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THE decision of the lower court (United States District Court for the Southern District of New York) in the suit of the Dwight & Lloyd Sintering Co., vs. John E. Greenawalt has been affirmed by the United States Circuit Court of Appeals for the Second Circuit. In the original suit, infringement of seven patents was alleged, these covering the process of producing a sinter .out of finely pulverized metalliferous ores as practised in shallow pans operating intermittently in distinction to the Dwight 6: Lloyd continuous machine. The court found that the long delay in bringing suit precluded any recovery of profits from the defendant under the basic down-draft sintering patent, although Dwight & Lloyd are recognized as the inventors of this' contribution to the art and its .importance is acknowledged.

Jan 1, 1928

By Y. P. Chugh, Rajiv Singh

This paper presents the feasibility analyses of terrace pit mining a single seam for depths beyond 33 m (110 feet) in a hypothetical model mine and at an operating mine in southern Illinois. One or two shovel- truck benches near the surface and a large dragline for the last bench are considered for overburden stripping in the proposed mining scheme. Mining and reclamation operations are integrated and reclamation efforts are minimized by proper spoiling techniques. The proposed mining scheme was optimized using the OPMHS (Open Pit Material Handling Simulator) model developed by Penn State. Equipment selection and economic analyses were also conducted using the simulation model. The effect of pertinent variables such as thickness of the coal seam, annual production, initial capital requirements, size of haul trucks, selling price of coal and expected rate of return were analyzed on the feasibility of terrace pit mining. Sensitivity analysis charts for the effect of these variables are presented in the paper.

Jan 1, 1983

By H. Evans, L. A. Hunt

The raw materials used in the blast furnaces at the Geneva Works of U.S. Steel Corp. have a high degree of variability in size-consist and chemical content. To overcome the problems caused by the use of highly variable raw materials in the blast-furnace operation, large blending piles are used. An investigation of the blending system showed that variability was significantly reduced by the use of these blending piles. This paper describes the blending system, the method used to evaluate the effect of the blending system, and the results of the investigation. The remarkable improvement in blast-furnace performance since World War II has been in large measure due to the use of beneficiated burdens to reduce the variation of both chemical analysis and size consist. This practice allows the operator better control of his blast furnace, enabling him to operate more economically and to produce chemically uniform hot metal. Planning for uniformity usually begins during mining by extracting ore from several locations within a pit to produce a final product with a specified analysis. Another approach is to stockpile ores having widely varying analyses in individual piles and then drawing the required amounts from each stockpile to provide a blend with a predetermined analysis. A further improvement in blending procedures is to take ores from several sources, bedding them horizontally in layers and reclaiming by vertical slicing from the blended pile. The last procedure, when properly executed, is one of the best methods for achieving maximum uniformity with highly variable ores. U.S. Steel Corp.'s Geneva Works initially obtained iron ore for their blast furnaces from the Cedar City area of southern Utah. These ores were formed primarily by the replacement of limestone and siltstone formations with solutions containing iron and several other elements. The original iron content of the ores in the ground varied from a high of 70% to practically zero with a minimum acceptable iron content for shipping of 37%. Substantial amounts of silica, calcium, magnesium and alumina were found in the ores along with minor amounts of copper, lead, zinc, nickel, titanium, manganese, phosphorus and sulfur which were sometimes present in detrimental amounts. Iron-to-silica ratios varied considerably throughout

Jan 1, 1968

By C. Dirksen

This study investigates whether oxygen consumption during segregated forward combustion may be affected by natural convection. Linear theory indicates that thermal instability occurs in a horizontal porous medium when the modified Rayleigh number N 'Ra exceeds a critical value of about 40. Most experimental results, including those described here, indicate this value to be about an order of magnitude smaller. N ', is derived from "differential similarity" and the proper time scale factor is also obtained. The critical value of N'ra for a horizontal, water-saturated porous medium at atmospheric pressure subjected to a uertical temperature gradient was found to be about 3.0. The ambiguity in the value of N'R, arising when fluid properties cannot be assumed constant is indicated. Natural convection was observed for oblique systems below N 'Ra , while simultaneous horizontal flow did not affect N Racrit. The expected range of values for the various parameters pertaining to segregated forward combustion is indicated and the corresponding values of N 'Ra calculated. Only under very favorable conditions, such as high permeability, high pressure and low top temperature, can the critical value of N 'R, be exceeded. Thickness of the convection layer should not become too large, since the time required to obtain significant mixing is proportional to the square of the thickness. For an oblique combustion frant the conditions for significant mixing may be less strenuous. LNTRODUCTION Laboratory1,2 and field314 experiments have shown that a markedly upgraded oil can be produced by in situ forward combustion. Under certain conditions injected air may move through a high permeability, gas-saturated channel over the oil-saturated layer, while combustion takes place, exclusively, at the horizontal interface (Fig. 1). Such a channel may be a natural gas cap, or it may result from a forward combustion process in which injected air and combustion gases fingered through the top of the formation, causing a premature breakthrough at the production well. In this particular case of segregated forward combustion, the air stream moves parallel to the combustion front. Molecular diffusion and transverse mechanical dispersion will be insufficient to cause all the oxygen in the air stream to reach the combustion front. When the oxygen in the air stream is not completely consumed in the combustion process, it will reach the production well and create a serious fire hazard. In addition, the reduced efficiency may make the process economically unprofitable while also serious corrosion problems may be experienced in the production we11.3 This undesirable situation should, therefore, be prevented. However, in a situation as depicted in Fig. 1, an unstable temperature gradient exists in the gas phase. The combustion is taking place at the lower boundary at a nearly constant temperature that may be anywhere from 600 to 1,200F, depending on the conditions. The upper boundary of the gas phase is overlying, impermeable rock; its temperature might be around 100F, but may increase to 300F or higher due to conduction and convection as the combustion process continues. This represents a steep temperature gradient and it is conceivable that under those conditions free or natural convection will take place in the gas

Jan 1, 1967

By R. Hogg, D. W. Fuerstenau

Based on a simplified model for the motion of particulate materials in horizontal, rotating cylinders, approximate expressions have been derived relating the power consumption of a tumbling mill to its dimensions and speed of rotation and to the amount and nature of the charge. The basic assumptions underlying the model are that there is no slip between the charge and the mill shell, that the free surface of the charge remains essentially planar during rotation, and that there is no transfer of momentum from the material flowing down the free surface back to the mill shell. The relationships formulated from this model have been shown to be in excellent agreement with experimental results taken from the literature. While the requirements of the model are most clearly met at low speeds of rotation, the results appear to be valid even for speeds up to 70-80% of the critical speed. Poorer agreement between theory and experiment is found when the charge consists of relatively large particles (balls) and when the filling of the mill exceeds 50% of the available volume. Qualitative explanations of these deviations have been offered.

Jan 1, 1973

By Ralph Hultgren

Few phase diagrams of alloys composed of two transition metals have been adequately studied, probably because of the high melting points involved. Transition metals are the elements that have inner shells incompletely filled with electrons. They comprise groups lIIa to VIIIa of the periodic table, including more than half of all metals. We have chosen to study two systems whose comparatively low melting points allowed the alloys to be melted in a molybdenum resistance furnace. The nickel-palladium system proved to consist of a simple series of solid solutions, but iron-palladium manifested several remarkable features. The main characteristics of the latter diagram were decisively established, but lack of time prevented precise determination of phase boundaries. The gamma to alpha transformation in this system is unusual and warrants further study. Grigorjewl determined the liquidus and solidus of the iron-palladium system by thermal methods. He found a minimum melting point, but no eutectic. He also found that palladium lowered the gamma to alpha and raised the gamma to delta transformation temperatures of iron, with a complete series of solid solutions existing between gamma iron and palladium. His measurements also indicated a compound or quptbr-lattice near the composition FePda. Jellinghausz found that annealing at 500" C. greatly increased 111 magnetic coercive force of an alloy of composition FePd. X-ray diffraction photographs showed that a tetragonal ordered phase had formed during the anneal. Hocart and Fallot made magnetic measurements over the entire range of composition. They found that less than 5 atomic per cent Pd

Jan 1, 1939

By Ralph Hultgren

Few phase diagrams of alloys composed of two transition metals have been adequately studied, probably because of the high melting points involved. Transition metals are the elements that have inner shells incompletely filled with electrons. They comprise groups lIIa to VIIIa of the periodic table, including more than half of all metals. We have chosen to study two systems whose comparatively low melting points allowed the alloys to be melted in a molybdenum resistance furnace. The nickel-palladium system proved to consist of a simple series of solid solutions, but iron-palladium manifested several remarkable features. The main characteristics of the latter diagram were decisively established, but lack of time prevented precise determination of phase boundaries. The gamma to alpha transformation in this system is unusual and warrants further study. Grigorjewl determined the liquidus and solidus of the iron-palladium system by thermal methods. He found a minimum melting point, but no eutectic. He also found that palladium lowered the gamma to alpha and raised the gamma to delta transformation temperatures of iron, with a complete series of solid solutions existing between gamma iron and palladium. His measurements also indicated a compound or quptbr-lattice near the composition FePda. Jellinghausz found that annealing at 500" C. greatly increased 111 magnetic coercive force of an alloy of composition FePd. X-ray diffraction photographs showed that a tetragonal ordered phase had formed during the anneal. Hocart and Fallot made magnetic measurements over the entire range of composition. They found that less than 5 atomic per cent Pd

Jan 1, 1939

By Alden Greninger

THAT metallographic structures analogous to the martensite of steel may be found in certain copper-aluminum and copper-tin alloys has been known for many years; similar structures recently were found in certain copper-zinc alloys.1 In all three of these alloy systems the martensite structures result from transformation of the metastable ß phase when the speed of cooling from the ß range is sufficiently high to suppress decomposition into equilibrium phases. ? In the normal decomposition of solid solutions into equilibrium phases, diffusion is needed to bring about the necessary changes in concentration, and the rate of reaction falls almost to zero at temperatures slightly above room temperature. The rates of reaction for martensite processes, however, are not dependent upon temperature; the transformation does not require readjustments of concentration. For example, the marten-site transformation in 60:40 (ß) copper-zinc does not begin until the temperature has dropped to about minus 30° C., and then continues down to minus 130° C. and probably even at lower temperatures.1 Further-more, martensite processes apparently proceed only while the tempera-ture is falling, within the proper range, and cease completely while the temperature is held constant; ? and they cannot be suppressed by extremely rapid cooling although the rate of cooling for some alloys may be increased to over 10,000 times the critical cooling velocity. Isaitschew, Kaminsky and Kurdjumow2 account for these observed behaviors of martensite processes by postulating that the mechanism " . . . consists in a regular rearrangement of the lattice in such a way

Jan 1, 1939

By Pol Duwez, Howard E. Martens

INTRODUCTION THE high temperatures encountered in the operation of jet engines have imposed most drastic requirements upon the materials used in their construction. There are two different approaches to the materials problem connected with the design of parts in contact with high temperature gases. The first approach is to use a material which will perform satisfactorily at a temperature comparable to that of the gas. The second approach is to use a cooling system so that the material is maintained at a temperature appreciably lower than that of the gas. Besides the conventional method .of cooling by means of a liquid in contact with the material exposed to a high rate of heat transfer, a less orthodox method consists of making the part to be cooled of a porous material, so that the cooling fluid can be forced through the pores. In this scheme, the temperature of the coolant moving in a direction opposite to that of the heat flow increases gradually while passing through the porous material, and the coolant forms a protective layer on the surface exposed to heat. This method, referred to as "sweat cooling," was proposed at the jet Propulsion Laboratory in September 1944, and the experimental work on the preparation of porous metals was started early in 1945. The sweat cooling method opens new lines of research in powder metallurgy by extending the field of application of porous metals. The porous metals available at the present time are used mostly as bearings or filters, and a rather limited number of alloys are made for these applications. In addition, the fabrication of bearings or filters does not require a very dose control of the permeability, while in the case of sweat cooling such a control is of primary importance. In designing a sweat cooled part it is imperative to assure a given rate of flow of coolant under certain conditions of pressure drop. Generally, the proper pressure drop and the rate of flow of coolant are deduced from heat transfer and design considerations, and consequently the permeability of the porous metal to be used is also determined. It is therefore necessary for the designer to have available a continuous series of porous metals covering a range of permeability as wide as possible. Contrary to the requirements established in the fabrication of filters, the actual pore size of a porous metal intended for sweat cooling is of little consequence, except for its effect on permeability. The tensile strength is likely to be of great importance for some applications. Since the tensile strength of a porous alloy decreases with increasing porosity, an important problem is to develop porous alloys having the maximum permeability with minimum porosity.

Jan 1, 1948

By K. H. Nimerick, B. E. Scott, F. J. Beafore

A unique freeze conditioning agent (FCA) which functions by forming structurally weak ice rather than suppressing the freezing point of water has been successful in alleviating frozen coal problems. Frozen coal treated with FCA has been quickly unloaded at temperatures below -17.8OC (O°F). Other applications of FCA include deicing: conveyor belts, idler, idler arms, and other moving parts that have been impeded by ice.

Jan 1, 1980

By Pol Duwez, H. E. Martens

The high temperatures encountered in the operation of jet engines have imposed most drastic requirements upon the materials used in their construction. There are two different approaches to the materials problem connected with the design of parts in contact with high temperature gases. The first approach is to use a material which will perform satisfactorily at a temperature comparable to that of the gas. The second approach is to use a cooling system so that the material is maintained at a temperature appreciably lower than that of the gas. Besides the conventional method of cooling by means of a liquid in contact with the material exposed to a high rate of heat transfer, a less orthodox method consists of making the part to bc cooled of a porous material', so that the cooling fluid can be forced through the pores, In this scheme, the temperature of the coolant moving in a direction opposite to that of the heat flow increases gradually while passing through the porous material, and the coolant forms a protective layer on the surface exposed to heat, This method, referred to as ((sweat cooling," was pro- posed at the Jet Propulsion Laboratory in September 1944, and the experimental work on the preparation of porous metals was started early in 1945. The sweat cooling method opens new lines of research in powder metallurgy by extending the field of application of porous metals. The porous metals available at the present time are used mostly as bearings or filters, and a rather limited number of alloys are made for these applications. In addition, the fabrication of bearings or filters does not require a very close control of the permeability, while in the case of sweat cooling such a control is of primary importance. In designing a sweat cooled part it is imperative to assure a given rate of flow of coolant under certain conditions of Pressure drop. Generally, the Proper pressure drop and the rate of flow of coolant are deduced from heat transfer and design considerations, and consequelltl~ the Permeability of the Porous metal to be used is also determined. It is therefore necessary for the designer to have available a continuous series of porous metals covering a range of permeability as wide as possible. Contrary to the requirements established in the fabrication of filters, the actual pore size of a porous metal intended for sweat cooling is of little consequence, except for its effect on permeability. The tensile strength is likely to be of great importance for some applications. Since the tensile strength of a porous alloy decreases with increasing porosity, an important problem is to develop porous alloys having the maximum permeability with minimum porosity.

Jan 1, 1949

By R. M. Schuster, F. M. Benavides

This study compares the costs of transporting coarse coal by pipeline versus more conventional belt conveyors. Hydraulic conveying of crushed (not pulverized) coal has not had widespread commercial acceptance. However, there is little doubt that the technology is available, so that, should this method be proven economical for a given application, implementation will become more acceptable.

Jan 1, 1984

By William H. Spice

Drilling activities in South Central Texas for the year 1945 continued the steady increase over the past two years, while new fields discovered for the year included four new gas fields and one field extension. In the 30 counties included in this area, which comprises district No. 1, Oil and Gas Division, Railroad Commission of Texas, 141 exploratory wells were completed, compared with 61 drilled in 1944 and 29 drilled in 1943. Of these 141 tests, 55 were field well and 86 were wildcats; 38 were completed as oil wells, S as gas and gas-distillate producers, and 95 were abandoned as dry. Atascosa and McMullen Counties were the most active in the district, accounting for 73 of the wells drilled.

Jan 1, 1946

US 4,190,434 - In the thermal production of magnesium metal, a mixture of calcined dolomite, an iron- silicon-aluminum alloy as a reductant, and residual slag from the production of ferrochromium is smelted to evolve magnesium vapor, which is then condensed. The use of bauxite is lessened or eliminated because of the relatively high alumina content of the residual slag. R. Bonfils, A. Mena, C. Payn, and L. Septier, assigned to Ste. Francaise d’Electrometallurgie (SOFREM). Feb. 26, 1980. 6 pp. (75-10R). Filed: 6-14-78 (915,387). Priority: France, 6-24-77 (77/20,227).

Jan 1, 1982

By Donald Towse

Geothermal energy can substitute for and compete with other fuels, but until now it has been used only in special situations where it costs much less than alternate fuels. Geothermal heat is expected to be developed where it can: (1) compete with alternate fuels, (2) replace scarce fuels, (3) be more environmentally acceptable, or (4) is especially adapted to local needs. Economic problems in development include the often high capital costs of wells and gathering systems and the long lead-times required for electric generating plants. The large investment and long payout times for large industrial uses adversely affect the economics.

Jan 1, 1977

By W. C. Winegard, C. J. Simpson, C. J. Beingessner

VARIOUS organic compounds, such as borneol, carbon tetr a bromide, and hexachloroethane, solidify as transparent plastics with a fcc structure. Each of these substances undergoes a solid-state transformation from the plastic phase to a brittle phase at temperatures slightly above 20°C. Since it was known that these plastic crystals solidified like metals,1 it was decided to investigate the possibility that solid-state grain growth would occur in the same way as it does in metals. Two-dimensional grain growth in thin films of plastic organic compounds has been studied with the aid of cinemicrophotography. Samples varying in thickness between 250 and 1000 @ were prepared by subliming a thin layer of the compound onto a microscope slide plate which was then covered with a second slide plate.

Jan 1, 1968

By John T. Dickman, Ralph E. O’Dette

Chemical Abstracts Service (CAS) is in the process of evolving a computer-based information system which will process all of the material selected for abstracting in the area of chemistry and chemical engineering and its related fields such as the earth sciences and technologies. This system is already operational to some extent and is expected to be fully utilized by 1971. The objective of CAS is to make chemical and related information more readily available, more usable and more used. Chemical Abstracts handle some 5000 abstracts weekly from 13, 000 journals and patents from 25 nations. These cover all of the 80 CA subject sections which relate to chemistry and also extend into areas of interest to geologists, mineralogists, and mining engineers. In this way, CAS fulfills its objective of complete coverage of its major fields, informative abstracting, and indexing to maximum specificity. The concept of a computer-based information system is that of a single machine-language data base into which the results of intellectual analysis of the literature are entered and from which computer programs produce a variety of publications and services applicable to the needs of a wide range of users.

Jan 1, 1969

By Robert W. Pack

Sooner or later in the development of any natural resource it becomes highly desirable to know the quantity of this resource in the country as a whole, as well as of the part that is being developed, for the general course and conduct of the development work must be governed, to some extent, by the total supply available. An accurate estimate of the quantity of any natural resource is difficult to make; yet if one is diligent enough one can obtain a pretty accurate idea of the quantity of marketable timber, the acreage of tillable land, or the horsepower that may be developed from the streams, for these are things that may be measured. But any attempt to estimate the quantity of some mineral in the ground appears to enter the realm of imagination and it seems that the estimate can be nothing more than a blind guess. It may appear to be especially futile to attempt to determine the quantity of oil and gas that is available in the ground, for these minerals are so vagrant that even if the quantity now available should be known quite exactly, the quantity that will eventually be obtained may be much less, for certain losses in the extraction of both oil and gas are unavoidable, and just what these losses will be cannot be predicted. Though necessarily inaccurate, estimates of such mineral reserves are, however, of distinct value, for they summarize the existing knowledge of the deposits of the mineral and thus enable those who are interested in some industry that depends in one way or another on this mineral to formulate a rational commercial policy. Some time ago, when the price of gasoline suddenly rose in a rather spectacular manner, the writer was one of the U. S. Geological Survey geologists called upon to help to estimate the quantity of oil that could be obtained in the United States, for the fear had become widespread that perhaps the rate of increase in the price of gasoline was a measure of the rate of depletion of the supply of petroleum. It thus became his

Jan 1, 1918

KNOWING the endpoint, or the equilibrium state, in steelmaking reactions is only part of the story. The rate at which the reactions proceed can be equally important. But the power of thermodynamics, which enables us to estimate the endpoint, is that a knowledge of the mechanism is not required. The methods of kinetics, however, are step-by-step analysis in which a knowledge of the detailed reaction mechanism is essential. As is evident from Chapter 16, a great deal of thermo- dynamic data for steelmaking are available and the underlying theory rests on a completely sound basis. This is far from the case with kinetic data and even kinetic theory. Nevertheless, it is worthwhile to examine the present state of knowledge, to see how far it may be applied to electric furnace reactions. KINETIC THEORY Heterogeneous Reactions. Classical kinetic theory and experimentation have been mainly concerned with homogeneous reactions taking place between different chemical species in a gas or liquid phase. The species are mixed together and the progress of the reaction can then be observed. This is possible because most experiments have been done at relatively low temperatures where the characteristic time for the mixing process is much shorter than the time for the chemical reaction to be completed. For example, in the homogeneous gas reaction, H2 (g) + I2 (g) 2HI (g) hydrogen and iodine may be added to opposite ends of a tube containing a diaphragm. When this is withdrawn, gaseous diffusion (and convection) mixes the two types of molecule almost completely before any hydrogen iodide molecules begin to appear. Such an experiment is inconceivable at more elevated temperatures, since the rate of the chemical process is so sensitive to temperature that reaction would be completed almost instantaneously wherever hydrogen and iodine came into contact; the rate of the mixing process would then determine the rate at which hydrogen iodide was formed. We should not, therefore, expect to observe many homogeneous reac-

Jan 1, 1964

By A. L. Field

Bureau of Mines Technical Paper 189 consists of a record of the scientific data obtained in the iron blast-furnace slag investigation which is reported in Technical Paper 187, "Slag Viscosity Tables for Blast-Furnace Work." It includes a description of the method of preparing the synthetic melts, construction of an improved electric furnace, and refinements in laboratory methods of measurement. Only the general features of the work and the conclusions drawn from the experimental data can be given attention here. Silicates in the Liquid State In the manufacture of refractories, Portland cement, glass, and porcelain, and in pyrometallurgical operations, importance attaches to the behavior of silicate compounds at temperatures beyond the range of common experience. This field of research has not been investigated as carefully as its scientific and industrial importance would seem to warrant. Probably the most important of the unsolved problems in the, chemistry of silicates is the question of their stability in the liquid state. That little progress toward the solution of this problem has been made is not strange if there be borne in mind the difficulties attending experiments made at temperatures at which silicates become fluid, and the comparatively short time since it became possible to measure these temperatures. On the other hand, considerable progress has been made in the study of the compounds in the solid state because of the directness and simplicity of methods of optical examination.

Jan 12, 1917