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The new Ceramic Engineering Building of the University of Illinois is to be formally dedicated on Nov. 20 and 21. The occasion will be made one of great interest to the clay-workers of the country. It is expected that the exercises will be attended by many representatives of the architectural, structural, mining, geological, chemical, and manufacturing interests. In connection with the dedication exercises, an industrial conference will be -held, in which a number of topics of current interest to the ceramic engineer, the clay-worker and the manufacturer will be discussed by well-known experts. : The number of students registered in the College of Engineering of the University of Illinois eleven days after the beginning of registration - for the new year, is as follows: Architecture, 116; Architectural Engineering, 167; Ceramic Engineering, 46; Civil Engineering, 190; Electrical Engineering, 266; Mechanical Engineering, 273; Mining Engineering, 25; Municipal and Sanitary Engineering, 26; Railway Engineering, 34; total, 1,143. The enrollment of students in the whole University, not including the College of Medicine, the College of Dentistry and the School of Pharmacy, which are located in Chicago, is 5,21.4.

Jan 10, 1916

By Bruno KERL

THE list of deaths reported during the year 1905 comprises the following names (the figures in parentheses indicating the year in which the persons named were elected to membership:- Honorary Member.-Dr. Bruno Kerl. Members and Associates.-Charles Christy Adams (1903), John Wesley Anderson (1898), William Burton Barber (1901), Thomas A. Bennett (1900), Luke W. Bryan (1901), Edwin S. Daugherty (1905), William Scott de Camp (1875), George H. Eldridge (1889), B. W. Frazier (1871), John Broome Guinn, Jr. (1897), Dana C. Irish (1900), Harry Hugh Lee (1899), William Alfred Lindsay (1902), Roland C. Luther (1884), James MacNaughton (1890), Gordon McLean (1899), Herbert Holmes McNamara (1902), August R. Meyer (1886), William Orr (1897), William J. Parker, Jr. (1898), Joseph Phillips, Jr. (1895), Charles O. Ripley (1902), Emmerich J. Schmitz (1883), Ludwig Philip Seeger (1900), Jacob Johnston Sperry (1900), Gustavus H. Stoiber (1902), William L. Study (1905), Robert Macnair Wilson Swan (1900), Richard Henry Terhune (1886), Joseph Thiry (1892), John N. Tisdale (1903), Alfred Isham Totten (1897), Walter H. Virgoe (1902), Charles H. Wellman (1890), Harvey L. Williams (1903). Of these, Dr. Bruno Kerl and Prof. B. W. Frazier have been made the subjects of special Biographical Notices in the Bi-Monthly Bulletin 1 the former in No. 4, July, 1905, p. 743, and the latter in No. 5, September, 1905, p. 1097. Concerning the remainder of the list, the following paragraphs comprise such information as could be obtained by the Secretary. Charles Christy Adams, who had been a member of the Institute since 1903, died in Johannesburg, South Africa, August 31. 1905. He was born in New York City, July 13, 1849, and received his technical training at the Colorado State School of

May 1, 1906

By H. Rush Spedden, A. M. Gaudin

IN the belief that a critical study of its operating problems might be a sound investment, the Cuban American Manganese Corporation initiated an ore-treatment research in cooperation with the Massachusetts Institute of Technology One of the early objectives of this research naturally became the relationship of the microscopy of the Cuban ores of the Corporation to their flotation treatment The operations in Cuba have already been described by F S Norcross, Jr 7 and the laboratory study of manganese oxide flotation goes back a number of years 4 Broadly speaking, the difficulties encountered in the flotation of manganese ores are that the consumption of reagents is extremely high, the concentrate contains more silica than is desirable and the tailing losses are relatively high An appreciable betterment on any of these scores would achieve a definite betterment in costs, quantity of minable ores, and quality of product The microscope study discussed in this paper was made on samples from the Quinto mine, from the Ponupo mine, and from mill products at various stages of passage of the ore through the mill The writers have had access to Company records and in particular to the petrographic studies made on thin sections of ore by the late Professors R J Colony and Philip Krieger, of Columbia University They acknowledge their debt to both of these men for the help derived from the reports Manganese oxides are black, friable, smudging It is therefore, very difficult to judge operations by inspection The mineralogy of manganese compounds seems to be confused, and the authors believe that many more minerals have been described than actually exist Much of this difficulty is due to the prevalence of the structural conditions that will be discussed further in this paper, namely, the porosity and the friability of the ores, and the extremely intimate association of minute manganifeous mineral crystals with impurities of various sorts By all odds the most important manganese mineral in Cuba is the one that in this paper is called "psilomelane " The name "psilomelane" has been used in so many different ways that the choice of it for this ore may not be approved by all However, it seems to be the best under the circumstances This mineral accounts for about 97 per cent of the manganese in the ores of the Quinto and Ponupo mines and in the mill feed The remaining odd 3 per cent consists mostly of pyrolusite together with minor amounts of other manganese oxide minerals DESCRIPTION OF PSILOMELANE Aggregate Structure In grains or lumps, psilomelane has a characteristic fibrous appearance and seems

Jan 1, 1942

By Roshan B. Bhappu

This is the Centennial year of AIME and many of us reading this issue of ' will be getting ready to attend the Centennial Celebration in New York from February 26 through March 4. The officers of the Division sincerely hope that a large number of our members will attend the fine technical sessions and social functions arranged for this really big meeting. The year 1971 will be a crucial one for MBD. This SME Division is a working group organized "to furnish a medium of cooperation among those interested in the basic unit processes and unit operations of minerals beneficiation; and to promote the advancement of this branch of mineral technology through meetings for professional intercourse, and to stimulate the preparation, reading discussion and circulation of papers connected therewith." No one can deny the worthiness of these objectives or minimize the efforts that Division officers and members have made to attain them. Much has been done over the past several years to achieve a smooth-running and effective MBD organization. However, there is still room for improvement and much more needs to be done in order to provide the best possible services for the membership and the profession.

Jan 1, 1971

Meeting of June 26, 1914.-The President was authorized to appoint Advisory Committees to co operate with the United States Bureau of Mines. The President announced the appointment of Edward H. Benjamin and W. C. Ralston as additional members of the Committee on Arrangements for the San Francisco meeting, 1915. H. T. Van Ells and Judd Stewart were appointed to represent the Institute on a joint committee of several technical societies to consider the standardization of graphical methods for the presentation of statistics. The President announced the appointment of H. Foster Bain to succeed Edward H. Benjamin, resigned, on the Committee of Management of the International Engineering Congress, 1915. The Secretary was authorized to issue a new circular advertising the sale of back Transactions and to sell back Transactions, bound in cloth, at a price of $35 for 46 volumes, provided sufficient orders were received to warrant the special binding. The sum of $177.50 was contributed to the San Francisco Local Section. Upon recommendation of the Committee on Membership, 70 Members, 4 Associate Members and 7 Junior Members were elected to their respective classes; there was also one change of status from Junior Member to Member.

Jan 8, 1914

By Walter S. McKee

When mixed with common cast steel in quantities ranging from 11 to 131/2 per cent. and properly treated, manganese increases the ductility of the metal and adds greatly to its toughness and resistance to abrasive action, which properties comprise the distinctive characteristics that make manganese steel so valuable for many purposes at the present time.. * At present the manganese-steel foundries of this country have an annual capacity of about 60,000 tons and most of the growth has occurred within the past 10 years. In the early days of the industry it was impracticable to make manganese castings weighing over a few thousand pounds, but at present crusher heads, rolling-mill pinions, and similar castings weighing up to 30,000 Ib. each are produced, and it does not appear that the limit of weight has been reached by a considerable margin. Manganese steel is similar in analysis to ordinary first-class converter metal except that it is high in carbon and contains from 11 to 13.5 per cent. of manganese. From one standpoint manganese steel is similar to malleable iron in that the casting as it comes out of the sand is hard and brittle and must be made ductile by a heat-treating process. The heat treatment is an essential part of the process of making manganese-steel castings and must be properly carried out to secure satisfactory results. The necessity for heat treatment limits the thickness of sections which may be made of manganese steel. Originally the annealing depth was comparatively small, but researches carried on during the past few years have resulted in an increase in the thickness of section up to 51/2 in., which it is possible to treat successfully. Large castings are cored out to a minimum thickness of 51/2 in., thus not only eliminating some of the internal stresses which are invariably set up in a very thick casting, but also reducing the weight and inertia of the piece, an important consideration if the casting is to be a moving part in a machine. At the same time, the thickness of 51/2 in. is sufficient to permit the use of manganese steel for the heaviest classes of machinery.

Jan 1, 1916

By John T. Crawford

Introduction Loading and hauling systems are evaluated in open pit mining for new properties, expanding existing operations, changing systems or equipment, and equipment replacement analysis. The objective of such evaluations is to determine the equipment needed to handle planned tonnages at the lowest cash flow cost. Cash flow costs are used to combine capital outlays with operating and maintenance costs. Leasing costs could be substituted for capital costs with appropriate modifications to calculation procedures. These modifications will not be covered. This chapter will describe methods of evaluating loading and hauling systems, concentrating on some of the more often raised questions concerning quantitative data. While the methods described are not the only ones in current use, they have a record of proven reliability. The shovel and haulage truck system is used In the examples because of its common use in open pit mines. In medium to large open pit mines, electric shovels and diesel-electric drive haulage trucks are normally used. The basic ideas presented in this chapter apply to all loading and hauling systems, with appropriate modifications. The process of performing a shovel and haulage truck evaluation can be time-consuming and tedious because of the quantity of data involved, but it is not particularly difficult. The examples used to Illustrate shovel and haulage truck evaluation are based on a hypothetical open pit mine operating 350 days per year producing 31 750- 000 t (35,000,000 st, 100,000 stpd) annually, of which 11 110 000 t ( 12,250,000 st, 35,000 stpd) are ore. Selection of the optimum shovel and haulage truck fleets will be shown. The principal sources of data for the examples or any other equipment evaluation are equipment manufacturers and actual operations. Whenever possible, actual operating experience should be used to verify estimates. The quantitative data presented herein are unrelated to a specific existing mining operation.

Jan 1, 1979

By Ta M. Li, Russell A. Carter

The first century of mining in northern Idaho's Couer d'Alene District will soon he drawing to a close. Like so many other great raining districts, it has been a period accompanied by a rich and colorful history. From its early days as a gold rush camp, the district has evolved into the leading silver producer in the US, but the going has not been easy: early-day labor disputes, the challenge of mining for profit in some of the deepest mines in the Western hemisphere, and the constant search for new reserves at great depths have taken their toll of mines-and miners-along the way. To these traditional mining problems have of late been added the burden of inflationary cost increases, pollution control, and reclamation. A recent visit to the district by MINING ENGINEERING, how ever, revealed that the deep commitment of the operating companies and the quiet competence and vitality of their engineering personnel are key factors in the continued prosperity of the district.

Jan 7, 1976

By Finney, W. R.

MUCH has been said and written of the "Big Inch," of the terrific obstacles encountered in its construction, of the colorful and tough men engaged in its building, but little has been publicized of the engineering and economic problems behind the scenes. Long before Pearl Harbor it was apparent to the petroleum industry that a critical oil shortage could be expected along the Atlantic seaboard, owing to delay in tanker deliveries as a result of convoy movements, and to allocation of vessels for foreign shipments. This area, with a normal consumption of approximately 1,800,000 barrels per day of oil and products, was almost entirely supplied by tanker. Pipe lines supplied an average of only 20,000 barrels per day in 1939, 40,300 barrels per day in 1940, and 55,000 barrels per day in 1941. A small amount of oil and products was also delivered via barge.

Jan 1, 1943

The high-grade orebody at Miami was mined successively by top-slicing, shrinkage, stoping and under caving. The method described in this paper was developed to enable the low-grade orebody (36,000,000 tons assaying 1.06 per cent copper) to be mined at a low cost without further dilution of the grade. The method is clearly described and illustrated by drawings and photographs, and the original paper should be consulted as it is impracticable to abstract it, beyond noting that the mining cost is just under 40 cents per ton and the average grade of ore now being produced yields less copper than the mill tailing of 1915, the tons mined per day having increased from 4000 to 18,000 in the same period. Vertical and Incline Shaft Sinking at North Star Mine By Arthur B. Foote, Grass Valley, Calif. (Tech. Pub. No. 324: Class A. Metal Mining, No. 36) THE main shaft of the North Star mine is an inclined one following the main vein at an average dip of 26 deg., a vertical shaft intersects it at the 4000-ft. (incline) level, the incline continuing to the 6300-ft. level. At this point the vein was found to give out and a new vein, called the No. 1, was found to dip in exactly the opposite direction.

Jan 1, 1930

By I. Zaplatynskyj, G. C. Kuczynski

SINCE the excellent studies of metal powder compaction executed by Kamm, Steinberg, and Wulff, no work on the subject has appeared in the technical literature. Kamm et al. were the first to investigate quantitatively the distribution of density in a powder compact, as a function of pressure, height and diameter of the die, powder particle size, etc. For this purpose they devised a very ingenious method. They inserted a thin lead grid into a die and then filled the die with powder. During cold pressing, the lead grid -moved downward. Due to its deformability it followed closely the downward descent of the adjacent powder. The die was then radiographed and, from the deformations of the grid openings measured on the radiographs, the density in the vicinity of each opening was evaluated. Their findings led them to the conclusion that the friction on the side walls of the die is a major controlling factor of the density distribution inside the cold pressed powder compacts. However, it is difficult to conduct tests similar to those of Kamm, Steinberg, and Wulff in a processing plant laboratory, which usually lacks the necessary expensive radiographic equipment. The purpose of this note is to describe a method which makes it possible to determine the density distribution in green powder compacts with the same accuracy as the lead-grid method but which is far simpler and faster and requires only standard laboratory equipment. Instead of using a lead grid, the hardness at selected points of the sectioned compact is determined. If the relationship between hardness and density is known the density distribution is readily obtained. This relationship is easily found from measuring hardness and densities of thin compacts. In such compacts the density, for all practical purposes, is constant throughout. The method was tested on a Plast nickel powder, grade FlA-A20, kindly supplied by Plast Metals Co. Thin compacts (height to diameter ratio 0.2) were pressed in a single action cylindrica1 die at various pressures. The density of the compacts was determined by weighing and by measuring the height and diameter with a micrometer. Subsequently the Rh hardness was determined. Up to ten readings were taken on each specimen. The difference in hardness readings on each compact was never greater than three corresponding to about 0.1 g per cu cm uncertainty in density. By varying the compaction pressure of the samples, a whole scale of densities was obtained allowing construction of a set of density-hardness calibration curves. To test the method several compacts of different height were pressed under varying pressures. Die walls were always well lubricated. After pressing, the compacts were mounted in bakelite and halved by grinding, and hardness readings taken along the diameters of the specimens. The distance between adjacent indentations was about 2.5 mm. After hardness readings were translated into densities, contour maps of densities of the compacts were prepared. One of them is reproduced in Fig. 1. The areas encompassed by the curves are labeled with numbers representing the density in g per cu cm of those regions. In Fig. 2 the same results are re-plotted to emphasize the radial density changes at various depths. The results thus obtained confirm the findings of Kamm, Steinberg, and Wulff kentioned previously. They are recapitulated here briefly. 1—The densest part of a compact pressed from one side is at the outer circumference at the top and the least dense part at the bottom, at the outer circumference. Figs. 1 and 2 show this clearly. 2—The density near the cylindrical surfaces of the compact decreases uniformly with height from top to bottom. 3—The density variation increases with the height to diameter ratio. References R. Kamm, M. A. Steinberg, and J. Wulff: Trans. AIME (1941) 171,'R. p. 439 ;MetaLs Technology (February 1941). R.p. Kamm, M. A. Steinberg, and J. Wulff: Trans. AlME (1949) 180, 2R.P. 694; MetalS Technology (December 1948).

Jan 1, 1957

By Stanford O. Grodd

The Sanford Lake district encompasses an area covering 24 square miles in the central Adirondack Mountains of northern New York State. Discovery of the titaniferous magnetite deposits dates back to 1826. Several attempts to exploit the ores for iron prior to 1942 proved uneconomical because of difficulties with the associated titanium, lack of transportation facilities, and the isolated location. Since 1942, the National Lead Company has produced ilmenite concentrates for the titanium pigment industry, and a magnetite by-product used in the steel and refractory industries. Rocks of the area are Precambrian in age and of igneous origin. The area has a history of erosion, deformation, and metamorphism, subsidence, and finally uplift and glaciation. The resulting topography is extremely rough with drainage patterns controlled by a combination of fault patterns and glacial modifications. The district is within the large anorthosite massif making up the central high peak area of the Adirondacks. All of the various lowsilica rock types associated with the massif are found within the boundaries of the district. These consist of both the Marcy and Whiteface types of anorthosite and of gabbroic anorthosite, gabbro, and different grades of titaniferous magnetite ores. All of the rocks contain the same minerals and differ only in their percentages of these consitituents. Gabbro, and ore associated with it, demonstrate flow structure as both have foliation and lineation. Anorthosite and its associated ores are massive and show very little primary structure. Minor pegmatites and diabase dikes provide evidence of remobilization in selected areas and of late intrusion as well. Faulting is prevalent and follows a regional pattern of major faults trending northeastsouthwest and of minor faults at nearly right angles to them. There are four mineralized areas where an economic grade of ore has been found. Three of these have both gabbroic-type ore and anorthositic-type ore. The fourth has only gabbroic ore. Ores are graded according to their TiO, content, and these range from 9.5 per cent to over 30.0 per cent TiO,. Ore bodies of both types are related to gabbro and conform to the configuration of the gabbro bodies within the anorthosite. At least three distinct theories of ore genesis have been expounded by different investigators. Others propose some variations of one or more of these. Although complete agreement probably never will be reached, it is certain that no one process of ore emplacement can explain the complicated picture as seen today. Further understanding of the ores and their origin will require detailed mapping, sampling, and mineralogical studies of the entire district, and then it may never be understood without qualification.

Jan 1, 1968

By Thomas L. Garrard, James A. Sprague, Rex B. McLellan, Samuel J. Horowitz

A simple rnodel for interstitial solid solutions has been devised in which each solute atom interacts with the solzlent lattice in such a way as to exclude an integral number of nearest-neighbor sites from being occupied by solute atoms. The vemaining interstitial sites ave not affected. In calculating the entropy of such a solution the increase in the number of interstitial sites available to solute atoms due to the ozlerlap of blocked sites is taken into account. The ther-modynamic functions and the solute activity fov the solution rnodel are calculated. It is shown that considevation of the overlap sues vise to a correction term of the order 8' ( where 0 is the ratio of solute to solvent atoms) in the thevmodynamic functions of the solution and the solute activity. The theo,uetical equation for the solute activity was used to analyze the available data for the activity of carbon in austenite at three different temperatures. The use of a computer enabled many comparisons to be made between the experimental activity data and those predicted by both the complex blocking model and the simple, widely used blocking model in which the ozierlapping of blocked sites is not taken into consideration. Even though at the highest concentvations oj carbon the value of 0 is small it is shown that the best fit to the experimental data is found with the complex blocking model. RECENTLY it has been shown by analysis of gas-solid equilibriums that many interstitial solid solutions can be described by the quasi-regular solution model in which the partial energy of solution E, is independent of composition and, apart from a composition-independent term due to nonconfigurational factors, the partial entropy is that of an ideal solution. Dilute solutions of nitrogen in both bcc and fcc iron,' dilute solutions of oxygen and silver,' carbon in a Fe,' and dilute solutions of carbon in ? Fe2 are all quasi-regular. In addition many hydrogen-metal solutions, both dilute and concentrated (with the notable exceptions of the H-Ni and H-Pd systems), can be described by this model.3 However, it has been shown that, at various temperatures, solutions of carbon in ? Fe begin to depart strongly from quasi-regular behavior at low concentrations. A plot of the activity of carbon in ? Fe relative to pure graphite vs atom fraction of carbon (Cc) calculated from Smith's data4 begins to depart from the (nonlinear) plot for a quasi-regular solution at about Cc = 0.02. Several statistical models have been proposed to account for the thermodynamic behavior of carbon in y Fe. Darken and smith4 set up a model in which a carbon atom in its octahedral site in the fcc lattice has either one or no neighboring carbon atoms in the twelve nearest-neighbor octahedral sites. It is assumed that the number of carbon atoms having more than one nearest neighbor is negligibly small and that a solute atom does not interact with another solute atom located at a greater distance than the first shell of interstitial sites. Thus this model contains two characteristic interaction energies. Darken and Smith showed that this model gives reasonable agreement with the measured variation of carbon activity ac with composition. It is noteworthy that Darken and Smith concluded from their analysis of the activity data using this model that there was a repulsive force between carbon atoms in austenite which reduces the concentration of C-C pairs below that corresponding to random mixing. Recently Aaronson, Domian, and pound5 have considered in detail the statistical model developed by Lachere and by Fowler and Guggenheim7 and have shown that it is compatible with the activity data for carbon in austenite. In Darken's model the energy of solution of carbon in austenite is dependent on temperature and concentration; the departure from Henry's law arises from the concentration dependence of the energy of solution. In Aaronson, Domian, and Pound's discussion of the Lacher, Fowler, Guggenheim model the interaction energy wy between adjacent carbon atoms in austenite is strongly temperature-dependent. Aaronson et al . suggested that this temperature dependence of wy and hence the energy of solution of carbon could be explained either by the formation of clusters of carbon atoms (despite the repulsive nature of wy) or by the dual occupancy of the octahedral and tetrahedral sites by the carbon atoms. However, a temperature-dependent heat of solution

Jan 1, 1968

By David B. Reger

Extensive drilling for gas and increased pipe-line building were the major petroleum activities in West Virginia during 1937. According to the West Virginia Department of Mines, 1034 permits to drill were issued. A running account of operations from trade journals and other reports shows that 1041 wells were drilled, resulting in 193 oil wells with 1238 bbl. of daily production; 680 gas wells with 1,048,057,000 cu. ft. of daily open flow; and 168 dry holes. The new oil-well average is 6.4 bbl. per well per day; the gas-well average is 1,541,260 cu. ft. per well per day; the ratio of dry holes to completions is 16.13 per cent. Very little attempt was made to develop new supplies of oil. Because of the continued low price, operators evidently considered it good business to leave oil in the ground rather than to produce it at a loss or on a small profit basis. The principal oil wells completed, by counties, are: Calhoun, 16; Clay, 10; Pleasants, 17; Ritchie, 42; Roane, 16; Tyler, 13; Wetzel, 11; Wirt, 14; Wood, 13. The leading counties in gas, with the number of successful wells in each, are: Boone, 54; Braxton, 31; Cabell, 48; Calhoun, 46; Gilmer, 82; Kanawha, 134; Lincoln, 44; Ritchie, 56; and Wayne, 26. General State of the Industry In Table 1 will be found an approximate summary of oil and gas territory and reserves, oil and gas production and number of oil and gas wells. The amount of land under lease is an approximation, because the exact figures are not available through any public or private agency. The proved land and reserves represent the opinion of the writer. The oil production for 1937 is subject to revision, and the gas production for the same year is only an estimate, based on demand and supply. The number of oil and gas wells now active is also an approximation, based on previous studies, and revised for completions and abandonments. Principal, Areas of Activity In Boone County, 62 wells were drilled in various localities, resulting in 4 oil wells and 54 gas wells with 18,170,000 cu. ft. of new production.

Jan 1, 1938

By AIME AIME

A discussion of the Papers by Prof. H. Hubert, Liege, Belgium ; Mr. Tom Westgarth, Middlesbrough, England ; and Mr. K. Reinhardt, Dortmund, Germany, presented at the London Meeting, July, 1906, and printed in Bi-Monthly Bulletin, No. 12, November, 1906; pp. 910 to 930, 971 to 987, 1037 to 1163. MR. ADOLPH GREINER, Seraing, Belgium :-I have nothing special to add to Professor Hubert's paper except to say that there are some little things that it would be well to have cor-rected when the paper comes to be published. In dealing with the thermal efficiency of the engine, you will find that the 29.84 per cent was a very high one. Professor Hubert has forgotten those engines built under the Cockerill type, but he has referred to them in Appendix II. At our works at Cockerill we have built 63 engines, giving 63,000 h.p., and the other companies who have received licenses have built 113 engines, making 103,000 h.p., and aggregating 176 engines and 166,000 h.p. Eight years ago I had the pleasure of giving to the Institute the results obtained up to that time. Since then a good many engines have been constructed. In 1898 I thought a blast-furnace producing 100 tons of pig iron would allow 3,000 h.p. Professor Witz and Professor Hubert show that with the same production of pig the new engines take 3,800 h.p. out of the gas. At present at Cockerill we make 700 to 800 tons of pig iron per day, and we hope to have 26,000 h.p; in a few years. At present we have only half of that in gas-engines, but we hope to have in five or six years all the gas out of these furnaces to the number of 25,000 or 26,000 h.p. MR. Tom WESTGARTH, Middlesbrough, England:-My contribution is not a paper in the ordinary sense of the word, because I am sure you will agree with me that what I have written is only supplementary to the other two papers. The notes are schedules of the larger-size gas-engines built by the engine-makers, of 500 h.p. and upwards. If you look at the schedules you will find that in England gas-engines have be-

Jan 1, 1907

By B. B. Gottsberger

IT SEEMS strange that so many years after the pas¬sage of the first acts requiring registration or licensing of engineers, so few members of the mining branch of the profession are aware of what has taken place. Laws regulating the practice of engineering have now been passed in 19 states of this country, and in many others, such legislation has been proposed. That such laws are necessary for the protection of life, health and property, as is stated in most of them, is doubted by many. That the standing of the engineering profession will be improved by them is certainlyy open to question. That such laws are a welcome addition to the regulation of business by governmental agency, is not likely to be a general opinion. That once more, and in spite of appeals to engineers to interest themselves in affairs of government, an active minority has succeeded in imposing its will on a passive majority, seems but too true. However, the laws are there and information regarding them should be of use and interest to those most directly concerned.

Jan 1, 1921

By George M. Fowler, J. P. LYDEN

T HE relationship of geological structure to orebodies and to the great masses of chert in the Tri-State mining district is of such significance that it prompts a brief recital of the existing information regarding the various periods of structural deformation. We began to note a relationship between structure and orebodies early in our studies of the field, and further work revealed a like relationship of structure to the great masses of chert so commonly associated with the ore-

Jan 1, 1934

By James R. Holden, Frederick E. Wang

Through both single-crystal and powder X-ray diffraction methods, ten A6B23-type compounds have been confirmed to exist between lanthanides (A) (plus scandium and yttrium) and manganese (B); A = Y, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, and Lu. The formation of a compound of this type is shown to he extremely atomic size-sensitive; hence it can be classified as a "size-factorH compound. The "enveloping effect", a geometrical consideration observed in its crystal structure, is proposed as the reason for the A6B23-type compound being size-sensitive. The approximate ideal geometrical ratio of the radii R/r is 1.31 while experimentally A6B23-type compounds have a radius ratio lying within the range 1.2 to 1.4. FLORIO t al.' characterized the structure of Th6MnZ3 as fcc, space group Fm3m, with 116 atoms in the unit cell. Since then, a number of isotypic binary compounds, and recently Gd n,,' have been confirmed to exist. The fact that strontium and barium form A6Bz3-type compounds with magnesium strongly suggested the possible existence of Ba6Liz3. However, investigation3 showed the compound Ba6LiZ3 to be absent. Since both strontium and barium are group 11-a elements and are therefore "open metals",6 the nonexistence of Ba6LiZ3 can hardly be explained satisfactorily by valence-electron considerations. On the other hand, the consistent atomic-radius ratio, (R/r),* observed for the known A6Bz3-type compounds,3 strongly suggests that the formation of compounds of this type is atomic size-sensitive. Therefore, one is tempted to explain the nonexistence of Ba6LiZ3 entirely on the basis of the atomic-size difference between strontium and barium. However, this approach is not entirely without objection. Atoms are not rigid spheres and are known to vary in size within certain limits.7 Since the atomic-radius difference between strontium and barium (0.07 to 0.09A) is within these limits, it is reasonable to assume that the size difference would have a negligible effect on the formation of Ba6LiZ3. This view is further supported by the fact that the radius ratio, R/r, in other known "size-factor" compounds is observed to range widely—for example, from 1.08 to 1.45 for ABz-type compounds (C15, MgCuz type)' and from 1.37 to 1.58 for AB5-type compounds (D2d, CaZn5 type).g The present investigation was undertaken in order to find a more satisfactory explanation for the non-existence of Ba6LiZ3 and, consequently, a better understanding of the nature of the A6Bz3-type compound. The primary objectives are to confirm the previous conclusion3 that the A6B23-type compound is indeed a "size-factor" compound and subsequently to determine the atomic-radius ratio range in which the A6Bz3-type compound can exist. In order to achieve these objectives, stoichiometric A6Bz3 alloys, where manganese (B) was alloyed with various lanthanide elements (A), were selected for investigation. The atomic-radius ratios of lanthanide elements with manganese range from 1.26 for Lu/~n to 1.46 for Eu/Mn. This radius ratio range includes and exceeds the range of all previously reported A6Bz3-type compounds—1.32 for Th/Mn' through 1.38 for Sr/Li. Furthermore, the atomic-size difference between successive elements of the lanthanide series in order of atomic number) is of the order of 0.01A (europium and ytterbium are exceptions). The series of lanthanon-manganese alloy systems is ideally suited to a precise determination of the limits of allowable atomic-radius ratio for A6Bz3-type compound formation. EXPERIMENTAL PROCEDURE The lanthanide metals, in ingot form, supplied by Michigan Chemical Corp. (St. Louis, Mich.) and Nuclear Corp. of America (Burbank, Calif.), were guaranteed by the suppliers to be at least 99.9 wt pct pure (traces of silicon, calcium, and other minor constituents present on occasion, not to be more than 0.05 wt pct) as shown by spectrographic analysis. Manganese metal, in polycrystalline form, was redistilled from the commercial, chemically pure grade and was analyzed to be at least 99.95 wt pct pure. In all cases, the atom ratio between the two elements in each charge was A (rare-earth meta1):B (manganese) = 6:23 and a constant weight, 3 g, of

Jan 1, 1965

By Vernon A. Mrak

The Powder River Basin of northeast Wyoming was the first area in the state to receive attention during the early days of uranium exploration. Although the uranium occurrences are many and widespread, most of the known ore deposits are quite small and difficult to mine. As a result of this, detailed regional exploration in the Powder River Basin has been neglected. The uranium ore deposits occur in that part of the Wasatch Formation that is of earliest Eocene age, and they are scattered over an area of about 400 square miles. All uranium ore deposits are associated with red beds or altered sandstones within the Wasatch Formation. Uranium ore was first shipped from the region in 1953. Total production through June of 1965 is 506,257 tons of uranium ore containing 1,922,527 pounds of U3O8. The average grade of ore is about 0.19 per cent U3O8. The major producing area of the Powder River Basin is the Monument Hill district where about 91 per cent of the basin's total uranium ore has been mined. The source of uranium is presumed to have been the Oligocene, Miocene, and perhaps Pliocene tuffaceous rocks that once overlay the area. Joints, fractures, and permeable beds or zones were the passageways for the migration of uraniferous waters from the overlying beds to the Eocene host rocks.

Jan 1, 1968

By J. C. Bierlein, R. A. Dodd

Endurance strengths at 10' cycles, fatigue-hardening rates, and endurance strength/0.2 pct proof stress ratios have been determined jbr a range of Cu(Ni), Cu(Si), and S.R.0. Cu(Au) solid solutions. Some douht is cast on simple cross slip models of fatigue hardening in view of opposite composition dependencies of hardening displayed by Cu(Si) and Cu(Au). The temperature dependencies of hardening also are the opposite of predictions made on the basis of a cross slip model. A correlation apparently exists between the fatigue strength/0.2 Pc~ proof s1.re.s~ ratios and rates of fatigue hardening. An increase in PS/PS due to alloying or temperature change is accompanied by a decrease in hardening rate, and vice versa. In recent years there has been much interest in the determination of the dislocation structure of fatigued metals and alloys. The accumulated evidence, e.g., Refs. 1 to 5, suggests that the structure may be dependent on the stacking fault energy, 7, of the fatigued metal in the same way that fatigue hardening rates have also been shown to apparently depend on u .6' 7 The above research followed the various earlier theories relating crack nucleation to ease of cross slip, e.g., Refs. 8 to 131 so "ggesting that y may indeed be the parameter of principal significance in all facets of the fatigue process. However, comparatively little attention has been paid to correlating engineering fatigue data with observations of the above type. Certainly, it would be useful if potential engineering fatigue performance could be assessed from a knowledge of easily determined alloy properties, and the present research originated from this standpoint. TO investigate the widest Possible range of 7 would require the use of two solvent bases, e.g., aluminum and copper, but a reasonable coverage can be provided by copper-based solutions alone. Therefore, it was decided to work with Cu(Ni) and Cu(Si) solid solutions, the approximate stackillg fault energies of which are given in Table I. The y range extends from low, Cu(7.5 at- Pet Si), to moderately high in Cu(2-5 at. ~ct ~i) and two of the Cu(Ni) alloys. The values listed in Table I should be regarded as qualitative only, being derived as follows. Dillamore and smallman14 quote a value of 85 i 30 erg.cm-2 for the stacking fault energy of pure copper, based on an earlier value due to Howie and swannl5 corrected by Brown's formula.'' Since the ratios (alloy)h(pure copper) have been reported17,18 for Cu(Ni) alloys containing up to 30 pct Ni, approximate ) values for these alloys can be computed, and a rough estimate of 7 for Cu(50 at. pct Ni) obtained by extrapolation. The relatively low y value obtained in this way for Cu(50 at. pct Ni) coincides with the observation of Nakajima19 that the stacking fault probability is a maximum at this composition. Likewise, the y values for the three ~u(~i) alloys are estimates based on values given by Swann and Nuttingo corrected on the basis Of Brown's estimate that the true 7 values are probably 2.3 times greater than those originally computed. In addition to the above alloys it was decided to investigate short-range ordered (s.R.O.) CU(AU) alloys containing up to 25 at. pct Au. This last alloy has been shown to have a well-defined planar arrangement of dislocations when deformed,21,22 probably due to cross slip being restricted by the S.R.O. Engineering fatigue data was to be represented by the determination of endurance strengths, and these were to be correlated with fatigue hardening and mechanical property data. EXPERIMENTAL I, order to study the desired properties and property changes, the following alloys were prepared: Cu(2.5 at. pct Si), Cu(5.0 at. pct Si), Cu(7.5 at. pct Si), Cu(5.0 at. pct Ni), Cu(25.0 at. pct Nil, Cu(50.0 at. pct Ni), Cu(5.0 at. pct AU), Cu(15.0 at. pct AU), Cu(25.0 at. pct AU). The copper and gold were zone-refined, while the silicon was semiconductor grade. The nickel was of 99.95 p,t. purity.* All alloys were induction-melted in a *Kindly supplied by the International Nickel co. helium atmosphere, appropriate precautions being taken to avoid segregation in the Cu-Au series. Rod stock was obtained by rolling and swag,ng. A few Bridgman single crystals were grown for fatigue-hardening studies, but most material was machined into polycrystalline fatigue speciments of the design shown in Fig. 1, and into polycrystalline tensile and fatigue-hardening specimens of simple cylindrical design. All specimens except Cu(Au) were annealed; the latter were quenched from above T, to produce short-range order. A few of the quenched alloys were examined for long-range order by step-scanning over

Jan 1, 1969