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By M. Garfinkle, W. D. Klopp, W. R. Witzke

The tensile properties of binary W-Re alloys containing up to 33 at. pct Re were determined at temperatures from 78" to 3630°F. Elongations as high as 260 pct were observed in electron-beam-melted tungsten containing 23 at. pct Re when tensile-tested at 3630°F after a 1-hr anneal at 3090°F. All alloys tested under these conditions with rhenium contents between 20 and 28 at. pct exhibited elongations of at least 200 pct. These alloys also showed enhanced grain growth rates. The values of strain-rate sensitivity ranged between 0.2 and 0.3 for the alloys exhibiting high elongations. Houlezler, for swaged alloys tested just above the re-crystallization temperature, strain-rate sensitivities as high as 0.8 were observed. The high-temperature strengths of the high-rhenium-content alloys were also less than those of alloys with intermediate rhenium contents. ALLOYING with rhenium has two distinct effects on the mechanical properties of tungsten. One effect occurs in dilute solid solutions and is most clearly seen in the lowering of the hardness and of the ductile-brittle transition temperature at about 5 at. pct Re.1-3 The second effect occurs in the concentrated solid solution at about 25 at. pct Re, and is characterized by twinning and a larger decrease in the ductile-brittle transition temperature. An aspect of the high-rhenium-content alloy which has received little attention is the higher-than-usual tensile ductility at 3500°F.3 Anomalous high ductility has been observed in several other alloy systems. usually associated with a phase transformation or a solid-solubility limit.4'5 The phenomenon is now commonly termed superplasticity. High-strain-rate sensitivities6 and grain boundary sliding7 have been reported for materials that undergo superplastic deformation. Also, it has been found that superplastic materials usually have a very fine grain structure (less than 10 pm).8 and it has been proposedg that such a structure alone is sufficient for superplasticity. The purpose of the present study was to further characterize the high-temperature tensile properties of W-Re alloys to determine the conditions under which they might be superplastic. Tensile and selected strain-rate sensitivity tests were conducted on alloys containing 0 to 33.3 at. pct Re at temperatures from 78" to 3630°F. Grain-growth rates were also determined on most alloys at 3630°F. Fig. 1 indicates the compositions evaluated and their locations relative to the solvus line in the tungsten-rich end of the W-Re phase diagram. Twelve binary W-Re alloys containing up to 33.3 at pct Re were double electron-beam-melted and subsequently fabricated to 0.3-in. rod by extrusion and swaging. The starting materials were commercial powders of tungsten and rhenium with impurity levels as listed in Table I. The various blended W-Re compositions were hydrostatically pressed at 70 ksi. The pressed bars were drip-melted into 1.5-in.-diam ingots and then remelted into 2-in.-diam ingots at a chamber pressure of 10~5 torr. The ingots were canned in molybdenum and extruded to round bar at a reduction ratio of 6:l. The alloy extrusions were swaged to about an 80 pct reduction at 2100" to 2900°F. Buttonhead tensile specimens with a reduced section diameter of 0.16 in. and a gage length of 1.0 in. were centerless-ground from the swaged bars

Jan 1, 1970

By D. S. Tannhauser, I. Bransky

Measurements of the electrical conductivity, the thermal electromotive force, and the deviation from stoichiometry by thermogravimetry were made on ferrous oxide (wüstite) single crystals as well as on poly-crystalline samples in the temperature range of -900" to 1330°C. In the region defined by T 2 1000°C and 1.05 5 O/Fe 5 1.10 the electrical conductivity was shown to be proportional to the sixth root of- the oxygen partial pressure and to be linearly dependent on the deviation from stoichiometry. The absolute Seebeck coefficient of single and polycrystalline wüstite was shown to be independent of temperature in the above region and a p to n transition of the Seebeck coefficient was observed at O/Fe = 1.09 in polycrystalline wüstite. Analysis of the results showed that the predominant defects in wüstite in the above region were doubly ionized cation vacancies. The analysis also ruled out the existence of complexes of the type postulated by Roth, except that below 1000°C there is some evidence of 'association of defects. Of the three oxides of iron (FeO, Fe3O4, Fe2O3) only FeO (wüstite) can exist within a wide range of the ratio O/Fe. This has been shown by several investigations of the phase diagram using for instance chemical analysis of quenched samples'-4 or thermogravimetric measurements. 5,8 Darken and Gurry's1 data for example in the temper- ature range 1100o to 1400°C show that the lowest O/Fe ratio obtainable for FeOl +. is about 1.045 and that the existence range extends to O/Fe = 1.20 at 1400oC. On the basis of detailed analysis of thermogravimetric measurements made by Vallet and Raccah6 the existence of three varieties of wüstite at elevated temperatures was suggested by these authors and by Kleman. It is well-established that wüstite has a NaCl structure with vacant cation sites.3, 8 From a neutron-diffraction study of wüstite samples quenched to room temperature Roth9 concluded that defects in wüstite are mostly complexes composed of two cation vacancies and one interstitial cation in a tetrahedral site. The atomic arrangement in the vicinity of such a defect is similar to that in magnetite, where each occupied tetrahedral site is surrounded by four vacant octahedral positions disposed at the corners of a tetrahedron, so arranged that each vacancy is shared by two tetrahedral cations. Thus there is an average of two vacancies per interstitial. Recent X-ray diffraction measurements made by Smuts10 on quenched wüstite samples confirmed the results of Roth's neutron-diffraction experiments. Roth's model of defects in FeO can be regarded as a solid solution of Fe3O4 in FeO; salmon1' used this defect model to calculate the activity of Fe3O1 in FeO at high temperature and claimed good agreement with the results obtained experimentally by Darken and Gurry.' Each missing cation in wüstite is accompanied by two trivalent cations, thus preserving charge neutrality. The "holes" which differentiate between the Fe 2+ and Fe3' states of the ions in octahedral positions can overcome the attractive field of the cation vacancies, and are then free to move through the crystal as charge carriers. A similar picture holds for COO, NiO, andMnO.l2, 13 Localization of the charge carriers in transition

Jan 1, 1968

By J. B. Dorsey, T. W. Brinkley

Performance of a high-pressure, vaporizing gas-drive project in a volatile oil reservoir is discussed. The project has been in operation for over 8 years. Present recovery from the over-all displaced portion of the reservoir is 40 percent, and an ultimate recovery of 60 percent is indicated. Calculations reflect an over-all displacement volume of 50 percent for the entire reservoir; therefore, ultimate oil recovery will be 30 percent of the entire reservoir oil originally in place. Laboratory vaporization tests conducted prior to project initiation also are presented and discussed, along with an analytical method of determining stock-tank oil production and gar injection requirements related to over-all volumetric displacement efficiency from these data. Introduction The Shoats Creek field is located in Beauregard Parish, La., in the extreme western part of the state (Fig. 1). Discovered in 1956, the field is productive in three Cockfield sand zones, ranging in depth from 8,000 to 9.000 ft. The upper two zones, 1st and 2nd Cockfield, are condensate-bearing gas reservoirs. The lowest zone, the 5th Cockfield, is a volatile-oil reservoir. Laboratory work conducted on crude oil from the 5th Cockfield zone shortly after field discovery demonstrated that, when contacted with dry gas, signidcant volumes of the oil could be vaporized at reservoir temperature and at an appropriately high reservoir pressure. Further study led to the conclusion that early initiation of a crude vaporization project in the 5th Cockfield zone would be superior economically to other methods of reservoir depletion. Consequently, the zone was unitized and gas injection operations started late in 1958. This paper discusses laboratory work performed in conjunction with the project, and project performance to the present. History of Development The 5th Cockfield zone in Shoats Creek is composed of a thin, very shaly, low-permeability sandstone. Oil accumulation is controlled by a structural trap bounded by faults along the north and west and by a water contact on the southern boundary (Fig. 2). The zone covers a productive area of 1,550 acres at an average depth of 9,000 ft. The net sand section is thin, having a maximum thickness of 10 ft and an average thickness of 5.5 ft (Fig. 3). Average reservoir rock properties, as determined from core analysis are presented in Table 1. Shaliness of the zone is illustrated by the typical electric log of the 5th Cockfield section in Fig. 4. Because of the thinness and poor quality of the sand, the 5th Cockfield was developed on a wide spacing. Eleven completions were made in the zone between 1956 and 1961 for an average density of 140 productive acres per completion, with the majority of wells being dually completed in the 2nd and 5th Cockfield. Average initial potential for producers in the 5th Cockfield was 130 BOPD. Oil from the 5th Cockfield has a stock-tank gravity of 50.5" API; with a bubble-point pressure of 3,515 psia, the oil was highly undersaturated at the original reservoir pressure of 4,675 psia. Pertinent properties of the oil as determined in the laboratory are presented in Table 2. Because of the volatile nature of the crude, laboratory studies of its susceptibility to vaporization, as well as a vapor-liquid phase study, were conducted in addition to a standard PVT analysis. The vaporization study was conducted in a visual cell; a stepwise illustration of this work and laboratory measurements are presented in Fig. 5. Field

Jan 1, 1969

By P. Shahinian, R. L. Stegman, M. R. Achter

Creep strength has been determined as a function of oxygen pressure for nickel at 510" and 600°C. Creep-rupture life drops from its highest value at the ultimate vacuum of 10-7 torr to a high pressure plateau of nearly constant life which, at 600°C, commences at torr. This behavior is described in terms of a model that relates surface gas adsorption and the generation of fresh crack surfaces. In a calculation based a this model the predicted pressure beyond which the creep strength should not decrease further has been found to agree well with the observed value. The introduction of oxygen during creep in vacuum was found to cause a prompt rise of the creep rate. The magnitude of the environmental effect was much less than generally observed in fatigue and this is attributed to the diffarent crack morphologies in creep and fatigue. GASEOUS environments are known to affect creep resistance adversely1-5 but the effects have received less attention than the much larger ones in fatigue. At low temperatures it has been shown for nickel that the creep rates are faster and the rupture lives are shorter in air than in vacuum and that these environmental effects can be correlated with faster crack growth rates in the reactive environment.' In support of a mechanism of gas adsorption at the crack tip to explain the above effects, a calculation based on kinetic gas theory showed that surface coverage by gas was not as rapid as the exposure of fresh metal at the crack tip in the ultimate vacuum but was in air.7 In fatigue a number of investigations have demonstrated that the reduction of life with gas pressure usually follows a step curve with most of the reduction occurring in a transition range at intermediate pressures and little or no change at high and low pressure.8 There have been no studies, however, in which creep strength has been determined as a function of reactive gas pressure to see whether similar effects would be found. This investigation was undertaken to study the kinetics of the environmental effect in the creep of nickel. EXPERIMENTAL PROCEDURES The environmental creep apparatus was constructed to minimize many of the experimental conditions which can cause scatter in data. Dead weight loading is employed and weights are contained within the environmental chamber to eliminate bellows and the necessity for compensation for gas pressure changes. Elongation over the specimen gage length is recorded from a Riehle Model DV Controlled Environment Extensometer which provides readout to 2.5 x 10- in. Temperature is monitored and controlled from a thermocouple at- tached to the specimen gage length to +0.5oC or better. The freon trapped oil diffusion pump vacuum system included an auxiliary liquid nitrogen trap and, with a wide range variable conductance leak valve, pressures from the ultimate vacuum of 10"7 to l03 torr of any desired gas are obtainable. Pressure is measured by means of a hot filament ionization gage below 10"3 torr and a NRC Model 530 Alphatron Vacuum Gauge above 10-3 torr. The oxygen, which was leaked into the environmental chamber, was an Aviator's Grade of 99.5 pct purity with a dew point of -80°F. Analysis of the nominal 99.8 pct Ni showed the following percentages of major impurities: 0.02 C, 4.01 Mn, 0.005 Si, 0.01 Cu, 0.02 Fe, and 0.034 Mg. Cylindrical specimens were machined with a 0.180

Jan 1, 1970

By Cheri Eby, William R. Eby

INTRODUCTION Pneumatic conveyance systems provide for material placement at high compaction rates in confined spaces. This method of conveyance provides proper roof support and ground stabilization important to underground mining activities. Today underground mining activities are conducted far differently than those of our ancestors, in that the reclamation process is the final step in any mining activity. Responsible mine owners are constantly seeking innovative methods to assist them in their reclamation procedures. During the last few years, particular attention has been paid to previously mined areas, as many of these abandoned areas lay open, imposing a constant threat to humans and animals. Considerable attention is being directed to applying proper methods for the filling and sealing of underground slopes, drifts, tunnels, and adits, because today we are experiencing the effects of past mining activities such as subsidence, acid mine water run-off, buring refuse piles, and underground mine fires. Furthermore humans and animals who have ventured into abandoned mine openings have died from exposure, suffocating gases, and mine collapse. This paper explains the method of pneumatically filling and sealing these openings and underground works by means of employing pneumatic equipment and proper backfill material together, thus achieving high material compaction and thereby providing the complete filling of the voids and alleviation of the mentioned dangers. NEUMATIC SYSTEMS The use of air to transport material is widely used; however, conveying abrasive material (e., rock, earth, and cement) requires certain pneumatic transport systems designed to handle the abrasiveness as well as the size of these materials. The Eby pneumatic transport sys tem, known as a Mobile Stower, in mounted on a 42-foot trailer pulled by a Kenwor th tractor. This arrangement allows for quick mobilization and project set-up. The pneumatic system, composed of several components assembled together, produces the volume and pressure of air required to transport the material. Knowledge of elevation, ambient temperature, and material composition at the locations to be backfilled play a big part in the design and useage of the pneumatic system. In this particular system design, material is placed by a front-end loader into an eight (8)-yard hopper which is located over a belt conveyor. The conveyor transports the material up to an air lock feeder, which is the metering devise used to feed the material into the Tee Injector located directly below. Air is supplied by a positive displacement blower which, in this instance, delivers up to 4400 CFM's of air at 8 to 12 PSI. Horse power requirements to drive the blower are met with the useage of either a diesel engine or an electric motor. A diesel engine enables the Mobile Stower to operate in remote areas. As the air flows through the upstream air piping, it passes through the Tee Injector and picks up the material and conveys it through the material conveyance pipe, (referred to as down-stream pipe), and out the placement nozzle. Depending upon material composition and the amount of tonnage to be moved, either mild carbon steel pipe or specially heat- treated hardened pipe is used for the material conveyance line. The entire pneumatic system is controlled from the operator's console. With the aid of instrumentation, only one person is required to operate the system. Tonnage rates vary in accordance with horse power and air supply, as well as

Jan 1, 1982

By E. D. Williamson

DURING the wartime rush to prepare the glass necessary for the needs of our army and navy, the problem of the temperature control of the annealing kilns became most serious. The narrow limits of strain allowable (all the specifications called for less internal strain than the average of the previously used German glass) made necessary a very exact procedure and the methods had to be used on a much larger scale than theretofore. At the Charleroi plant of the Pittsburgh Plate Glass Co., the members of the staff of the Geophysical Laboratory, which was cooperating with the company, had occasion to study the methods available, and reached a number of conclusions (many of them by no means new except in their application) that may interest and assist those who have to meet similar problems in other fields. The following is a short account of the essential features of the system of temperature control evolved, along with a rather abridged statement of the reasons that led to the adoption or rejection of various schemes.

Jan 8, 1919

By E. F. Bailey, W. J. Harris

THE temperature of the ferrite to austenite re-action is established frequently by continuous heating experiments. However, equilibrium studies of this reaction have demonstrated that austenite may form at temperatures considerably below those at which the reaction is first observed during continuous heating. Because of this discrepancy, tempering is sometimes performed above the true critical temperature and in these cases austenite forms during tempering. The lowest temperature at which austenite forms and the kinetics of the reaction have been studied by Bain,' Bleakney and Gros-venor,2 and Dube and Cunningham. This austenite can affect the properties either as austenite per se, if it is retained at room temperature, or as a decomposition product if it transforms. The effect of austenite formation during tempering on low temperature impact properties of an 8 1/2 pct nickel steel was reported by Brophy and Miller4 in work published after the present investigation was initiated. They concluded that the improvement in low-temperature notch toughness which followed tempering at certain temperatures could be attributed to the austenite formed during tempering. Kramer et al.5 found anomalous hardness increases and embrittlement after tempering of a low-carbon manganese-nickel steel. They concluded that austenite formed during tempering, and that the decomposition products were responsible for the increase in hardness and the embrittlement. Quan-titative correlations of the microconstituents and mechanical properties were not made by these investigators. The present study was undertaken in order to establish the kinetics of formation of austenite at various temperatures, the characteristics of the decomposition of this austenite, and the relationship between mechanical properties and the phases present. Experimental Procedure A low-carbon manganese-nickel steel was selected because of the sluggishness of its austenite decom-position reactions. The composition of this steel in percent was: C, 0.10; Mn, 3.52; Ni, 2.34; Mo, 0.52; Cr, 0.17; Si, 0.19; V, 0.15; P, 0.019; and S, 0.020. Samples were prepared by forging sections from a large ingot to 3/4 in. bars. Formation and decomposition of austenite were investigated by dilatometric techniques which were checked by X-ray measurements. Dilatometer specimens were hollow cylinders 1 in. long, 1/2 in. diam, with a 1/8 in. central hole. All specimens were aus-tenitized for 1 hr at 1650°F and quenched in water prior to insertion in the dilatometer. Oxidation was prevented by using an inert atmosphere of purified nitrogen. Dilation was measured with a dial gauge which could be read by interpolation to 0.00005 in. Temperature was maintained within ± 3°F by a Brown Electronik Controller. Chromel-alumel thermocouple leads were welded to opposite ends of the specimen with the specimen serving as the hot junction. As a check on temperature uniformity comparison was made of the specimen temperature as measured with the chromel-alumel leads and the temperature of the center of the specimen as measured with a calibrated platinum—platinum-rhodium thermocouple embedded in asbestos in the central hole of the specimen. During heating a 5°F temperature difference was noted below 1000°F, but none above, while in cooling, a 5°F difference was observed from 1300" to 735°F, but none below. Heating rates of 35°F per min and cooling rates of 60°F per min were employed for all dilatometric studies. For transformation studies below room temperature, the dilatometer was allowed to cool to 150°F and then was quenched into liquid nitrogen.

Jan 1, 1951

By R. T. Gallagher, C. G. Brennecke

This paper is the result of a research program entered into cooperatively by the General Reinsurance Corporation and Lehigh University in January 1944. The research program was instituted to find a more positive method to determine the presence of hazardous roof conditions in mining operations. The co-authors, together with Mr. R. D. Currie, Engineer for the General Reinsurance Corporation, started working on the project in January 1944, first undertaking a library search; second, a preliminary study based on some existing equipment; third, the design of new and more suitable equipment; and finally, the field testing of equipment and methods. PURPOSE Any study of the accident statistics of mining operations will disclose the rather startling fact that approximately 50 to 60 per cent of all fatal underground accidents in the anthracite and bituminous mines are caused by falls of roof and coal, the metal and nonmetal mines showing only a slightly smaller percentage. Advancements in safety engineering have produced definite results in the decrease of accidents due to blasting, haulage, electricity, and explosions but no such decrease is shown in those caused by falls

Jan 1, 1946

By Albert R. Ledoux

In Great Britain all analytical chemists are styled assayers, but in the United states a slight distinction is made, assayers being considered those analytical chemists who have chiefly to do with the determination of the precious metals. There have grown up around the assayers of precious metals a number of customs and traditions which, as a rule, do not fetter American chemists when called upon to determine the composition or constituents of any samples submitted to them for analysis. In Great Britain, on the other hand, trade-customs even go to the extent of enforcing the employment of an admittedly erroneous atomic weight in certain alkali-determinations. If the American chemist is asked to determine the amount of lime in a water, potash in an alkali, or silica in an ore, the owner of the sample does not presume to suggest what method he shall employ, nor does he question his report on the ground that he should employ another method. But even in America it is different with the assayer. Unfortunately for the guild, as well as for those who have to base business operations on the reports of assayers, customs and traditions as well as divergent interests seek to circumscribe him in his choice of method and sometimes dictate how he shall perform his operations. This was true at one time of copper, which to-day in England is still determined by the so-called Cornish fire-assay, an attempt to imitate in the laboratory the various metallurgical operations in the smelting-works; but nowhere in this country is the assayer forced to employ any particular method for determining copper so long as his certificate indicates the true total percentage of copper in the sample. It is true that both buyers and sellers demand use of the electrolytic method, but only because it is the most accurate. In America the trade accepts the assayer's statement as final, and makes

Jan 1, 1895

By Joseph L. Patrick

Geologic exploration, which has experienced an upward trend in the United States since 1962, continued with increasing activity through 1965. New, spectacular discoveries of recent years and continued questionable economic and political climates in many areas of the world have continued to focus the exploration attention of an increasing number of companies on the United States. Traditional geologic field methods are being bolstered by development of new methods, techniques and geophysical instruments. Reports from the states emphasize that successful exploration is dependent upon the combined effort of geochemistry, geophysics and geology, with high quality laboratory support of the field effort becoming increasingly necessary. PROGRAMS NOW UNDERWAY IN WEST During 1965 mineral exploration reached an all- time high in Nevada. Although examinations are being carried on throughout the State, much of the work is limited to two areas. The first area to attract recent exploration interest, initiated by discovery of the Carlin gold mine by Newmont Mining Corp., is an area of windows near the leading edge of the Roberts Mountains thrust fault in northeastern Nevada. Included in this area are the old camps of Mountain City, Battle Mountain, Cortez, Mineral Hill and Eureka. Major mining companies are using a combination of surface mapping, geochemistry, geophysics (largely induced potential surveys), following up with drilling. The second area of exploration is along the Walker Lane, a wide shear zone that parallels the Nevada-California boundary from Virginia City to Las Vegas. Activity has been intense in the Tonopah-Yerington area. Discovery of a large copper-iron deposit following an airborne magnetometer survey first focused recent attention on Walker Lane. Sixteen major companies are involved in exploration in the State.

Jan 2, 1966

By S. Marion Tucker

THE aggregate number of "papers" read within any one year before more or less bored and bewildered audiences is simply appalling. We have seventy to eighty engineering societies alone, not to speak of the many hundreds of societies of every other imaginable kind. And each meets at least once a year to tell what it has found out since the last meeting. All this is very fine and fortunate, at least in the case of the scientific and technological societies; for if even only one significant discovery, one new truth, one new idea comes out at the meeting, the session has been abundantly justified. To many of us, not scientists or technologists, the scientific and technological societies seem to release by far the most useful and important information. What they have to say is often of prime importance directly to human life and to industry, and is perhaps even more important indirectly in its final influence upon social and economic conditions, thus ultimately determining the course of what we like to call civilization. The paper read by that quiet, unpretentious man on the platform ma; mean the revolutionizing of a great existing industry, the creation of an entirely new industry, the gain of millions of dollars to some persons, the loss of millions to others. But, lamentably,

Jan 1, 1940

By Sylvain Pirson

THE number of seismograph field crews employed in the active survey of potential oil territories is still on the increase, owing to the ever pending threat of a shortage in the supply of crude oil. It is to be expected that for years to come the seismograph will be responsible for discovering many new oil fields, both in wildcat territories and in deeper formations, and that the seismographic campaign will go on unabated. Yet improvements in instrumental design, in the field and interpreta-tive techniques, are brought about year after year, and lead to the reshooting of areas many times surveyed previously. Notwithstanding the experience gained by the past eight years of active work in reflection seismographic surveys, the results given by this method of mapping deep formations have in many instances been at variance with the information subsequently obtained by the drill. To overcome this shortcoming, geophysicists have used closer spacing of the shot points and closer control of the depth points. The method dis-cussed here is being used actively in the Mid-Continent region and endeav-ors to reduce the interpretation work to a mere mechanical technique, leaving as little as possible to the opinion of the interpreter.

Jan 1, 1937

By A. B. Young

In the original design of the flue system, the flues from the roasters delivered their gases to a large brick dust chamber which discharged into another flue with stack connection, as shown in Fig. 1. The treater is so situated that the gases are taken by it directly from the chamber and discharged again into the flue. The complete installation comprises two treater units, only one of which has been installed at present. The treater is essentially a flue 1.0 ft. high, 12 ft. wide, and 61 ft. long. (3 by 3.6 by 18.5 m.). Suspended inside, vertically and running lengthwise, are four banks of No. 20 corrugated iron plates; each bank is 10 ft. long, making an effective treater length of 40 ft. The spacing from center to center of the rows of plat,es is 9 1/8 in. (23 cm.) giving six-

Jan 1, 1921

• Pellets of concentrated iron ore have been smelted in the blast furnace by Armco and the results proved satisfactory. Various percentages of pellet burdens were tried and it has been found that charges up to 70 pct pellets are workable. •In the reorganization of the Department of the Interior, two new assistant secretaries were appointed and the work divided between the four assistant secretaries. C. Girard Davidson will head a division of mineral resources including the Bureau of Mines, Geological Survey, Division of Oil and Gas and Division of Geography. •Germanium, one of the rarest of metals and a wartime strategic material, has been discovered almost in the shadow of the Capitol. The only catch is that the scattered nature of the deposits makes profitable recovery extremely doubtful. Nevertheless, experts have tabbed the concentration in the District of Columbia area the world's second richest known concentration of the element. • Cakes of mica, weighing up to 500 lb, have been formed at the Colorado School of Mines by a new "cool hearth" method. The process avoids use of crucibles and contains the molten mica in a basin of unmelted raw mixture from which the melt was derived. Crystallization takes place in this melting basin which forms a center pool surrounded by a solid cool mass of the unmelted raw mixture. • William 1. Baxter, of the International Economic Research Bureau, predicts a period of deflation because of war-essential restrictions on consumer credit and materials use. He stated; "the recent prosperity was based mainly on the sales boom in autos, homes, and household accessories." •Two subsidiaries of United States Steel have decided to build four new ships immediately to augment iron ore and limestone carrying capacity on the Great Lakes to meet demands created by the national defense emergency. •The Norfolk and Western Railway is making a complete change over to coal to drive its locomotives. •A national roster of scientific personnel similar to the one used in the last war will be established by the Office of Education, by agreement with the National Security Resources Board. The new unit, the National Scientific Register Project, will make studies of the Nation's scientific manpower supply and recommend steps to increase the numbers of skilled personnel where needed. •National Lead Co. will start construction immediately of new facilities at St. Louis, Mo., for production of titanium pigments for paints. Producers of titanium pigments have been under considerable pressure to meet all demands from paint manufacturers, particularly for titanium dioxide. •The basic criteria for deferment of reservists in civilian occupations are (1) the Department of Labor List of Critical Occupations, and (2) the Department of Commerce List of Essential Activities, both of which were announced Aug. 3. Fundamentally, the reservist deferred must be engaged in a critical occupation which is necessary to a highly essential activity, and he will be deferred only until he can be satisfactorily replaced in that occupation. A delay in call to active duty, it was emphasized, may not be considered as an indefinite exemption from military service.

Jan 9, 1950

By Carl Lee

WITH the modern trend toward motor drive in coal mines, more careful forethought should be given to future layouts than has usually been done in the past. Both top and bottom equipment of future new mines is likely to differ radically from those of a decade ago. No one is able to predict very far ahead, but provisions can be made to allow for uncertainty. One thing stands out: the mine of the future will be laid out for long life compared to that of the small mine of the past, where an inexpensive top plant, simple equipment, a small timbered shaft, small cars, light rail, hand loading and mule haulage all contributed to a short economical life.

Jan 1, 1933

By R. S. Rickard

Chemical processing of ores has gained new im¬petus in recent years. The reasons are many. They range from the need to process ores that are difficult to beneficiate to the avoidance of pollution. Although many think of chemical processing as a hydrometallurgical operation there are other techniques. An example is chlorination. Chlorination, although examined and discarded by many investigators, is again being considered as a means of extracting uranium1, treatment of silver-lead ores2, and the recovery of base metals from pyrite cinder and ores3. Segregation roasting of copper and nickel ores, a process similar to chlorination, is another chemical treatment being revived.

Jan 1, 1970

By Kenneth E. Skiff

INTRODUCTION United Nuclear Corporation and Homestake Mining Company are partners in a major uranium mining and milling venture near Grants, New Mexico. The partnership was formerly called Homestake-Sapin Partners and was recently renamed United Nuclear-Homestake Partners (UN-HP). The mill, originally built in 1958, had a capacity of 1,650 tons per day. With subsequent improvements and the addition of the adjacent Homestake - New Mexico Partners mill, the UN-HP mill is currently rated at about 3,500 tons per day. An alkaline type leach process is utilized by the mill. Milling consists of five basic steps: A. Ore handling and preparation B. Extraction C. Solid-liquid separation D. Precipitation and purification E. Product preparation MILLING Ore Handling and Preparation The primary source of ore for the UN-HP mill is from its four

Jan 1, 1983

By Norman J. Gibbs, John Sroka

INTRODUCTION At the point a company decides to begin mine development and wishes to convince lending institutions that the proposed operation will return their borrowed funds, plus interest, over the terms of the loan, communications between lender and borrower are crucial. The importance of the mine feasibility presentation should not be underplayed, especially as new projects continue to increase in size, complexity, and cost. While the content and emphasis of a report to the lender will vary according to the particular project and type of debt financing sought, there is a general base of information upon which all such studies are built. THE PROJECT'S TECHNICAL ASPECTS Here, the object is to satisfy the lender that he will not be unduly exposed to technical risks as a result of the physical scope of the project. Reserves The feasibility report submitted to financial institutions should include an adequate description of the geologic setting, mineralogy, ore types, and reserves broken down into such recognized categories as proven/probable/possible or measured/indicated/inferred. Rather than a bald statement of reserves, lenders prefer to have detailed information on: History of exploration Drilling, both percussion and core, with core recovery, drill hole spacing, analyses, and continuity of mineralization Bulk sampling, with core assay comparisons Overburden, with stripping ratios Specific methodology of reserve calculation, and Geologic reserves vs. mineable reserves. As a rule of thumb, a lender would prefer to see that reserves in the proven class alone are sufficient to support operations at the design rates until the borrowed funds are repaid. (See also Schreiber above in this Chapter.) Mining The rationale for adoption of a particular mining technique should be presented as well as descriptions and justifications for: Preproduction development Preliminary mine plan, with forecasts of grades and material movements Geotechnical test work which influenced decisions Mining recoveries and efficiencies Major equipment, with type, model, rating life, spares, replacement schedules, utilization, and productivity Manpower requirements and work schedules Design assumptions Ore stockpiling and blending Environmental requirements, and Waste disposal Processing If a new ore body is to be developed or a new process used, it is important to provide details of test work, scale up, and extrapolation factors. A basic process description with a summary of the studies which justify the intended processing route should be included with the following data:

Jan 1, 1985

No review of underground mining should begin with anything but the new world safety record set at the Grace underground iron mine of Bethlehem Steel at Morgantown, Pa., on Friday, November 12. There had not been a disabling injury (an injury which keeps an employee away from his next scheduled shift) for 550 working days. In all, 2,660,080 man-hours had been worked by nearly 950 employees without a disabling injury. The record was wrested from Johns-Manville's Jeffrey mine at Asbestos, Que. At 3 p.m. Friday, December 3, miner Stanton E. Friend was completely buried under several feet of coarse rock, fortunately sustaining only cuts and multiple abrasions. But with his fall, the accident- free period came to an end at 2,778,600 man-hrs worked without a disabling injury-the new record!

Jan 2, 1966

Albin, B. R Billings, Mont. '28 Amster, Nathan L . , 25 Broad St, New York, N. Y. '28 Bache, Jules S 42 Broadway, New York, N. Y. '28 Barrett, C. P 5338 Harper Ave, Chicago, Ill. '28 Baum, Frank G Hobart Bldg., San Francisco, Cal. '28 Bayless, Ron. William S Russ Bldg , San Francisco, Cal. ' 28 Bean, Louts H., V.P., Dwight P. Robinson & Co, Inc 125 E. 46th St, New York, N Y. '23 Beatty, Ross J 1105 First National Bank Bldg., Chicago, Ill. '28 Benwell, Oswald F 205 Colorado National Bank, Denver, Colo. '28 Beymer, Albert S., V.P., Keystone National Bank Pittsburgh, Pa. '28 Bingham, Charles W 1542 Hanna Bldg, Cleveland, Ohio. '28 Blumenthal, Hugo 44 Pine St, New York, N. Y. '28 Boettcher, Charles Ideal Cement Bldg., Denver, Colo. '28 Bowlus, Thomas H Iola, Kans. '28 Bragg, E. B Carmel, Cal. '28 Brown, Colvin B Chamber of Commerce, Washington, D. C. '28 Burt, Maxwell Struthers Southern Pines, N. C. '28

Jan 1, 1923