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By Wm. B. Price

The work of Leon Guillet concerning the effect of nickel on the structural properties of brass is checked. The best value for the coefficient of equivalence t, that is, the amount of zinc replaced by 1 per cent. of nickel, is shown to be-1.1 per cent. The best hot- and cold-working nickel silvers, varying in nickel content between the limits of 4 and 18 per cent., are tabulated and plotted diagrammatically. Also, some data are given showing a comparison between the physical properties of a hot- and cold-working low copper-nickel silver, and a commercial cold-working nickel silver containing approximately 8 per cent. more copper. THIS investigation of low copper-nickel silvers was undertaken to check the work of Leon Guillet on special brasses and to determine, more accurately, the effect of the addition of nickel on the microstructure of the binary alloys of copper and zinc. It was hoped that the results could be successfully applied to the practical production of low copper-nickel silvers. To explain the results of his investigations on special brasses, Leon Guillet evolved his conception of "fictitious compositions." He states,1 in his general conclusions, that on the introduction of a small amount of a third metal to a copper-zinc alloy, it enters into solid solution with the normal constituents up to saturation, but by so doing it brings the ternary alloy into a state microscopically equivalent to a binary copper-zinc alloy of fictitious composition, and physically more nearly like the latter than the brass containing copper-zinc in the ratio actually present. The physical properties of the ternary alloy, when compared to the same properties of an actual brass of the fictitious composition, are modified by the natural properties of the third element. Beyond the point of saturation, a special constituent appears and the above generalization no longer holds.

Jan 2, 1924

By M. C. Udy, C. H. Lorig

THROUGH the years much interest has been centered in attempting to develop a direct method of iron-ore reduction, to replace or supplement the present indirect blast-furnace process. It would not be difficult to produce a list of more than 500 patents dealing with the direct production of iron and steel, but the few of this type of process that have proved successful do not produce in competition with the blast furnace; they produce special products. A survey of the literature reveals that the equilibrium conditions for the reduction reactions (iron oxides with carbon monoxide and with hydrogen) have been fairly well established but that data on the rate of reaction are discordant, although the general effects of the variables are known. This dissertation deals with the rate of reduction of a magnetite concentrate with hydrogen. The following variables have been studied: bed depth, gas velocity, particle size and temperature. The behavior of a single particle was also studied. LITERATURE Two general factors should he considered in a study of reduction of iron oxide: (1) equilibrium relations, and (2) rate of reaction. The first factor, equilibrium, has received the attention of many investigators and the equilibria Fe3O4-FeO-H2-H2O, Fe304-FeO-CO-CO2, FeO-Fe-H2-H2O, FeO-Fe-CO-CO2 are fairly well established. Of the second factor, the rate of reaction, much less is known. Data are comparatively scarce and there is very little concordance. The discordance probably results from the large number of variables influencing the reactions. However, the general effect of the variables is known. Among these variables are temperature, gas velocity, particle size, porosity, gas composition (distance from equilibrium), presence of impurities, greater or less prevalence of side reactions, and even design of the apparatus itself. Wetherill and Furnas1 published an excellent paper in 1934. They point out that any one or more of five processes (the chemical reaction, diffusion of the reactant through the gas film, diffusion of the reactant through the solid phase, diffusion of the reaction product through the solid phase, or diffusion of the reaction product through the gas film) may be the slow process, and thus the rate-controlling process. It is regretted that the work of these authors was limited to experiments at one temperature, and that the range of gas compositions was limited. Langmuir2 has shown that heterogeneous reactions take place at phase boundaries.

Jan 1, 1942

By Shosei Serata

Stress control methods of mining have been developed separately in at least four different parts of the world in entirely different types of mining -- coal, trona, salt and potash -- during the decade of the 1960s. They all utilized yield pillars as tools for ground control. Today, yield pillars are becoming widely used in under- ground mines in a variety of geological conditions. Stress control methods are effective in stabilizing openings in weak, complex grounds, especially at greater depths. Their advantage is that they utilize existing ground media to stabilize mine openings by altering the stress distribution patterns around the openings, by controlling design parameters such as room width, pillar geometry, and excavation sequence, rather than by using a conventional means of artificial ground support such as roof bolts, cribbing, or arches. Stress control methods, therefore, are suitable for both advance and retreat mining, including total extraction mining. Adaptation of these methods results in substantially greater safety, productivity, and ecnomy over conventional methods. These methods are based on scrutiny of the actual stress conditions in the ground, by both in-situ measurement and computer simulation. This paper provides a summary of stress control methods as developed over the last ten years. The field examples are limited largely to salt and potash mining applications, although the method has been used successfully in other mining applications. The examples illustrate that stress control methods actually address general ground weakness problems -- separation at discontinuity planes, swelling by shale expansion, deterioration by brittle fracture, and interference by ground water. That is, although the principle is developed mainly with reference to salt and potash applications, it is generally applicable to weak ground.

Jan 1, 1983

By J. H. Henderson, T. E. Morrisson

An irvestigation has been made of the production of oil through horizontal fractures of high capacity and large radius placed at the base of producing formations. The specific aitns of the study were to (I) determine by model studies the reservoir performance when gravity drainage is the only producing mechanism, and (2) develop a method of predicting such perfortnance from commonly measured reservoir proper-ties. Although the theoretical approach tailed to develop a rigorous analytic sorution to the transient problem, it (lid lead to a practical method of predicting performance. Predictions (Ire in good agreement with rates and recoveries observed in scaled-model experinzents. Capillary effects and the influence of relative permzenbil-ity are taken into account. The experimental program was mainly concerned with the influenre of fracture radius, fracture capacily and capillary hold-up on the total recovery and the rate of recovery. Much of the experimental work was done on a triangular model which represented one-eighth of a square well pattern, so constritcted that horizontal fractures of varying radii and flow capacity could be studied. An electrolytic model was used to relate the initial production rates to fracture radius, formation thickness and the drainage radius of the well pattern. The conclusions reached as a resrtlt of the work are as follows. I. The production of oil under gravity force alone into a well-propped horizontal fracture, whose radius is of the order of hundreds of feet, is a recovery method which combines high recoveries with very acceptable production rates. 2. The mechanism is effective in "dead oil" reservoirs as well as in reservoirs which possess the energy of solution gas. 3. A method of predicting performance has been developed which gives good agreement with experimental behavior in cases of practicnl interest. Even for very thick beds and large fracture radii, where actual conditions do not conform to the assumptions made, the method gives order of magnitude predictions which would not otherwise be possible. INTRODUCTION Gravity drainage of oil from a formation which has continuous ver- tical permeability over a reasonable depth interval is a surprisingly effective method of recovery. However, for a conventional well the production rates which result from gravity drainage are so low that the economics are seldom attractive. The same formation may produce rapidly and profitably by gravity alone through a high capacity, extensive (i.e., > 100-ft radius) horizontal fracture placed near the bottom of the pay section. Fig. 1 shows a schematic diagram of the plan. Energy in the reservoir gas is not a necessary condition for this recovery process. With a sufficiently large fracture, attractive production rates will result from gravity flow alone, and the producing GOR need only be the solution GOR. It is, of course, necessary to keep the fluid level in

By C Gunther

Secondary minerals are the result of a process of concentration and enrichment and are commonly richer than the primary minerals of the same deposit. Secondary ores that contain abundant sulphides are commonly dibtinguishable in the field from primary ores; this distinction is more difficult with ores that carry a small quantity only of sulphide minerals, and microscopical examination of the ore in thin section is advisable in all doubtful cases. It is frequently difficult, and in some cases impossible, to determine the primary or secondary character of quartzose gold ores. The safest guide is the presence or absence of gaseous or fluid inclusions in association with the ore minerals; such primary association coupled with a lack of traces of oxidation is indicative of primary origin. Any ore that carries traces of oxidation, such as iron stains, dendritic oxides of manganese, kaolin and so forth must be considered to have been acted upon by surface agencies, and secondary enrichment must be suspected. Further examination, however, may indicate that the contained value is primary, and, therefore, persistent in its vertical distribution. The manner of occurrence of secondary minerals is frequently characteristic; secondary minerals, being due to the action of surface waters, are commonly found in cracks through earlier minerals, or as crusts lining vugs or surrounding nucleal masses, or in general, in some distribution later than and not conforming to the arrangement of the primary minerals. Secondary sulphides are often found as soft black pulverulent masses or coatings, although they frequently occur well crystallized or as

Jan 1, 1932

By John Goheen

RECENTLY the head burner at a brick. plant with over 40 years' experience said that he had burned brick by guess for over half his lifetime and had used pyrometers for 2 1/2 years but hoped that he would never have to burn kilns without pyrometers again. The ceramic engineer in making a special study of the burning of clay ware and the effect the heat of the kiln has on color and vitrification is also rapidly placing the burning of clay on a twentieth-century basis. Clay ware may be divided into various groups, brick and drain tile; sewer pipe; firebrick; and pottery, which, in turn may be subdivided into special classes. As nearly as the analysis of the clay type of kiln, etc., will allow, there are practically the same problems to solve in burning in all of the processes or operations. The underlying objective is the same, namely the production of the best grade of ware under the most efficient and economical manufacturing system. The principal problem in the production of clay ware is the burning off of the kilns. The most modern steam shovel may dig the clay and the most advanced types of pug mills and wire cut machines or molds of various kinds may be installed, but unless the drying and burning of the ware is successful, all of the previous operations will be useless. On this final operation depends the entire result of the plant. In reality, burning of all. clay ware is purely a heating proposition. The kilns, or furnaces, should be so designed as to give equal distribution of heat. Consequently, the problems of design and construction of kilns to produce equal distribution of heat require serious consideration, as do also the questions of heat control and draft control. The three most important factors in the burning of practically all types of kilns may be

Jan 9, 1919

By Joseph A. Holmes, Henry Kreisinger

At the Mining Experiment Station of the U. S. Geological Survey, in Pittsburg, an investigation of the process of combustion is being carried on in a specially-designed furnace having an unusually long combustion-chamber. This work is conducted by a con~mittee consisti~lg of 11. Kreisinger, mechanical engineer; Dr. J. C. W. Frazer, chemist; and Dr..J. K. Clement, physicist. The problem, essentially one of physical chemistry, is estremely interesting to all who are concerned in the burning of coal or the construction of furnaces. The main object of these experiments is to ascertain the relation between the amount of' the volatile combustible driven from the coal and the combustion-spaces necessary to burn it completely. Our best steam-coals vary from 15 to 45 per cent. in volatile matter and from 40 to 75 per cent. of fixed combtistible. The greater part of the latter is burned on the grate: but the volatile combustible leaves the freshly-charsed coal and must be burned in the combustion-space. If this space is not large enough, the volatile combustible mill leave the furnace only partly burnecl, and the result will be a considerable heat-loss and a smoky stack. Strictly speaking, the factor which determines the completeness of combustion of the volatile matter, after it has been mixed with a certain amount of air, is the length of time the mixture is allowed to remain in the combustion-space; but this length of time depends on the extent of the space itself. Let us suppose, for instance, that, when a given coal is burned at a certain standard rate, the volume of the volatile combustible driven oft' per second is 10 cu. ft. Adding, say, 10 cu. ft. of air, the volume of the resulting burning mixture is increased to 20 cu. ft. If the combustion-space is 30 cu. ft., the burning mixture will stay in it,

Jan 1, 1911

By Oscar M. Wicken

Industrial minerals - being the basic materials for much of the industrial activity in the world -suffer or gain in the market place with changes in that activity. The period 1970 and early 1971 has been one of little growth in many of the mineral-consuming industries, particularly those associated with building and construction. Consequently, the production of many commodities revealed little or no increase above 1969 levels. The pick-up of construction activity in the last half of 1971, however, is expected to be at an intensity which will result in an over-all good year; for example, cement shipments may, establish a record. Some industrial minerals products that bucked downward trends were those allied with the agricultural industry. Phosphate rock shipments increased, particularly from Florida which contributes over 400/c of the phosphate rock in the western world. Potash had higher sales and production for the third straight year, which means that inventories are being eased. The catch-all term of ecology is an oft-mentioned theme among industrial minerals suppliers. Specifically, the need for control of dust emissions is adding a heavy capital investment burden to many of the producers; such a burden, in fact, that plants have had to cease operations because the cost of dust collection equipment could not be born. As an order-of-magnitude estimate, dust collection equipment for cement plants can run $2-3 million for a single plant; some estimates are that the total cost of dust collection equipment in a new plant can be approximately 20% of total investment. All minerals processers have dust control expense of greater or lesser proportion.

Jan 1, 1972

By William E. Ford, Edward Salisbury Dana

THIS Appendix contains a series of tables, more or leas complete, of minerals arranged according to chemical composition or to certain prominent crystallograhic or physical characters. These, it is believed, will be of service not only to the student, but ago to the skilled mineralogist. The type used in the printing of the mineral names indicates their relative importance. Table I is a complete list of the species named in this book arranged fist according to the prominent basic elements which they contain and secondly according to their acid radicals. Table II is of Minerals arranged according to their System of Crystallization The other tablets make no claim to completeness, being limited often to common ah important species. For an exhaustive system of Determinative Tables based particularly upon blowpipe and chemical characters, the student is referred to the work of Professors Brush and Pen- field, mentioned on p. 330.

Jan 1, 1922

By H. F. Perkins

CORROSION as an economic problem is growing rapidly in importance not only because it entails a replacement of corroded parts, but because it interrupts operation and causes hazards of damage and injury through failures of corroded equipment. Nearly all industries are interested in this subject. This paper, although concerned chiefly with corrosion in a complete refinery on the sea coast, discusses many of the various forms of chemical decomposition, most of which are found universally. The petroleum refining industry, in the writer's opinion, is seriously afflicted by the presence of sulfur in nearly all crude oils. The complete removal of sulfur from the crude as it enters the plant would cause such a relief from corrosion that this problem for research would seem to demand active attention. Next to sulfur the most troublesome corrosive agent is the saltmagnesium chloride, found in the water associated with crude oil, the last traces of which are so difficult to remove. This is much less serious, however, than the sulfur. Refinery corrosion can be tabulated as follows: Causes of Corrosion and Places of Attack in a Refinery CORROSIVE ELEMENTS MATERIAL ATTACKED Air: Pipe lines Moisture Tanks COQ Electric fixtures Sulfur gases Still towers Chlorine Condenser boxes Other acid-forming gases Ladders and stairs Smoke stacks Steel buildings All exposed metal Water: Alkali Fire lines and hydrants Acids Cooling water lines Air Condensers and coolers Other dissolved gases Boiler tubes Steam Steam pipes and valves Turbines Oil Sulfur compounds Tanks, pipes, valves, stills, towers MgCl2-Hydrochloric acid Condensers Air contamination

Jan 12, 1926

By Richard Smith

After a brief history of the phosphate industry of Tennessee, the distribution and origin of the phosphate rocks are described. Then the mining and treatment, together with costs of production, and the uses of the rocks are given. THERE are three distinct varieties of phosphate rock, in Tennessee, known commercially as: (a) the "brown" rock, which is the residual product of the weathering and natural concentration of certain phosphatic Ordovician limestones; (b) the "blue" rock, which is an unaltered phosphatic stratum of Mississippian or Devonian age; and (c) the "white" rock, which is the result of chemical replacement and deposition. Before 1894, South Carolina and Florida had supplied most of the phosphate of the United States, South Carolina leading until that date and Florida from then until the present time. In December, 1893, the blue phosphate of Tennessee was discovered almost simultaneously on Swan Creek, in Lewis County, by two independent parties-by one as the result of a careful and systematic search for a workable deposit of the long known kidney phosphate, and by the other through mistaking it for a "bloom" of coal. Leases were taken and, with further prospecting disclosing other deposits in the region, the development progressed as rapidly as could be expected without railroad transportation. In January, 1896, Judge S. Q. Weatherly, who was interested in the development of the blue phosphate, while riding along the road south of Mt. Pleasant, noticed some slabs of a brown rock in place above the limestone. He took samples, and had them analyzed, thus discovering the high-grade brown phosphate of this district. This discovery was kept a secret until July, 1896, when mining was started at the village of Mt.

Jan 9, 1924

P. L. Pratt (University of Birmingham, Birmingham, England)—The author has measured the hardening effect of isolated edge and screw dislocation boundaries in a remarkably elegant manner, and he proposes that the detailed structure of the boundary determines its effectiveness as a barrier to slip although "there are still unknown details of the distribution which may be extremely important." On p. 678 the author states "that for a good crystal (one having a yield of about 30 psi) a change in annealing temperature from 300" to 400 °C resulted in a negligible shift in the level of the stress-strain curve." Is this in agreement with the results of the earlier paper by Li, Washburn, and Parker8 in which such a change of temperature produced notable hardening in crystals with a yield of about 30 psi? Or were these earlier crystals, of the same nominal purity, less perfect than those used in this work? The experiment illustrated in Fig. 15, p. 681, shows that the boundary has sharpened after annealing at 400 °C, the temperature at which the hardening effect first becomes apparent. Did the author verify that no sharpening of the boundary occurred at, say, 300 °C where no hardening was found? This would seem to be an important check on the proposed mechanism, especially since zinc of this purity should polygonize at temperatures well below 400 °C within the annealing times used here. There seem to be at least two alternative explanations which could fit these facts: 1—The boundary may sharpen at 300 °C or even lower temperatures but be unable to contribute greatly to the hardening until jogged by thermal vacancies and other impurity atoms after 400 °C anneal. This mechan- ism, discussed in the earlier paper,' is believed to account for the thermal hardening observed by Blank'" in NaCl, as stated elsewhere: and by results from recent experiments which tend to confirm this view. 2—The dislocations in the diffuse boundary may be locked by impurity atoms at 300 °C and thus only sharpen the boundary at 400 °C with the aid of thermal vacancies. In this case it would be difficult to distinguish between the two sources of hardening (sharpening or jogging), using metal of this purity. Jack Washburn (author's reply)—The author wishes to thank Dr. Pratt for his discussion. In connection with his first comment, it should be pointed out that the temperature of testing in the present series of experiments was —196°C, whereas, in the earlier experiments he referred to,' it was 20°C. Therefore, the yield values should not be directly compared. It is likely that the crystals used in the present work were initially more perfect macroscopically than the large shear specimens used previously. The small size of the test section in the kink specimens made it possible to select regions of the large crystals, from which they were acid-cut, that were free of observable small angle boundaries. The sharpening of a microscopically diffuse boundary such as that in Fig. 15 begins in zinc of this purity well below 300°C. However, it is probably not justified to conclude that because a boundary looks sharp under the microscope it has attained the ideal structure. The author agrees with Dr. Pratt that jogging of dislocation lines is one of the structural features of a small angle boundary that should be important in determining its strengthening effect. More detailed information concerning the changes in boundary structure as a

Jan 1, 1956

By R. J. Charles, G. Agar

Experiments on single particles show that the amount of material created during impact that is finer than any chosen size is proportional to the energy of the impact. As the underlying principle of comminution, it might be stated that each unit of energy input to a given comminution system tends to add to the system an identical assembly of new particles and subtract an equivalent volume of larger particles. Thus, two of the consequences of the fact that each unit of energy tends to add identical assemblies of new particles to the system are: 1) on continued application of energy the total charge in any batch comminution system tends to assume the characteristics of this assembly, and 2) the process of comminution may be described by a relationship such as E = Ak-a. Recently Schuhmannl presented a theory of comminution which puts rational perspective on the extensive controversy surrounding most of the existent theories of comminution. With hindsight the origin of controversy can be ascribed to a relatively simple circumstance. In general, a progressive shift of a size distribution curve towards finer sizes is observed as energy is added to a comminution system. It is also observed that, with continued grinding, the size distribution curves usually change and appear to approach some constant shape. Inves-tigators generally felt that an appropriate method of relating and generalizing such data would be to consider the hypothetical case where particles in the system were uniformly subjected to comminution such that each of these particles, receiving its proportion of input energy, was transformed into a number of smaller particles of uniform size. Since the changes in shape of the size distribution curves during size reduction were clearly associated with the coarse particles in the system, it was also assumed that these changes accounted for little of the input energy and one could deal solely with the equilibrium shape towards which the size distribution curves tended. Although the unrealistic nature of the foregoing points of view was realized some justification was felt for such treatments since, in most cases, the resulting mathematical formulae could, by the adjustment of at most two parameters, satisfactorily describe experimental observation. Difficulties arose, however, in that the formulae required a specific influence of the feed size on the comminution process. In actual fact, the application of a feed size term in fitting experimental data was often found to be unnecessary or contrary to the above formulae. Secondarily, much discussion arose concerning the appropriate energy number that would relate the size change of one particle to the amount of comminution energy it received. As has been previously shown3 all the above theories that treat comminution as a continuous process of size reduction may be related to a proposition of the following form: dE = -Cfn [1] where dE is the increment of energy, dx is the size change, x is the particle size, and C and n are constants. It is now clear, as pointed out by Schuhmann, that Eq. 1 is inapplicable to comminution processes, since comminution cannot be considered other than as a discontinuous mixing process in which the overall size distribution of the product results from mixing, in various proportions, finished material with unfinished, and sometimes untouched, material. A striking illustration of this mixing phenomena may be obtained by comparing the size distributions of grinds in a typical batch ball mill with size distributions calculated on the basis of mixing various proportions of feed material with a ground material which obeys a power law size distribution relationship. Figs. la and lb illustrate such a comparison and the similarity of these figures indicates that mixing plays an important role in determining the overall shape of the product size distributions. Figs. la and lb illustrate, additionally, the underlying basis of the comminution theory presented by Schuhmann.' In the preliminary grinding of relatively close sized feed particles in a batch ball mill, one may visualize that, when a successful encounter of a ball with a feed particle occurs, then the particle undergoes severe size reduction and the size range in which the resultant particles reside is far removed from the size of the feed particles. After a number of feed particles are reduced by independent but similar impacts and one examines the size dis-

Jan 1, 1961

By John B. Porter

Within the last year or so, a great deal has been heard about Southern iron ; even the Eastern markets have felt the effect of the cheap Alabama ores and coals, and public attention has again been drawn to what is now getting to be an old story—the great mineral wealth of the South. The following paper is based on a report prepared several years ago for a special purpose; but since then, through association with Mr. C. B. Going in a large analytical practice and as chemists to the Queen and Crescent Railway, I have had opportunity to increase my material so greatly that the present paper is really a completely different work. I am under very great obligation to Mr. Going, without whose assistance my work would have been very incomplete, and have also been materially assisted by Mr. F. P. Dewey, of Washington, and a host of gentlemen connected with the railroads and furnaces of the South. The arrangement of this paper is not all that could be desired. Some localities of importance are very poorly represented, both in the description and the tables of analyses. This, however, was in most instances unavoidable, as the study has been done ill the intervals of professional work. I have visited almost all the localities described, and, in all cases possible, have taken my own samples, and have made careful per-

Jan 1, 1887

By definition the word "grout" means a thin mortar, or a kind of plaster or cement, and "grouting" means to fill up or finish with grout. The words "cement," "plaster" and "mortar" mean a substance that is used in a soft state which subsequently hardens. Thus, grouting is the filling of void space with a substance that hardens. Construction cements are the most common substances used, either by themselves or in mixtures, but the term grouting is applied quite correctly when other substances such as plastics and certain chemicals are used. Also, the use of the term grouting to cover the filling of voids with materials that do not actually become hard, such as the flotation tailings used in grouting in the southeast Missouri lead district, should be considered correct, as some stiffening does take place and, anyway, it is a better descriptive term than any substitute. Engineers are interested in grouting because some of the materials with which they must work contain voids, and certain conditions can be improved if these voids can be filled with something solid and permanent. Grouting is done to accomplish several purposes: I. To stop the passage of fluids and gases, 2. To cement materials together to make them stronger, and 3. To prevent consolidation of materials by filling void space with something solid as a replacement for the air and water that could be forced out under load. The construction industry uses grouting extensively for all three purposes. Grouting is used to stop water percolation under and around dams. It is used to control water flow in tunnel driving and in shaft sinking. It is used to improve foundation conditions under civil engineering structures by permanently filling void space and thereby reducing settlement, or by cementing broken rock together and increasing its supporting strength. The oil and gas industry does a lot of grouting, primarily to stop the passage of gases and fluids. The search for oil at increasingly greater depths has meant greater investment per well, and the oil industry has spent large sums on development of improved drilling methods. This

Jan 1, 1949

By Edmund Kirby

THE results to come from the application of cheap oxygen to industry in general will be so great that it is not possible to enumerate them beforehand and still less to estimate them. We naturally think first of the fuel to be saved; yet this is only a minor item. The main results will be changes in methods of manufacture or of operation. The speed of operation will be greatly increased, with consequent savings in labor and fixed charges, and also, in most cases, in the cost of fuel. High temperature will be brought within the reach of every manufacturer, whereas it is now available only to those operating expensive electric furnaces located within reach of large water power. New speeds and new temperatures mean improvements and processes not thought of at present. Incidentally the changes in methods will probably change the location of important world industries, the tendency being to concentrate at the fuel centers. The whole subject is so new that most of the data which an engineer requires for definite estimates do not exist. All that is possible now is to obtain a general view of the subject with rough and fragmentary estimates for some of the industries with which we are specially concerned. Most of the figures presented deal with fuel saving merely because there are available no data from which to estimate the effect on speed of operation. When working out the practical problems involved in substituting oxygen for air, in most cases the change will be made step by step; by trying out air enriched with increasing percentages of oxygen. Such partial applications of oxygen will be temporary expedients during the transition and there will be no stopping place short of the complete substitution of air by oxygen. This final stage is therefore the one discussed in this paper.1

Jan 11, 1924

By Marion Rice

THE copper-mining district of Jerome, Ariz., is of such economic importance that the following brief notes may be of interest. The ore deposits are said by Ransome1 to be pre-Cambrian, and are contained in the pre-Cambrian schists of the region. In the vicinity of the mine (the United Verde) the schist stands nearly vertical .and strikes a little west of north. At least three varieties are distinguishable-(1) a green rock, schistose, on its margins but grading into massive material, which is evidently an altered dioritic intrusive; (2) a rough gray schist with abundant pheno-crysts of quartz, apparently an altered rhyolite; and (3) a satiny, greenish gray, very fissile sericitic schist that may be a metamorphosed sediment. The ore occurs in varieties (2) and (3), the main belt of dioritic rock (1) lying just west of the orebodies. The ore is said to follow as a rule the layers of fine sericitic schist. T. A. Rickard2 says that the ore at the United. Verde Extension mine is found at the contact of diorite and schist, that both diorite and ore are earlier than the regional metamorphism, and that the quartz porphyry (" rhyolite" of Ransome) is of post-Cambrian age.

Jan 9, 1918

THE Geophysics Education Committee has devoted several years to a consideration of the problem of training geophysicists. Past reports have dealt largely with fact finding and with the discussion of particular aspects of geophysical education. In the present report it is proposed to review the subject more comprehensively. This involves the question of what educational qualifications the geophysicist of the highest professional standards should possess, and the related question of what changes must be effected in existing educational institutions in order that prospective professional geophysicists may obtain instruction of the desired quality. The type of geophysicist here contemplated is one familiar with what is known already in the several branches of earth physics, and capable not only of following contemporary progress in any of these branches, but of contributing to that progress in a research capacity. Geophysics in its broadest sense, as has been emphasized repeatedly by this Committee, is the study of the physics of the earth and of terrestrial processes. This includes both the static and the dynamic characteristics of the gaseous, the liquid, and the solid portions of the earth, as well as its gravitational, thermal, and magnetic and electrical manifestations. Some branches of earth physics have been cultivated but slightly; others have reached an advanced state of development. Those branches whose development is sufficient to warrant explicit recognition in the form of organized Sections of the American Geophysical Union are: geodesy, seismology, tectonophysics, and volcanology, dealing with the rock constituents of the earth; oceanography and hydrology with the aqueous constituents; meteorology with the atmospheric constituents; and terrestrial electricity and magnetism with the electromagnetic manifestations. At present, instruction on the professional level in any of these branches of earth physics can be obtained in but few universities in North America. In most institutions where such instruction is undertaken different subjects are given in different and independent departments. Geodesy and hydrology are taught, if at all, as a part of civil engineering. The nearest approach to volcanology and tectonophysics ordinarily is represented by petrology and structural geology given

Jan 1, 1944

By G. T. Pruitt, T. L. Irby, P. B. Crawford, H. Ferrell

In water flooding peripheral, center-to-edge, line-drive or water-encroachment patterns the question has arisen, "when should a producing well be converted to a water-injection well?". It is realized that, if the producing well is shut in when water breakthrough occurs, some oil could be left in an unswept area. Yet, operation to high water-oil ratios may require processing much additional water. If a well is shut in, "where should the allowable be transferred?". A review of the literature indicates that very few data are available to the engineer to assist him in answering these questions. It is the purpose of this paper to present information which may be of value in selecting the flooding technique and the injection and producing wells and in scheduling injection and production rates. Certain phases of these problems can be studied in the laboratory. The Potentiometric model is well suited for studying many waterflooding problems. This model assumes that steady-state flow exists, that the mobility ratio is equal to one and that gravitational effects are neglected.'-' The three-phase sand model also has been recognized as an effective means for studying certain reservoir problems. Both models were used in making the study reported here. This paper discusses seven cases utilizing various waterflooding techniques. Data for the first five cases were obtained on the potentiometric model. Data for Cases VI and VII were obtained by constructing and flooding an unconsolidated sand pack (a three-fluid-phase system) and by determining the swept area and cumulative oil recovery for various types of operations. APPARATUS AND PROCEDURE The potentiometric model reservoir was 30 in. long X 10 in. wide by about 1/2 in. deep. Four wells were equally spaced in a line array along the lateral center line. (See Fig. 1.) Well No. 1 initially was an injection well for each of the patterns reported. The cases studied with the potentiometric model and sand model are described herein. The laboratory sand model reservoir was a 30- 10-in. rectangular Lucite vessel packed with sand to a depth of about 0.65 in. Four wells were equally spaced in a line array along the lateral center line. The reservoir material was an unconsolidated sand into which the reservoir fluids were mixed to yield fluid saturations of 55 per cent oil, 25 per cent water and 20 per cent gas. The water was added to the sand and the material mixed, after which the oil was added. Kerosene and water, the fluids used, gave a viscosity ratio of 1.64:1. In packing the reservoir, care was taken to assure constant fluid saturations and constant porosities. A new mixture was prepared for each run. During water flooding, a colored water was injected by a constant rate pump. The injection rate was 1.1 B/D/ft of sand thickness. For this series of tests, each of the producing wells was open to the atmosphere and, as in the potentiometric model study, Well No. 1 initially was an injection well for each of the patterns. KESULTS OF POTENTIOMETKIC MODEL STUDlES Two cases (Cases I and 11) involving equal pressure injections were studied, with the following results. Case Water injection was initiated at Well No. 1; the producing wells (Nos. 2, 3 and 4) were operated at constant and equal bottom-hole pressures. When water broke through at Well No. 2 and achieved the selected water-oil ratio, Well 2 was converted to a water injection well, resulting in two injection and two producing wells. The injection pressures at Wells 1 and 2 were maintained equal and constant; pressures at the producing wells were held equal, but they were lower than those at the injecting wells. A similar process was repeated when water broke through at Well No. 3. The flood was terminated when

By E. F. La Vigne

On Aug. 10, 1884, the Retsof Mining Co. began the sinking of an 18 by 12-ft. shaft at Retsof, N. Y. Rock salt was reached in 1885, in September, at 1008 ft. below the surface. The first salt was shipped in the fall of 1885. A timber breaker was built in 1886. In July, 1895, there was a consolidation of the Retsof Mining Co., the Greigsville Salt & Mining Co., the Livonia Salt Co., and the Lehigh Salt & Mining Co. These consolidated salt companies are now known as the Retsof Mining Co., a subsidiary of the International Salt Go. Eventually all of the mines were closed except the mine of the Retsof Mining Co., at Retsof, Livingston County, New York. On July 6, 1921, about 1/2 mile south of the original shaft arid plant of the Retsof Mining Co., a new 9 by 28-ft. concrete-liried shaft was started. The shaft is 1063 ft. deep from the top of the shaft collar to the bottom of the salt bed. At the same time a reinforced-concrete breaker and other buildings were erccted. This new plant began operations on Dee. 15, 1923. It was designed for a capacity of 3000 tons in 8 hours. Geology The workable rock-salt bed is 1063 ft. below the surface and 326 ft. below sea level, and varies in thickness from 9 to 10 ft. The total thickness is greater than that but is contaminated with shale above and below the pure mineral. The characteristics of the formation are shown in Tables 1 and 2. The bed dips uniformly 0.87 per cent to the south. Prospecting As the salt deposil in New York State is known, very little prospecting has been necessary. Before the sinking of the Retsof No. 1 shaft, a well was drilled to prove the existence of salt. No. 1 shaft was sunk where the well was located. The several salt wells drilled in Livingston Courlty proved generally the existence of salt throughout the county. (See U. S. Geol. Survey Bull. 669: Salt Resources of the U. S.)

Jan 1, 1938