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By J. W. Koger, R. E. Hurnrnel

QUENCHED, bcc p brass, P1, transforms to a mar-tensitic phase, when it is cooled below room temperature.' This transformation can be followed using resistance measurements since the resistivity of the martensitic phase is considerably larger than that of the parent phase, Fig. 1.' phillips3 first reported that, when Cu-Zn alloys containing between 37.0 and 39.0 wt pct Zn were quenched from the 0 region to room temperature, variable amounts of a phase could be observed depending on the mode of quenching. If the quench occurs very rapidly, the a phase forms by a "massive transformation". The resultant phase has the same composition as the high-temperature P phase from which it was formed. If the quench is less severe, the alloy is retained largely in the p form; however, some a is formed by precipitation. In this case, a contains more copper than the high-temperature 0 phase from which it has formed. The a phase most probably does not undergo a transformation in the temperature range where p transforms to low-temperature martensite. This can be deduced from the Eesistivity-temperature relation which is linear in this temperature range, Fig. 2. The stable a phase which is present along with R. E. HUMMEL is Assistant Professor, Department of Metallurgical and Materials Engineering, University of Florida, Gainesville, Fla. J. W. KOGER, Junior Member AIME, formerly with University of Florida, is now with Oak Ridge National Laboratory, Oak Ridge, Tenn. Manuscript submitted December 13, 1967. IMD.

Jan 1, 1969

By G. F. Loughlin

THE matter of grading Indiana oolitic limestone has been under a cooperative study by the Supervising Architect's office, the U. S. Geological Survey, the Bureau of Standards, and the former Indiana Limestone Quarrymen's Association. As the criteria for grading are necessarily based on a number of geologic and related factors of which those quarrying and using the stone had only imperfect appreciation, the first part of the report is a very elementary account of the origin, structure, and the chemical and physical properties of tie stone, and their relations to durability and utilization, and serves as a foundation for the second part, which discusses grading and pro- poses limits for grades established by the quamymen. Salient features of Part I of a report that has been prepared are the variations in uniformity of stone due to cross bedding, and local uncomformities; the relative prominence of weathering effects on the coarser uneven grained surfaces, and its apparent absence on fine, uniform grained surfaces, although the amount of weathering is the same on each; the attributing "crow feet" (stylolites) to solution under pressure, and the explanation that, whereas the thinnest "crow feet" have no noteworthy effect on weathering quality or strength, the thicker ones are likely to weather out rapidly and to promote splitting; the influence of fracturing on the oxidation of the original gray or "blue" to buff color above the ground water level; the interpretation of chemical analyses and the pointing out that both the gray and buff colors are due mainly to organic

Jan 1, 1929

By Carle R. Hayward

THOUGH recent months have seen a rapid decline in lead-smelting activity and consequent uncertainty as to the future, the first half of the year showed progress in keeping with similar activity in other metals. Demand for scrap increased and various lead-bearing materials found their way to plants producing secondary lead. Some of these materials introduced complications into normal smelting procedure and were the cause of many conferences among plant officials attempting to find the most satisfactory method of treatment. If a blast furnace is to do itself justice it must be run with an open charge. Troubles inevitably result when materials are added to a charge which tighten it up and pre- vent free burning of the coke and con- sequent rapid smelting with a clean hearth This fact has long been recognized by plants producing primary lead, but only recently only it received the attention it deserves.

Jan 1, 1938

By John M. Loveioy

EVERY producer of crude oil knows what is meant by the Rule or Law of Capture. It means that the ultimate ownership of a migratory substance such as oil is not determined until that substance is reduced to physical possession. Unless, therefore, the producer moves quickly to capture his share from the common pool, he may lose to any neighbor who is drilling and producing more rapidly than he a portion of the oil originally underlying his property. And there is no recourse open to him if his property is so drained. Under this rule it is obvious that the owner of an oil property, if he is to protect his' ownership, must be governed in his development and production policies by the activities of his neighbor rather than by his own business requirements. He must drill as densely and as fast as the other operators in the field or lose part of the oil to which he should be entitled.

Jan 1, 1936

By E. H. Cho

INTRODUCTION Activated charcoal has been used for several centuries in many capacities including the recovery, isolation and purification of various materials (1). The first use of charcoal in a gold metallurgical system was in the extraction of gold after chlorination (2, 3,4). The gold was dissolved in a chlorine system and subsequently filtered through charcoal. The application of charcoal with cyanide extraction was patented by Johnston (5) in 1894 and adopted commercially in Australia in 1897. The process consisted of dissolving the gold and silver in a potassium cyanide solution and passing it through a series of charcoal filters. The charcoal was subsequently smelted to recover the gold and silver. The interest in the use of charcoal diminished in the first part of the twentieth century as the practice of the use of zinc as a precipitating agent increased. However, in 1916, the Yuanmi Mine in Australia replaced their zinc precipitation plant with a charcoal adsorption plant. In 1926, Scott and Gross (7) of the U. S. Bureau of Mines con- ducted extensive research on the adsorption of gold and silver from cyanide leach solutions. Among their findings was the result that the most important factor in improving the adsorptive power of charcoal was heat treatment with oxidation by air or steam. The work of Zadra (8) in 1952 stimulated renewed interest in the use of activated charcoal in gold and silver recovery with the development of a method of recovery of the gold and silver from the charcoal other than its destruction by burning. The process involved simultaneous desorption

Jan 1, 1983

By Anthony Anable

HOOVER DAM, rapidly nearing completion in the Black Canyon of the Colorado River at Boulder City, Nev., taxes the superlatives of the vocabulary to describe. For by all odds, it is the largest construction project of its type ever essayed by man and the plants providing the essential materials of construction are also in a class by themselves not only in size but in advanced design, mechanization, and accurate control. Picture, if you will, the great aggregate plant, as it is called, situated about 4 mi. upstream from the site of

Jan 1, 1934

By J. V. Vogel

Jan 1, 1969

By M. R. Klepper, H. Landsberg

Many of the sedimentary rocks contain small amounts of radioactive constituents. These vary in quantity in different layers. Some recent deposits show rather high activity as; for example, the deep sea oozes and some lake deposits.lv2 Measurements made in boreholes have also shown considerable changes in activity from horizon to horizon. The first to publish data on this fact was Ambronn,3 and recently Russian geophysicists have shown remarkable variations of activity from one layer to the next in various wells. Spak4 felt even that he was able to line up horizons from data measured in two neighboring wells.‡ The measuring of radioactive radiation is fairly difficult. Large errors are possible by the circulation of gaseous emanations in the well and porous strata. It is, therefore, never certain whether the activity of the layer where the instrumental device or collector is located will be measured, or that of some adjacent layer. For this reason it seemed to be advantageous to take samples of rocks into the laboratory and test them there for their contents of radioactive material. Such a method has been followed in the past to distinguish radioactive ore from other rocks. Radioactivity of rocks, especially of the igneous type, was also determined in the laboratory by numerous authors for absolute age investigations.= Corresponding data from studies of sedimentary formations are scarce. Specimens taken from a core of the Bradford oil sandstone were tested by Landsberg and Ingham,7 with the results illustrated in Fig. 1, which shows that within relatively small vertical distances the differences of relative activity were considerable. If one assumes that the distribution of radioactive material is fairly uniform throughout a layer, measurements of radioactive radiation in various horizons would offer additional information for stratigraphic

Jan 1, 1940

By K. E. N. Hanney

INTRODUCTION Slurry systems and mechanical conveying, represent the main methods of transporting solids from one area of a mineral processing plant to another. A well-designed slurry handling system can assist in lowering plant capital costs by reducing building size, simplifying plant layout and reducing operating costs by lowering maintenance and labour costs. This Paper has been prepared with the object of providing a practical approach to designing slurry systems. SLURRY CHARACTERISTICS Slurry is a mixture of crushed or ground rock mixed with water or a chemical solution, and can flow under several different conditions: (a) As a homogeneous suspension; (b) As a heterogeneous suspension; (c) With a moving bed (saltation); (d) With a stationary bed. Homogeneous flow takes place when the solids are uniformly distributed throughout a pipe and when particle sizes are smaller than 325 mesh. Heterogeneous is the most common slurry suspension. In this system, there is a gradual increase in concentration of solid particles towards the bottom of a pipe. There is a fairly wide range of velocities that fall within this system. In moving bed systems, the coarse particles settle out and bounce along the bottom of a pipe. Operating under these conditions tends to minimize wear and power requirements, but because this system operates within narrow velocity limits, pipelines frequently plug. Stationary bed conditions exist when coarse material has settled in the bottom of the pipe restricting the available area. These conditions should be avoided. DESIGNING A SLURRY SYSTEM Slurry can be transported either by pumping through a pipeline or by developing a gravity head and flowing through a pipe or along a launder. When considering any slurry system, whether for the design of a new plant or to make modifications to an existing operating plant, design criteria are required. The design criteria provide the information for calculating the material balance and sizing the equipment. The quantities on the material balance can then be assigned to the flowsheet for reference. The equipment can then be laid

Jan 1, 1982

By M. R. Klepper, H. Landsberg

Many of the sedimentary rocks contain small amounts of radioactive constituents. These vary in quantity in different layers. Some recent deposits show rather high activity as; for example, the deep sea oozes and some lake deposits.lv2 Measurements made in boreholes have also shown considerable changes in activity from horizon to horizon. The first to publish data on this fact was Ambronn,3 and recently Russian geophysicists have shown remarkable variations of activity from one layer to the next in various wells. Spak4 felt even that he was able to line up horizons from data measured in two neighboring wells.‡ The measuring of radioactive radiation is fairly difficult. Large errors are possible by the circulation of gaseous emanations in the well and porous strata. It is, therefore, never certain whether the activity of the layer where the instrumental device or collector is located will be measured, or that of some adjacent layer. For this reason it seemed to be advantageous to take samples of rocks into the laboratory and test them there for their contents of radioactive material. Such a method has been followed in the past to distinguish radioactive ore from other rocks. Radioactivity of rocks, especially of the igneous type, was also determined in the laboratory by numerous authors for absolute age investigations.= Corresponding data from studies of sedimentary formations are scarce. Specimens taken from a core of the Bradford oil sandstone were tested by Landsberg and Ingham,7 with the results illustrated in Fig. 1, which shows that within relatively small vertical distances the differences of relative activity were considerable. If one assumes that the distribution of radioactive material is fairly uniform throughout a layer, measurements of radioactive radiation in various horizons would offer additional information for stratigraphic

Jan 1, 1940

By C. S. Corbett

EARLY in the development of every oil field, the operators of relatively large tracts of land must decide upon a spacing plan for the wells to be drilled upon their respective tracts. Usually it is desirable to have a system of regular spacing laid out over the entire tract, making such adjustments as may be necessary near land boundaries. Unless the dip of the producing formation is very steep, the equilateral triangular arrangement is the one most generally preferred, for the very good reason that it gives the maximum amount of drainage area for the wells up to the limit at which mutual drainage interference begins. Assuming that the equilateral triangular pattern is to be used, there still remains to he decided the matter of distance between wells. Many variable factors enter into the problem of proper spacing, some of which are physical and some economic. It is not the purpose of this paper to discuss these factors, as that has been done in several comprehensive articles during the past few years. In the end the decision must be based upon an estimate of the relative importance of various factors which apply to the field in question and to economic conditions in the oil industry at the time the development is getting under way. Even if the best possible spacing distance should be chosen when the problem arises, changing economic conditions and variation in physical conditions in different parts of the field may cause the original choice to become more or less unsatisfactory. Obviously, it is advantageous, once a spacing plan has been adopted, to avoid alteration of it as the field becomes better known or as conditions in the industry change, and yet be able to vary somewhat, the acreage per well in extending the area of development. Or, it may be desired to provide for an ultimate spacing considerably closer than conditions seem to warrant early in the development of the field. With these contingencies in mind, it is of interest to examine the possibilities which the equilateral triangular system affords. Orientation of Coordinate System In this system the well locations may be considered as the inersectionst of three sets of coordinate lines, the lines of each set intersecting those of the other two sets at 60. For convenience in placing such a system

Jan 1, 1930

By George M. Fowler

EVERY year it becomes more difficult to find new mining districts and new ore deposits. Nearly all of the important discoveries so far can be attributed to surface manifestations overlying the ore deposit. In the future greater skill will be necessary to find ore deposits that give little or no indication of their presence. Mining geology is making progress by broadening its attack upon mineralized regions, by including in its investigations studies of the relation of physical-chemical processes to ore precipitation and various phenomena that heretofore have not always been looked upon as major factors in the problems. Such, for example, are petrographic peculiarities that will help determine structure, aspects of strata or formations favorable or unfavorable to structural deformation or mineralization, and renewed studies of chert and dolomite. This broadening attack is not necessarily being directed to the study of large areas, but rather by doing extremely detailed work in three dimensions in relatively small critical areas to find the key to the structure, reasons for the manner of rock deformation, composition and texture of the rock, and other con¬trolling factors in the larger areas.

Jan 1, 1935

By WILLIAM J. LINNEY

MAGNETITE ore from Lyon Mountain, so- called "Low Phos Chateaugay," has long been known to the iron and steel industry for its almost complete absence of impurities. These magnetites occur along the northern foothills of the Adirondacks in several parallel and folded stringers which are continuous for several miles, striking generally northeast-southwest and dipping usually over 45° to the northwest, or roughly toward the St. Lawrence River. Ore of minable thickness is found in shoots of various sizes as to length and breadth, but of undetermined and possible great depth.

Jan 1, 1943

By C. R. Hayward

CARLE R. HAYWARD.-I do not want it understood that I think that the conclusion that the time of tempering temperature is immaterial has been definitely proven, but since these are the first definite figures put out, I thought before continuing on more work ourselves, it would be well to present them as progress and for information. J. A. MATHEWS, Syracuse, N. Y.-I think that if Prof. Hayward would consult the paper of Profs. Barus and Strouhal,1 1885, he would find about 250 pages, mostly figures, on this subject, in which they investigated the tempering effect by electrical and magnetic methods. There are so many figures in the paper that it is very difficult reading. One point particularly brought out was that even at a low temperature, such as the boiling point of alcohol, about 60° C., there is a tempering effect, increasing up to 4 hr. One reason they obtained those results, with which the present authors are at variance, was that they started with a high-carbon steel which hardens thoroughly, whereas the steel Prof. Hayward and his collaborator used was a comparatively mild steel which does not take a great deal of hardening. About 3 years ago Mr. Stagg and I published 2 a few figures bearing on the same subject, but we used .a low-carbon alloy steel of high tempering qualities and found a great deal of improvement, particularly in ductility, by continuing the drawing up to 4 hr. We used a chrome-vanadium steel showing after heat treatment 250,000 tensile strength. On short drawing, we got almost no ductility, but by continuing to 4 hr., we raised it to 12 per cent. I believe Prof. Hayward's results are due to using comparatively mild steel, whereas Prof. Barus used drill rod and carried out a, wonderfully exhaustive

Jan 4, 1917

By F. W. Davis

SOME idea may be gained of the tremendous consumption of refractories by the open-hearth steel manufacturers from a statement made by A. T. Green at a meeting reported by T11.e Industrial Chemist of London, as follows: "At a very progressive steel plant in the Midlands, with a battery of five open-hearth furnaces working. twelve months and making 3000 tons of steel per week, the cost of refractories per ton of steel produced averages about $0.50 for the actual open- hearth casting and $0.12 for those operations incidental to the rolling of the metal." .These figures, when translated into the annual tonnage of steel, represent a very considerable expenditure.

Jan 1, 1930

By Arthur Dwight

WE NOT have to go so very far back, when measured in actual years, to what may be considered the beginning of the industrial era of the great West, the discovery of gold in California in 1848, just 74 years ago. By a strange coincidence, this event occurred within a few days of the signing of the treaty with Mexico which ceded California to the United States. Needless to describe the mighty wave of humanity that hurled itself toward the setting sun in response to that call. The single thought in every one's mind was gold. The gold as they found it in placers or ledges could be so easily worked, and the product was so readily transportable, and available immediately as money, that practically no attention was paid to deposits of the base metals, in the treatment of which cheap transportation was a paramount con-sideration; consequently little progress was made in anything but gold mining until after the Civil War. The next great step was accomplished when East and West were united by the successful construction of the Union Pacific Railroad from Omaha across the great plains and through the Rockies to meet the rails of the Central Pacific coming eastward across the Sierras. The industrial history of our great West really dates from the day when those two hands of steel were joined, on the shores of the Great Salt Lake at Prom-ontory Point,. May 10, 1869. That seems a long time ago when we think of the enormous changes that have been wrought since that day, and when we regard the rich empire that has sprung up in that western land. Into the new empire thus made accessible, by this first thread of steam transportation, flocked a new brood of adventurous spirits from the older communities of the East. This way walked Fate; and as she, went, flung far the line of destiny, That bound an untracked continent to brotherhood from sea to sea; That long gray trail of dream and hope, marked mile by mile with graves that keep On every barren hill and slope some stout heart lost in dreamless sleep. Patience and faith and fortitude were willed to it and justified; Stern, homely virtues, plain and rude, eternal as the sky and wide. Nor ever sea-king dared the sea in sterner mood than these who went Strong armed to wrest from Mystery their birthright, half a continent.

Jan 4, 1922

By F. Z. Schellenberg

(Pittsburg Meeting, March, 1910.) SYSTEMATIC exploitation in the Pittsburg coal-seam on a large scale is simple where the boundaries of the property do not interfere by forcing drainage-, ventilation-, and transport-lines of entries to be run to particular confined fronts. A prime condition governing development is the natural direction of the seam's perpendicular cleavage-planes, giving long lines of smooth faces near together and parallel, bearing about 65° to the left of the meridian and therefore crossing the basins. The gradients of dip into the basins change from 10 per cent at the east rim to practical flatness northwestward across the great coal-fields, a hundred miles wide; the clip being halved in rate at each successive crossing-over of an anticlinal crest. Elevations above sea-level on this transverse section, in scope of present development, differ by 1,000 ft. between low trough and high outcrop. Local irregularities of dip are found, but the main feature to be recognized is the pitch of the basins-the general rise northeastward at 20 ft. per mile, from 100 ft, below sea-level at the low point near the. SW. corner of Pennsylvania to 1,500 ft. and more above tide, and the appearance then, at the surface, of the lower coal-seams carried in the next deeper-lying thousand feet of rock-measures; below which series come the oil- and gas-sands of Oliphant's charted column of strata, reaching down altogether 3,000 ft. below the Pittsburg coal-seam. Because of -the general regularity of occurrence of the coal-seam, the mine-map depicting the courses of economic operation to be undertaken and the steps in controlled exhaustion, need be but a projection of two dimensions on the horizontal plane of space, and this for the most part composed of natural, almost unbroken lines, on the face and on the end of the coal, co-ordinating rectangularly.

Jul 1, 1910

By Frank C. Smith

THE following article covers the history of a metallurgical campaign, commenced in March, 1905, at the mines of the Socorro Gold Co., in the so-called desert region of Yuma county, Arizona. The results obtained were simply a function of necessity, as will be seen from the description of the local economic conditions and the character of the ores treated. The mines and mill of the Socorro Gold Co. are located near the small village of Harrisburg, about 60 miles from Congress Junction, Arizona, which, at the time this work was undertaken, was the nearest railroad station, and from which all supplies were brought by wagon through the desert, at a cost varying from $10 to $15 per ton in addition to the railroad freights. Wood, the only available fuel, cost $7 per cord. Water for all purposes was pumped to the plant from a well in the valley about 4 miles away. Under the Arizona law, a working-shift is 8 hr. Wages were $6 per day for foremen and mill-men, $4 per day for blacksmiths and engineers, $3.50 per day for miners, and $3 per day for shovelers and trammers. The ore consisted of quartz, in which, above the 250-ft. level, the iron-minerals were largely oxidized and some free gold was visible; below that level few traces of oxidation occurred, and pyrite constituted the principal mineralizer in the quartz, together with occasional pockets of galena and a few eccentric specks of covellite. The 20-stamp mill was equipped with plates for amalgamation, and three Standard tables for concentration. The tails from the tables were elevated by a centrifugal pump to a launder, by which they were conveyed to a 60-ton cyanide-mill for further treatment. The cyanide-mill was erected at so great a distance from the stamp-mill that a separate crew of workers and a separate power-plant were necessary. No arrangement had been made for the treatment of the concen-

Jan 1, 1907

By William F. Boericke

RESEARCH in the modern refractories laboratory has two practical ends in view-to develop refractory materials for the metallurgist that will meet particular operating difficulties more effectively and to ?manufacture these refractories at a cost sufficiently low to make their use economical to the metallurgist. At the research laboratories of E. J: Lavino and Co., at Plymouth Meeting, Pa., the technical staff, under Dr. Gilbert E. Seil, is giving principal attention. to an. exhaustive investigation of the following factors in refractories:

Jan 1, 1931

By G. Sachs, S. I. Liu

Introduction In a previous investigation on the effects of repeated strains of large magnitude on the aluminum alloy 24 ST, it was found that the reduction in ductility by straining in tension was partially restored by a subsequent compression.&apos; As illustrated by the dashed line in Fig I,$ the ductility (e~) retained after prestraining in tension by a certain amount (el) and measured in a subsequent tension test is represented by a straight line sloping down under 4s°. If a compression of the same magnitude as the first tension is inserted (€2 = — €1) between prestraining and final testing in tension, such a "balanced" tension-compression cycle yields a ductility considerably higher than that present after prestraining in tension only. The results of these tests can be correlated with those of an investigation on the effects of prestraining in compression.~ As also shown in Fig I, the ductility in subsequent tensile tests decreased with com- pression, at a rate considerably slower than that after prestraining in tension. The above discussed testing conditions can be considered as special cases of a general straining cycle, consisting of first, straining in tension by an amount el, subsequently straining in compression by an amount e2, and finally determining the retained &apos;ductility, e,, in a tensile test. Prestraining in tension is then represented by el > o and e2 = o. Prestraining in compression is given by e~ = o and e~ < o. Balanced cyclic straining is defined by the condition el > o and cz = — 61. In order to obtain further information on the effects of straining cycles consisting of tension and subsequent compression, further tests were made, varying both the tension strain, el, and the compression strain, e2, within extreme limits; el varied between 0.06 and 0.28 and e2 between — 0.008 and —0.h approximately. Apparently, such tests have not been previously performed. They revealed phenomena which have not been recognized to date, The results of the investigation are herewith reported, without attempting to correlate them with internal processes within the metal structure. However, in order to assist in an analysis of this type, the results have been represented in various manners. In addition, further test data on the effects of prestraining by compression were provided by using specimens of various contours (notched specimens) in the sub-

Jan 1, 1949