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By N. De Nevers

A calculation method has been developed for carbonated water flooding. This method takes into account the effects of oil viscosity reduction and oil swelling, due to carbon dioxide transferred to the reservoir oil from the carbonated flood water. It shows the effect of changes in carbonation pressure and carbonated water slug size. The method is based on a Buckley-Leverett-type linear flow model. The mathematical approach is similar to that developed by Welge, et al, for enriched gas drives. However, it contains a very important advance over the previous papers in its solution to the problem of injection of a "slug" of carbonated water rather than continuous injection of fluid of constant composition. The method also shows the chromatographic nature of the transport of Co 2 in a carbonated water flood. Sample calculations indicate that viscosity reduction is the most important source of incremental oil recovery. Swelling contributes to a lesser extent. Raising the carbonation pressure increases recovery, but this effect diminishes as pressure is increased. increasing the slug size also increases recovery, but again this effect diminishes as slug size is increased. INTRODUCTION In recent years there has been considerable interest in carbonated water flooding as a secondary recovery method. Several carbonated waterflood field tests are now in progress.1'3 Yet there is no published method for predicting the results of a carbonated water flood. This paper presents a method for predicting the oil recovery for ; carbonated water flood. In a carbonated water flood. a carbonated water slug is injected into the reservoir. Then this slug is driven forward by injecting plain water behind it. The field operator must choose the carbonated water slug size and the CO2:water ratio in the slug. The calculation method presented here shows the effects of both slug size and CO2:water ratio on oil recovery. The calculation assumes that the addition of carbon dioxide to flood water increases the oil recovery by two mechanisms: 1. Carbon dioxide transfers from the flood water to the oil, thereby reducing the viscosity of the oil. At the lower viscosity, the oil flows more readily and is more easily swept out by flood water. 2. The carbon dioxide which transfers to the oil phase causes the oil phase to swell. Assume that the residual oil saturation (volume per cent of pore space) is the same whether the oil is carbonated or not. Then the same volume will contain less stock tank oil if it is carbonated, due to oil swelling. The plain water driving the carbonated water slug forward will strip the CO2 out of this residual oil., causing this oil to shrink. This swelling-followed-by-shrinking leaves behind a lower residual oil saturation than would have been left behind by a plain water flood. Since some oils swell to almost twice their original volume at reasonable CO2 pressures, this effect may be large. Two additional benefits sometimes claimed for carbonated water flooding are: 1. Adding CO2 to flood water greatly increases the water injectivity in some cases.1 (Injectivity = BPD of water injected/ft of sand x differential bottom-hole pressure, psi.) CO2 forms a weak acid in water; injecting carbonated water is, therefore, somewhat like acid treating. If a formation responds to acid treating, it will probably have a higher injectivity for carbonated water than for plain water. Although the increased injectivity increases the profitability of a carbonated water flood over a plain water flood, it does not change the production curve based on total fluid injected. Therefore, the method presented here does not show any effect of increased injectivity. 2. It is claimed in one patent4 that carbon dioxide will react with some constituents of the oil to form detergents. These detergents are expected to increase the oil recovery. There is little data available to support this idea. The calculation method presented here takes no credit for extra oil recovery due to the formation of any such detergents.

Jan 1, 1965

By D. W. Loucks

There is plenty of evidence to indi-cate that at least one of man's chief interests in life is to make himself as comfortable as possible. If you doubt this, just watch the fellow next to you for the next half hour trying to find the most comfortable position that a hard chair has to offer. Comfort, however, does not always mean an easy chair. To some, it may mean a wealth of money; to another, freedom from worry. But to most of us, it means first of all a comfortable atmosphere in which to live, and to a great many of us it probably also means freedom from that annoying task of firing the furnace. Today more than ever before. automatic heat is one improvement that is placed high on everyone's list. Perhaps this is because automatic heating is becoming relatively cheaper. Perhaps it is because of a good publicity campaign on the part of the oil and gas men or maybe it is just that we are getting lazier day by day. At any rate, almost every issue of Better Homes and Gardens, House Beautiful, or your other favorite home magazine carries an article extolling the virtues of this or that automatic heating system. If I were to ask you to name the first thing that came to your mind when I said automatic heat, you would prob-ably say either gas furnace or oil burner. Or if you had just been studying heating systems, you might possibly say heat pump. But chances are you would not mention anything about coal, and yet coal is the most common source of the greatest automatic heat of them all. I say this because coal is the fuel used almost universally by the district heating industry in producing and delivering to certain heavily populated areas heat ready to use at the touch of a valve or the click of a thermostat. Although the industry is over a half century old, it has not experienced the widespread development of other utility industries because of certain limitations which I believe you will realize from the next few minutes discussion. District Heating Operations We may define district heating as any operation where two or more buildings are heated from a central heating plant. The method of heat transfer may be hot water or in some cases warm air, but generally the medium of heat transfer is steam. So universally is steam used that the industry is frequently referred to as the district steam industry. The Allegheny County Steam Heating Co. which operates the district heating system in downtown Pittsburgh is a subsidiary of the Du-quesne Light Co. Although organized in 1912 primarily as a means of securing the electric load of downtown buildings, the service has now become so valuable and so popular that it is no longer considered a necessary adjunct to the electric business but rather a separate business standing on its own feet. Fig 1 shows the layout of the plants and distribution system of downtown Pittsburgh. Two generating plants, one known as the Stanwix and the other as Twelfth Street, supply the area. Each has two boilers with capacity totaling 1,350,000 lb per hour. The Stanwix Plant is supplied coal by truck. The coal is pulverized at the plant and burned as powdered fuel. Coal is supplied to the Twelfth Street Plant also by truck but the boilers arc stoker fired. Over 1 1/2 miles of tunnel house a portion of our main lines, but it requires over twelve miles of pipeline, ranging in size from 32 down to 1 in. in diameter, to supply all our customers. The distribution system consists of two systems in a sense, one high and one low pressure with certain interconnections between the two. Our high pressure system supplies steam up to 125 Ib to some but not all customers, while the low pressure system operates in the range of 10 to 20 psi. Note that the two plants are tied together through large steam mains and that the system to some extent is a loop system, making it possible to have a portion of the line shut, down without interrupting service to any customer. Fig 2 conveys a picture of the extent to which steam service is used in the downtown triangle. The black area indicates the buildings which now use district steam. The dotted area indi-

Jan 1, 1950

By R. H. Schnitzel

Internal-friction peaks have been observed in tungsten single crystals at about 300° and 400°C. The characteristics of these peaks are similar to interstitial peaks observed in other bee metals; therefore, the origin of these peaks appears to he the Snoek mechanism. The interstitial responsible for the peak at about 300°C has not been identified. Carburizing increases the magnitude of the peak at about 400°C; consequently, it appears reasonable to suppose that the specific interstitial associated with this peak is carbon. The activation energies associated with the 300° and 400°Cpeaks are about 35,000 and 45,000 cal per mole, respectively. INTERNAL - friction peaks resulting from the stress-induced diffusion of interstitials (Snoek relaxation peaks) have been frequently observed in bee metals.1-5 Attempts to detect Snoek relaxation peaks in tungsten have, however, not been fruitful.' Failure to find Snoek peaks in sintered tungsten can perhaps be attributed to one or more of the following difficulties: a) the relatively low purity of the sintered tungsten; b) the lack of extensive metallurgical knowledge about tungsten-interstitial alloys, such as suitable interstitial dosing and quenching procedures; and c) the inconsistency of some of the interstitial analyses of tungsten, which reflects itself in one's inability to be sure of the nature of the specimens. This present investigation did not overcome all of these difficulties for successful tungsten internal-friction measurements. Some of these difficulties still persist and new difficulties were encountered during the course of this investigation. Nevertheless, the use of electron-beam tungsten single crystals having somewhat greater purity levels than sintered tungsten combined with appropriate carburizing and quenching procedures permitted a reasonable attempt to be made. As a consequence, internal-friction peaks were observed in these tungsten single crystals at about 300° and 400°C. These peaks were found to be unstable, since they annealed rapidly away during a sequence of internal-friction measurements. Hence, it was necessary to construct an apparatus having a faster heating rate to study some of the details of these peaks. From the behavior of these peaks as well as our knowledge of similar peaks in other bee metals, one can reasonably conclude that these peaks are caused by residual interstitial impurities within these crystals. Further investigation of these peaks after the application of various metallurgical treatments lent credence to this supposition. EXPERIMENTAL TECHNIQUE The internal friction of tungsten single crystals was measured using two different pieces of apparatus both of which are of essentially the same conventional design, namely the KE type of torsion pendulum. The important difference between these two types of apparatus was in the attainable heating rate and method of protection of the specimen from atmospheric contamination. The apparatus designated "number 1" was enclosed in a vacuum chamber which was heated by an externally mounted furnace. It had a slow rate of heating which was estimated to be about 4°C per min from room temperature to about 350°C and then about 1°C per min to 600°C. The internal friction of tantalum was measured with this apparatus and the established Snoek peaks were found.' These tantalum peaks in the temperature range from room temperature to 400° C served as a check for the apparatus. The apparatus designated "number 2" having a faster heating rate than number 1 was not elaborate. It consisted of a mounted nickel tube to which split heating elements were attached. Argon was used as the protective atmosphere. The measured heating rate was about 12° to 15°C per min whereas the cooling rate was somewhat slower at about 10° C per min because of the increased difficulty encountered in stabilizing the temperature. No surface oxidation of the specimen was noted after any test. This apparatus was also checked with the known peaks of tantalum.1 The preparation of the single-crystal specimens for internal-friction measurements consisted of centerless grinding the crystals from an approximate 0.200 in. diameter to 0.030 to 0.040 in. in diameter, and then electropolishing them to about 0.020 in. in diameter. Single crystals processed in this manner are designated as being in the virgin condition. Since the length of crystal varied from 3 to 9 in., the test frequency varied from about 1 to 2 cps. The frequencies of measurement, axial orientations, and chemical analyses for the various crystals are listed in Table I. The controlled addition of carbon into tungsten is a difficult problem. Attempts to find the critical conditions necessary for an equilibrium treatment were not fruitful. Therefore, a simple nonequi-librium method was used. The addition of carbon to these crystals consisted of appropriately combining three treatments—carburizing to achieve a case, annealing to partially dissolve the carbon into the

Jan 1, 1965

By Jerry L. Straalsund, D. Bruce Masson

A dew-point technique was used to determine the thermodynamic activity of zinc at 430°C in a series of e phase Ag-Zn alloys. The composition of the alloys ranged from 72 to 88 at. pct Zn. This range included the composition at which Massalski and King3 found a reversal in the composition variation of the crystallo-graphic c/a ratio, which they attributed to an overlap of the Fermi surface across the (002) faces of the Brillouin zone. The data is presented in a graph in which RT In yz,, where yz, is the activity coefficient of zinc, is shown as a function of atomic percent zinc. This curve has an unmistakable change in slope at the same composition that Massalski and King observed the beginning of the reversal in the c/a ratio. This change in slope of the thermodynamic data is also attributed to a Brillouin zone overlap. Equations are presented to demonstrate that the thermodynamic activity can be related to the density of states of the conduction electrons, and that the observed phenomena are consistent with this model. It is also demonstrated that the contribution of the density of states can be related to the excess stability, a phenomenological parameter recently shown by Darkeen" to be significant in the interpretation of thermodynamic data of metallic phases. The data seem to indicate that zone overlap has caused a spinodal point, and the resulting misci-bility gap, in the phase diagram. THE problem of developing an adequate thermodynamic model of solid solutions has proven to be difficult, and is still only partially solved. The main approach has been to develop a statistical model, such as that of an ideal solution, regular solution, and so forth, to which can be attached corrections for electronic, vibrational, magnetic, ordering, or other contributions. Such corrective terms are usually derived on an ad hoc basis, and it is difficult to predict in advance what their relative importance will be. This problem has been discussed in general terms by Oriani and Alcock,' who have reviewed several thermodynamic models and a few empirical correlations. The measurements described in the present paper were made to demonstrate in a special case the importance of one such corrective term, the contribu- tion of the energy of the conduction electrons of an alloy. It was our premise that the contribution of the energy of the conduction electrons to the thermodynamic activity of the alloy components could be detected; further, that such an effect would be observed at alloy compositions where other phenomena, also ascribed to the energy and density of states of the conduction electrons, are observed. The idea of the importance of the conduction electrons is hardly new. Hume-Rothery and his adherents have developed the well-known theory of alloy phases in which the sequence of phase fields in binary equilibrium diagrams, especially those involving the noble metals with the IIB, IIIB, and IVB subgroups, can be correlated by replacing the composition variable with the ratio of conduction electrons to atoms, e/a. Jones and others have developed a physical explanation for this correlation, in which they consider the solubility limits of phase fields to be restricted by an intersection between the Fermi surface and a Brillouin zone. The general features of the model are also quite well-known—presumably zone intersection causes the density of states to decrease at critical alloy compositions. The attendant increase in energy of conduction electrons in the original crystal structure allows an alternate structure to become more stable as the concentration of polyvalent solute is increased. In spite of the wide acceptance of these ideas on phase stability, there is only indirect* evidence, such as the variations in lattice parameter recorded extensively by Massalskizy3 and others, that Brillouin zone interactions occur. There are few experimental measurements, other than the correlations of the phase sequence, that substantiate the premise that the energy of conduction electrons affects the solubility limits of alloy phases. Much thermodynamic data of alloys has been found to be consistent with the theory; yet there is a lack of detailed data at compositions where zone intersection and overlap are thought to occur. One would expect that the energy of the conduction electrons would make a measurable contribution to the thermodynamic properties of alloys at compositions near zone intersection and overlap if the theory of Hume-Rothery and Jones is correct. This conclusion cannot be avoided, because the phase boundaries are determined by the requirement that the chemical potential of the components be equal in both phases at equilibrium. An electronic effect large enough to alter the stability of a phase should also affect the thermodynamic activity by a measurable amount.

Jan 1, 1969

By Frank Firmstone

IN the early decades of the past century the method of starting iron blast-furnaces by "scaffolding-down" seems to have been in universal use for coke-furnaces and, at least in this country, for charcoal-furnaces also. It was likewise used at some of the early anthracite-furnaces, as is stated in the important "Reminiscences" printed by the late Samuel Thomas. I It had been generally superseded in Great Britain as early as 1850, by some variations of the plan now used, and was rarely used when Percy wrote.' On the Continent it was still followed in the 60's,3 and was elaborately described by Valerius in 1852. I have never read any statement as to when and by whom '4 scaffolding" was first dispensed with, but the following extracts from journals of my father seem to fix an authentic date for an instance in this country:

Mar 1, 1907

By AIME

The Taconites Are Ready, the editorial appearing on P. 933 of the September issue, has provoked comment from several informed engineers to the effect that the indicated profit margin was considerably exaggerated. The cost figures in the editorial, taken from the Congressional Record, were characterized as inaccurate by some correspondents. The theme of the story was, however, substantiated in the announcement (P. 1023, October) that Republic and Armco had joined forces in a $160 million project for taconite development. Chief among the dissenters was E. W. Davis, , Director of the Mines Experiment Station at the University of Minnesota. Mr. Davis has worked up the following set of cost figures:

Jan 1, 1950

By C. Gatlin, N. E. Garner, A. Podio

Experimental data from single chisel blows on Leuders limestone are presented. A pressure chamber, similar in design to well known microbit drilling chambers, was utilized to impose variorcs stress states on the sample. Confining pressure of zero to 10,000 psi and borehole pressures from zero to 5,000 psi have been used in the studies. Pore pressure was zero and the rock samples dry in all instances. Force-displacement records and visual examination of the craters indicate that the mode of failure depends on both confining and borehole pressure in certain ranges, ranging from brittle, through a transition, to near plastic. The mode of failure is reflected in the observed blow force and energy data, as well as the shape of force-penetration curves. INTRODUCTION A previous paper' presented initial data from the project on which this paper is the second report. While the first paper dealt with impact studies on synthetic rocks, the literature cited there is also pertinent to this paper, but will not be listed again in order to avoid needless repetition. This paper presents experimental data from single chisel impacts on limestone at certain simulated wellbore stress states. Specific variables investigated were combinations of borehole and confining pressure, crater geometry, a narrow range of impact velocity and the forces required to drive the chisel into the specimens under the varying conditions. EXPERIMENTAL PROCEDURE The same basic apparatus described in our earlier paper, except for the pressure vessel, was used in this study. Fig. 1 shows the complete experimental system. Fig. 2 shows details of the pressure cell, which is quite similar to the well known microbit drilling chamber. The confining (overburden) pressure system provides independent pressure control over the sample except for two, 21/4 in. diameter areas located on the sample ends. These two areas provide a pore pressure entrance on the bottom and a striking surface on the top where borehole pressure can be controlled. The ends are isolated from the confining pressure by O-ring seals. The borehole and pore pressures are related through the striking surface; they will be the same unless a seal is deposited on the borehole surface, either a mud cake or some other impermeable membrane. In these studies pore pressure control was not used, as the rocks were dry and unsaturated in all cases. Rock samples were prepared from 4-in. cubes as illustrated by Fig. 3. The circular disks of adhesive vinyl plastic protected the impact surface from the resin coating (Scotchcast No. 2) and were removed just prior to each test. This procedure insured a fresh uncontaminated surface for the impact. Fig. 4 shows the dimensions and loading of the sample, including the concentrations around the "borehole" periphery (O-ring seal). The rock used in this study was Leuders limestone, of Permian age (Leonard), quarried near Leuders, Tex. Geologically, Leuders limestone is a light gray, fossili-ferous limestone (oolitic foraminifera1 biosporite). Its fossil content is 80 to 90 per cent and consists primarily of calcitornellid, ostracods, pelecypods and oolites with the remaining part intraclasts. There are hematite or limo-nite rims on some of the intraclasts. The porosity is approximately 20 per cent, but the permeability is less than 1 md. There is no apparent orientation in the structure. Triaxial tests have been conducted to determine the variation of the physical properties of Leuders limestone in three orthogonal directions', and it is known to be unusually isotropic and uniform. Physical parameters for this rock are: uniaxial compressive strength = 9,700 psi; F = 32 and C = 2,700 psi; where + and C are Coulomb equation values (t = C+u tan +). Impact tests were run under the combinations of confining and borehole pressures shown in Table 1. Samples were dry with atmospheric pore pressure in all cases. Tests, in which elevated borehole pressures were applied, used a single layer of household Saran-Wrap to prevent horehole fluid invasion into the sample. This proved to be simple and reliable. The blunt wedge used in all the tests was 0.75 in. long and had an included angle of 60" with a 0.05-in. flat. In addition, a sharp 60" wedge was used for all confining pressures at zero borehole pressure. The chipper speed

CRUSHING and concentration flow-sheets of western mills have become greatly simplified and more or less standardized of recent years with the introduction of modern grinding methods and flotation. Improvement has not stopped, however, and advancement is continually being made in crushing and milling practice. A case in point, where remarkable improvements in efficiency have resulted from comparatively minor changes in the flow-sheet, is in the New Cornelia mill of the Calumet and Arizona Mining Co. at Ajo, Ariz. This mill, completed in 1924 for the concentration ,of the sulfide ores of the New Cornelia mine, was originally designed for a 5000-ton capacity. Before recent changes and additions were made the five 1000-ton units were handling 6500 to 7000 tons per day, giving a flotation feed of approximately 14 per

Jan 1, 1930

By E. J. Roberts

F. C. Bond (Allis-Chalmers Mfg. Corp., Milwaukee) —This paper considers comminution as a first order process, with the reduction rate depending directly upon the amount of oversize material present. The data show that other factors should be taken into account, and it is possible that in time these may be evaluated as simultaneous or consecutive reactions: Development of the theory of comminution has been retarded for many years by the assumption that surface area measurements constitute the sine qua non of the work done in crushing and grinding, and it is encouraging to note the belated growth of other ideas. In the Abstract the term "net power" should be changed to "net energy." Throughout the paper the term "hp per ton" should be changed to "hp hrs per ton", or "hp hr t." The term "Probability Theory" in the title does not seem appropriate, since it is not clear how the probability theory is used in developing the ideas in the paper. There seems to be a contradiction between the large calculated advantages of closed circuit operation and the statement following that the closed circuit test results showed no significant change in grinding behavior, when compared with the batch grind curves. Tables I and II show that between 75 pct and 50 pct solids the energy input required decreases with increasing moisture content and may indicate the advisability of grinding at higher dilutions in certain cases. The calculation of the hp-hr per ton factor indicates an input in the laboratory mill of only 7.32 gross hp per ton of balls; this casts some doubt upon the accuracy of the factor used, since the power input in commercial mills at 80 pct critical speed is customarily much higher. The tests show that within fairly wide limits the amount of ore in the laboratory mill may be varied and a product of constant fineness obtained, provided that the grinding time is varied in the same proportion. This has often been assumed, and confirmation by actual testing is of value. The Cavg corrections for differences between the plant and laboratory size distributions do not seem very satisfactory, since in many cases the plant/laboratory ratio is farther from unity after correction than before. The following equation has been derived from the data in Table VI: Relative Energy (log new ball diam in in. + 0.410) Input = --------------—--------------- from which the relative energy inputs for balls of different sizes can be calculated and compared. The relative energy input is unity for balls of 2.715 in. diam. The equation indicates that the work accomplished by a ton of grinding balls per unit of energy input is roughly proportional to the square root of the total ball surface area; provided, of course, that the balls are sufficiently large to break the material. The data in support of this statement are admittedly meager, but are fairly consistent when plotted. The relative grindability values listed in Table VI for 200 mesh multiplied by 4/5 apparently correspond approximately to the A-C grindability at 200 mesh.' It would seem that for open circuit tests comparable accuracy could be obtained much more simply by the old method' of plotting the test grind, extending the mesh grinds to the left of zero time if necessary, and determining from the plot the equivalent time required to grind from the plant feed size to the plant product size, using the average of several mesh sizes. The en- ergy input value of one time interval could be determined by tests on materials of known grinding resistance, and this multiplied by the interval required should give the desired energy input value. The relative grindabilities would be the relative time intervals required for a specified feed and product size. When the plotted mesh size lines of a homogeneous material are extended to the left beyond zero time they meet at one point at zero pct passing. The horizontal distance of this point from zero time indicates the equivalent energy input required to prepare the mill feed. The author's results show that the closed circuit grinding tests give about the same K values as open circuit tests, from which he concludes that open circuit tests are satisfactory in many cases. The value of the closed circuit test is its ability accurately to predict energy requirements in closed circuit grinding for both homogeneous and heterogeneous materials. If the material is homogeneous, the open circuit test gives satisfactory results; but if the material contains appreciable fractions of hard and soft grinding ore, the open circuit tests will not be accurate because of the accumulation of hard grinding material in the circulating load. Since in most cases it is not possible to determine a priori whether the material contains hard and soft fractions, the closed circuit tests are preferable and more reliable. B. S. Crocker (Lake Shore Mines, Ontario)—Dr. Roberts probability theory of grinding is very similar to our log pct reduced vs. log tonnage method of plotting and evaluating grinding tests at Lake Shore. However, although we both seem to start at the same point we finish with different end results. Shortly after publishing our grinding paper (referred to by Dr. Roberts) in 1939, we did pursue the subject of the "constant pct reduction in the pct +28 micron material for each constant interval of time. We ran innumerable tonnage tests on the plant ball mills, rod mills, tube mills with 11/4 and 3/4 balls, and lastly pebble mills, with tonnage variations from 180 tons per day to 950 tons per day. We found that when we plotted the log of the tonnage against the log of the pct reduced of any reliable mesh, we had a straight line up until 90 pct of the mesh is reduced. We have also tested this in our 12-in. laboratory mill with the same results. We have used this method of evaluating grinds for the past 8 years and developed the recent four stage pebble plant on this basis. By pct reduced we mean the percentage of any given mesh that is reduced in one pass through a mill at a given tonnage (or time). For example, if the feed to a rod mill is 90 pct +35 mesh and the discharge at 500 tons per day is 54 pct +35, the pct reduced is 90 — 54/90 = 40 pct. If the feed had been 80 pct +35 the discharge would have been 48 pct +35 or pct re- duced 80-48/80 = 40 pct as long as the tonnage re- mained constant at 500 tons per day. Thus we can easily correct for normal variation of mill feeds. This log — log relationship derived from the tonnage tests of all our operating mills has proved of tremendous help in checking laboratory work and in designing alternate layouts or new plants. The difference between the log — log and the semi-log plot is only shown up when the extremes in tonnages are plotted. When the relationship between the pct reduced and the tonnage was first investigated, we used semilog

Jan 1, 1952

By AIME AIME

REPUBLIC STEEL'S new iron blast furnace in Alabama, shown on the cover of this issue, is the first to be completed of those authorized by the Government last year when a shortage of scrap became acute. In addition to the furnace, the new equipment includes a new battery of by-product coke ovens, a boiler plant, a generating unit, a 3-mile-long 60-in. water line, a huge gas washer, and precipitators in which the dust from the furnace is washed, separated from the water, and fed back into the furnace as raw material. The new unit is a cylindrical steel giant reaching 130 ft. into the air above the ground level. Because of the high humidity in the deep South, the furnace has been air-conditioned to avoid blowing eighteen tons of water into the furnace daily. Designed by Republic engineers who also had charge of the actual construction, the new furnace incorporates the best in modern blastfurnace practice. Orders to proceed with the construction of the furnace were received Sept. 22, 1941. The engineering crew, which was immediately organized, made more than 1500 drawings. Excavation started the next day, and simultaneously work was begun on demolishing existing buildings and preparing the site. The first concrete was poured Oct. 7 and the first piece of steel swung into place by a giant derrick on Jan. 30, 1942. It began operating May 28. A total of 70,000 cu. yd. of earth was moved and 30,000 cu. yd. of concrete poured.

Jan 1, 1942

By S. G. Lasky

EVENTS during and since the war indicate that the nations of the world are trying to initiate an era of international co-operation. Definitions and objectives include social, economic, and human considerations no less than political considerations. The mineral resources of the world and the absolute and relative position of each nation enter into this situation. The possible use of armed might, the application of sanctions, the international flow of commerce, the ways in which this flow may encourage or hamper international well-being, and the influence of international and domestic well-being upon one another are all matters that must take mineral resources into account. If the United States is to act wisely and forthrightly in such matters we must be thoroughly informed as to our position with respect to mineral resources. What is the mineral position of the United States? A variety of widely conflicting opinions are held in authoritative and intelligent quarters: (1) For practical purposes our mineral resources are already exhausted.

Jan 1, 1946

By J. Kent Smith

VANADIUM is generally spoken of as a rare element; but, even in the light of our resources as known a couple of years ago, this description could be accepted in a qualified sense only. In fact, vanadium is very widely distributed, being a constituent of most clays, while even caustic soda has been shown to contain almost regularly a minute proportion of it, although the quantity in each case is so small as to render impracticable the extraction of the metal there from with profit. The opening-up of a large deposit of vanadium sulphide ore in South America has put a new phase on the commercial outlook of vanadium, the technical value of which for the improvement of steel has been proved by rigorous scientific investigation.

Sep 1, 1907

By WALTER M. DAKE

WITH the renewal of the contract between bituminous miners and operators, whereby a period of three years is assured without the devastating effect of irregularity of operation due to general strikes; and, with the increasing comprehension on the part of the large consumers as to the stabilizing effect of adequate storage upon prices; the coal industry has reached that period of its history in which permanence of purpose towards necessary changes is being crystallized, and these changes accomplished by the industry. It is to be hoped that during this era the phrase- " Our National Coal Problem "-will be relegated to the limbo of' antiquated expressions. That this epoch is upon us is evinced by the fact that operators are turning to consolidations, whereby financially sound companies will acquire smaller production units and place themselves in position to maintain constant supervision and control of their development and output; and, as further proof of the arrival of these changes, may be cited the entrance of additional members of the engineering profession into the many phases of management and operation, where- by the cost per ton of output will be, constantly reduced through the increasing use of modern methods and equipment. As an instance, attention is specifically called to the developments in mechanical loading, proposed and actual continuous underground transportation systems and betterment in methods of preparation.

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