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By Thomas Leonard Watson

Introduction,...... Historical Statement,....644 Geology of the District,....645 The Weisner Quartzite,....647 Topography,. .....653 Rock-Weathering,..... The OcheR-Deposits,.....655 Petrography of the Quartzite,..655 Associated Ore-Deposits,....657 Chemical Composition of the Ocher,. 658 Mode of Occurrence of the Ocher,..659 In the Fresh Rock,....660 In the Residual Clays,...661 Origin of the Ocher,....662 Economic Features,..... Methods of Mining,..... Preparation of the Ocher,...664 Uses,........ Introduction. Knowledge of the existence of yellow-ocher deposits in Bartow county, Georgia, dates back to the early mining of manganese- and iron-ores in the vicinity of Cartersville. Systematic mining of the ocher in this area really began, however, probably not longer than a decade back, although the date of its first working is as early as the year 1877. The district has been, for a number of years, one of the principal producers of yellow ocher in the United States; and at no period of its development have mining activities been greater and more successful than at present. Systematic field-study of the ocher- and manganese-deposits of Georgia was begun by me while I was a member of the

Jan 1, 1904

By E. G. Williams

Manganese-ore has been found upon the Isthmus of Panama throughout' a region of nearly three hundred square miles, over the greater part of which, however, it is known only in small bodies without commercial value. Only six mines, controlled by two companies, have actually shipped ore, although a large area has been taken up in miningelaims. The ore-bearing region extends along the coast of the Carib. bean Sea, beginning on the west near Puerto Bello and extending easterly about 35 miles toward Point San Blas. Ore has been discovered in the interior, at a maximum distance of about 10 m. from the coast. Fig. 1 is a map of a portion of the Isthmus

Jan 1, 1903

THIS paper presents briefly some of the principal results of 3 ½ months field work during the summer of 1938 in the Chichagof mining district, southeastern Alaska. The report is preliminary and presumably will be followed later by a more complete report to be published by the Geological Survey. The paper is concerned principally with the structural geology of a block of steeply dipping graywacke as revealed underground in the Hirst Chichagof and the Chichagoff mines, the two principal mines of the district. The two mines have produced about $16,000,000 worth of gold and silver. The attitude of the graywacke, which is locally cut by dikes and sills of aplite, is remarkably uniform and trends about N. 62º W. The average dip is about 67º SW. The graywacke is cut by large faults, the best known of which are the Hirst and the Chichagof, whose average trends are about N. 30ºW. and average dips about 75º SW. The faults at some places split into the bedding of the graywacke and at others are deflected from their normal trends for considerable distances along the bedding. The relative movements along the faults was northwest and up at about 30º for the south- west or hanging-wall sides. The ore bodies are elongate quartz lenses in the faults. Most of the quartz is mineralized but locally large quartz masses are too low grade to be mined. The emplacement of the ore bodies appears to have been structurally controlled in large part by the intersections of the faults with the bedding surfaces. Places where the faults split or are deflected appear to have been particularly favorable places for ore deposition. There has been some post-quartz movements along the faults but it is thought that such movements have not been extensive enough to greatly modify the original positions and shapes of the ore bodies.

Jan 1, 1939

By Arthur Fleischer

THE Kalunite process? for the production of metal-grade alumina from alumina-containing ores is applicable, considered from a general point of view, to any aluminous raw material that can be converted to potassium alum or equivalent normal alum. This result of modern technology has been the subject of a continuous study and development since 1929, on a laboratory and test-plant scale, with initial emphasis on the utilization of alunite as the raw material. The research and developmental program was carried out by the Kalunite Company and its successor, Kalunite, Inc., an affiliate of the Olin Corporation of East Alton, Illinois. The process is now approaching the time for a major test in its history with the completion of construction of a plant having a capacity of zoo tons of alumina per day in Salt Lake City for the conversion of Marysvale, Utah, alunite ores to alumina and potassium sulphate. The Salt Lake Alumina Plant is a Defense Plant Corporation project. PRODUCTION OF ALUMINUM The known existence of alunite deposits, especially in the Marysvale district, furnished the motive for the original inquiry into the utilization of this raw material for aluminum production. The deposits in this region were actively explored during World War I and utilized for the production of potassium sulphate, an essential fertilizer, of which a shortage of monumental proportions then existed. Up to the twentieth century for alunite is a mineral with an ancient history-it was used in Europe and in China as a source of potassium alum. It never had been used successfully in. this country as a source of oxide for reduction to metal. Although the known reserves of this ore, which undoubtedly will be greatly expanded with a commercial outlet for this ore, are recognized to be sufficient for only a part of the present-day needs of aluminum, it has a definite place in the aluminum industry. Academically it points the way for future raw materials. The aluminum industry has undergone a remarkable growth in the past few years as a result of defense and war requirements. Its expansion in many ways has been beyond belief and prediction, both in volume and location. This wartime status of the industry has accelerated the consumption of bauxite to such an extent, that a re-evaluation of the raw material reserves for the future peacetime industry and for eventual wartime reserves is seemingly of concern. The generally accepted picture of bauxite ore reserves in the United States, especially in raw material suitable for treatment by the Bayer process, focuses attention on other possible sources of raw material of metal-grade oxide. The perspective for the development of a suitable process may have changed in the interim

Jan 1, 1944

By Ulick R. Evans, Maurice Cook

The structural changes in metals brought about by annealing follow-ing a deformation at a low temperature has been the subject of many investigations. No less than eleven metals and alloys have been studied in some detail; namely, aluminum, tungsten,2 iron,3 copperI4 gold, zinc,6 cadmium, tin: lead: brass,1° and cupronickel. As a result, it is possible to frame a qualitative statement of the effect of the degree of deformation and the temperature of annealing on the structure finally attained.

Jan 1, 1925

By Hugh Rose

THE properties of the company lie within the Pachuca district, State of Hidalgo, Mexico, connected by three railway lines with Mexico City, 55 miles southwest, and by two lines with Vera Cruz, 250 miles southeast. The ores were formerly divided by sorting into two classes, smelting and milling, the former averaging about 2 oz. gold and 335 oz. silver, the latter 0.12 oz. gold and 23 oz. silver. The smelting ores were sold to custom plants, principally the American Smelting & Refining. Co. at Aguascalientes. The milling ores were treated by the patio process at the Guadalupe Hacienda, at Pachuca. This patio was probably the largest in existence at the time and continued in active operation up to March, 1910. In January, 1910, the mines and patio were sold to English interests, represented by Camp Bird Limited. Two new companies were formed, the Compañia de Santa Gertrudis, S. A., to operate the mines, and the Compañia Beneficiadora de Pachuca, S. A., to build and operate a custom cyanide milling plant. (Fig. 1.) GEOLOGY The historical geology of the Pachuca district is described by Fred J. Pope as follows: 1. The most recent sedimentary rocks in the district belong to the Cretaceous period. 2. The Cretaceous rocks were penetrated by large intrusions of ande-site (referred to hereafter as primary andesite) which occur as elliptical dome-shaped masses, striking northwest-southeast. These andesite bodies are from 8 to 15 miles long and from 6 to 10 miles wide. 3. A period of erosion during which the contour of the andesite domes was changed. 4. Andesite flows (secondary andesite) which rest unconformably on the primary andesites.

Jan 8, 1916

By Louis S. Cates

At the annual meeting of the American Institute of Mining and Metallurgical Engineers in February, 1923, the Chairman of the Committee on Ground Movement and Subsidence appointed a sub-committee to work out a form of questionnaire and to collect data on subsidence and ground movement resulting from underground metal and coal-mining operations, and on ground movement and safe slopes in connection with open-cut metal-mining operations. The author was requested to take charge of the collection of data and the preparation of a questionnaire in connection with the Committee's studies of open-cut metal-mining operations. This paper is a summary of the work carried on and information received therefrom up to February, 1924. The first approach to the problem of safe slopes is to gather all information that pertains to finished slopes; in other words, the steepest economic angle from the horizontal that will stand in order to uncover the ores to be mined and be safe while the extraction of the ore at the base of these slopes is in progress. Whether or not this angle is 35" or 45" depends on many factors. The number of benches maintained to take care of falling rock and their height and width are direct functions of this overall slope. The slope is here taken to mean the angle from the top edge of the pit through the edges of the respective lower benches to the bottom of the pit. If we accept this definition of the slope, it might save some confusion as there would be a difference if one took the line from the top edge of excavation to the toe of the bottom slope. This latter slope would not be constant, but would vary with the number of benches. The depth of the various ore faces will vary, of course, depending on the deposit; Table 1 shows this to range from 50 ft. to 1100 ft. The geology is an important factor, as are the climatic conditions under which one is operating. A saturated condition in some rock structure causes rock flows; in the Panama Canal excavation, slides have run on a ratio of as low as one on ten, which is a 10 per cent. grade, or a slope of less than 6' with the horizontal. Slopes as steep as 60' have been noted in the Utah Copper operations, so that a wide divergence will possibly be met. The work of securing data that will be of value to the operator or estimating engineer will be difficult and will mean little unless a detailed

Jan 1, 1927

By George K. Foster, Charles D. Borror

THE Jeffrey mine of the Canadian Johns-Manville Co., Limited, is in the town of Asbestos, situated approximately 100 miles northeast of Montreal and about the same distance southwest of Quebec, in Richmond County, Quebec. Mining operations were started in 1881 on outcrops on a hill, as a side-hill cut, followed by a second and third cut. This development was the forerunner of the present large open-pit operations, the mine now ranking as the largest openpit asbestos mine in the world. Operations were first carried on by hand, then by horsepower and later by stem cableways. By 1924 the derrick spans, 2000 ft. or more long, became unwieldy. To overcome this, and also to eliminate hand labor as much as possible, steam shovels and railroad haulage were introduced. The steam shovels were replaced in 1928 by larger electric shovels of the full-revolving type. THE ORE BODY The ore body is a serpentinized peridotite rock mass. The chrysotile fibers form a network of veins throughout, varying from microscopic width to two or more inches measured across the veins (Fig. I). These veins may be continuous for a few or many feet; they may increase or decrease in width within a few feet. The veins in which the fibers occur perpendicular to the veins are known as cross fiber. Those in which the fibers lay parallel to the veins are known as slip fiber. The cross fibers are of better quality, and more in demand. The majority of the fiber [ ]

Jan 1, 1946

By Charles C. Russell, Glenn C. South

A primary factor in the selection of coals for making coke at high temperatures is the amount of pressure the coal will exert upon the oven walls when carbonized in modem by-product ovens.l-3 This factor has become increasingly important in recent years because of demands for increased throughput and higher coke yields. As a result of the increasing necessity for assessing coals in regard to their carbonization pressures, more and more research work is being directed toward developing labora-tory-scale tests for predicting carbonization pressures and for showing how blends of coking coals may be modified to eliminate pressures liable to damage coke-oven walls. The specific reasons have never been defined as to why some blends of coking coals develop dangerous carbonization pressures and others do not, therefore specific procedures to eliminate dangerous pressures could not be prescribed. It is true that the major processes occurring during carbonization have been described by many writers,4 and there is a general agreement on the ideas of the changes that occur as coal is transformed into coke. However, there is little evidence relating the processes occurring during carbonization to the pressure developed and the available evidence is very incomplete and often contradictory. This deficiency arises in part from the fact that the fundamental causes of pressure development have not been defined, at least from experimental data, and in turn this is the result of the lack of satisfactory testing equipment for studying the problem. Operating experience has shown several ways of reducing or eliminating dangerous pressures,5 but probably none of these ways is applicable to all blends of coking coals, and such empirical methods often lead to production of inferior coke. They are trial-and-error methods, not designed to remedy specific causes of pressure development. The number of laboratory-scale testing devices designed to estimate the carbonization pressures that result when coals are carbonized in commercial ovens is probably well over a hundred.6 Few of these instruments have remained in use for any length of time, either because the predictions were not sufficiently accurate or, more often, because too many exceptions were found. Often testing devices are operated without any attempt at duplication of conditions in commercial ovens and erroneous and contradictory results are frequently obtained. Therefore, it has seemed desirable to study the properties of coal itself and to determine any relationships between the properties of the coal and the carbonization pressures developed. Relationship between Properties of Coal and Carbonization Pressure Attempts to determine relationships between various properties of coal and carbonization pressures, for the most parti have been indirect because no satisfactory and reliable laboratory testing device has

Jan 1, 1944

By Carroll C. Bailey, William F. Boericke

Mine financing, or providing adequate capital for developing and bringing a mining property into production, is an essential requirement for a successful operation. Today it presents a different picture than even twenty-five years ago. The day appears to be gone when a mining property could pay its own way from grass roots to production. The country has been quite thoroughly combed for surface showings from which sufficient initial profit could be immediately garnered to pay for further development and production facilities. The four M's for success in mining-mineral, market, management, and money-are still essential, but doubled or tripled wage costs and steep advances in cost of equipment and supplies throw increased emphasis on adequate capital funds for converting a prospect into a producer. Consequently, the old picturesque, although seldom rewarding, grub- staking procedure where a single venturesome citizen might advance funds to a prospector on a fifty-fifty basis for whatever discovery he might find, has largely disappeared. Its place, to some degree, has been taken by the small syndicate of venturesome members who band together for furnishing funds to a group of prospectors for the same general purposes. Such a syndicate has a definite organization and is usually assured of sufficient initial funds, or flow of funds, to carry on work for several years. It is usually headed by an engineer-promoter or an entrepreneur trader who has had considerable field experience as well as personal knowledge of his prospecting crews. For the owner of a potential mining property who has ample capital, the problem is to determine (1) justification for the necessary investment in exploration and development, and (2) the economics of the enterprise as to size and degree of integration of the ha1 operating entity. If the owner of such a property has little or no capital, he also faces these same basic problems but, in addition, must be able to present the findings of fact and persuade the prospective investor that the enterprise will produce

Jan 1, 1964

By Norman Pilling

The micrographic analysis of silicon steels is possible if a dilute solution of nitric acid and methyl alcohol in nitrobenzol is used. The action of this reagent differs from that of sodium picrate in that there is no persistent deep-seated staining and the solution is used cold. THE technical difficulties hampering the metallographic analysis of silicon steels are chiefly the result of the extreme corrodibility of these alloys. The addition of silicon to iron in increasing quantities, up to about 6 per cent., rapidly increases the susceptibility of the alloy to chemical attack, not only in acid solution, but in water. This renders the preparation of metallographic sections very difficult, because of a non-selective attack upon the finely polished surface by the water used as a lubricant in polishing. This water attack masks the true structural details revealed by suitable etching reagents. It is thus necessary to use alcohol as a polishing lubricant in the last stages of preparation and to avoid all etching reagents having an aqueous base. A specific reagent for the identification of iron carbide in ferrous alloys, and the one hitherto used almost exclusively by metallurgists, is an alkaline aqueous solution of sodium picrate, which stains this constituent selectively. Its application to silicon steels has not proved successful, as its distinctive selective action is more or less completely hidden by the general attack of the aqueous solvent on the silico-ferrite, greatly accentuated by the fact that this reagent must be used at its boiling temperature (105° C.). Thus, a powerful metallographic aid to the study of the higher silicon alloys, such as transformer steels, is lost. A new reagent has been developed for the purpose of overcoming this difficulty. It is with some hesitation that the list of etching reagents, already overburdened, is increased, but the properties of this new reagent are advantageous in several ways and a definite field for it may be found in the metallography of ferrous alloys.

Jan 1, 1924

By Glenn C. South, Charles C. Russell

A primary factor in the selection of coals for making coke at high temperatures is the amount of pressure the coal will exert upon the oven walls when carbonized in modem by-product ovens.l-3 This factor has become increasingly important in recent years because of demands for increased throughput and higher coke yields. As a result of the increasing necessity for assessing coals in regard to their carbonization pressures, more and more research work is being directed toward developing labora-tory-scale tests for predicting carbonization pressures and for showing how blends of coking coals may be modified to eliminate pressures liable to damage coke-oven walls. The specific reasons have never been defined as to why some blends of coking coals develop dangerous carbonization pressures and others do not, therefore specific procedures to eliminate dangerous pressures could not be prescribed. It is true that the major processes occurring during carbonization have been described by many writers,4 and there is a general agreement on the ideas of the changes that occur as coal is transformed into coke. However, there is little evidence relating the processes occurring during carbonization to the pressure developed and the available evidence is very incomplete and often contradictory. This deficiency arises in part from the fact that the fundamental causes of pressure development have not been defined, at least from experimental data, and in turn this is the result of the lack of satisfactory testing equipment for studying the problem. Operating experience has shown several ways of reducing or eliminating dangerous pressures,5 but probably none of these ways is applicable to all blends of coking coals, and such empirical methods often lead to production of inferior coke. They are trial-and-error methods, not designed to remedy specific causes of pressure development. The number of laboratory-scale testing devices designed to estimate the carbonization pressures that result when coals are carbonized in commercial ovens is probably well over a hundred.6 Few of these instruments have remained in use for any length of time, either because the predictions were not sufficiently accurate or, more often, because too many exceptions were found. Often testing devices are operated without any attempt at duplication of conditions in commercial ovens and erroneous and contradictory results are frequently obtained. Therefore, it has seemed desirable to study the properties of coal itself and to determine any relationships between the properties of the coal and the carbonization pressures developed. Relationship between Properties of Coal and Carbonization Pressure Attempts to determine relationships between various properties of coal and carbonization pressures, for the most parti have been indirect because no satisfactory and reliable laboratory testing device has

Jan 1, 1944

By M. G. Corson

INFORMATION regarding the use of manganese alloys has hitherto been incomplete and available only from widely scattered sources. This paper attempts a systematic description of properties and uses of alloys other than manganese bronze, manganin and duralumin, which are probably the only non-ferrous alloys associated with manganese in the minds of most metallurgists.1 PROPERTIES OF MANGANESE Manganese can react either acid or basic; it is hard to obtain in the pure state; it has two different crystalline lattice structures, both of the cubic system, one stable above 850° C. and the other below 650° C., both coexisting in the intermediate range. Although the commercial product is hard and brittle, the pure metal seems to be ductile. In fact Zhemchuzhny, in Russia, was able to obtain ductile manganese and draw it to fine wires by the simple expedient of adding about 3 per cent. copper to the alumino-thermic product. Copper most probably brings the silicides, aluminides, nitrides and carbides present in the commercial product into a much less harmful form of distribution. One industrial use that can be foreseen for wrought manganese articles is as anodes for electrolytic processes in sulfate and nitrate solutions, particularly with high voltages. A practically insoluble skin of manganese peroxide is likely to form in such cases and an insoluble and strong anode material will be available. MANGANESE AS A SCAVENGER Because of its activity manganese might become the most efficient scavenger and refiner of copper, were it not for the fact that 0.01 per cent.

Jan 1, 1928

By B. L. Landrum, P. B. Crawford

Theoretical and potentiometric model studies have been made of the effect of non-uniform lateral permeabilities on pattern sweep efficiency and production capacity in waterflood and gas-cycling programs. It is shown that a diflerence in directional permeability by a factor of three may result in a sweep efficiency of only 43 per cent for a five-spot pattern or a sweep of either 79 or 38 per cent for a direct line-drive square pattern, depending on the direction of the line-drive flood. Changes in the pattern conductivity varied from about 0.8 to 1.34 over this same permeability variation, depending on the pattern used. It is suggested that measurements be made to determine the possible magnitude and extent of the directional permeability phenomenon early in the field developinent and certainly prior to the initiation of any fluid-injection progmm. INTRODUCTION Irregularities in reservoir sand properties long have been a major difficulty to anyone attempting to explicitly describe the field characteristics of oil production. In particular, it is well known that vertical and lateral permeabilities often differ appreciably; however, the existence of large regions with lateral permeabflity variation is not widely recognized. A number of years ago, extensive studies were conducted by the Secondary Recovery Research Labcratory of the Pennsylvania Grade Crude Oil Association, primarily on the Bradford field. Johnson and Hughes' reported a permeability trend in the northeast-southwest direction. They indicated that flow in the preferred direction may be 25 to 30 per cent greater in that direction than in the northwest-southeast direction. They also reported that similar effects may be found in other nearby fields. The origin of the permeability variation has been discussed by Griffith Hutchinson' described the results of labora- tory tests on limestone cores, pointing out that per-ferential directional permeabilities were significant in one-half of 10 formations studied and that the average permeability ratio was 16:1. Barfield, Jordan and Moore analyzed the fluid-injection displacement performance in the Spraberry and reported that the effective ratio of permeability parallel to the major axis to the permeability perpendicular to this axis was 144:l and that it inclined along an angle of about 30". To prevent the reduction of sweep efficiency which would normally result from flooding or cycling in such reservoirs, well spacing could be varied from the customary square to a diamond-shaped pattern. Johnson and Hughes' presented a method for determining the desired shape. Another method will be discussed in detail in the next section. It is the purpose of this paper to investigate quantitatively the effect of directional permeability upon the sweep efficiency and production capacity of the five-spot and line-drive well patterns. Information currently in the literature will be applied to this particular problem and augmented by a potentiometric model study. It is stressed that the effects herein discussed may or may not be of great importance because field data on this phenomenon are far too scant to form such an opinion. It is suggested that, if conditions similar to those found by Johnson and Hughes frequently exist (as may well be the case), more consideration cdrtainly should be given to this problem.

By R. J. Pfister

The development of a water-input profile instrument based on the introduction of brine and fresh water into an input well with the electrical location of, the boundary developed between them is reported. Two methods are available in the use of this instrument to measure the foot by foot water-intake rates of the various sand strata: the moving boundary method in which variable well bore diameters can be determined and/or cancelled out and the constant boundary method. The type of results obtained and the relative advantages of each of these methods are described in detail. Representative data are included covering the use of this instrument in experiments involving selective acidizing, selective plugging, and selective shooting. In such experiments, this instrument has been used to diagnose the unfavorable distribution of water intake in input wells and also to determine the effectiveness of the resultant treatments. The data included also serve to illustrate the type of problems which can be studied with this technique. Introduction For ten years or perhaps longer a number of progressive water-flood operators have felt the need for some to to measure the foot by foot water-intake rates of various strata in water-injection wells. The primary need is to diagnose unfavorable water distribution in various strata and to evaluate the effectiveness of the corrective measures such as selective acidizing, selective plugging, and selective shooting. Previously described methods for obtaining this type of data were not considered entirely adequate.l,2 The profile equipment described in this paper embodies the separate introduction of brine and fresh water into the well at carefully measured and controlled rates and the electrical location of a sharp boundary developed between these fluids. At present this instrument is a research tool of value in determining the effect of various well treatments on an individual sand strata. lts primary use has been on wells in which different sections require different treatments (e.g., wells with an open sand to be plugged and a tight sand to be acidized)- It has, thus, made possible the determination of a rearrangement of the water intake of a well. The instrument can also be used to direct the treating material into a given zone. In completing a well the less permeable sands are shot more heavily with nitroglycerine in order to equalize the water intake between the permeable and less permeable sands. The extent to which such corrective shooting has been successful Can be determined by a water-input profile. The combined profile and well-bore diameters should also provide a method for determining the direction and effect of various selective shooting techniques. Equipment The essentials of the water-input profile technique for measuring the intake per foot of individual sand strata are the injection of a nonconducting fluid, water, at the top of the well and a conducting fluid, brine, through a separate string of

Jan 1, 1948

By R. J. Pfister

The development of a water-input profile instrument based on the introduction of brine and fresh water into an input well with the electrical location of, the boundary developed between them is reported. Two methods are available in the use of this instrument to measure the foot by foot water-intake rates of the various sand strata: the moving boundary method in which variable well bore diameters can be determined and/or cancelled out and the constant boundary method. The type of results obtained and the relative advantages of each of these methods are described in detail. Representative data are included covering the use of this instrument in experiments involving selective acidizing, selective plugging, and selective shooting. In such experiments, this instrument has been used to diagnose the unfavorable distribution of water intake in input wells and also to determine the effectiveness of the resultant treatments. The data included also serve to illustrate the type of problems which can be studied with this technique. Introduction For ten years or perhaps longer a number of progressive water-flood operators have felt the need for some to to measure the foot by foot water-intake rates of various strata in water-injection wells. The primary need is to diagnose unfavorable water distribution in various strata and to evaluate the effectiveness of the corrective measures such as selective acidizing, selective plugging, and selective shooting. Previously described methods for obtaining this type of data were not considered entirely adequate.l,2 The profile equipment described in this paper embodies the separate introduction of brine and fresh water into the well at carefully measured and controlled rates and the electrical location of a sharp boundary developed between these fluids. At present this instrument is a research tool of value in determining the effect of various well treatments on an individual sand strata. lts primary use has been on wells in which different sections require different treatments (e.g., wells with an open sand to be plugged and a tight sand to be acidized)- It has, thus, made possible the determination of a rearrangement of the water intake of a well. The instrument can also be used to direct the treating material into a given zone. In completing a well the less permeable sands are shot more heavily with nitroglycerine in order to equalize the water intake between the permeable and less permeable sands. The extent to which such corrective shooting has been successful Can be determined by a water-input profile. The combined profile and well-bore diameters should also provide a method for determining the direction and effect of various selective shooting techniques. Equipment The essentials of the water-input profile technique for measuring the intake per foot of individual sand strata are the injection of a nonconducting fluid, water, at the top of the well and a conducting fluid, brine, through a separate string of

Jan 1, 1948

By Thomas L. Kesler

The Cartersville mining district, 35 miles northwest of Atlanta, Ga, has been of varying but continuous importance in the southern mineral industry during the past century. Noted chiefly for its production of brown iron ore, manganese oxide ores, barite, sienna, and magnesian limestone, the district and its environs have produced brick and tile clays, slate, gold, bauxite, and graphitic schist. Minor deposits of serpentine, sericite schist, copper ore, and red iron oxide have been prospected. The obvious deposits of brown iron ore, together with some associated specular hematite, were mined out years ago, although a little ore was left in the workings. Moderately steady production of sienna reached a peak about 1930, then declined rapidly. Manganese mining passed through a relatively active period from the World War to 1931, but has subsided to a small but rather constant output for the Birmingham market. However, the White Manganese Corporation has prepared for possible increased production by constructing a new washer capable of handling about 300 tons of ore per day. Principal activity in the district proper has centered for some years in the production of barite and magnesian limestone. General Geology Geologic relations of the ore deposits of this district are more or less similar to those of many Appalachian districts. The lowermost Cambrian formation, heretofore called Weisnerl in this region, supposedly partly or. wholly equivalent to the Erwin and Hesse quartzites as recognized to the northeast, is overlain conformably by the Shady† formation, also of Lower. Cambrian age. In the Cartersville district, the sedimentary rocks of these formations were folded with increasing intensity eastward, and were recrystallized.

Jan 1, 1941

By J. H. Richards, G. Derge, W. Peifer

A WIDE Variety of metallurgical defects in steel have commonly been attributed to the presence of excessive amounts of hydrogen. These defects include flakes in rails and forgings, cracks in welds, and blisters in enameled ware, They have been related to hydrogen largely by circumstantiat evidence because the proper sampling and analysis of steel for hydrogen has been known to be difficult and because no general agreement has existed with regard to the relative suitability and accuracy of available methods. The need for a direct approach to these problems has been widely recognized. This general situation has been well described in the publications of the British committee on the Heterogeneity of Steel Ingots,' and current approaches to the problem were reviewed in a recent symposium of the AIME.I2 The plans described by the present authors at that meeting have now matured satisfactorily and will form the basis of this paper. The principal object of this paper will be to describe the methods of sampling and analysis which have been developed and to illustrate the usefulness and limitations of these methods by citing their application to a specific problem, The first problem selected for investigation was the behavior of hydrogen in rail steel. This was chosen because the occurrence of shatter cracks in rails has received a great deal of study over a long period of time. The defect can be controlled by the expensive procedure of slow in However, it may be hoped that a better understanding of the factors influencing the hydrogen content of rails will lead to a more efficient control of this problem. Rails provide a good starting point for a more general study of hydrogen in steel because they provide a cross-section large enough to develop cracks, Yet small enough for convenient handling and sampling. Rails were also selected because they arc made from plain carbon steel and it was felt that the initial work should not be complicated by the effects introduced by alloying elements. The considerations which determined the original planning of this study should be reviewed. The inherently complex nature of most hydrogen problems requires that a large amount of data must be collected for any particular case. This in turn means that any analytical procedure should be as rapid and simple as possible. The same objective of speed is indicated by the fact that it may finally become desirable to use hydrogen analysis in process control. It is also known that hydrogen is highly fugitive and that any procedure which facilitat~s early analysis of the sample without prolonged or irregular storage has distinct advantages. The most important previously reported methods of analysis may be classified into three general groups: (I) Vacuum fusion, (2) Vacuum extraction (without melting), (3) Total combustion.

Jan 1, 1949

By Yves Dardel

The literature concerning the remelting of alunlinum and its alloys is very rich. Unfortunately the majority of the papers on this subject have no scientific value, for the theories or explanations are too often in opposition to the laws of physical chemistry. Furthermore only a few of the methods of purification are considered in the literature. Hence it has seemed necessary to the author to sketch a general theory of the purification of secondary aluminum. The purpose of the purification is to eliminate the impurities that the charges, and the atmosphere of the furnaces bring into the bath during the successive remelt-ings. Indeed scrap as well as metal can be used when soiled with oil, greases, water, or others, if it has been sufficiently dried and contains oxides. At the melting point of the metal, the oils and greases are decomposed into their constituent elements H², O2, H²O, co², CO, CH,, and others. These gases are added to the corresponding gases in the atmosphere of the furnace. The impurities introduced into the metal during the remelting will accordingly be the products resulting from the action of these gases on the liquid bath. The quantity of hydrogen that is soluble in aluminum and its alloys is given by the relation of sieverts3 as a function of its partial pressure PH2 in the atmosphere m = K vPH² [I] where K is a constant, which depends only upon the temperature and increases with it. The experiments of Rijntgen and Braun4, RÖntgen and M611er5, Bircum-shaw6 and Winterhagerl have rendered it possible to determine the value of K, when the temperature is less than 1.000°C. One obtains: log K = - 4,702.5T + o 238 [2] Besides its usual significance, the term Ph~ represents also the internal pressure of dissolved hydrogen, since in the equilibrium, that is1 when no gas exchange Occurs between the two phases, the Pressures of hydrogen in the metal and in the atmosphere must be equal. Eq I shows that when the partial pressure of H2 increases the amount of dissolved hydrogen in equilibrium increases, and that, if the contrary Occurs, the quantity of H² should diminish. However, if for any reason the diffusion of hydrogen is hindered and the total amount of dissolved gas remains constant while the temperature decreases, the internal pressure of H² increases until it reaches the value of the hydrostatic pressure. At this point, bubbles of hydrogen appear in the bath and escape out of it. The amount of hydrogen in the metal is then limited by a a depending On the hydro- static pressure, which is practically equal to one atmosphere. Indeed hydrogen does not accumulate in the form of a hydride appearing as a separate solid phase. However1 even the mechanism of the solubility is not yet elucidated. One does not know exactly as yet, whether the

Jan 1, 1949

By Thomas L. Kesler

The Cartersville mining district, 35 miles northwest of Atlanta, Ga, has been of varying but continuous importance in the southern mineral industry during the past century. Noted chiefly for its production of brown iron ore, manganese oxide ores, barite, sienna, and magnesian limestone, the district and its environs have produced brick and tile clays, slate, gold, bauxite, and graphitic schist. Minor deposits of serpentine, sericite schist, copper ore, and red iron oxide have been prospected. The obvious deposits of brown iron ore, together with some associated specular hematite, were mined out years ago, although a little ore was left in the workings. Moderately steady production of sienna reached a peak about 1930, then declined rapidly. Manganese mining passed through a relatively active period from the World War to 1931, but has subsided to a small but rather constant output for the Birmingham market. However, the White Manganese Corporation has prepared for possible increased production by constructing a new washer capable of handling about 300 tons of ore per day. Principal activity in the district proper has centered for some years in the production of barite and magnesian limestone. General Geology Geologic relations of the ore deposits of this district are more or less similar to those of many Appalachian districts. The lowermost Cambrian formation, heretofore called Weisnerl in this region, supposedly partly or. wholly equivalent to the Erwin and Hesse quartzites as recognized to the northeast, is overlain conformably by the Shady† formation, also of Lower. Cambrian age. In the Cartersville district, the sedimentary rocks of these formations were folded with increasing intensity eastward, and were recrystallized.

Jan 1, 1941