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By Yin Zhang, Xiaoyu Huang, Mi Wang, Bencheng Du, Youduo He

"Burners are important facilities for blast furnace stoves to raise hot-blast temperature up to 1200°C. Common types of two-ring ceramic burners have very long flames so that part of combustion occurs in the upper part of the chequers and will cause damage to the refractory materials. Using computer simulation to analyze the turbulent diffusion flame in the combustion chamber, some good results were obtained. A new type of ceramic burner will be installed by Anshan Steel Complex in stoves of blast furnace number 4. A pilot experiment was done on the new burner. The experimental data have shown that the mixing condition was improved and the length of flame was shorter with the new type of ceramic burner.IntroductionPulverized-coal injection can give significant operating saving, reducing coke rate in blast furnace(BF) operation. However, during high rates of coal injection, extra heat must be compensated in hearth to maintain certain raceway adiabatic flame temperature. One of the effective methods for heat compensation is to raise hot-blast (HB) temperature up to 1200°C. Nowadays, since the fuel being combusted in stoves is BF gas only, in which the calorific value is down to round 3000 kJ/m3 , to increase the combustion ability and to provide a suitable length of flame in combustion chambers of stoves becomes more important. In other words, designing a good ceramic burner which will affect to HB temperature and stove lifetime is drawing more attention."

Jan 1, 1999

By T. E. Sedysheva

The study of Co-rich manganese crusts has reached the level which allows to start prospecting works in the observable future, and furthermore, probably, exploitation of ore deposits. In this connection, among other goals, the necessity to analyze a distribution of ore bed parameters in details is quite urgent. Foremost, these are crust thicknesses in connection with landforms and elements of submarine mountains relief. This report is based on representative sampling made in course of research cruises run by SSC Yuzhmorgeologiya over guyots of the Magellan Seamounts. Crustal covers could overlie seafloor surfaces which are confined to a various landforms and elements of relief under the condition, that they are free of sediments. These are planed parts of a summit surfaces, edges, spurs, rectilinear parts of slopes, intermountain saddles and volcanic edifices. It is known, that crustal thicknesses are different at a various forms of relief [1]. We processed statistically the data around crustal thicknesses, which were sampled by dredging and submersible drilling (Tables 1, 2).

Jan 1, 2010

By A. E. J. Engel

The New York talc deposits of commercial importance are in St. Lawrence and Lewis counties, in the northwest Adirondack Mountains (Fig 1). All of the deposits are of pre-Cambrian age and occur within highly deformed and recrystallized marble of the Gren-ville series. The deposits in St. Lawrence County, near Gouverneur, are the largest and most productive of their type known in the Western Hemisphere. In 1948 the seven mines which are in operation will produce about 130,000 tons of ground talc. All talc production in Lewis County is from one mine. There the annual production ranges from 15,000 to 30,000 tons. These so called talcs of New Yorb State include earth materials of different chemical and mineral compositions. In general the mineral talc is subordinate in amount to other minerals in both the Gouverneur and Natural Bridge deposits. In the Gouverneur district the mineral talc comprises less than 25 pct of the mined and ground rock. Most of the rock mined is a tremolite- or tremolite-anthophyllite schist somewhat altered to serpentine and talc. This characteristic in no way tlevaluates the "talc" for certain markets, and in some instances makes the material more desirable. The Natural Bridge talcs include types high in serpentine, as well as complex aggregates of serpentine, talc, carbonates, and diopside. Usage of the term talc, however, for

Jan 1, 1950

By Chris Uys, Johan Labuschagne

Sishen Iron Ore Mine, located in the Northern Cape, is an open cast mine excavating approximately 100 million tons rock to produce 25 million tons of high grade haematite ore per annum. The size of the pit is approximately 12 km ‘1.5 km ‘150 metres. The final depth is planned to be around 350 metres. It is hard rock mining operation employing the conventional truck and shovel method. Mining benches are twelve and a half metres in height and are divided into blasting blocks, each consisting of approximately 300 000 tons of material.

Jan 1, 1997

By F. Louis Grammer

THE difference between blast-furnace gas and ordinary producer-gas is chiefly that blast-furnace gas is richer in CO, and poorer in hydrocarbons and hydrogen, as is shown in Table I. TABLE I.-Volume-Composition of Producer-Gas and Blast-Furnace Gas.. Producer-Gas. Blast-Furnace Gas. Per Cent. Per Cent. (Volume.) (Volume.) CO . 22 to 33 25.5 00., . 6 to 3 13.0 H . . 13 to 7 1.5 CH, 3 to 1.5 0.0 N . 54 to 60 60.0 If natural gas, water-gas, or by-product coke-oven gas be available, blast-furnace gas can be made to resemble very closely in calorific value the average producer-gas by merely mixing in one of these products, which are richer in hydro-carbons and, hydrogen. Blast-furnace gas, however, possesses a virtue which is sometimes absent in producer-gas, especially with coals very high in sulphur-namely, that blast-furnace gas is relatively free from sulphur. In some regions the sulphur in coal is an acute problem, and it is highly desirable to find uses for the products which are specially high in sulphur-content. An advantage would be gained if coal was coked before charging into the gas-producers, but this adds to the expense. Sulphur may be partly eliminated from coal by washing it, the success depending upon the form in which the sulphur occurs, and upon the efficiency of the washer, but it cannot always be removed to the extent desired at most American plants. It is not practicable to remove all the sulphur from producer-gas by washing it, though Mr. Reinhardt, of Germany,

Sep 1, 1908

By Kenneth Seaver

It is rather gratifying that in the field of the manufacture of refractories, in which, as a whole, foreign practice has surpassed us, the United States stands pre-eminent in the making of silica brick. In some instances European manufacturers have refused point-blank to credit the possibility of making to such specifications as are Common with us, until the actual completed shapes were shipped for inspection. But both the manufacturer and consumer in foreign lands are now frankly learning from us, and benefiting by our advanced practice in this field, as is evidenced by the orders placed here and the efforts put forth abroad to come up to the standard of American-made material. In no metallurgical operation has the employment of silica brick spread with such leaps and bounds as in the building of plants for the carbonization of coal, particularly in the byproduct coke oven. Today, in practically all types of oven, the structure above the floor level (except the facings) is of silica, while in the recuperative and in some regenerative types, its use is extended to that portion of the oven below the floor as well. By reason of the fact that there are a number of classes of refractories of higher silica content than the usual so-called fire-clay brick, there is sometimes a misunderstanding as to the class of material referred to as "silica" brick. We here refer only to a brick having a silica content of 94 per cent. or more and made usually from quartzite rock with a small percentage of lime as a binder. The term "silica" brick is sometimes rather loosely applied to brick from highly siliceous clays, or to a quartzite refractory of mingled fire-clay and quartz rock; but such products are not considered in this discussion. : Materials The rock from which practically all high-grade silica brick are made is a true quartzite or metamorphosed sandstone, variously known as

Jan 1, 1916

By H. H. Stoek

Mine models have three distinct uses: 1. As exhibits in expositions and museums. 2. As exhibits in law suits. 3. As illustrations in teaching mining engineering. All three uses are in a sense educational. The third, or distinctively teaching function, has not been extensively developed in America as it has been abroad, chiefly because of the cost of the models and the scarcity of model makers. In connection with expositions, such as the Columbian, the Louisiana Purchase, and the Panama-Pacific, a number of very good mine and metallurgical models were prepared with funds furnished by State commissions, by mining organizations or mining companies. At the close of these expositions, some of these models have been deposited in National or State museums or in educational institutions, but too many of them haw been lost, or have been stored away in some mining company's office or in the basement of some State building, where they have been lost sight of and have gradually fallen to pieces. A visitor to a German mining school is impressed by two facts: 1. The mining laboratories are in general inferior to those in America. 2. The mining museums are infinitely superior to ours, particularly in models exhibited. One may reply to this comparison by saying that a museum is necessarily a work of time. From the historical standpoint this is, of course, true, but it is not necessarily true in connection with a working museum intended to illustrate current practice. For instance, the oldest mining school in Germany, that at Freiberg, has much excellent historical material, but very little on modern practice, while Berlin, one of the youngest German mining schools, has a most extensive and valuable collection of modern appliances and models. This is true in spite of the fact that one of the best-known model shops is at Freiberg, from which many of the models to be seen in America have come. Because many of the models in American mining schools have come from

Jan 1, 1918

IN accordance with a programme arranged by a committee of the Institute, consisting of Mr. William P. Shinn, of St. Louis, chairman, and Mr. Joseph D. Weeks, of Pittsburgh, secretary, the member's of the Institute, with their ladies and invited guests, assembled in Chicago on Sunday morning, August 22d. A special train, provided by the Chicago and Northwestern Railway,. left Chicago on Monday morning at 7.50 o'clock, and conveyed the party to Marquette, arriving at 9 o'clock P.M. Here the steamer Northern Queen, which had been chartered by the committee for the accommodation of the Institute, was in waiting, and the members and ladies at once took up their quarters on the boat. EXCURSIONS IN THE MARQUETTE IRON REGION. Local Committee. EXECUTIVE. -J. C. Morse, chairman; C. Y. Osburn, secretary ; D. F. Wadsworth, treasurer; C. H. Hall, H. Merry. RECEPTION.-S. P. Ely, J. P. Pendill, E. Breitung, W. F. Swift, A. P. Swineford, J. C. Fowle, C. G. Griffey. TRANSPORTATION.-Samuel Schoch, D. Morgan, D. H.. Merritt, J. Pickands. FINANCE.-Peter White, A. W. Maitland, W D. Rees, E. R. Hall. EXCURSIONS.-W. E. Dickinson, H. A. Burt, A.. Kidder, C. E. Wright. REFRESHMENTS.-J. Q. Adams, H. H. Stafford, Joseph Kirkpatrick, D. H. Bacon. On Tuesday the iron mines in the vicinity of Negaunee and Ishpeming were visited, transportation being provided by special trains on the Marquette, Houghton and Ontonagon Railroad. In the morning the McComber, South Jackson, and Jackson mines were inspected, and in the afternoon the Cleveland, New York, Lake Superior, and Barnum mines. Dinner was provided at Negaunee, and gracefully served by, the ladies of the town. In the evening the first session of the Institute was held in the saloon of the steamer. The President, William P. Shinn, of St. Louis, congratulated the Institute on the happy consummation of the wishes of its members to have a meeting on Lake Superior. After tedious and baffling negotiations arrangements had been com-

Jan 1, 1881

By F. Sheykh-Jaberi, S. L. Cockcroft, A. B. Phillion

A coupled fluid/structure model has been developed to simulate semi-solid deformation in an industrial aluminum casting alloy, A356. Although this alloy has a significant eutectic fraction, nearly 50%, it still shows susceptibility to hot tearing. The model geometry consists of solid grains, created from a Voronoi tessellation of the domain, surrounded by liquid. The simulation is performed using the commercial codes, Abaqus Standard and Abaqus CFD. The solid model calculates the velocity, stresses and distortions in response to an applied uniaxial strain, and transmits them to the fluid-flow model, which computes the velocity and pressure fields in the liquid. It was shown that grain size and configuration, fraction solid and fluid properties all affect the semi-solid deformation behaviour.

Jan 1, 2014

By A. Becker, C. Gauvreau, L. S. Collett

"A scale model was designed to simulate the airborne Barringer INPUT time domain electromagnetic system. The amplitude of the response to a vertical conductive dyke varies considerably with the conductor's thickness conductivity product (TCP). The response increases from a minimum detectable level at a TCP of about 2 mhos, rises to its maximum value at a dyke TCP of 15 mhos and then falls again so that conductors with a TCP exceeding 500 mhos would probably remain undetected. Measurements made with both standard receiver coil configurations (maximum or minimum coupled) indicate comparable effectiveness for both systems, either from the viewpoint of vertical conductor detection or from the viewpoint of discrimination against overburden anomalies."

Jan 1, 1972

By C. A. Allen

When the writers were asked to prepare a paper on this subject for this meeting of the Institute there was some question in our minds as to what to say that would be of interest to the members. You all know that Utah has some wonderful seams of good coal, on which have been opened some of the most modern mines in the United States, and that her coal operators have been putting forth many efforts to reduce losses due to accidents as well as disease. While I believe that the physical condition of Utah's mines is as good as in any other state we are not unaware of the fact that a great deal can still be done and we are always willing to frankly discuss the accident situation in the state. Dr. Murray has assembled some interesting figures showing the monetary loss due to accidents and disease which I will will proceed to give you to show the necessity of continued efforts in welfare work regardless of humane considerations.

Jan 1, 1922

By G C. Sen

All mining and quarrying operations that employ blasting to fragment and move broken ground have a price to pay for æby-productsÆ such as vibration and noise. These æby-productsÆ cannot be eliminated but they can be controlled and modern blasting techniques have improved to the point that excessive environmental restrictions can be adhered to whilst maintaining acceptable production rates and quality. Accurate measurement is the key to control, and as the environmental limits are becoming tighter, the proper way to measure vibrations from blasting operations becomes an integral part of the mining or quarrying operations. The basic vibration monitoring system consists of a primary sensor connected to a data logger and computer software for the analysis of the signal received and recorded. Currently, as with all fields of measurement, much improvement has occurred over the past decade, and electronic devices are much more accurate and reliable. Data analysis has also improved considerably with the computing power that is available to field operatives today. Mounting the primary sensor has been often overlooked in supposed æstandardsÆ with procedures such as double sided tape, resting on a flat surface provided the vibration level is less than a given amount. But if it is worth going to the expense of the monitoring equipment and manpower, surely it is worth a little extra effort to ensure the primary sensor is coupled to the ground effectively. The primary sensor must move with the ground and measure this movement; so if the primary sensor is allowed to move without respect to the ground (ie poor coupling to the ground) then a false record of the physical event will be measured. This scenario can easily be a practical reality if the primary sensor coupling method to the ground is not effective. In this study a number of mounting methods were fabricated and connected to similar data monitors and a series of ænormalÆ production blasts were used as the vibration source. These mounting devices were measured against an in-house procedure (the æstandardÆ) and the relative merits compared. A laboratory investigation was also carried out to look at the physical parameters of the æsoil and their effect on vibration attenuation of the in-house standard method.

Jan 1, 1999

By B. S. Crocker

Pebble grinding was used at Lake Shore Mines in 1949. A full description of experimental evidence and test plant results was published in 1952 1 and further operating details in 1954 2.' In more recent years the term autogenous grinding has been coined and is now frequently seen in the technical literature. Autogenous crushing and/or grinding covers any grinding mill in which the larger pieces of ore are made to grind the fine pieces; the crushing and grinding may be either dry or wet. This discussion deals only with wet autogenous grinding, and only in the fine grinding part of the circuit, i.e., from 6 mesh to 92 pct —325 mesh. The term pebble milling could apply to fine autogenous grinding in which the pebbles are made from the ore itself, or it could also refer to grinding with pebbles, such as flint pebbles, from a source outside the mine. The first mill to use screened ore to grind the ore (1949) was Lake Shore Mines, Kirkland Lake, Ont. Pebbles were screened from the jaw crusher discharge and used in 5x16-ft tube mills which had been converted to 6 ft 8 in. by 16-ft grate discharge pebble mills. The same general practice was adopted the following year by the Wright-Har-greaves Mine in Kirkland Lake. Shortly after that the Neptune Mines in Nicaragua started correspondence with the writer concerning the possibility of using screened ore for grinding in their plant. They first ran some plant-scale tests which confirmed the Lake Shore findings, with the ultimate result that their plant was successfully converted in 1956 to an autogenous grinding plant. In 1957-1958 the writer was successful in converting the grinding plant of Renabie Mines in northern Ontario to autogenous grinding. In all these plants the existing grinding equipment was converted, usually by expanding the diameter of the shell to make the change from steel grinding to ore pebble grinding mills. In all the above plants primary grinding was done in either small rod mills or ball mills. These mills first reduced the pebble mill feed to about 6 mesh. The final grinding in the pebble mills varied from 75 pct —200 mesh to 92 pct —325 mesh. At Lake Shore three stages of pebble milling were used, with a different size pebble in each stage. In other parts of the world interest was being shown in this form of grinding, and in March 1952 the writer had some correspondence with the mill staff at Outokumpu in Finland, with regard to the pebble system used at Lake Shore. At Stockholm in 1957 the account of the crushing and grinding system at Outokumpu was presented in a paper by H. Tanner and T. Heikkinen.V his is the only ore grinding plant that does not use grate discharges on its pebble mills; trunnion discharges equipped with heavy reverse spirals retain the pebble load. The first new mill designed to use screened ore as a grinding medium was the Bicroft mill at Bancroft, Ont., which began operation in the fall of 1956. In 1957 this plant was followed by similar installations at Faraday Mines, also in the Bancroft area, and the North Rankin Nickel Mines in the North West Territories. In 1958 the Dyno Mill at Bancroft was converted, using the same type of grinding. Since all these plants, designed by Kilborn Engineering (1954) Ltd., were originally planned as pebble grinding mills, they were able to take full advantage of the latest design and technique. They are neat in appearance and very efficient and easy to operate. Effect of Ore Hardness: It is often commented that this type of autogenous grinding applies only to hard siliceous ores. Experience has shown that this is not so. In the past ten years the author has had an opportunity to test more than a dozen ores, several of which were quite soft. One of these was shale. The softer ores actually make better looking pebbles than the hard ores. These soft ores produced no particles in the intermediate size range which could not be ground by the largest pebbles in the mill charge. Slabby ores, such as shales, make a suitable pebble for the —6 mesh grinding. It is not generally recognized that for fine grinding a spherical medium is not essential or more efficient. Another frequent objection to pebble grinding is the belief held by some operators that there is too much variation in the hardness of their particular ore to make it acceptable as a source of pebble media. Experience has also shown that this is not a serious problem at all. The variation in pebble load due to changes in the ore hardness is nothing like as great as most people would expect, and the method used for feeding the ore and controlling the the load in the mills is more than sufficient to take care of daily variations in ore hardness. This point

Jan 1, 1960

By Roland D. Parks

CORUNDUM, little publicized as an industrial abrasive, has, in its small way, contributed greatly to the production of many specialized items vital to our war program and to our allies. Optical elements of the highest quality for range finders, bombsights, and scientific instruments; precision metal parts for torpedoes and airplane engines; quartz crystal plates for military radios; armorplate and malleable castings for tanks and guns; and eyeglasses for everyone; these are some of the products that corundum has helped to produce in the quantities needed and on time. Unlike metals and many other raw materials, corundum is not incorporated into any of these finished products. It is simply a grinding medium used to produce the desired finish or precision; an operating supply or tool, so to speak. With a Mohs' scale index of o, corundum ranks next to the diamond in hardness among the natural minerals and is superior to emery and garnet. The gem varieties of corundum, including the Oriental ruby and sapphire, are frequently more highly prized as jewels than the diamond. It is the intent of this paper to deal only with a description of the corundum industry, the administration of wartime control, and certain economic aspects as seen by the author. Several references are listed to assist anyone who wishes further information on the geological occurrence of the mineral. ORE PRODUCTION AND CONSUMPTION For the past two decades, South Africa has been the world's sole producer of corundum ore. A possible exception is Russia, where, it is understood, there was considerable production during the thirties for domestic consumption but for which statistics are lacking. The United States is the world's principal consumer of corundum ore; imports for the period 1934 through 1940 averaging 3000 short tons per year. The years 1935 and 1936 were close to the 5000-ton mark, and imports during 1941, the last prewar year for which statistics have been released, were approximately 6000 short tons. Again lacking statistics on Russia, the United Kingdom ranks second, but far below the United States in consumption of ore. Historically, corundum has been found in some 35 countries throughout the world, but the principal deposits are in South Africa, Canada, Madagascar, Russia and the United States. Deposits are generally small and subject to rapid exhaustion. Thus, the United States was the principal world producer for the period 1870 to 1900, when operations ceased except for two years during World War I. India was a producer of ore from 1898 through 1921, with peak output in 1916 through 1918. Canada came into production in 1901 with substantial output of ore and finished grain until 1914; the production thereafter was smaller until 1921. Madagascar has produced ore since 1910 but has had important output in only a few scattered years. South African production started in 1912,

Jan 1, 1945

ARTICLE I NAME AND OBJECT SEC. 1. This Institute is incorporated under the Membership Corporations law of the State of New York; its corporate name is American Institute of Mining and Metallurgical Engineers, Inc.; and its objects are such as are stated in its Certificate of Incorporation. ARTICLE II- MEMBERS SEC. 1. The membership of the Institute shall comprise four classes, namely: 1. Members; 2. Honorary Members; 3. Associates; 4. Junior Associates. All members shall be equally entitled to the privileges of membership, excepting that Honorary Members, Junior Associates, and Members and Associates whose residences shall be outside of the United States, Mexico, and Canada shall not e entitled to vote. Members and Associates residing within the United States of America, Mexico, and Canada, and not in arrears for dues, shall be entitled to vote in person at the meetings of the Institute, or, as hereinafter provided for, by letter ballot. SEC. 2. Members shall comprise all those persons who on the third Monday of February, 1918, were members of the Institute, and in addition thereto, all those thereafter elected or transferred into the class of Members. A person to be eligible for election or transfer into the class of Members must be at least 27 years of age and must have had at least six years' employment in the practice of-engineering, mining, geology, metallurgy or chemistry, during at least three years of which he must have held positions of responsibility in one or more of these fields. Graduation from the scientific course of a college, approved by the Committee on Membership, shall be considered equivalent to two years' employment, as required in the previous sentence. Employment as a teacher of engineering, mining, geology, metallurgy or chemistry, if in direct charge, may be considered a position of responsibility as specified in the second paragraph. Persons employed in research or any scientific literary work or in teaching in the scientific departments of colleges, approved by the Committee on Membership, who at the same time are engaged in consulting or in the active practice of mining, geology, or metallurgy, shall be entitled to consider the time so spent in active practice as equivalent to an equal length of time of employment in positions of responsibility, . provided the work done or the positions held seem to the Committee on Membership to warrant the. equivalency. The requirement of three years' employment in positions of responsibility may be waived by the Committee on Membership in the case of persons who have done notable original work in mining,. geology, or metallurgy, or have won distinction by

Jan 1, 1925

By R. L. Frink

I FEAR that my treatment of this subject may not, in all instances, meet the approval of those who read my opinion as to the utility and efficiency of pyrometers in the making of glass, or bottle-glass. It may be superfluous for me to add that this opening statement is based on over 15 years' experience in an endeavor to successfully apply pyrometers, or heat-measuring instruments, to glass-melting furnaces, particularly the type known as tank-furnaces, and that such endeavors have proved more or less futile. It is my desire, therefore, to herein set forth the problems encountered, hoping thereby to stimulate further effort in the successful application of pyrometers. It is my desire, also, to invite criticism of the methods used and suggestions from those who may have a wider experience, or who may have better methods. Fin. 1.-GLASS TANK FURNACE. In general, I believe that the inefficient application of pyrometry to the melting of glass in tank furnaces is not due as much to the instruments as to the conditions under which they must be used and the character of the medium in which they must reside. Most of those present no doubt, are familiar, at least in a general way, with the methods and apparatus used in the melting and making of bottle-glass, or glass that is formed into containers of various shapes and designs. Most of this glass is made in what is known as a tank furnace, these furnaces vary widely in design and construction. In general, they consist of a rectangular tank-like form, built up of fireclay blocks, and range from 2 by 4 ft. (0.6 by 1.2 m.) to 24 by 140 ft. (7.3 by 42.6 m.) with a depth of glass from 2 to 5 ft.; or a capacity of from approximately. 2 to 700 tons. Fig. 1 shows the general

Jan 9, 1919

By C. Zangerl, W. Fellin, M. Holzmann, B. Hofer, S. Perzlmaier

"Four deep-seated rockslide systems were investigated and are under surveillance by TIWAG (Tyrolean hydro-electric Company) since the mid-1960s after impoundment of Gepatsch reservoir began. These rockslide systems consist of several individual sliding masses (slabs) which show variable activity from zero to a few centimetres per year. The focus in this paper will be on the findings for the transient deformation behaviour of the Hochmais slab which is part of the “Hochmais-Atemkopf” rockslide system.The rock mass has slid over moraine deposits in the last post-glacial period and was in equilibrium (or slow to extremely slow moving, respectively) until the filling of the reservoir began. During the initial reservoir filling in summer 1964 considerable movements had been observed over a length of 1000 m accompanied with an activation of the Hochmais slab. Geological investigations, additional surface and subsurface measurement showed that the sliding mass is characterized by an en bloc movement and the deformation accumulates within a several metre thick shear zone located within the moraine. In contrast to the deformation characteristics for the first impoundment process (1964 – 1966) where the magnitude of deformation occurred during impoundment, the maximum amount of deformation since 1967 occurs during the drawdown of the reservoir. Based on long term measurement it can be shown that the magnitude of deformations per year correlates with the minimum storage level in the reservoir. Other external influences such as precipitation and snowmelt have no observable impact on the deformation characteristic of the landslide. On the basis of long-term data series it was possible to determine the factors of influence and to elaborate a conceptual mechanical model which describes the transient deformation behaviour of the Hochmais slab induced by the drawdown of the reservoir. The mechanical model considers the reduction of uplift forces in the highly fractured and permeable rock slab during drawdown as well as increasing seepage forces in the less permeable moraine material."

Jan 1, 2015

By H. M. Chance, T. M. Chance

The term 'Llow-sulfur coal," as used in this discussion, is limited to coals containing less, or very little more, than 1 per cent. sulfur. For certain purposes it might be advantageous to include coals that contain as much as 1.25 per cent. sulfur, because such coals have been considered as available for making metallurgic coke of fair grade; but the same reasoning might apply to coals containing as much as.1 1/2 per cent. sulfur, if facilities exist for utilizing such coal by admixture with coal containing less sulfur. , In Pennsylvania, it is not possible to define the exact geographic limits of the areas in which coals relatively low in sulfur exist, because variations in the percentage of sulfur occur irregularly and often abruptly. It is not uncommon to find areas, more or less circumscribed in extent, in which the coal is relatively high in sulfur although all the surrounding territory contains low-sulfur coal; and, similarly, small areas of low-sul. fur coal exist in districts where the coal is normally high in sulfur. These generalizations apply, with few exceptions, to the whole area underlaid with bituminous coal in the State of Pennsylvania, and also to each of the individual beds of coal in this state. Pennsylvania is poorly supplied with coals of the low-sulfur class. We find, however, as an offset to this condition, very large areas in which coal ranging from 1 to 2 1/2 per cent. sulfur exists in beds of good workable thickness. This coal, by washing, can be reduced in sulfur low enough to make coke of a high grade. While a considerable tonnage of workable low-sulfur coal remains in the Pennsylvania bituminous districts, it has been necessary to turn to the areas of higher sulfur coal for the supply of metallurgical coke. This utilization of the higher sulfur areas has been made possible either by washing or by selective mining. Washing.—Fine crushing of the entire feed is not generally necessary to the successful washing of Pennsylvania coals. This is due to the fact that the pyrite is rarely finely and uniformly disseminated throughout the coal but is usually confined to high-sulfur benches in the bed or to concentrations on the cleavage planes of the coal. Hence, by graded crushing and sizing it is frequently possible to at once reclaim those portions of the coal bed containing coal that is relatively free from pyrite.

Jan 1, 1920

By R. D. Nelson, F. E. Bowman

Evidence has been found for a (010)a?(111)B[102]a /,11[341]/B crystallographic relationship between the monoclinic a and B phases of plutonium during the a?B transformation. The results of an X-ray diffraction study, where [010] fiber textured a samples were used in the absence of suitable single crystals indicate that the (OIO)a planes become (111)B planes upon transformation under near-equilibrium conditions. The transformation strain along the fiber axis, which was the [010] direction, was measured dila-tomekically; the measured 8.5 pct expansion compares favorably with the 8.44 pct expansion in the in-terplanar spacing represented by the (010)a?(111)B relationship. From plots of the atom positions in each of the related planes, a correspondence was deduced between the [102]a, direction and the [341]B direction. Further analysis of the two lattice structures in the light of this relationship revealed a rotation about the [102] direction of 1 deg 43 min and a slight shearing in this same direction of about 30 min. THIS paper discusses the (B crystal structure of plutonium and the orientation relationship existing between the monoclinic a and B phases during the a?ß transformation. The kinetics of the a?ß and (3 — a transformations have received extensive consideration, and because of the crystallographic complexity of these phases, the question of the mechanisms by which these transformations occur is especially intriguing. Nelson and Shyne1 evaluated the existing experimental evidence and concluded, from the indirect evidence available, that both the ß ? a and a ? ß transformations occur by a martensitic process. Their data reveal the anisotropic nature of these transformations which suggests the existence of specific crystallographic relationships between the parent and product phases. In this paper, we are concerned with the confirmation of the existence of such a relationship resulting from the a ? ß transformation and the derivation of the crystallographic details necessary to specify it. EXPERIMENTAL RESULTS X-ray diffraction and dilatometric data were obtained from samples of a plutonium having a [010] fiber texture. These cylindrical specimens, approximately 1 cm in diam, were prepared by transforming the ß phase to a under the influence of a uniaxially applied compressive load.' The [0l0] direction is parallel to the direction of applied stress; it is also perpendicular to the (010) planes. This correspondence between the plane normal and the direction having the same indices is, in the monoclinic a plutonium structure, restricted solely to this (010)[010] combination. Such a specimen was mounted in an evacuated, elevated temperature specimen holder on an X-ray dif-fractometer so that the diffracting surface was perpendicular to the fiber axis. The a diffraction pattern, Fig. 1, taken at about 115ºC, revealed the predominance of the (020) reflection. This monoclinic, P 21/rn space group yields no (0k0) reflections when k is odd. The temperature was raised slowly to 160°C to effect the complete transformation to the phase; then it was lowered to 120°C so that a diffraction pattern of the ß could be obtained near the a = ß equilibrium temperature for direct comparison with the a at the same temperature. The (3 diffraction pattern, Fig. 2, obtained under these conditions showed a (222) reflection relatively much more intense than in the random pattern. The other reflections appearing with sig-

Jan 1, 1970

By Renato Ferreira Lima e Corrêa Pereira

Na manufatura de produtos metálicos, o forjamento é o processo de transformação a quente de materiais dúcteis, como aços e ligas, através de conformação mecânica efetuada com esforço de compressão por uma prensa, de modo que eles assumam os formatos desejados. Este processo normalmente é utilizado para produzir peças de formas complexas e com uma maior precisão dimensional de acordo com a especificidade exigida pelo cliente final. Para obter resultados de qualidade, foi necessária a implantação de técnicas de medição indireta de última geração, que proporcionam ganho de tempo e a redução de desperdício de energia e material, além de aumentar a segurança, reduzindo a presença de pessoas próximas aos materiais para medições manuais. O presente trabalho trata da criação de um sistema de visão que, por meio de análise de imagem, é capaz de coletar a medida do perfil de barras em uma Forjaria em tempo real, podendo ser utilizado durante a operação da prensa, para garantir que o material está em conformidade com o especificado. A execução do sistema em produção aponta que as medidas realizadas apresentam desvio máximo de 2mm em relação àquelas realizadas pelos operadores.

Jul 30, 2018