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By G. Austin Schroter, Ian Campbell

Although there is now an extensive literature on the bleaching clays, not a great deal of material is to be found concerning the geological features of these deposits and their bearing on problems of exploration and development. At the same time, chemical and crystallographic research on the clay minerals during the past few years has laid a suitable foundation upon which to base conclusions of economic value drawn from field observations. All of the criteria and deductions herein presented are based upon extensive field work by the senior author, both in the United States and Canada, and when .subjected to the ultimate tests of development and exploitation they have held up remarkably well, despite the fact that many of these conclusions apparently have not been reviewed in the literature heretofore. The nomencelature of the bleaching clays is rather confusing in the light of present-day commercial standards and has even led to litigation.'" The old term "fuller's earth" is largely based upon trade usage and the definition of the term therefor? is dependent upon the changing standards of commerce. For statistical purposes the Bureau of Mines8' classes as "fuller's earth" all natural bleaching or filtering claylike materials that possess high adsorptive capacity without previous chemical treatment or activation. Conversely, the so-called activated or acid activated clays are now generally recognized as any clay mineral or mixture of the clay minerals whose adsorptive capacity has been developed to commercial standards by chemical or physical treatment. Therefore, without attempting to propose any additions to the nomenclaturc: of bleaching clays, this paper will refer to naturally adsorptive clays and activable clays, respecbively, for the two types indicated.

Jan 1, 1942

By James P. Kimball

Sulphur is always present in mineral coal of every variety. In the oxidized state it may exist as sulphuric acid in combination with a base. In the unoxidized state it exists in combination with iron as bisulphide of iron. It is also supposed by some chemists to exist in unknown combinations with the organic elements of the coal. This supposition requires the demonstration as a fact that certain coals yield more sulphur than what may exist in a free state, or what belongs to recognized combinations, not only with the accompanying iron but with other inorganic bases abundantly occurring in coals, but which unfortunately are very rarely estimated. This practically as well as theoretically important question it is at present impossible to decide, simply for want of available thorough ultimate coal analyses including the ash. Such analyses, at the best imperfect, are luborious and intricate, and therefore seldom made, the much simpler proximate analyses, so-called, being resorted to by most chemists for technical purposes, and commonly substituted for more scientific work even in the laboratories of government surveys. And it is unfortunate enough that few ultimate analyses are extended to the composition of the ash, much less to its relation to the original constitution of the coal. Sulphur chiefly occurs in most coals in the form of yellow pyrites (pyrite) and white pyrites (marcasite), both minerals, characterized by differences in crystalline form and in physical properties as well as in color, but having the same chemical composition (FeS2). No coal is entirely free from one or both of these dimorphous forms of bisulphide of iron. It may be disseminated through the mass so as to be invisible, in plates or scales between the laminæ of the coal, or in conspicuous segregations or nodules, sometimes of considerable dimensions. Coals greatly differ as to the proportion of sulphur which they contain. They also differ as to the relative proportion in which its several forms of combination occur. Such qualitative and qnantitative disparities arc scarcely, if at all, more marked in separate coal seams of a uniform type than in different parts of one and the same coal seam, whether it be considered locally as constituted of several

Jan 1, 1880

By L. F. Mondolfo

An investigation of the relationship between properties of the elements and type of binary diagram formed was conducted. It was found that, for each type of equilibrium diagram, the factors for the size, valence, electronegativity, period, melting point, entropies of fusion, and sublimation calculated for each pair of elements cover a range of values. However, these factors show sufficient relationship to the equilibrium diagram so that the correlation of several of them can be used to predict the type of diagram formed, or at least limit the choice to only a few types. ThE goal of the metallurgist concerned with alloy development has always been to find a method that predicts the properties that can be obtained when a certain metal is added to another one. In most cases a qualitative predictiton of properties can be made if the equilibrium diagram is known. However, this means that for new metals the alloy development has to start with the experimental determination of the equilibrium diagrams. Because this determination is at least as complicated and time-consuming as the determination of the properties themselves, most alloy development has taken place by trial and error, and the study of the equilibrium diagrams has followed rather than preceded the creation of new alloys. Alloy structures and properties depend on the interaction between electrons and a complete knowledge of these interactions would permit prediction of structure and properties of alloys. Unfortunately direct measurement of these interactions is extremely difficult and somewhat doubtful and only properties that depend on them can be measured easily and with certainty. Study of the relationship between properties of the elements and equilibrium diagrams is not new. Besides the well known Hume-Rothery rule of the necessity of an atomic diameter fit within 15 pct for extensive miscibility in the solid, and the wide knowledge of the effect of such factors as size, electronegativity, electron-atom ratio on solid state features,"' work relating to liquid state and liquid-solid reactions can be found in the literature. Of particular interest is the work by Axon,3 who investigated the effect of size and melting point on a selected number of eutectic and monotectic dia-

Jan 1, 1962

By H. F. Beeghly

UNTIL recently the only criteria by which steels were judged were their cost and their mechanical, chemical, and physical properties. The user was concerned with such properties as corrosion resistance, tensile strength, response to thermal treatment, hardness, ductility, and, to a growing extent in recent years, with behavior at high temperature. As plans were made to build power reactors, a new set of properties became important—the nuclear characteristics, which had to be considered by the designer and engineer in building his plant. The nuclear engineer developed methods for the rare and new metals and produced them in high purity, often at great expense. The pure metals then provided the raw materials for tailor-made alloys. For more common structural metals, such as steel, the nuclear industry depended on commercially available materials. Generally, the quantities required were small and specifications were rigid. It is not surprising, therefore, that difficulty was frequently encountered in procuring structural mate-

Jan 1, 1957

WITHOUT in any way detracting from the credit due those engineer-miners of copper who operate with power shovels, it may be said that compared with block-caving underground their work is simplicity itself. True enough, ingenuity and foresight of high order are required to lay out an open-cut operation to the best advantage; good organization and intelligent care and use of machinery are required to achieve minimum costs. But really successful undercut block-caving demands all this; and, in addition, it requires a conception and application of unseen natural forces that reflect a type of genius that is rare. Assuming that preparatory work has gained access to the orebody, mining of whatever kind consists essentially of three operations: 1. Breaking the ore "in place," as Nature left it, into pieces small enough for convenient handling. 2. Loading these pieces into some kind of a vehicle on wheels. 3. Transporting the broken ore to some central plant on the surface where the process of extracting the valuable metals can be commenced. In shovel mining, dynamite and steam or electric power are used-with remarkable efficiency, be it said-to accomplish each of these three processes. In underground-caving methods the old force of gravity is called upon to accomplish, in large part, processes 1 and 2. To do this with success is an artistic achievement of a sort. Put it another way. The earlier methods of underground mining constituted a translation of surface procedure to an underground theater. The ore was blasted and dug out in small quantities; in its place were put props, usually of timber, to prevent the caving of the rock above; and men toiled with

Jan 1, 1933

By W. H. Basssett

THE amount of oxygen present in refined copper bears an important relation to the effects of various impurities on physical properties of copper, as well as the effects of reducing gases at higher temperatures. It seems fitting at this time, when the effects of reducing gases on copper are being discussed, to describe methods that have proved satisfactory for the determination of oxygen and sulfur, and to present some results obtained by investigation of these methods in the authors' laboratory. The procedure for the determination of sulfur is closely interrelated with that for oxygen and has, therefore, been included. It was first proposed by Hamper that oxides in copper could be accurately determined by the loss in weight sustained by finely divided copper when reduced at red heat in pure hydrogen, or by the weight of water produced. Hampe's method was later modified by Archbutt,2 who established the accuracy of the method and demonstrated that equally accurate results were obtained by noting the loss in weight or by weighing the water formed. The determination of oxygen by heating in carbon monoxide has been proposed by West.3 In our hands this method has given slightly lower results than obtained by heating in hydrogen.

Jan 2, 1926

By H. Shaw

In the author's previous paper an attempt was made to analyze in detail the gravitational effects arising from certain subterranean anomalies of simple form, and extending to infinity in three directions. As a result of this critical examination, certain features—which were considered to be characteristic of the anomalies under investigation—were disclosed, a close observance of which enables a complete interpretation to be reached. The most simple case was first considered; viz., that of a heavy horizontal plate, bounded above and below by horizontal planes, and extending to infinity on one side of a vertical plane containing the y axis, in the three directions + y, —y, and +x. After this, the investigation was extended to the case of a similar infinite horizontal block having an inclined face. In each case the form and behavior of the gradient curve and the curve of differential curvature were analyzed, and entirely distinct interpretations were put forward, based upon (1) the gradient, (2) the differential curvature and (3) a comparison of these two quantities. In continuation of the previous work, and as a preliminary to further analysis of more complex structures, certain factors will now be examined which characterize (1) the simple infinite vertical block and (2) an infinite block which is inclined to the vertical, formations which are of considerable practical interest, being typical of important. geological structures—intru-sive dikes, lodes, veins, etc.—and because, even though in nature these may be irregular, valuable guides to a more complete interpretation are obtained by assuming, as a first approximation, that they have the simple characteristics to be studied hereafter. In the previous paper certain preliminary assumptions were made in order to render the resulting deductions universally applicable and entirely independent of the particular scale employed. Consideration was limited to homogeneous deposits of unit positive effective density (and this condition is retained in the present investigation), so that in the case of

Jan 1, 1932

By M. A. Orehoski, J. M. Hodge

It is now generally conceded that if a steel is to develop optimum physical properties in the conventionally quenched and tempered condition, the microstruc- ture after quenching should consist wholly of martensite; and that transformation of austenite to intermediate-temperature products during quenching will have a deleterious effect upon the physical properties, particularly the toughness, of the tempered material. This implies that, in order to obtain the optimum physical properties from a given steel, its "harden-ability " should be high enough to suppress all transformation except that to martensite under the heating and quenching conditions to which it will be subjected, and this premise is probably the most important reason for hardenability control. However, the criterion of hardenability that at present is most widely accepted and used is based on a microstructure of 50 per cent martensite. This criterion, which was suggested by Grossmann,' does have considerable justification. It may be readily measured by a fracture or etch test and, since it represents the point at which the hardness is changing most rapidly with variations in cooling rate, it may be determined empirically from a hardness-depth curve by determining the point of steepest slope (the inflection point). Furthermore, in plain carbon steels or in steels of low hardenability, the difference in hardenability expressed in

Jan 1, 1947

By J. M. Hodge, M. A. Orehoski

It is now generally conceded that if a steel is to develop optimum physical properties in the conventionally quenched and tempered condition, the microstruc- ture after quenching should consist wholly of martensite; and that transformation of austenite to intermediate-temperature products during quenching will have a deleterious effect upon the physical properties, particularly the toughness, of the tempered material. This implies that, in order to obtain the optimum physical properties from a given steel, its "harden-ability " should be high enough to suppress all transformation except that to martensite under the heating and quenching conditions to which it will be subjected, and this premise is probably the most important reason for hardenability control. However, the criterion of hardenability that at present is most widely accepted and used is based on a microstructure of 50 per cent martensite. This criterion, which was suggested by Grossmann,' does have considerable justification. It may be readily measured by a fracture or etch test and, since it represents the point at which the hardness is changing most rapidly with variations in cooling rate, it may be determined empirically from a hardness-depth curve by determining the point of steepest slope (the inflection point). Furthermore, in plain carbon steels or in steels of low hardenability, the difference in hardenability expressed in

Jan 1, 1947

By W. F. James, Richard Murphy, S. N. Kesten, A. H. Lang

The paper is a summary of information on Canadian deposits of uranium and thorium up to the end of 1948, prepared by geologists of Eldorado Mining and Refining Ltd. and by the specialist on uranium deposits for the Geological Survey of Canada. The paper contains a history of Canadian uranium and thorium discoveries, a working classification of the deposits, fairly detailed descriptions of the Eldorado mine and of properties in northern Saskatchewan, and shorter accounts of several other discoveries.

Jan 2, 1950

By A. C. Boyle

PaGE I. Introduction.........68 II. Location of the District,....... • 70 .. III. Stratigraphy...........73 Description of the Rocks.......73 Triassic Eruptives (Andesite Flows and Tuffs) ....73 Triassic Sediments (Shales and Slates)..75 Areal Geology ............75 Structure...-.......76 Folds............. 76 Faults..........79 Shear ...........80 Intrusives..........81 Alaskite Dike.........81 Andesitic Intrusion.......82 IV. PetrogRaphy of thE Rock Types......83 Andesite Flows.........84 Tuff 8...........84 Andesite Tuff........84 Rhyolite Tuff.....-.......85 Alaskite-Porphyry.......89 Andesite Dike........91 V. Description of the Mines......92 VI. Metalliferous Deposits ........ 95 Character of the Ores...........97 Mineralogy of the Ores.......97 Metallic Minerals.......97 Microscopic Character of the Ores...98 Secondary Enrichment....... 103 Genesis of the Ores ...........104 VII. The Sulphate Deposits.......109 Gypsum ..... HO Anhydrite......... ,... 110 Barite............ 110 Origin. with special reference to Gypsum....111 VIII. Summary.............. 113 IX. BIblYogRaphY.............114

Jan 1, 1915

By John Langton

In determining what kind of pourer should be adopted for the works of the Moctezuma Copper Co. at Nacozari, Sonora, Mexico, certain considerations imposed by local conditions had to be taken into account. Water.—During most of the year the water-supply is abundant for all purposes, but it dwindles rapidly when the dry season sets in, reaching a minimum flow which is entirely undergrouad. It was evident, that with the greatest care in keeping down the unavoidable loss of water in milling and smelting, these operations and hence the capacity of the works mould ultimately be limited for about two months of the year by the small watersupply available at the period of minimum flow. Transportation.—The nearest railway terminus was in Arizona, at the international boundary-line; and the price of supplies at that point would be enhanced at Nacozari by the additional cost of a 90-mile wagon-haul. During the rainy season, transport to Nacozari was much impeded, and at times made impossible, by the condition of the roads. Hence, to insure continuous operation at the works, it would be necessary to provide for hauling the year's supplies, including fuel for power and coke for smelting, in less than eleven months. In other words, the average freight delivered daily at the works should be at least 10 per cent. more than the average daily consumption. For moderate quantities of freight, pack-carriage by burros is astonishingly cheap. But it has a capacity-limit which is generally very soon reached. A 200-lb. load, and 10 miles a day, 5 with and 5 without load, is the full capacity of a burro. This means one burro per ton-mile of the round trip; and,

Jan 1, 1904

By Willard P. Ward

I DESIRE to put on record a fact in relation to the effect of manganese on pig iron which I have never seen in print, and which may, perhaps, not have been observed by anyone except myself. In 1875, while experimenting on the production of ferromanganese in a blast furnace, I had burdened the furnace with a charge which I calculated would produce a 15-per cent spiegel. The furnace was very hot, having been running for a couple of days on a very light burden, and making a burnt iron, preparatory to the experiment I proposed to make to produce a high grade of spiegel. I calculated that the charge would begin to work in the furnace in about twelve hours after it was put on. After the lapse of that time I commenced to watch the furnace carefully, but found little or no. change in the appearance of the metal, although there was a very decided change in the cinder, showing that the manganese ore had come in work. The iron was quite gray and very tough. The character of the cinder was good for a spiegel cinder, and I could not imagine where the manganese was going to, as it (lid not appear to be in either metal or cinder in anything like the quantity indicated by the charge. The next morning things were still in, the same condition. The furnace was very hot, the cinder good, and the iron very gray. I was then sorely puzzled. I had never heard of a gray iron with over 4 or 5 per cent, of manganese, and had no notion that an iron with more manganese could be gray and tough. With great difficulty a piece for chemical test was broken from a pig. Not less than a hundred blows from a heavy sledge were required to break it off I took the specimen to the shop and directed that some borings from it should be brought to the laboratory, as soon as possible, whither I myself at once repaired -to put things in readiness for a rapid manganese determination. In about half an hour the machinist came in with the iron specimen in one hand and about, a dozen blunted and broken steel drills in the other, saying that it was impossible to drill the iron. There were several little depressions in the iron, which was malleable enough to be indented by the point of the drill, but not a chip had been cut from it. The metal was never subjected to further physical tests. A chip broken from

Jan 1, 1882

By Franklin R. Carpenter

In area, the Black Hills are about equal to the State of Connecticut. As the accompanying geological map indicates, they exhibit in the main a simple structure, presenting a central mass of granite and Archæan rocks, on all sides of which the later sedimentary rocks dip

Jan 1, 1889

By Joseph Pogue

THE writer visited the Muzo emerald mines in July, 1915, and spent six days in their study. This paper embodies the results of his observations, plus information personally communicated by Robert Scheibe, FIG. 1.-SKETCH MAP SHOWING APPROXIMATE LOCATIONS OF ALL IMPORTANT EMERALD MINES AND PROSPECTS IN COLOMBIA. (Data in part supplied by Robert Scheibe, July, 1915.) Professor of Geology in the Mining Academy of Berlin, who at the time of the visit was completing a detailed field investigation of nearly a year's duration of the emerald deposits of Colombia. An elaborate account of this valuable work may be expected at a future date from the pen of Professor Scheibe.

Jan 5, 1916

By Samuel Wyer

THE art of natural-gas compressing is now over 25 years old, and has grown at practically the same rate as the increase in domestic natural-gas consumers. There are now over 200 natural-gas compressing stations in North America, aggregating more than 320,000 hp. of compressor capacity and representing a property value of more than $22,000,000, and compressing more than 85 per cent. of all the gas used. The age and magnitude of the art make it evident that the use of gas compressors is a recognized integral part and universal custom of the natural-gas business. The public also is not without its rights and vital interests in this problem. Approximately 1,700,000 domestic natural-gas consumers in North America are dependent upon gas compressors for their natural-gas service. That is, if the use of compressors were to be prohibited, the majority of these consumers would be unable to secure adequate natural-gas service. Each consumer represents between four and five persons, and it therefore follows that the comfort and well-being-as far as natural-gas service is concerned-of at least 8,000,000 persons would be affected if the use of natural-gas compressors should be prohibited. These 1,700,000 consumers have invested, in services, house piping, fixtures, and appliances, an average of about $90 each, or an aggregate of $153,000,000, which is much more than the companies' investment in gas compressors. Furthermore, in all cases where the rate paid by the consumers is fair to the gas company-considering the value of the service rendered by the gas company-the consumers are entitled to continued service and protection of the investment they have made on the faith that the gas service would be continued in the future.

Jan 2, 1916

By S.S. Clarke

The sheet-ground deposits of the Tri-State district, because they are fairly uniform in thickness (7 to II ft.)—rather flat, with an easy dip to the west—and cover a large acreage, offered a problem of improved transportation. Heading advance in this kind of mine is very rapid and track haulage requires a larger crew of trackmen than do other mines, and a heavy investment in track. The use of some type of rubber-tired truck equipment for underground haulage was under consideration for some time by the Eagle-Picher Mining and Smelting Co. The nature of some ore bodies made them not adaptable to truck haulage and some mines that did offer possibilities were equipped with other types of haulage, and the expected savings by the use of trucks did not offset the loss of investment that would be incurred in discarding other equipment. The decision was made to sink a new shaft, designed for skip hoisting, on the Blue Goose ore body, and then develop truck equipment. Developing Tractors and Trailers A study was made of internal-combustion engines for power units in the tractors, but the extreme difficulty of controlling air circulation, and the heavy cost of drilling large churn drill holes for blower installations, led to the adoption of a tractor with a storage battery. The storage-battery tractor that was on the market for mine haulage was impossible to obtain because all were needed for defense work. Several standard electric-truck chassis were purchased and rebuilt in the Eagle-Picher shops. The steering wheel was shortened and set vertical, permitting the driver's seat to be moved forward, and the frame was shortened enough to take the battery box and the fifth wheel support that carried the gooseneck of the dump trailer. The fifth wheel, or turntable, is of the ball and socket type. Tig. I shows the ball fastened to the gooseneck. The socket is split to permit introduction of the ball and is held by through-bolts, and the socket is welded to a ½-in. plate, which in turn is attached to the tractor frame. Smaller wheels and tires were put on to reduce over-all height. If it had been necessary, the spring: could have been reversed, or taken off entirely, to gain additional clearance. The tractors are equipped with 48-cell, 23-plate, 400-A.H. batteries. With the initial tonnage and mileage, the batteries were about 50 per cent down at the end of a shift. Tractors have truck tires 7.50 by 20, 8-ply, front and rear, the rear being dud. After four months of use, the .tires are beginning to show signs of failure.* In

Jan 1, 1943

By S. S. Clarke

The sheet-ground deposits of the Tri-State district, because they are fairly uniform in thickness (7 to II ft.)—rather flat, with an easy dip to the west—and cover a large acreage, offered a problem of improved transportation. Heading advance in this kind of mine is very rapid and track haulage requires a larger crew of trackmen than do other mines, and a heavy investment in track. The use of some type of rubber-tired truck equipment for underground haulage was under consideration for some time by the Eagle-Picher Mining and Smelting Co. The nature of some ore bodies made them not adaptable to truck haulage and some mines that did offer possibilities were equipped with other types of haulage, and the expected savings by the use of trucks did not offset the loss of investment that would be incurred in discarding other equipment. The decision was made to sink a new shaft, designed for skip hoisting, on the Blue Goose ore body, and then develop truck equipment. Developing Tractors and Trailers A study was made of internal-combustion engines for power units in the tractors, but the extreme difficulty of controlling air circulation, and the heavy cost of drilling large churn drill holes for blower installations, led to the adoption of a tractor with a storage battery. The storage-battery tractor that was on the market for mine haulage was impossible to obtain because all were needed for defense work. Several standard electric-truck chassis were purchased and rebuilt in the Eagle-Picher shops. The steering wheel was shortened and set vertical, permitting the driver's seat to be moved forward, and the frame was shortened enough to take the battery box and the fifth wheel support that carried the gooseneck of the dump trailer. The fifth wheel, or turntable, is of the ball and socket type. Tig. I shows the ball fastened to the gooseneck. The socket is split to permit introduction of the ball and is held by through-bolts, and the socket is welded to a ½-in. plate, which in turn is attached to the tractor frame. Smaller wheels and tires were put on to reduce over-all height. If it had been necessary, the spring: could have been reversed, or taken off entirely, to gain additional clearance. The tractors are equipped with 48-cell, 23-plate, 400-A.H. batteries. With the initial tonnage and mileage, the batteries were about 50 per cent down at the end of a shift. Tractors have truck tires 7.50 by 20, 8-ply, front and rear, the rear being dud. After four months of use, the .tires are beginning to show signs of failure.* In

Jan 1, 1943

By Arthur Knapp

The practical application of mud-laden fluids in wells has been the subject of many papers.' However, there seems to have been little investigation of what actually happens when mud-laden fluids are applied to a loose porous sand. The assumption is that the fluids penetrate the sands and that there is some plastering action. The degree of penetration and the relation of plastering action to wall stability is not generally known. This paper describes a series of experiments made in an attempt to observe, in laboratory apparatus, the action of mud-laden fluids under conditions simulating those to be found in a well. For the purposes of this discussion all fluids containing solid matter in suspension are mud-laden fluids. Series I: Penetration of the Pores of Uncemented Sands The subject of the penetration of porous formations by water is discussed in detail in Water-Supply Paper No. 67 of the U. S. Geological Survey. No attempt was made to repeat the experiments described therein. The results of the first experiment of this series are given simply to show the capacity of the apparatus used. The conditions in this first experiment were maintained throughout the remainder of this and the second series, except where noted. The experiments of Mills, McCoy, and others on subsurface flows, adjustments, migrations, etc., deal with the oil, water or gas within the porous beds.V he experiments described herein deal with the conditions immediately surrounding the bore hole.

Jan 1, 1923

By Arthur Knapp

The practical application of mud-laden fluids in wells has been the subject of many papers.' However, there seems to have been little investigation of what actually happens when mud-laden fluids are applied to a loose porous sand. The assumption is that the fluids penetrate the sands and that there is some plastering action. The degree of penetration and the relation of plastering action to wall stability is not generally known. This paper describes a series of experiments made in an attempt to observe, in laboratory apparatus, the action of mud-laden fluids under conditions simulating those to be found in a well. For the purposes of this discussion all fluids containing solid matter in suspension are mud-laden fluids. Series I: Penetration of the Pores of Uncemented Sands The subject of the penetration of porous formations by water is discussed in detail in Water-Supply Paper No. 67 of the U. S. Geological Survey. No attempt was made to repeat the experiments described therein. The results of the first experiment of this series are given simply to show the capacity of the apparatus used. The conditions in this first experiment were maintained throughout the remainder of this and the second series, except where noted. The experiments of Mills, McCoy, and others on subsurface flows, adjustments, migrations, etc., deal with the oil, water or gas within the porous beds.V he experiments described herein deal with the conditions immediately surrounding the bore hole.

Jan 1, 1923