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By Gordon Fletcher

Pacific Rim countries currently have plans to import about 100 Mt/a (110 million tpy) of steam coal by 1990. Due to its close proximity, Powder River Basin coals offer a long term economic and dependable source of supply to the Pacific Rim. In existing boilers, Powder River Basin coals can be blended with Australian, South African, or Canadian coals. For new units, Powder River Basin coals are very competitive on a total evaluated cost basis. The advantages of using Powder River Basin coal include: assurity of supply, consistent coal quality, stable labor force, and attractive mining economics. (NOTE: PAPER NOT RECEIVED IN TIME FOR PUBLICATION.)

Jan 1, 1982

CANADA, which appears to be growing into one big mining camp, may soon be the background for another impressively large iron ore development. And again it will be Fenimore Iron Mines who will be the motivating force. Dr. J. A. Retty, Fenimore president, who was one of the important figures in the development of Labrador iron deposits, predicts a great future for property on the west coast of Ungava Bay in deep northern area of New Quebec. Fenimore properties consist of a 200 sq mile concession in addition to several hundred claims over about 112 miles along the Labrador trough, mainly in the Ungava Bay region.

Jan 5, 1953

By Charles L. Elliot

Worldwide manpower utilization reached a new high at 10,482 professional man-months and expenditures increased to $19.9 million for mining geophysical activity during 1965. This is up from 9323 man-months and $14.5 million in 1964. Worldwide geophysical activity measured in percent distribution of the total manpower utilization and expenditures is presented in the accompanying Figs. 1 and 2. In terms of the total manpower utilization, ground surveys accounted for 61%, airborne surveys 18%, and mining geophysical research activity 21%. For expenditures, the breakdown was ground surveys, 49%; airborne surveys, 3901o; and research, 12%. Industry was responsible in general for 74% of the manpower utilization and 80% of the expenditures. Manpower costs in 1965 averaged $1900 per professional man-month.

Jan 11, 1966

By Kendall Y. Keuhey

The Mercur Mine, developed and operated by Getty Mining Company, is designed to process 3,000 tons/day of gold ore from the historic Mercur Hill mining district. The mill process involves crushing, grinding, and cyanide carbon-in-leach for recovery of gold from ores ranging from 0.08 to 0.10 oz/ton. During the mining of normal grade ore, a substantial tonnage of material containing 0.02 to 0.05 oz/ton is mined and would be available for heap leaching. Also, Getty Mining is developing methods to test and prepare lower grade material for heap leaching by rejecting a coarse rock fraction from the grinding SAG mill circuit. This lower grade fraction is suitable for heap leaching, and its removal will upgrade the regular mill feed. Other test methods are directed toward leaching techniques on some 4.0 million tons of tailings that resulted from roasting and/or cyanide leaching Mercur ores in the early 1900's. The natural carbons associated with the Mercur deposits require special treatment to reduce their gold adsorption effects when leached with cyanide.

Jan 1, 1984

By Edmond S. Miksch

The morphology and growth rate of ice grown in supercooled water are markedly affected by convection of the water. A dendritic ice sheet with water flowing past the dendrite tip exhibits deflection of the dendrite spine toward the upstream direction, accelerated growth of secondary spines on the upstream side, and suppression 01" secondaries on the downstream side. Flow causes a thin disk to become corrugated, the corrugations being parallel to the flow. Flow causes an increase in the growth rate of the ice. IF a small seed of ice is placed in slightly supercooled water, it grows initially as a disk with the axis of the disk parallel to the c axis of the ice crystal.' It appears that growth in the c direction is inhibited, while growth occurs with equal facility in all directions in the basal plane. It appears that growth rate as a function of interface temperature is very nearly equal for all directions similarly oriented relative to the c axis. Subsequent to the discoid growth, branching occurs and dendrites develop. The primary dendrite spines grow parallel to the six equivalent a axes of the crystal. Secondary, and in some cases, tertiary spines also grow in these directions. The highly anisotropic: dendritic growth indicates that there must be some finite difference of growth rate for different directions in the basal plane. These differences must be quite small, however, since if they were large, the discoid mode would not occur. Hence, it was expected that the dendrite growth direction could be deflected from the crystallographic direction by perturbation of the thermal field at the dendrite tip. Experiments were done in which perturbation of the thermal field was accomplished by causing the supercooled water to flow past the dendrite tip. The flow direction was perpendicular to the c axis of the crystal, and was perpendicular to the primary spine of the unperturbed crystal. Supercooled water was supplied by a 15 cm cubical copper box, which was refrigerated and insulated so it could cool water to temperatures down to —2oC, and maintain the temperature constant to O.l°C for the duration of a run. A lucite channel of rectangular cross-section, 12 by 24 mm, was mounted horizontally in the box, with one end open so water could flow into it, and the other end leading out through the wall of the box to a length of tubing leading: to an orifice plate 123 cm below. cnunMn s MIKSCH, MemberAiMe, formerly Research Associate, Research Associate, Fig. l(b)—Vertical section of apparatus A horizontal cross-section is shown in Fig. l(a), and a vertical section is shown in Fig. l(b). Means for observing the ice are shown in Fig. l(a). Collimated light passes through the ice sheet and forms an image on the ground glass screen. A lucite box containing dry air was employed to prevent condensation. Ice of the desired orientation was provided by the seed holder shown in Fig. l(b). This device was made of lucite, and had a reservoir in which ice could be frozen by placing it in a freezer. This reservoir com-unicated with the outside only through a narrow gap between two sheets of lucite. The seed holder (after ice had been washed off its exterior) was immersed in the tank of supercooled water, the narrow gap terminating in a slot in the top of the flow channel. Ice growing through a thin water layer in the gap between the two sheets of lucite was oriented so its c axis was perpendicular to the sheets. This orientation is an application of a growth phenomenon2 which causes ice growing along a smooth solid surface in supercooled water to orient itself so its c axis is normal to the surface. After the ice grew into the channel, further orientation was necessary, since the direction of the a axis

Jan 1, 1970

By H. Hooykaas

A few years ago Marsal published a method of predicting oil recovery as a function of time for an edge-water-drive reservoir with several rows of wells.' The method is based solely on oil- and water-production data obtained during a short period for the first row of wells and the gross productions (past and future) of all wells. This paper presents a streamlined version of the original publication and experimental evidence showing the reliability of this version. For this purpose scaled experirnents were performed in a large model (750 X 500 X 23 cm, 24.4 ft X 16.2 ft X 8.9 in.) in which edge-water-drive reservoirs with three rows of production wells were simulated. From the results of the experiments it is concluded that the method gives a fairly accurate prediction of the future production behavior of the reservoir and enables us to select the most profitable production plan. Results obtained with the method were always slightly conservative. INTRODUCTION The calculation method developed by Marsal aims at forecasting future reservoir behavior.' It can be applied to floods in which a number of down-dip wells are rapidly going to water. Essentially it is a method for predicting the future behavior of the up-structure wells on the basis of the observed behavior of the down-structure wells. As such, the method is especially useful for predicting behavior of edge-water drives toward several rows of wells. The requirement to be met for justifying the approach is identity of production mechanism in all regions of the reservoir. The attraction of the method then lies in the fact that it applies even when we have no complete description of the prevailing production mechanism. The original publication was in the German language and for this reason, perhaps, did not attract widespread attention. In our opinion it deserves to do so because it does offer in a simple way results which are in fair agreement with observed data. The aim of the present paper is to bring the method to the attention of a wider audience. The method in its most simplified form is reviewed and experimental data in support of it are presented. PRINCIPLES To show Marsal's principle. we will first write the continuity equation for very simple conditions, linear flow (in the positive x-direction) in an incompressible porous body [cross-section A(x), porosity +(x)], saturated with incompressible fluids (oil saturation S). When the oil in this formation is displaced by water, injected at x = 0 (inlet face), we get where q(t) is the total gross displacement rate and f the fractional oil flow. The equation can be solved if we make the assumptions: (1 ) that the fractional oil flow (f) is a univalent function of saturation (S); and (2) that the function is the same throughout the porous medium. Then: f = f(S) Solving this equation with the method of characteristics, we obtain

Jan 1, 1966

US 4,181,520 - Direct reduction of iron oxide ore to sponge iron in a rotary kiln. Ore is fed into the kiln along with coal briquettes and passed through a preheating zone and then a reducing zone countercurrent to the flow of a kiln atmosphere which includes air or other oxygen-containing gas. The agglomerated coal is heated at such a rate that it disintegrates into fine particles in the preheating zone. The coal is largely recovered for reuse, while reduction is effected with a reducing flame rather than the coal. G. Reuter and W. Schnabel, assigned to Metallgesellschaft AG. Jan. 1, 1980. 6 pp. (75-36). Filed- 10-19-78 (952,870). Priority: West Germany, 1-14-75 (2,501,182). Same: British 1,532,969, dated Nov 22, 1978.

Jan 1, 1982

By Robert R. French

Beneficiation of low-grade nonmetalliferous mineral deposits by electronic color sorting is currently undergoing a period of rapid development. For those deposits in which the specific gravity, strength, soundness, and electric and magnetic properties of the ore and gangue are similar, the possibility of separation by color, reflectivity, or fluorescence offers hope for the utilization of much poorer quality ore than previously thought possible. For those ores in which consistency of color is required or for which a dry process is preferred, the electronic color sorter is particularly adaptable. Tests performed late in 1966 and reported herein are the result of the continued interest in the dry beneficiation of gypsum and the development of higher capacity color sorting machines. The ore used was a discarded fraction that consisted of – 1 ¼ -in, to + 3/8 -in. ore containing 63.1 to 71.4% (average 67.7%) gypsum. This material was contaminated by various amounts of both carbonate rock and shale, but no pretreatment was performed other than screening to closer size limits before electronic color sorting.

Jan 4, 1969

By M. Kashiwada

The zinc leach residues are introduced into waelz kiln to fume volatile metals and before the end of 1967, the waelz-fume containing zinc, lead, cadmium and indium was directly recycled back to the leaching process for the production of electrolytic slab zinc. However, since 1968, we have been recovering with success those valuable metals contained in the fume separately instead of direct leaching. According to the improved process, the waelz-fume, after being mixed with chloridizing agents, is fed into the rotary kiln to be roasted, wherein most of lead and cadmium content is collected as fume and most of zinc remains in the calcine. Zinc calcine thus obtained, containing 70 to 75 per cent zinc and, less than 1.0 per cent lead is sent to zinc plant for further recovery and the fume containing 40 to 50 per cent lead and 3 to 6 per cent cadmium is further processed to recover lead, cadmium and indium. The advantage of this process can be secured to the utmost when it is combined with the following subsequent treatments. (a) Blast furnace smelting of non-magnetic waelz slag to recover copper, silver and gold as matte. (b) Gallium recovering process from magnetic waelz slag. (c) Soda process of lead bearing cake produced after removing cadmium and indium from the said fume. Thus the extractions of zinc, lead and cadmium from leach residues account for 87 per cent, 72 per cent and 85 per cent respectively.

Jan 1, 1970

By J. J. Mike

During the past few years the combination of continuous billet casting with in-line reduction has been studied and several machines have been built with this capability included in the design parameters. (1,2,3,4,5) In-line reduction and continuous casting in combination are obvious and attractive. As pinch rolls are already in place for the continuous casting operation, it can be readily seen that a redesign of the mechanical and electrical equipment of the pinch rolls is all that is necessary to have in-line rolling. There have been numerous in-line reduction experiments conducted by simply increasing the pinch roll pressure on existing machines. (6,7,8,9) These generally failed to produce quality billets and often resulted in internal metallurgical defects (Figure 1).

Jan 1, 1972

By George W. Bain

SOME problems concomitant with commercial exploitation of marble are presented as examples of interesting, useful and profitable fields for application of scientific knowledge. The marble industry is only one such field and is selected because its varying new aspects are familiar to the author. However, what is true for marble is equally so in principle for many industrial minerals. The problems of any stone industry are to maintain markets, create new outlets for stone already in demand, and develop varied uses for varieties that are not so popular. Here the geologist has a different role from most of his colleagues in metal mining. The producing branch may ask about the expectable variation in thickness or size of a deposit as development proceeds. The stock department may call for the available amount of a given type of stone before accepting a large order. The sales force requires data on the use for stone from certain parts of deposits in order to divert grades to the most suitable use. The service department wants defects rectified and the cause determined to avoid recurrence. The mills want data on durability and cutting quality of abrasives. The geologist occupies no special department; he is on general call, as may be illustrated by a few types of problems that may be classified as: (1) dominantly geological in character, (2) dominantly chemical in character, (3) dominantly physical in character. GEOLOGICAL PROBLEMS The geological problems deal almost exclusively with the size of blocks. Size across the deposit is limited by thickness of individual beds, and along the strike by the space between crosscutting joints. Frequently the vertical depth of a block is reduced by exfoliation shells arising from spontaneous expansion. All these factors require consideration in developing a deposit to fill an order. Thickening of Marble Beds The limestone beds that became the marble deposits of the northern Appalachians and of the Yule locality in Colorado were seldom homo-

Jan 1, 1940

By C. W. MacGregor

IN the testing of materials there exist various methods of recording graphically the behavior of a material subjected to tensile stress. Prob-ably the most common method is to plot the tensile stress So, obtained by dividing the load P by the original area of cross section AO at the start of the test, as a function of the strain ?o, which is obtained by dividing the ?Lo or the change in the gauge length by the original gauge length Lo. A list of the symbols used here is given in Table 1. This method, while it has proved useful in the routine testing and comparison of various materials, does not have a very sound physical basis, as was first pointed out by P. Ludwik1, and consequently does not afford a very deep insight into the true physical behavior of the material under stress. Among the objections to this method may be mentioned: (1) that by dividing the load P at any stage of the test by the original area Ao a fictitious stress is obtained, which does not actually exist; (2) that the strain ?o = ?Lo /Lo is not an exact expression for the true strain for large values of ?Lo in per cent of Lo; (3) that when necking starts the strain varies considerably along the gauge length and the above expression no longer gives the true strain existing at any point on the outside of the bar; and (4) that the axial strain varies over the cross section of the necked portion and ?o does not represent an average of these strains over the cross section. Stresses taken from such a diagram would be only approximate and, if used to compare results of a test on a given material under simple tension with results obtained under combined stresses, certain errors would he thus introduced. In order to overcome some of these objections, various methods have been suggested, both as to the quantities to be measured and as to their graphical representation. In some cases the so-called "true stress," obtained by dividing the load P by the actual area of cross section A existing when the load P was applied, is plotted as a function of the strain

Jan 1, 1937

By Ronald D. Hill, Janet L. Auerbach

It is estimated that the mining industry generates over 2.1 petrograms per year of solid waste. These wastes are overburden, waste rock, low grade ore, concentrate (tailing), sludges from treatment facilities and wastes from support facilities. Concentrate wastes present the greatest environmental problem. Three recent federal laws impact the disposal of waste from mining: Resource Conservation and Recovery Act of 1976 (RCRA), Surface Mining Control and Reclamation Act of 1977, and Uranium Mill Tailings Radiation Control Act of 1978. RCRA specified a special study on mining waste which was to include an analysis of: (1) sources and volumes of waste produced, (2) present disposal practices, (3) potential dangers to health and the environment, (4) alternate disposal methods, (5) cost of disposal, and (6) potential for use of waste.

Jan 1, 1980

By Helmer Heldstrom

Gravity surveying with the torsion balance or the pendulum for ore prospecting purposes has generally not been considered practical or even possible. It is the intention of this paper to show that a fast and sensitive gravimeter can be very useful in ore prospecting, as an auxiliary to the electrical and magnetic instruments. A number of gravimeters have been constructed and put in practical use in the last seven or eight years; for instance, by Ising, Lejay-Holweck, Haalck, Hartley, Thyssen, Noergaard, the Humble Oil and Refining Co. and the Gulf Production Co. Their main application, apart from their use for geodetic surveys, has been for structure mapping in oil prospecting. There is no record that any of them have been used for ore prospecting. About the middle of 1934 the Boliden Mining Co., in Sweden, began experiments in constructing a static gravity meter sensitive enough for ore prospecting. Calculations and considerations that will be discussed later in this paper showed that this would necessitate an accuracy in the measurements of 0.1 milligal—roughly, one ten-millionth part of the total force of gravity. The first successful practical field tests of the instrument were made in January 1936. About the middle of 1937 the Boliden gravimeter was perfected. Ore prospecting with this instrument is now regular practice in Sweden, especially for the testing of indications given by geoelectric and magnetic methods. Gravity Anomalies that May Be Expected from Ore Bodies According to Newton's law, a mass M attracts the unit mass in a distance r with the force , GM where G = the gravitational constant = 6.68 . 10-8 c.g.s units. In the c.g.s., or centimeter-gram-second, system the force of attraction is expressed in the unit "dyne," which has the physical dimension c.g.s.-2 and denotes the force needed to accelerate the unit mass in one second to

Jan 1, 1940

By Helmer Heldstrom

Gravity surveying with the torsion balance or the pendulum for ore prospecting purposes has generally not been considered practical or even possible. It is the intention of this paper to show that a fast and sensitive gravimeter can be very useful in ore prospecting, as an auxiliary to the electrical and magnetic instruments. A number of gravimeters have been constructed and put in practical use in the last seven or eight years; for instance, by Ising, Lejay-Holweck, Haalck, Hartley, Thyssen, Noergaard, the Humble Oil and Refining Co. and the Gulf Production Co. Their main application, apart from their use for geodetic surveys, has been for structure mapping in oil prospecting. There is no record that any of them have been used for ore prospecting. About the middle of 1934 the Boliden Mining Co., in Sweden, began experiments in constructing a static gravity meter sensitive enough for ore prospecting. Calculations and considerations that will be discussed later in this paper showed that this would necessitate an accuracy in the measurements of 0.1 milligal—roughly, one ten-millionth part of the total force of gravity. The first successful practical field tests of the instrument were made in January 1936. About the middle of 1937 the Boliden gravimeter was perfected. Ore prospecting with this instrument is now regular practice in Sweden, especially for the testing of indications given by geoelectric and magnetic methods. Gravity Anomalies that May Be Expected from Ore Bodies According to Newton's law, a mass M attracts the unit mass in a distance r with the force , GM where G = the gravitational constant = 6.68 . 10-8 c.g.s units. In the c.g.s., or centimeter-gram-second, system the force of attraction is expressed in the unit "dyne," which has the physical dimension c.g.s.-2 and denotes the force needed to accelerate the unit mass in one second to

Jan 1, 1940

By H. B. Heller, T. J. LaChapelle

Phosphorus nitride has been used as a diffusant for introducing phosphorus into silicon under various conditions. It has a temperature -dependent rate of decomposition beginning in the 500°C range, increasing very rapidly above 1000 C, producing gas -eous phosphorus and nitrogen. Best control was obtained with a two-temperature arrangement, with silicon at the proper higher diffusion temperature. It is an easier compound to use than the usual P2O5 because it is nonhygroscopic and yields temperature-controlled surface concentrations together with excellent final surfaces. Surface doping nearly as high as that produced by phosphorus pentoxide has been observed for sources at 850" to 900°C. Reproducible high sheet resistances were obtained by using slow flow rates (1 linear in. per min) and staggered-baffle gas mixing with the nitride at 550°C. Both inert gas (argon, nitrogen) and oxidizing ambients have been examined. Oxygen reacts to produce anhydrous P2O5, consuming the source at a rapid rate. Nitrogen, except for short diffusion times, suppressed the dissociation reaction and sometimes produced inferior surfaces. Argon appears to be a more useful ambient. PHOSPHORUS is a common impurity atom which may be introduced into a semiconductor lattice to create a p-n junction or an nn contact region. Various investigators1-4 have described techniques which can be used with either elemental phosphorus or certain of its compounds. This paper discusses a newly available compound of phosphorus, phos- some processes silicon wafers are precoated with a phosphate glass which acts as the doping source. Although a nonoxidizing form like elemental phosphorus or a phosphine can be used, most diffusion methods usually involve the use of phosphorus pentoxide. Because of the rapid volatility of this compound, a two-step process is often used, combining a gaseous deposition to introduce a predetermined quantity of phosphorus into the silicon with a later redistribution to obtain the desired distribution and surface concentration. Such a process usually involves predepositing phosphorus at surface concentrations greater than 1020 cm-'. At such doping levels the phosphorus-diffusion coefficient appears to be strongly concentration-dependent.596 Distribution profiles5'9 for these high concentrations of phosphorus do not follow Fick's laws, having extended subsurface regions which appear electrically to be nearly uniformly doped with ionized impurity atoms. Radioactive-tracer experiments also show near-surface anomalies in the distribution profile. Additionally, it has been shown1' that the introduction of very high surface concentrations of impurity atoms into silicon (a step necessitated by the subsequent lowering of concentration during the redistribution) creates dislocations, even in material having no dislocations originally. For device fabrication the use of oxide masking introduces certain difficulties and limitations.7'8 The standard practice of using phosphorus pentoxide as an impurity source adds other problems to these because of the speed and ease with which this compound reacts with moisture present in any gas in contact with it. In fact, P2O5 is one of the fastest and most effective drying agents for gases. Because it is such an excellent desiccant, completely anhydrous phosphorus pentoxide is difficult to obtain and is even more difficult to keep dry. Adequately dry gloved boxes must be used for storage and transfer of the chemical. The presence of even traces of moisture will cause formation of phosphoric acids which, during the high-temperature diffusion, results in polyphosphoric acids of variable composition. Such reaction by-products end up as gradually accumulating viscous fluids in the cooler parts of the diffusion furnace. The calculation of the final solute distribution for

Jan 1, 1964

By J. C. Wright

A practical program of education for workers of the mining industries is being formulated by the Federal Board for Vocational Education in cooperation with the states in which this industry is a dominant one. The Federal Government last year passed a law, known as the Federal Vocational Education Act, that provides for the promotion of vocational education and for cooperation with the states in the promotion of such education in agriculture and trades and industries and in the preparation of teachers of vocational subjects. More than 1,000,000 men in the continental United States are employed in mines and quarries. The following table, from the 1910 Census Report, shows the relative importance of mining and manufacturing pursuits: Manfactures Mines and quaRRies Employees.......... 7,405,313 1,109,410 Capital............. $18,428,269,706 53,380,525,841 Value of product..... $20,672,051,870 $1,238,410,322 Of the more than 1,000,000 men employed in mining, almost three-fourths are engaged in the production of bituminous and anthracite coal; one-fifth, in the production of copper, iron, lead, zinc, and other metals; and the remainder in getting out structural and miscellaneous materials from quarries. The meeting of the needs of the coal-mining industry, therefore, is the problem of greatest importance in the point of numbers to be served. Moreover, the dangers in coal mining are greater than in metal mining. Practically all states have set up educational and technical standards for the position of foreman, boss, superintendent, etc., and every applicant for these positions must have a certificate of competency. The qualifications, too, are becoming increasingly difficult in the field of technical information. In some states, every miner must have a certificate, which is issued by the mine examining board only after an oral examination. Did these state laws not call for definite and comprehensive plans for the vocational education of men in the mining regions, the conditions

Jan 1, 1919

By G. W. Doepel, W. P. Sibley

A three-dimensional, multilayer, mathematical model has been developed for predicting performance by mis-c.ible displacement. Areal and vertical coverage, total gas-oil ratio, propane-oil ratio and oil-recovery factor for the multilayer system are computed as functions of hydrocarbon pore volumes of solvent injected. The technique has been programed for use on the IBM-7090 digital computer and was used in calculating perfortnance for continuous miscible displacement of a five-spot, 50-layer .system. Results reported are based on the use of published laboratory data for a single, uniform five-spot layer. However, the technique is sufficiently generalized to calculate performance of any system of layers of any pattern configuration and mobility ratio, provided data are available to describe perfortilance of a single layer. The technique has also been adapted for predicting oil recovery resulting from various gas-driven slug sizes. The results presented for both continuous and slug-type injection show, that permeability variation has 0 significant effect on oil recovery but that solvent composition, within the range studied, has a lesser effect on oil recovery. INTRODUCTION Experience from many of the miscible-phase displacement projects currently in operation indicates that the injected solvent flows preferentially through the more permeable zones in the reservoir. This preferential solvent flow in the high-permeability streaks results in a reduction of vertical coverage (C,) and an attendant decrease in oil recovery. The multilayer technique presented in this paper uses areal coverage (C.,) data for a single layer from the literature and from laboratory measurements of displacement efficiency (herein referred to as microscopic coverage, C,,) to calculate areal coverage (C,) and vertical coverage (C,) for the multilayer system. Oil recovery for the multilayer system is obtained as the product of (Ca) (Cm) (Cv). It is assumed that C, in a single layer is 100 per cent; therefore, (C,) (Cm) is a measure of oil recovery from that layer. Data presented in the literature for a single layer generally deal only with areal coverage and/or microscopic coverage —but seldom specifically with oil recovery. Nevertheless, this technique is flexible in that either Ca and C,, of an individual layer or a direct measurement of oil recovery for the layer may be used. In developing this technique, the problem arose concerning a method of determining the relative amounts of solvent that will enter each layer during any increment of solvent injected. To solve the problem, a dimensionless equation was derived for expressing solvent injected into each layer as a fraction of total injection. A finite-difference method was applied in integrating the equation to determine oil recovery for the system of layers as a function of pore volumes injected. The technique subsequently was programed for solution on a digital computer. The method was applied to predict performance of a deep California reservoir under continuous miscible displacement and has been extended for calculating oil recovery as a function of slug size for gas-driven slug injection. The technique may be applied to any petroleum reservoir that can be adequately represented as a layered system, by considering permeability variation,1-3 permeability range and average permeability. Each layer is then assigned its appropriate permeability, porosity and hydrocarbon saturation. RESERVOIR VOLUME CONTACTED BY SOLVENT It has been recognized for some time that high microscopic coverage (C,) can be obtained by injecting a miscible agent, such as propane, into an oil reservoir. These high values of C,,, have been demonstrated in the laboratory and are normally between 80 and 100 per cent, depending on solvent and reservoir oil composition as well as on reservoir temperature and pressure. In miscible-phase displacement, because there is no interface between solvent and oil, effective permeability to solvent is the same as that to oil. (This assumes that oil saturation has not changed and that water is immobile.) Consequently, mobility ratio (M) simply reduces to that of viscosity ratio . Perrine4 and Habermann5 have shown that large

By Nicholas J. Grant, Michio Yamazaki

Cast copper alloys containing 10, 20, and 30 pct Ni and 0.75 to 0.80 pct Al were machine-milled into chips, then comminuted in a rod mill to fine flake powder utilizing a number of processing variables. The powders here internally oxidized, mostly at 800°C, in a low-pressure oxygen atmosphere. The consolidated powders were hot-extruded into bar stock. Room-tenmperature tension tests, stress-rupture tests mostly at 650°C, but also at 450° and 850°C, and hardness measurements after various annealing temperature treatments to study alloy stability were perfomted. Excellent room-temperature strength, high rupture strength at 650°C, and resistance to recrystallization at 1050°C were obtained. Problems in optimizing conditions for internal oxidation of Cu-Ni base alloys are discussed. THE interesting high-temperature properties of SAP' have stimulated considerable effort in the study of more refractory alloy systems where the potential for high-strength alloys at high temperature is great.2-13 A number of methods have been utilized to produce the desired fine, hard particle dispersions, of which internal oxidation2,9,7 of dilute solid-solution systems offers considerable promise by virtue of the potential for producing ultrafine, well-dispersed oxides. While most of the published works are concerned with pure metal matrices, a number of investigators have studied the effects of solid-solution strengthening.10,19 Use of more complex alloy matrices (for example, aging systems) has been unsuccessful because overaging still occurs at high temperatures in the oxide-containing alloys.14.15 Solid-solution strengthening is, however, effective at very high temperatures9,10 and might be expected to contribute importantly to the strength of oxide-dispersion strengthened alloys. For this study, internal oxidation of solid-solution alloys of copper and nickel, containing small amounts of aluminum, was chosen as the method of alloy preparation. PREPARATION OF ALLOYS Three copper alloys containing about 10, 20, and 30 pct Ni and each containing 0.75 to 0.80 pct A1 (enough to yield about 3.5 vol pct alumina) were prepared as air-cast ingots measuring 2.5 in. diameter by 6 in. high (see Table I for the analyses). Processing steps for all the alloys were as follows (also see Table 11): 1) Homogenization of the ingot at 982°C (1800°F) for 45 hr in an argon atmosphere. 2) Machine milling of ingots into fine chips. Average thickness was about 0.1 to 0.2 mm. 3) Hydrogen reduction of chips at 593°C (1100° F) for 1 hr to reduce copper and nickel oxides. 4) Rod milling of chips to finer powders. 5) Hydrogen treatment of powders as in step 3. 6) Internal oxidation of the powders. 7) Hydrogen treatment of oxidized powders as in step 3. 8) Hydrostatic compression of evacuated powders. 9) Sintering of compacts in hydrogen. 10) Hot extrusion. Variations in processing among the alloys were made in steps 4, 5, and 10 (see Table 11). In the past, two methods were utilized to internally oxidize alloy powders. Preston and Grant3 surface-oxidized dilute Cu-Al powders to obtain the necessary amount of oxygen to oxidize the solute metal (aluminum and silicon), and then permitted the formed copper oxide to diffuse and react with the solute in an argon atmosphere. Bonis and Grant4 exposed Ni-A1 and other nickel alloys to an oxygen pressure derived from the decomposition of nickel oxide at a preselected temperature, in an argon atmosphere. Both methods are applicable and can be modified to generate a range of oxygen pressures for oxidation of the solute but not the solvent metals. Procedure I: Surface Oxidation of Alloy A3, Cu-10Ni-0.76A1. Powders of -20 to +28 mesh were surface-oxidized at 500°C (932°F) to obtain the desired amount of oxygen for oxidation of the aluminum to alumina; the powder was then sealed in Vycor and heated at 900°C (1652°F) for various times up to

Jan 1, 1965

By Jacob T. Wainwright

AS a means for increasing the efficiency in modern blast-furnaces by supplying to them blast of a much higher temperature than is now possible, the writer offers as a suggestion a modification in the construction of regenerative hot-blast stoves. Stated briefly, the plan proposed is to pre-heat both the gas and the air for its combustion in a manner similar to that generally adopted in Siemens openhearth furnaces. After thus carrying the temperature of the stove to a point much higher than that common in hot-hlast stoves, the cold blast passes through it. Without entering into the details relating to the reversing valves and the system of flues, the general plan may be outlined as follows, referring to the accompanying drawings: The valves are so placed in heating up the stove that the blast-furnace gas enters at B, Fig. 1, and the cold air for combustion at A. Ascending in flues, F and E, respectively, combustible gas and air meet and mix in the combustion-chamber, I. Flowing through K, they descend through the flues, G and H, escaping through the chimney. In this manner the walls of the combustion. chambers, I and L, are highly heated, and the right-hand side of the stove is carried to a higher temperature. By reversing the valves, blast-furnace gas enters at C and cold air for combustion at D. Both are pre-heated in their ascent through the flues, G and H. They burn in the combustion-chamber, L, and the hot gases of combustion, flowing through K, I, E and F to A and B, heat the left-hand side of the stove. In this manner the stove is carried to a temperature greater than that of those now generally in use, in which air and gas are burned without preliminary pre-heating. In the plan proposed, that side of the stove will, of course, be relatively cooler through which cold air and furnace-gas last passed in its ascent to its combustion-chamber. After having sufficiently heated the stove in the manner outlined, the cold blast is admitted through all the flues, A, B, C and D. It ascends through the highly-heated regenerative material to the chambers at the top and descends through the flue, P, Fig. 2 (dotted

Jan 1, 1889