simply related and, if not, were at [ ] least not too variable (Raabe, 1970). By now, the difficulty with this assumption has been recognized and more sophisticated modeling techniques have been attempted which presumably present a more realistic picture of exposure conditions (Holtzman and Rundo, 1981). There is, nevertheless, the pessimistic view that due to the variety and variability (in time as well as in character) of sources that may exist for the origin of 210Pb in bone, it may [never] be possible to estimate past lung exposures accurately by an indirect, predictive model. For example, the origin of 210 Pb in the skeleton may include such sources as: 1) the decay of short-lived 222Rn daughters, inhaled and ingested; 2) the decay of 222Rn dissolved in body fluids and tissues; 3) directly from 210 Pb present in air, inhaled and ingested; and 4) 210Pb from non-occupational sources, e.g., food, water, smoking and endogenous 226Ra. The contribution of each of these sources may vary depending upon specific site conditions such as ventilation and mining operation. On the other hand, empirical evidence seems to indicate a trend reflecting the simplest of direct

Jan 1, 1981

By R. M. Waterstrat, B. N. Das, Paul A. Beck

The central region of the Ti-Mn system was studied by means of x-ray diffraction and metallography. The following intermediate phases were found: an MgZn2-type Laves phase having a wide range of homogeneity, the p-phase of unknozvn structure, and the + -phase with a large tetragonal unit cell, stable at 930°C and lower temperatuves. MaYKUTH, Ogden, and jaffee1 determined the soh-inh bility limits of manganese in and titanium. They also confirmed the structure of the intermediate phase TiMn2 which was previously identified as a Laves phase of the MgZn2 type.2 In the equiatomic region they found an additional intermediate phase, y, which presumably formed by a peritectic reaction at approximately 1200°C. This last observation was disputed by Rostoker, Elliott, and McPhers0n,3 who reported the formation of TiMn by a peritectoid reaction between 900" and 1000° C, but found no evidence of any intermediate phase other than the Laves phase at higher temperatures. Elliott and Rostoker4 reported furthermore that the X-ray diffraction pattern of TiMn could be identified as that of a o phase, although their data were not consistent with this inter~retation. Margolin and Ence6 presented X-ray diffraction data for the and TiMn, phases, and obtained metallographic indications for the existence of additional intermediate phases. They concluded from metallographic observations that two Laves phases are formed, separated by another phase, designated as &. A phase diagram for the Mn-Ti system has recently been published by Savitskii and Kopetskii,' which shows considerable disagreement with the work of Hellawell and Hume-Rothery,' in particular with regard to the terminal solid solutions based on the allotropes of manganese. The present investigation was undertaken primarily to clarify the phase relationships in the equiatomic region of the Ti-Mn system. The metals used in preparing the alloy specimens Were iodide titanium and electrolytic manganese, the latter having a nominal purity of approximately 99.9 pet. The electrolytic manganese was covered with a thick coating of a brown manganese oxide which was reduced by heating the manganese flakes for several hours at a temperature of 1100°C in an atmosphere of dry hydrogen. Three alloys, see Table I, were made using sponge titanium and manganese not treated in hydrogen. The alloys were prepared by arc-melting in an atmosphere of helium or argon. The composition of each alloy was calculated by assuming that the entire weight loss during melting was due to evaporation of manganese. Subsequent chemical analysis of certain alloys indicated that the compositions calculated in this manner were usually correct within 1.4 pct, as shown in Table I. All alloy specimens were wrapped in molybdenum foil before sealing them in silica tubes containing argon at a pressure of 1 atm at the annealing temperature. After quenching in cold water, the alloy specimens were bright and clean, with no evidence of any surface reaction. The alloys listed in Table I were examined metallographically, using an etchant consisting of 20 pet HNO3, 20 pet HF, and 60 pet Glycerine. powder for X-ray diffraction examination was prepared by crushing a portion of each annealed alloy

Jan 1, 1962

By W. J. Helfrich, C. L. Sollenberger

Many present direct reduction processes utilize iron ore concentrates for the production of sponge iron and the sponge iron is usually preferred as an agglomerate. Pelletizing a high grade iron oxide concentrate prior to reduction is a simple approach to the high capacity production of a uniform and agglomerated sponge iron product. The present paper describes the effect of different atmospheres and physical characteristics on the reduction of pelletized iron oxide concentrates. The kinetics of iron oxide reduction have been I studied by numerous investigators1-4 and a rate equation for the hydrogen reduction of hematite and magnetite has been proposed. Mc Kewan' obtained kinetic data for the reduction of hematite spheres sintered at 13'70°C (2498'F'). The kinetics of magnetite reduction was studied by Quets. He compacted the oxide at a pressure of 1 ton per sq cm and sintered the specimens to densities of 95 to 96 pct of theoretical. These studies demonstrated that the reduction of iron oxide is a topochemical process and that the rate of reduction is proportional to the receding surface area of remaining iron oxide. Thus, the measurement of the kinetics of iron oxide reduction depends upon the development of a measurable and well defined interface between metal and reacting oxide. It is evident that the reduction rate will be constant only when the rate of formation of the reaction product layer is constant. It was recognized by Joseph' and Edstrom' that the physical character of the oxide will determine the configuration of the interface between oxide and metal. The reduction of oxides which exhibit few pores or no interconnected pores should proceed by topochemical processes. However, if a massive or dense crystalline ore cracks during the reduction of the oxide, thus allowing the reduction to Proceed away from a well defined oxide/metal interface, then the observed reduction rate will vary or change during reduction. From a process standpoint, it would be difficult to apply absolute reduction rates determined for crystalline or nonporous iron oxide to the direct reduction of a porous pellet of iron ore concentrate. Most present direct reduction processes are attempts to utilize iron ore concentraates in the production of sponge iron. The sponge iron is usually preferred in an agglomerated form for subsequent melting practices. Pelletizing a high grade iron oxide concentrate prior to reduction is a simple approach to the high capacity production of a uniform and agglomerated sponge iron product. One process for preparing such a product has already been de-scribed. This paper describes the effect of different atmospheres and physical characteristics on the reduction of pelletized iron oxide concentrates. ORE CONCENTRATES STUDIED A magnetite concentrate from Reserve Mining Co. and a hematite concentrate from U.S. Steel Corp. were used in preparing pellets for these experiments. A head analysis of these concentrates is given in Table I. To compare the reduction rates of pelletized concentrates, it was necessary that each pellet contain equal amounts of oxygen which could be removed by reduction, regardless of the oxidation state, i.e., Fez% or Fe304. Also, because of the difficulty in preparing spherical pellets of uniform size, weight, density, and porosity for experimental purposes, pellets of a cylindrical shape were formed in a press.

Jan 1, 1961

By C. L. Thornburg

FLANKING the Valley of Mexico on the northeast is a mountain range known as the Sierra de Pachuca. This northwesterly-trending range is about 30 miles long and 5 miles wide, its summit attaining an elevation of more than 10,000 feet above sea level, or 2000 feet above the valley floor. Pachuca, a town of 50,000 inhabitants, lies nestled at the southwest base of the range, 60 miles northeast of Mexico City. Three miles to the east, just over the summit and on the northeasterly slope, is the mountain town of Real del Monte with a population of about 20,000. These are the two principal towns in a 40-sq mile area whose yield has brought the district to its high rank among the world's silver producers. Total production probably exceeds 1.25 billion ounces of silver and 4.5 million ounces of gold. Exploitation by the Spanish was under way by 1530. As the mines were deepened operations became handicapped by the inadequate method of handling water with horse whims and bull skins. To offset this disadvantage a two-mile drainage tunnel was started in 1749 and completed ten years later. John Taylor of London acquired the mines from the third Count of Regla in 1824 and formed the Compania de Real del Monte y Pachuca. Two years later Cornish pumps were brought from England. A Mexican company purchased the British interest in 1848 and within a few years resumed an old project of driving a second, lower three-mile drainage tunnel, completing it in 1857. After American interests acquired control of the property in 1906 operations expanded to an unprecedented scale, despite periods of political strife, unstable prices, labor problems, and a growing burden of taxation. An idea of the scale of operations may be gained from records of the last two decades prior to 1947, the last year for which production information is at hand, during which time production ranged from 1.4 million to 1.1 million tons per year, and the combined development and exploration, exclusive of diamond drilling, amounted to about 18 miles annually. Pachuca differs from Zacatecas and some other Mexican silver vein districts that flourished and declined in earlier centuries in that a substantial part of its total production was made after 1900. While the district's accelerated activity in this century was largely due to the successful application of the cyanide process to the treatment of the ores, improved pumping methods, and new mechanical equipment, it was at the same time stimulated by the opening up of important new orebodies as a result of active and extensive exploration of the vein system. Some of these orebodies were found on veins which terminate upward far below the surface, and though these particular veins do not crop out, they show relationship with a type of alteration which may be their surface expression. The district has been studied by many able geologists, and a large store of information has been accumulated, much of which is recorded in published as well as private papers. Wall Rocks Extrusive Rocks: The Sierra de Pachuca is a thick accumulation of Tertiary eruptive rocks consisting mainly of flows, breccias, and tuffs. Numerous recognizable volcanic vents within the range itself manifest that the range was built up by material ejected from these vents. The maximum thickness of the volcanic pile is not known, but from deep exploration and from relationship with Mesozoic sediments to the north and east it is inferred that the average thickness in the main part of the district may be at least 6000 ft. The extrusive rocks comprise four general types, which in ascending order of age are: andesite, rhyolite, dacite, and basalt. The veins are confined largely to the andesite, the dominant rock of the region. Characteristically this rock is augite andesite, but it includes comparatively acidic as well as basic layers, the acidic strata being

Jan 1, 1952

By R. V. Ramani, R. Stefanko

"The favorable mining conditions in the United States of America that resulted in the development of the highly productive room and pillar systems are largely disappearing. Increasing mechanization, poorer natural conditions, and greater concern for health, safety and environment gave impetus to the enactment of the Federal Coal Mine Health and Safety Act of 1969. These regulations prescribe more stringent requirements in face ventilation and mine air distribution, necessitating significant changes in existing ventilation systems. Stringent mandatory standards were applied to respirable dust control for the first time, and simultaneous control of both gas and dust has affected the face as well as primary distribution, most notably on haulage entries.The size and complexity of the present-day mining operations, and the need to evaluate various system changes in a limited time, call for scientific methods in mine planning. In this paper, the authors trace the previous applications of computers to mine ventilation planning and discuss the results of their work in applying a ventilation simulator developed at Penn State. The paper includes an analysis of current trends and suggestions for future research and development."

Jan 1, 2014

By J. H Lightfoot, Stuart E. Buckley

Deep drilling has led to the development of numerous pools which yield products consisting predominantly of natural gas accompanied by high-gravity water-white or slightly straw-colored liquid. Yields of this "condensate" or "distillate," as it is commonly called, vary from traces to over a hundred barrels per million cubic feet of gas. The fact that this liquid exists in the reservoir as an integral part of the gas phase and is formed by condensation attending simultaneous reduction of pressure and temperature after its entry into the well was apparently first recognized about 1932.l The nature of the physical phenomena involved in this condensation was clarified for the petroleum industry in 1933 by a report by Sage, Schaafsma, and Lacey2 of the results of an experimental investigation of the behavior of mixtures of methane and propane. Search of the literature has revealed that the condensation of liquid from gaseous mixtures by isothermal pressure reduction is not a new discovery. Kuenen was led by theoretical considerations to expect such a phenomenon, and in 1892 reported3 the results of experimental verification of his deductions. This was followed by a considerable amount of work on the phase relations of mixtures by Kuenen 4,5,6 and by 0thers,7,8 mostly in European universities. Since 1930 investigators in this country have reported experimental data on the properties and behavior of a number of hydrocarbon systems."' It is now generally known that in the presence of natural gas the solubility in the gas phase of the heavier and normally liquid hydrocarbons increases rapidly with increasing pressure above 500 to 1000 Ib. per sq. in. Thus, at pressures of 2500 Ib. per sq. in. or higher a gas may contain appreciable quantities of hydrocarbons with normal boiling points as high as 6o0°F., which in turn may be condensed from the gas phase by the reduction of their solubility therein attending pressure reduc-tion. The combined effects of pressure and temperature on condensation and vaporiza-tioi of mixtures are most readily visualized by the study of phase diagrams. Since the construction, application, and interpreta-tion of such diagrams have been described fully in readily available literature, 18-20 this paper will not review the theoretical aspects of this subject. While the behavior of gas-distillate sys tems is now clearly understood, at least in a qualitative way, most of the published work deals with the results of laboratory studies of binary systems or of synthetic mixtures of hydrocarbons, and although several systematic investigations of the effects of separator pressure and temperature on the yields of liquid product from gas-distillate wells have been made21,12z it appears that in all cases the limitations have precluded the construction of even approximately complete phase diagrams for naturally occurring systems. There has 2

Jan 1, 1941

By J. H. Lightfoot, Stuart E. Buckley

Deep drilling has led to the development of numerous pools which yield products consisting predominantly of natural gas accompanied by high-gravity water-white or slightly straw-colored liquid. Yields of this "condensate" or "distillate," as it is commonly called, vary from traces to over a hundred barrels per million cubic feet of gas. The fact that this liquid exists in the reservoir as an integral part of the gas phase and is formed by condensation attending simultaneous reduction of pressure and temperature after its entry into the well was apparently first recognized about 1932.l The nature of the physical phenomena involved in this condensation was clarified for the petroleum industry in 1933 by a report by Sage, Schaafsma, and Lacey2 of the results of an experimental investigation of the behavior of mixtures of methane and propane. Search of the literature has revealed that the condensation of liquid from gaseous mixtures by isothermal pressure reduction is not a new discovery. Kuenen was led by theoretical considerations to expect such a phenomenon, and in 1892 reported3 the results of experimental verification of his deductions. This was followed by a considerable amount of work on the phase relations of mixtures by Kuenen 4,5,6 and by 0thers,7,8 mostly in European universities. Since 1930 investigators in this country have reported experimental data on the properties and behavior of a number of hydrocarbon systems."' It is now generally known that in the presence of natural gas the solubility in the gas phase of the heavier and normally liquid hydrocarbons increases rapidly with increasing pressure above 500 to 1000 Ib. per sq. in. Thus, at pressures of 2500 Ib. per sq. in. or higher a gas may contain appreciable quantities of hydrocarbons with normal boiling points as high as 6o0°F., which in turn may be condensed from the gas phase by the reduction of their solubility therein attending pressure reduc-tion. The combined effects of pressure and temperature on condensation and vaporiza-tioi of mixtures are most readily visualized by the study of phase diagrams. Since the construction, application, and interpreta-tion of such diagrams have been described fully in readily available literature, 18-20 this paper will not review the theoretical aspects of this subject. While the behavior of gas-distillate sys tems is now clearly understood, at least in a qualitative way, most of the published work deals with the results of laboratory studies of binary systems or of synthetic mixtures of hydrocarbons, and although several systematic investigations of the effects of separator pressure and temperature on the yields of liquid product from gas-distillate wells have been made21,12z it appears that in all cases the limitations have precluded the construction of even approximately complete phase diagrams for naturally occurring systems. There has 2

Jan 1, 1941

By A. Masutomi

Although great strides have been made during the past two decades in the reduction of the severity of accidents and injuries in underground coal mining, the number of accidents resulting in disabling injuries and lost time has continued to increase. Looking ahead to the 1990s, the reduction of accidents and incidents typically found in these latter categories should be emphasized in safety training for underground coal mining. Loss control is an approach which shows promise for applications in mine safety training since loss-control strategies focus on the pre-contact stages of an incident rather than on the incident, itself. Applied to safety training, the heightened awareness of personnel to workplace hazards at the pre-contact stages should result in a reduction of accidents and injuries. This paper explains the concept of loss control and shows how it can be applied in the development of the needs assessment for miner training programs. An example, based on research conducted at the continuous-miner worksite, is provided.

Jan 1, 1991

By César Sotillo

"El presente texto describe el proceso de la industria del acero en México. La compañía fue fundada en el siglo XX y tiene sus altos hornos en Monterrey, capital del estado Nuevo León, donde se funden los minerales de fierro que provienen de los yacimientos del Cerro de Mercado, situado en la región central de Durango. El yacimiento consiste de cuerpos inclinados hacia el oeste y que tienen contactos bien definidos con la roca encajonante; Asimismo afloran cuatro cuerpos de mineral, de los cuales el más grande tiene cerca de 800 metros de longitud. El cuerpo mineral está dividido en dos partes por resbalamientos producidos por fallas en la porción occidental del valle; los mismos que junto con la erosión, han producido la peculiar topografía de esta parte del estado de Durango. "

May 1, 1953

By F. Q. Barnes

"Uranium, thorium and yttrium have been recovered, since the 1950s, from pyritic quartz-pebble conglomerates occurring in the basal sediments of the Quirke syncline at Elliot Lake. Gold, an element of interest in similar type deposits occurring worldwide, is a very minor constituent of the Elliot Lake conglomerates because the provenance area of the sediments had few gold-bearing rocks.Uranium, thorium and rare elements are found in resistate and diagenetic minerals occurring in the matrix of the conglomerates. The valuable elements are recovered from the acid soluble minerals during the milling process.Large uranium reserves occur in mines found on both limbs of the Quirke syncline. Major reserves are being developed on the South Limb of the syncline, where the Stanleigh Mine, among four past-producers, has been reactivated.IntroductionUranium and thorium commonly occur in anomalous amounts in coarse basal sediments. Radioactivity in basal conglomeratic sediments is generally attributable to resistate minerals, that rarely occur in concentrations high enough to be of economic significance. One type of basal conglomerate found worldwide, in Precambrian cratonic basins, has uranium or uranium and gold concentrations large enough to be of economic interest. Principal among the occurrences are the pyritic quartz-pebble conglomerates of the Huronian in Canada, of the Witwatersrand in South Africa and at Jacobina in Brazil.The uranium and gold mineralization of these conglomerates was derived from provenance areas where both elements occurred and were later concentrated through source degradation and deposition in placers in a reducing environment. Only the Huronian conglomerates, generally much richer in uranium but with negligible gold, have been exploited solely for their uranium content.The uraniferous conglomerates of the Huronian at Elliot Lake, 500 km north of Toronto, continue to represent a major world source and supply of uranium concentrate."

Jan 1, 1986

A plan which has just been approved by President Wilson, by, the Secretary of the Navy, and the Naval Consulting Board, provides for the active cooperation of the Associated Advertising Clubs of the World with the 30,000 engineers who will soon undertake the task of making a card index survey of American industry, so that it may be prepared for national defense, if need comes. Herbert S. Houston, President of the Associated Clubs of the World comments on the plan. "Through the great power of advertising we expect-to arouse manufacturers, workingmen, businessmen, in fact the whole country, to the vital need of making industry the basic line of defense so that, if necessity arises, it can supply munitions quickly and abundantly. "This is not a war measure, but a peace measure. The militarist will support it and so will the pacifist, as well as the great body of Americans in between. So the slogan `national defense and international peace, has been adopted believing that the two causes will be best served by linking them together. "While the primary thing, of course, is service to the country, it is manifest that this work of the engineers will be of the greatest service to industry in times of peace. If industry is mobilized for defense, it will be placed on a basis of efficiency to meet the keen competition that will surely follow the present war." Howard E. Coffin, one of the leaders of the American automobile industry, in outlining the far-reaching plans of his committee, the Committee of Industrial Preparedness of the Naval Consulting Board, said: "At the outset I wish to emphasize the absolutely non-partisan nature of this work. I am not even familiar with the political affiliations of the great majority of the members of the Board or of my committee. In setting out to, mobilize the industrial resources of the United States, we are concerned only with the benefit to the nation, and to that end we have called into being an organization made up of the best technical and business brains of the country, and that organization will work along business lines with strictly business methods. I think it reasonable to say that this is a movement perhaps unique in the history of national governments, and one geared up to the highest standards of twentieth century efficiency. "It is vitally necessary that American industry be made aware of the part it must play in the national defense. Our whole conception of warfare has been changed almost overnight. Our military heads at Washington are largely, of course, graduates of the very best technical schools, have been taught the profession of fighting, and are masters of that profession. As members of the Naval Consulting Board, we are unable to tell these men how to do their work. But while these departmental heads have lived with military problems all their adult years, we on the other hand have slept and eaten and lived with the industrial problems of the country. The two questions are wholly distinct, and the masters of one cannot possibly be the masters of the other. We are confronted then with the necessity of interlocking these two vast elements of our national life into a great working organization for the national defense. It is that which we are about to do.

Jan 5, 1916

By ED. E. Furman, R. H. Atkinson

HITHERTO the practical creep testing of precious metals has received little or no attention. The only previous creep tests of precious metals have been made with wires under conditions such as to yield much more rapid rates of creep than in engineering tests.', ' Up to the present time the value of creep bars of adequate size, in the absence of real need for engineering data, has deterred investigators. However, the increasing use of platinum at high temperatures has demonstrated the need for reliable creep data for the guidance of engineers, especially those engaged in designing certain specialized chemical plant equipment. In order to supply this need, creep tests were conducted at 1382°F (750°C) on 0.290 in. diam specimens of platinum, 90 pct Pt, 10 pct Rh and palladium. The platinum was high purity, nominally 99.95 pct Pt. The 90 pct Pt, 10 pct Rh was of the same high quality as is used for making gauzes for the catalytic oxidation of ammonia. The palladium was also of high purity; two batches of palladium bars were tested, one deoxidized with calcium boride and the other with aluminum. Spectrographic examination of the palladium confirmed its good quality; the only significant impurities apart from the residual deoxidizers were traces of silicon and lead. Procedure The creep bars, which were furnished by Baker and Co. to our specification, were 6 ¾ in. in overall length with a 4½ in. (4 in. gage length) reduced section 0.290 in. in diam and had the ends threaded (?-NC16). It may be of interest that the bars were valued at up to $600 each. The specimens were supplied in a 50 pct cold-worked condition to facilitate attachment of the creep extensometer, which was of the push rod type. Because of the softness of the platinum and palladium, the extensometer rings were secured to the test section by means of circular knife edges instead of the usual pointed set screws. The extensometer rods extended through the bottom of the furnace and readings were taken with a 0.0001 in. "Last Word" dial gage fastened to the rods for the duration of the test. The bars were directly loaded by hanging weights from the lower specimen grip. All tests were conducted at 1382°F ± 2°F, and an effort was made to maintain the temperature gradient over the test section within 2°F. The ends of the furnace tube were packed with asbestos wool, which allowed a very slow circulation of air through the tube. Annealing was accomplished in the creep furnace before the load was applied. The platinum and palladium specimens were annealed at the test tem- perature for about 17 and 24 hr respectively; in the case of the rhodioplatinum it was found expedient to anneal for 1 hr at 1922°F (1050°C). Pilot samples cut from the same stock as the bars were used to check annealing procedures. Pertinent measurements of grain size and hardness were recorded. Results and Discussion The creep data obtained are given in Table I and the creep curves are plotted in Figs. 1, 2, and 3. Two platinum specimens, tested under a stress of 250 psi, had almost identical creep rates at 2000 hr, namely 0.000008 and 0.000009 pct per hr. A third platinum specimen, stressed at 400 psi, had a creep rate at 2000 hr of 0.000026 pct per hr; the reason for a rather sharp decrease in creep rate during the period from 1200 to 1600 hr is unknown. As it was thought that 90 pct Pt, 10 pct Rh would have a lower creep rate than platinum, the first sample was tested at 400 psi; however, the creep rate was approximately 50 pct greater. Microex-amination revealed that differences in grain size might be responsible for the unexpected result, as annealing at 1382°F developed an average grain diameter of 0.0021 in. in the rhodioplatinum specimen compared with 0.004 in. in the platinum bar. Annealing the alloy for 1 hr at 1922°F (1050°C) increased the average grain diameter to 0.0032 in. and materially improved the creep resistance, making it much better than platinum. A second specimen annealed at 1922°F (1050°C) and tested under a stress of 550 psi had a creep rate of 0.000022 pct per hr at 2000 hr, which was still substantially lower than that shown by the specimen annealed at 1382°F (750°C) and stressed at only 400 psi. In contrast to the creep behavior of the platinum and rhodioplatinum specimens, the palladium bars, whether deoxidized with calcium boride or aluminum, were characterized by high first stages of creep. However, after about 1200 hr of test, the creep

Jan 1, 1952

By R. F. Miller

DUE to wartime secrecy restrictions a large part of the technical information developed by government and industrial laboratories was withheld from distribution. Much of this information has now been released or "declassified" and reports of technical work carried out during the war in allied and enemy countries are also becoming available. Information on the latter subject has been augmented by the work of the Technical Industrial Intelligence Corps of the U. S. Army. Through the Joint Chiefs of Staff, rep¬resentatives of this Corps co-operated with the British Combined Intelligence Observations Subcommittee, and some of the observations were made by combined personnel of both groups. The U. S. Government has undertaken the indexing and abstracting of all of this information in the Bibliography of Scientific and Industrial Reports, a weekly bulletin which appeared first early in 1946. Other publications, such as the Bulletin of the British Iron and Steel Institute and The Metals Review of the American Society for Metals, provide abstracts of domestic and foreign magazine articles and papers presented to technical societies. However, they do not cover the industrial and government reports recently released by the Government nor the reports of the Army investigators hence the new bibliography is a welcome addition to our metallurgical library.

Jan 1, 1947

By C A. Foss, D A. Clark, D Hillan

While magnetic surveys are the most common geophysical method used in mineral exploration, magnetics and geology remain to be fully integrated quantitatively in iron ore provinces. Although high-resolution aeromagnetic data has been collected over prospective areas of the Hamersley Province, much of the information in the data sets has hitherto not been fully exploited due to a lack of suitable interpretation methods. Recent advances in the processing and modelling of magnetics in highly magnetic terrains, constrained inversion and 3D visualisation and understanding the magnetic properties of banded iron formations and iron ores potentially create the capability to generate realistic 3D mapping of magnetite and hematite concentrations over large areas. Initial processing of conventional total magnetic intensity data produces true potential field maps that are unaffected by local perturbations of the regional geomagnetic field direction by intense local anomalies. The true potential field can be converted into vector and tensor components, each of which emphasises different structural features of the geology. Scalar quantities derived from these components simplify interpretation, using new methods, developed by CSIRO and elsewhere, that are less sensitive to magnetisation direction. Preliminary interpretations allow interpolation between mapped units and structures and evaluation of remanence and anisotropy effects. Accurate modelling requires rigourous treatment of self-demagnetisation and magnetic interaction effects. Semi-automated constrained inversion, combining magnetics with available geological information and other geophysical data, can be utilised to generate models of disposition of major magnetic units and the 3D magnetisation distribution within them. The final stage of interpretation is to exploit the understanding of magnetic properties (susceptibility, anisotropy and remanence) developed over many studies by CSIRO, the University of Western Australia and others to convert the interpreted magnetisation distributions into 3D maps of magnetite and hematite contents, which are the quantities of direct exploration interest.CITATION:Clark, D A, Foss, C A, Austin, J and Hillan, D, 2015. Three-dimensional mapping of magnetite and hematite concentrations from reprocessing of detailed aeromagnetic data, in Proceedings Iron Ore 2015, pp 229–240 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By S. O. Choi, C. Park, C. Sunwoo

Two methods of stress measurements have been executed on the surface and underground to con-struct an oil storage cavern using hydro-fracturing and overcoring method. The first measurement has been performed to make a design of the caverns before excavating and the second to confirm the stress state during excavation. Six measurements have been carried out in the hydro-fracturing test at the depths between –17.8 and 54.5m from the sea level and a single measurement in the overcoring test in a single borehole at the depth of –21m from the sea level. The ratios of the maximum horizontal to vertical stress measured using hydro-fracturing and overcoring method are 2.95 and 3.1, respectively. Also, the orientations of the maximum horizontal stress are N53E and N58E. These measurements show that both methods give almost same results and significant horizontal stresses are acting on this cavern. Deux méthodes de mesure de contrainte ont étè exécutées sur la surface de terrain et sous la terre pour construire une cavité de stockage de pétrole en utilisant l’hydro-fracturing et l’overcoring. La première mesure a étè faite pour le plan des cavités avant l’excavation et le seconde pour con-firmer l’état de contrainte durant l’excavation. Six measures ont étè faites dans le teste de l’hydro-fracturing à la profondeur entre –17.8 et 54.5m depuis l’élèvation maritime. Une seule mesure a étè faite dans le teste de l’overcoring dans une seule trou de songdage à la profondeur de –21m. Le ratios de la maximale contrainte horizontale à la contrainte verticale mesure par les deux méthodes sont 2.95 et 3.1, respectivement. Les orientations de la maximale contrainte horizontale sont N53E et N58E. Ce montre que les deux méthodes donnent presque m me résultats et la contrainte im-portante est activée sur ces cavités. Zwei Druckmessungen wurden durchgeführt auf der Erdoberfläche und im Innern von Ölspeicher-kavernen unter vergleichender Anwendung des Hydrofraktionierungs- und des Kernbohrungsver-fahrens. Die erste Messung wurde durchgeführt um einen Plan der Kavernen vor der Herstellung zu erstellen und die zweite um die Druckverhältnisse während der Bohrung zu überprüfen. Sechs Messugnen wurden mit der Hydrofraktionierungsmethode bei einer Tiefe von 17,8m und 54,5m unter dem Meeresspiegel und eine einzige Messung mit der Kernbohrungsmethode in einem Bohr-loch bei einer Tiefe von 21m unter dem Meeresspiegel vorgenommen. Das Verhältnis von maxi-malem horizontalem zu vertikalem Druck bei der Hydrofraktions- und der Kernbohrungsmedthode ist 2,95 bzw. 3,1. Die Bezugspunkte des maximalen horizontalen Drucks in beiden Verfahren sind N53E und N58E.

Jan 1, 2003

By H. Warlimont

Precipitation of cementite plates from carbon-rich austenite gives rise to localized formation of martensite in the matrix next to the precipitate upon quenching. The growth of this martensite is urmsually restricted. A distinct lattice relationship is found between this martensite and the cementite phase. It is concluded that the martensite is nacleated in the region of lowest carbon concentration at the austenite-cementite integace, with low-energy matching to the cementite lattice. The restriction of the growth of the martensite phase to the vicinity of the cementite plates can be explained by misfit in the austenite -martensite glissile interface and the uphill carbon gradient in the austenite. The investigation was carried out by light- and electron-microscopy and by electron-diffraction of thin foils. THE precipitation of cementite from carbon-rich austenite gives rise to a localized formation of martensite in the matrix next to the precipitate upon quenching. This behavior has been described previously by A. B. Greninger and A. R. Troiano1 for a 1.78 pct C steel ("pseudomorphic martensite"), and by A. Hultgren2 for a Fe-0.99 pct C—5.20 pct Mn steel. By measuring the axial ratio of the martensite phase,' it was found that the carbon content of this martensite was lower than that of the martensite which formed without prior partial transformation to cementite. Therefore, it was concluded that lowering of the carbon concentration in the matrix next to the precipitate raised the M, temperature locally and thus led to nucleation of martensite at the ce-mentite-austenite interface. However, the restriction of the growth of the martensite phase to the vicinity of the cementite plates cannot be explained by localized carbon impoverishment alone. Under ordinary conditions a martensite plate which has been nucleated in a favorable site can continue to grow until it encounters a physical barrier, or until it encounters a compositional barrier in the matrix, where the total free-energy change for the reaction is not negative, since it has been shown by numerous experiments that the activation energy for growth of ordinary martensite is virtually zero.' An investigation was conducted by transmission electron microscopy and electron diffraction to study this extraordinary martensite. It was expected that crystallographic in addition to compo- sitional conditions caused this abnormal mode of martensite formation. MATERIAL AND PROCEDURE An Fe-C-Mn alloy containing 1.15 pct C and 5.1 pct Mn was used for most of the experiments. For metallographic work, specimens 15 by 15 by 3 mm were used. For preparation of thin films, the initial specimen size was 15 by 15 by 0.7 mm. The heat treatment of each specimen consisted of austenitizing for 1/2hr at 1100'~ in an argon atmosphere, subsequent isothermal holding in a lead bath at one of a series of different temperatures, and, finally, quenching into brine at room temperature. For metallographic examination, the specimens were mounted in bakelite (slight tempering effects resulted from the heat in the mounting press) ground, polished, and etched in nital. Thin films for transmission electron microscopy and electron diffraction were obtained by grinding the specimens to approximately 0.2 mm thickness and subsequent electrolytical thinning. The orientation relationships were evaluated from sets of electron micrographs and selected-area electron diffraction patterns of single units of the transformation products and the adjacent matrix. RESULTS In the alloy which was used for the experiments, proeutectoid carbide precipitates over a wide tem-

Jan 1, 1962

By Paul F. Sikora, John W. Weeton, Philip A. Clarkin

Effects of variations in carbon content and micro-structure on the stress-rupture properties of a liquid-phase-sirztered, Izeut-resistunt alloy were studied. Using the powder rnetallurgy technique, specimens could be produced having stress-rupture profierties equivalent to or better than those of the alloy in wrought form. In addition, sintered specimens were easily hot worked even when carbon contents were as high as I pct. Correlations between stress-rupture properties and micro structure were obtained in some cases. IT is well known that many alloys used in high-temperature service are quite complex both from the standpoint of chemical composition and microstruc-ture. During the development of these alloys their complexity has in some cases led to treatment schedules which, while practical, often do not fully utilize available alloying elements. For example, in some alloys, massive carbides that form during ingot practice may never be dissolved by reasonable solution treatments and therefore are unavailable for subsequent precipitation hardening, Ref. 1. This investigation was undertaken to determine whether the powder metallurgy method of consolidation might provide distinct advantages over the conventional melting method. First, segregation of alloying elements might be eliminated or reduced and thus a more efficient use of these elements obtained. Second, the structures produced in powder specimens might differ considerably from those normally seen in castings, which would perhaps result in better response to subsequent mechanical or thermal treatments. If these results could be achieved, it was felt that both forgeability and stress-rupture properties might be improved. The alloy used in this investigation was S-816 produced by powder metallurgy methods. The influence of carbon content over the range of 0.1 to 1.0 wt pct was studied for the alloy in the as-sintered condition and after three additional treatments involving heat treatment, hot swaging, and combinations thereof. EXPERIMENTAL Standard S-816 has the composition shown in Table I. It is a cobalt-base alloy having a nominal carbon content of 0.4 pct and is classified as a precipitation-hardening alloy. This alloy was chosen because it is representative of a class of heat-resistant alloys and because adequate information was available concerning its response to various treatments and its subsequent properties. For this study, -100 mesh alloy powder having essentially the same composition as shown in Table I but without the 0.4 pct C was used. Desired carbon variations, achieved by wet mixing the alloy powder with graphite, ranged from 0.1 to 1.0 wt pct. Specimens were hydrostatically pressed and then sintered in vacuum by slowly heating until incipient melting was observed. Sintering this way gave a liquid phase in the interstices of the powder particles and achieved reasonably high densities. The average density of as-sintered specimens was about 95 pct of wrought alloy density. In order to obtain various microstructures, some specimens were heat treated (solution treated for 24 hr at 2150°F, water quenched; aged 16 hr at 1400°F, air cooled); others were hot swaged at 2150 o F (50 pct reduction in area), while still others were hot swaged (50 pct reduction in area) and then given the above heat treatment. During hot swaging it was observed that forgeability was quite good even when specimens contained as much as 1.0 pct C. Specimens were evaluated by stress-rupture test-

Jan 1, 1962

By Eugene Larochelle

The serpentine of the Eastern Townships of Quebec is more or less seamed and impregnated with chrysotile asbestos, of which we note two types: the cross-fibre and the disseminated fibre. The cross-fibre type always appears in fibres or crystals arranged parallel to one another, and disposed at right angles to the walls of the matrix serpentine. The length of fibre of these veins, which run in every conceivable direction, even crossing ?one another, varies from microscopie dimensions to three and sometimes four and even five inches. It is the principal form of asbestos found in the serpentine of Thetford Mines, Black Lake, Coleraine, and Asbestos. The disseminated-fibre type, which is the main product of the serpentine of Broughton township, in which ate located the mines at East Broughton, does not form veins, but occurs in the serpentine without any definite arrangement. There is a difference in the toughness and hardness of the rock of the two types, the Broughton serpentine being softer than that at Thetford. The disseminated-fibre section of the serpentine belt is probably more regular in its content than is the cross-fibre section. Nevertheless, it contains no 'crude,' which is the most valuable of asbestos, and the fibre is usually shorter than the cross-fibre average.

Jan 1, 1928

By H. F. Mills

The Iron King mine is I2 miles east of Prescott Arizona, in low foothills of the Agua Fria mining district. It was operated in 1906 and 1907, using gravity methods of concentration, mostly on oxide ores. In 1923 and 1924 shipments of sulphide ores were made to the Humboldt smelter. It remained inactive and stripped unti1 1936, when it was unwatered and sampled to the 400-ft level, the bottom at that time. In 1937 the Iron King Mining Co. purchased the mine and shipped oxide ores. During 1938 a bulk flotation plant of I40 tons daily capacity was erected. The mill has been enlarged and operations have been continuous since the mill first started. In July 1942, the Shattuck Denn Mining Corporation purchased the physical assets from the Iron King Mining Co., and since that time it has operated as the Iron King Branch of the Shattuck Dcnn Mining Corporation. Economic metals recovered are gold, zinc, silver, lead, a little copper, and fluxing pyrite. The ore occurs as a series of northward-dipping shoots arranged in echelon pattern, the series extending over a length of 3500 ft. Strike lengths of shoots vary from 60 to 600 ft, and widths from 3 ft to as much as 14 ft. The ore occurs in a sheared zone in pre-Cambrian chloritic schist. This schist belt is about 6 miles wide, and the ore zone is about 4 miles from the pre-Cambrian granites to the west. No intrusive rocks have been found in the mine, nor is there evidence of any on surface that might indicate a genetic connection with the ore occurrence (Fig I). The schists strike N23°E and dip 75° to the northwest, which might indicate an overturned thrusting from the granites. In the upper levels, the echelon pattern in which the ore occurs was quite regular. no disturbance of the enclosing schist, or of any faulting that might contribute to the formation of the ore pattern was noted. There is a possibility that the ore zone may be on the axis of an isoclinal fold. Another interesting feature is the more or less typical zoning of minerals along the strike in each of the ore shoots (Fig 2). The north end of each shoot is enclosed by schist, while the south ends usually extend out at full width beyond the economic mining limits in a pyrite-quartz low-grade material. The plane of demarcation between ore and schist is very sharp, with little or no impregnation of sulphide in the schist, especially on the footwall side. The footwall schists are usually firm and strong, and vary from dioritic phases to fine-grained, lighter colored bands, almost silky in texture. The hanging wall for a width of 50 to 80 ft consists of alternating sheetings of chloritic and pyritic schists. The mine is now partly developed to the 920-ft level, with some diamond drilling from the 1150-ft station of No. 6 shaft. Economically there has been little change in nature or grade of ore from the top of the sulphides, about 200 ft below surface, to the bottom levels. There have been a few echelons in depth, just as there are in plan, and while a few shoots have had

Jan 1, 1949