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By Alfred Boyles

THE experiments described below are a continuation of work on the graphitization of cast iron conducted as part of the program of funda-mental research at Battelle Memorial Institute. In previous work it was found that melting in hydrogen increased the amount of eutectic and in others i produced al marked changes in the size of the graphite flakes. These effects seemed to be III sulphur and manganese present in the material studied. Iron-carbon- respond silicon alloys did same manner as mg cast iron and there was no evidence to show that hydrogen was able to stabilize the carbide in such alloys unless additions of sulphur were made. The two alloys examined contained about 2 per cent of FIG. 1.-APPARATUS FOR MELTING UNDER PRESSURE. silicon. The present paper is con- A, inlet for gas. cerned with alloys of lower silicon B, outlet for evacuation. content and describes the structural C, power lead. D thermocouple changes produced by melting in E, plug for access to furnace. various atmospheres at pressures F, crucible. ranging from a partial vacuum up to 300 lb. per sq. inch.

Jan 1, 1939

By O. B. Bucklen, J. P. Matoney, P. G. Meikle, R. L. Terry

INTRODUCTION The trend in the coal industry for many years has been to make every- thing "bigger and faster." This also holds true for loading and storage facilities. Where once a 1 million st per yr (910,000 mt/yr) mine was rare, 3-5 million st per yr (2,730,000-4,550,000 mt/yr) mines are not uncommon today in the bituminous industry. This great increase in production, made possible through mechanization, requires greatly improved loading facilities just to get the coal away from the mine. Also, there is a trend to- ward combining production from more than one mine and cleaning it in a single preparation plant. In addition to increased loading capacity, this frequently necessitates raw-coal storage and blending facilities. The development of the unit train with its attendant economics has contributed more than any other factor to the widespread construction of storage and high-speed loading facilities. In the export market, the construction of ever larger coal colliers has added to the need for faster and larger loading facilities. In this climate of rapidly changing technology, any written ac-

Jan 1, 1979

By Thomas Kesler

THE Cartersville mining district, 35 miles northwest of Atlanta, Ga., has been of varying but continuous importance in the southern mineral industry during the past century. Noted chiefly for its production of brown iron ore, manganese oxide ores, barite, sienna, and magnesian limestone, the district and its environs have produced brick and tile clays, slate, gold, bauxite, and graphitic schist. Minor deposits of serpentine, sericite schist, copper ore, and red iron oxide have been prospected. The obvious deposits of brown iron ore, together with some associated specular hematite, were mined out years ago, although a little ore was left in the workings. Moderately steady production of sienna reached a peak about 1930, then declined rapidly. Manganese mining passed through a relatively active period from the World War to 1931, but has subsided to a small but rather constant output for the Birmingham market. How-ever, the White Manganese Corporation has prepared for possible increased production by constructing a new washer capable of handling about 300 tons of ore per day. Principal activity in the district proper has centered for some years in the production of barite and magne-sian limestone.

Jan 1, 1940

By Thomas Kesler

THE Cartersville mining district, 35 miles northwest of Atlanta, Ga., has been of varying but continuous importance in the southern mineral industry during the past century. Noted chiefly for its production of brown iron ore, manganese oxide ores, barite, sienna, and magnesian limestone, the district and its environs have produced brick and tile clays, slate, gold, bauxite, and graphitic schist. Minor deposits of serpentine, sericite schist, copper ore, and red iron oxide have been prospected. The obvious deposits of brown iron ore, together with some associated specular hematite, were mined out years ago, although a little ore was left in the workings. Moderately steady production of sienna reached a peak about 1930, then declined rapidly. Manganese mining passed through a relatively active period from the World War to 1931, but has subsided to a small but rather constant output for the Birmingham market. How-ever, the White Manganese Corporation has prepared for possible increased production by constructing a new washer capable of handling about 300 tons of ore per day. Principal activity in the district proper has centered for some years in the production of barite and magne-sian limestone.

Jan 1, 1940

Mining as an industry of Utah had its inception in the activities of United States soldiers who came to the Salt Lake valley under the command of Gen. P. E. Connor, founder of Fort Douglas, in October, 1862. Many of these soldiers were from California and naturally employed their spare time in the search for minerals. Although their military status did not permit them to make locations in their own names, they assiduously prospected the region in accordance with their own knowledge and with in- formation conveyed to them by Indians and others. Their efforts were encouraged by their commander, who thereby fairly earned the title of father of the industry here, and by their other officers, and many discoveries that subsequently proved of great value were made by the soldiers. No systematic prospecting or mining had been done in the Territory previously although early Mormon settlers in the southern portion had mined a little ore from time to time in order to provide supplies of lead for bullets. The Mormon leaders at that time did not encourage mining. They held that agriculture was more important and profitable for their followers.

Jan 1, 1925

By Herbert Clark Hoover, Lou Henry Hoover

DIGGING of veins I have written of, and the timbering of shafts, tunnels, drifts, and other excavations, and the art of surveying. I will now speak first of all, of the iron tools with which veins and rocks are broken, then of the buckets into which the lumps of earth, rock, metal, and other excavated materials are thrown, in order that they may be drawn, conveyed, or carried out. Also, I will speak of the water vessels and drains, then of the machines of different kinds,1 and lastly of the maladies of miners. And while all these matters are being described accurately, many methods of work will be explained. There are certain iron tools which the miners designate by names of their own, and besides these, there are wedges, iron blocks, iron plates, hammers, crowbars, pikes, picks, hoes, and shovels. Of those which are especially referred to as " iron tools " there are four varieties, which are different from one another in length or thickness, but not in shape, for the upper end of all of them is broad and square, so that it can be struck by the

Jan 1, 1950

By Frank C. Greene

The year 1941 was uneventful in oil and gas development in Missouri. No new pools were opened and several areas with promising structures, in the northwestern part of the state, were disappointing when drilled. In looking for an explanation of these failures, it is suggested that it will be necessary to find areas in which the lower beds of the Mississippian are upfolded, in order to obtain production in northwestern Missouri. To do this, geophysical exploration or test drilling far enough into the Mississippian beds to get cores or cuttings of definitely established age appear to be the best methods. Although not leading to new production, drilling in Missouri established two new state records, one for depth and another for the amount of rotary drilling. An important well† in sec. 24, T. 19 N., R. 11 E., Pemiscot County, in the southeastern corner of the state, was drilled with a rotary to 4740 ft., several hundred feet deeper than any previous hole. The total footage drilled by rotary rigs of various types was 31,135 ft. and that by cable tools, 29,166 feet. The total number of completions was 85, of which 18 were gas wells with an initial open-flow capacity of 12,528,000 cu. ft., and 67 were dry holes. Of the latter, 19 were drilled into Mississippian or older formations. Table I gives a summary of activities by counties.

Jan 1, 1942

By Richard H. Terhune

The use of water-cooled breast-jackets or cinder-tap blocks is a great convenience in lead-smelting, even when siliceous slags are made. If the charges are at all basic it is almost imperative. Jackets of riveted wrought-iron or steel are expensive; those of cast-iron are liable to crack; those of bronze are costly and not durable, being easily penetrated by tapping-bars or destroyed by streams of matte impinging against them. To overcome these objections I introduced at the Hanauer works, in April, 1886, castjackets of steel, which have been in constant use since that time and are to-day as good as new. These jackets were made for us by the Chester Steel Castings Company, of Chester, Pa., at a cost of ten cents a pound at the works of that company. The metal is 5/8-inch thick, and the jackets were cored and tapped for l1/2-inch bushings, affording two large holes for the removal of dirt and incrustations. The same holes are used for feed- and discharge-water through 3/4-inch pipe. I hope the successful introduction here of cast-jackets of steel will lead to their more extended use in all branches of metallurgy where water-cooled surfaces are severely taxed, and where the size and thickness of the castings are not unfavorable to the production of a sound article, impervious to water and of high tensile strength.

Jan 1, 1889

By Frank C. Greene

The year 1941 was uneventful in oil and gas development in Missouri. No new pools were opened and several areas with promising structures, in the northwestern part of the state, were disappointing when drilled. In looking for an explanation of these failures, it is suggested that it will be necessary to find areas in which the lower beds of the Mississippian are upfolded, in order to obtain production in northwestern Missouri. To do this, geophysical exploration or test drilling far enough into the Mississippian beds to get cores or cuttings of definitely established age appear to be the best methods. Although not leading to new production, drilling in Missouri established two new state records, one for depth and another for the amount of rotary drilling. An important well† in sec. 24, T. 19 N., R. 11 E., Pemiscot County, in the southeastern corner of the state, was drilled with a rotary to 4740 ft., several hundred feet deeper than any previous hole. The total footage drilled by rotary rigs of various types was 31,135 ft. and that by cable tools, 29,166 feet. The total number of completions was 85, of which 18 were gas wells with an initial open-flow capacity of 12,528,000 cu. ft., and 67 were dry holes. Of the latter, 19 were drilled into Mississippian or older formations. Table I gives a summary of activities by counties.

Jan 1, 1942

THE Institute assembled on Tuesday evening, in the building of the University of Pennsylvania. In the absence of President Thomas, Vice-President Raymond occupied the chair. The Institute was welcomed in an eloquent and thoughtful address by Prof. J. P. Lesley, to which Mr. Raymond responded. Invitations were announced from the proprietors of Sellers' Tool Works, Whitney's Car-wheel Works, the Baldwin Locomotive Works, Lewis & Brothers' White Lead Works, the Southwark Foundry, Harrison's Boiler Factory, the University of Pennsylvania, and the Academy of Natural Sciences. The following gentlemen, being duly recommended by the Council as members and associates, were unanimously elected : Alexander, John S., . . . . . Philadelphia, Pa. Biddle, E. R., . New Pork. Britton, J.. Blodget, . . . . . Philadelphia, Pa. Brooks, Maj. T. B., . . . . . Marquette, Mich. Brown, D. P., . Pottsville, Pa. Canfield, Edw., . . . . . . Dover, N. J. Cogswell, W. B., . .Franklin IronW'ks, N. Y. Cornwall, Prof. H. B., . .New York. Edwards, Daniel, . . . . . . Danville, Pa. Estabrook, Juhn D., . . . . . Philadelphia, Pa. Firmstone, William, . . . . . Easton, Pa. Fritz, John, . . . . . . . Bethlehem, Pa. Gignoux, Charles, . . . . . . New Pork. Grant, E. M., . . . . . . . Tuskegee, Ala. Humphreys, A. W., . New York. Ingham, W. A,, . . . . . . Philadelphia, Pa. Keyes, W. S., . . . . . . Eureka, Nev. Kimball, Dr. J. P., . New Pork. Law, Charles, . Pittston, Pa. Neilson, W. O., . . . . . . Philadelphia, Pa. Newberry, Prof. J. S., . . . . . New York. Pearse, John B., . .Steel Works P. O., Pa. Ricketts, P. De P., . . . . . New Pork. Scranton, Col. Charles, . . . . . Ox ford, N. J. Sontag, Hugo, . . . . . . Cologne, Prussia. Steele, Thomas C., . .Summit, Pa. Wharton, Joseph, . . . . . . Philadelphia, Pa.

February 20th, 1872. THE Institute assembled on Tuesday evening, in the building of the University of Pennsylvania. In the absence of President Thomas, Vice-President Raymond occupied the chair. The Institute was welcomed in an eloquent and thoughtful address by Prof. J. P. Lesley, to which Mr. Raymond responded. Invitations were announced from the proprietors of Sellers' Tool Works, Whitney's Car-wheel Works, the Baldwin Locomotive Works, Lewis & Brothers' White Lead Works, the Southwark Foundry, Harrison's Boiler Factory, the University of Pennsylvania, and the Academy of Natural Sciences. The following gentlemen, being duly recommended by the Council as members and associates, were unanimously elected Alexander, John S., - Philadelphia, Pa. Biddle, E. R., - New York. Britton, J.. Blodget, - Philadelphia, Pa. Brooks, Maj. T. B., - Marquette, Mich. Brown, D. P., - Pottsville, Pa. Canfield, Edw., - Dover, N. J. Cogswell, W. B., - Franklin IronW'ks, N.Y. Cornwall, Prof. H. B., - New York. Edwards, Daniel, - Danville, Pa. Estabrook, John D., - Philadelphia, Pa. Firmstone, William, - Easton, Pa. Fritz, John, - Bethlehem, Pa. Gignoux, Charles, - New York. Grant, E. M., - Tuskegee, Ala. Humphreys, A. W., - New York. Ingham, W. A., - Philadelphia, Pa. Keyes, W. S., - Eureka, Nev. Kimball, Dr. J. P., - New York. Law, Charles, - Pittston, Pa. Neilson, W. G., - Philadelphia, Pa. Newberry, Prof. J. S., - New York. Pearse, John B, - Steel Works P. O., Pa. Ricketts, P. De P., - New York. Scranton, Col. Charles, - Oxford, N. J. Sontag, Hugo, - Cologne, Prussia. Steele, Thomas C. - Summit, Pa. Wharton, Joseph, - Philadelphia, Pa.

Jan 1, 1873

Engineers and masters of enterprise are waking fast to the realization that there is something more in the relations of employer and employee than mechanical output, which can be measured mathematically, and that the human side of service must receive greater consideration for the future. So much has been said and written on this subject that it has passed into a truism. Should not the same element, long neglected, be considered as of even greater importance than questions of "administration and membership, in the plans of engineering societies? Should mutual service and interest end with mere technical output by members and the rendering of care and management by officers? The world is recognizing, as never before, obligations for service to fellowmen clue from all, high or low, in rank or wealth. Our technical societies, organized for professional protection and advancement, are, insensibly to themselves, almost without conscious intent, widening their field of service to members and dealing heartily with questions broader than technique. Those who are doing such service find unconsciously more and more satisfaction in work so rendered. The growth of knowledge that comes to subaltern engineers or veterans by converse and contact with their fellows, working along and versed in the same subjects, brings interest and friendship. In this way are built some of the warmest friendships of life, coming as incidental and pleasurable result of meetings undertaken for other purposes. Should not the friendly purpose, the desire for service one to another, and es-

Jan 1, 1919

By B. Ramaswami

INTERNAL oxidation occurs readily in silver due to the rapid diffusion of oxygen in silver.' It has a marked effect on creep in polycrystalline silver2 and raises the critical resolved shear stress in single crystals of silver.3 However, the effect of oxygen on the work-hardening parameters of silver is not known. It is the aim of this paper to describe the effect of internal oxidation on the work-hardening characteristics of single crystals of silver and an Ag-0.1 at. pct A1 alloy. The materials used were: 99.99 pct Ag from Handy and Harman and 99.993+ pct A1 from Alcoa. Single crystals, 6 mm by 6 mm in cross section of silver and Ag-0.1 at. pct A1 of mo.5 orientation, i.e., the orientation with the Schmidt factor m = 0.5. were grown by the Chalmers technique.4 One set of specimens, referred to herein as oxidized specimens, was annealed at 940°C for 24 hr in a muffle furnace, in air, and furnace-cooled to room temperature. Another set of specimens, referred to as nonoxidized specimens, was annealed in oxygen-free helium at 940°C for 24 hr and furnace-cooled over a period of 7 hr to room temperature. The annealed single crystals were tested at room temperature in a floor-model Instron testing machine. The results are presented in Figs. 1 and 2. A

Jan 1, 1965

By J. E. Burke

THE origin of recrystallization textures continues to be a matter of controversy. One explanation is that a recrystallization texture occurs because only grains having a limited range of orientations ever appear in the deformed matrix—the oriented nuclea-tion* hypothesis. Another explanation is that grains essentially having all orientations are nucleated but that those having certain orientations grow much more rapidly than any others in the deformation texture, and thus only the rapidly growing grains survive when recrystallization is complete. There has recently appeared a great deal of evidence'- indicate that recrystallized grains of face-centered cubic metals are frequently related to their parent grains by rotations of 20" to 40" about a common [lll] direction. Furthermore, it has been observed that the growth rate of the new grains depends upon their orientations with respect to the matrix, and that the most rapidly growing grains lie within the stated range of orientations. In a recent note, Beck7 has concluded from observations of this type that oriented growth alone is responsible for the appearance of preferred orientations in re-crystallized metals. It should be pointed out. however, that many of the available data indicate that oriented nucleation operates in addition to oriented growth. Thus, while oriented growth may permit a selection to be made among nuclei of several orientations, only a limited number of orientations are available in the first place for such selection.

Jan 1, 1953

Another excellent Swedish underground crushing plant is that at Crusher Station 51 of LKAB in Kiruna, Sweden. Bottom-dump rail cars pass over a dump scroll to discharge magnetite ore into a 288 cu yd (220 m3) pocket equipped with a Hewitt Robins E-13 vibrating grizzly feeder. The grizzly section is 59 in. (1500 mm) long and has bar spacings 3 in. (76 mm) wide. Any oversize boulders which will not pass the chute opening to the feeder are blasted. The primary breaker is a Morgardshammar overhead eccentric 55 in. by 71 in. (1400 by 1800 mm) jaw crusher powered by a 200 hp (149 kw) motor. An open side setting of 10. 8 to 11. 8 in (275 to 300 mm) accounts for the high capacity of this crushing unit (2760 stph or 2500 mtph). This figure compares favorably with the capacity of many gyratory crushers but is typical of the Swedish jaw crushing installations, which are often followed by three more stages of crushing or by autogenous grinding. Crushed ore from the jaw crusher is combined with the grizzly under- size in the crushed ore pocket and is fed by a second vibrating grizzly feeder to the secondary cone crusher. Both crushers are serviced by 50/5 ton overhead bridge cranes. During maintenance operations air -operated gates shut off the flow of ore from the dump and primary crushed ore pockets.

Jan 1, 1978

WALTER N. CRAFTS,* Toronto, Canada (written discussion?).-During the forging of 9.2-in. shells -for the United States Army, it was noticed that better results were obtained in certain instances when test bars had been held sometime before pulling. An investigation, therefore, was made by our metallographer, Mr. F. M. Arnold, to determine the effect of seasoning. The forging consists of a single operation, piercing a solid cast blank. The test sections were cut from the walls by an oxyacetylene flame, one piece from the nose end and one from the base on the opposite side. The test pieces were not heat treated in any way and the tests and seasonings were carried on at normal atmospheric temperatures. The specifica-tions were as follows: Standard 2-in. test bar, 0.505 in. in diameter; elastic limit, over 19 long tons, or 42,500 lb.; ultimate stress, 39.6 to 49.1 long tons, or 87,500 to 110,000 lb. per sq. in.; elongation, over 13 per cent. As a preliminary test two heats were selected; BP555, which was tested and reported failed on elongation on Aug. 20; and B01771, which was tested and reported failed on Aug. 24. On Aug. 29, retests were cut and machined from the same shells and held till Sept. 3 (5 days) when they were pulled. Both sets of results are given below.

Jan 12, 1919

By A. Kounosu, T. Fujita, J. Shimoiizaka, K. Nakatsuka

Stable aqueous dispersion of magnetite colloid of about 10 nm in diameter was obtained by allowing an anionic or nonionic surfactant to adsorb on the hydrophobic surface of magnetite particles prepared by monomolecular adsorption of oleate. Sodium dodecylbenzene sulfonate, sodium oleate and poly (oxyethylene) nonyl phenyl ethers whose hydrophilic-lipophilic balance (HLB) are higher than 12 were suitable for giving a second adsorption layer to obtain a stable dispersion. Stability of the colloidal suspensions depends upon pH of the solution and is controlled by the dissociation of the adsorbed surfactant in the second layer. The addition of ethyleneglycol, which was used for lowering the freezing point of the dispersion, did not affect the stability when used in amounts smaller than 60% of water. Preparation of diester-based ferrofluids was also attempted by the same procedure using a nonionic surfactant as second layer molecule. Hydrophobic magnetite colloid, which had been preliminarily coated with mono-molecular oleate, was suspended in di(2-ethylhexyl) agipate, azerate, and sebacate respectively, and dispersion stability was investigated by adding various poly (oxyethylene) nonyl phenyl ethers of different HLB values. It was found that those with HLB values between 10.9 and 13.3 were suitable for this purpose. Stabilities of the dispersions in a magnetic field were investigated up to 1 T by applying an electromagnetic field. No separation of dispersant was observed and each magnetite dispersion displayed the characteristics of a magnetic fluid.

Jan 1, 1980

By H. C. Rolseth, R. H. Kohler

Jet channeling made its entry into the granite industry in 1955 and quickly gained acceptance as an economical method of quarrying. Developed by the Linde Division of Union Carbide Corp., this method employs a small rocket-jet burner with a high-temperature, high-velocity exhaust flame that causes granite to disintegrate. It can thus make continuous vertical cuts to free large blocks from granite formations. The Thermal Spalling Process The effect of a thermal device on rock depends upon the rock's spallability. In simplest terms, spalling is the decrepitation resulting from differential expansion of rock crystals due to thermally induced stresses.1 the individual rock properties influencing the spalling characteristic are so numerous and their interaction is so complex that it has so far been impossible to predict with accuracy the reaction of any particular rock to a high-temperature source of heat. Perhaps computers will eventually make such predictions possible, but for the present it is necessary to impose the thermal shock conditions on a sample of the rock to establish its spalling characteristics. The properties most favorable to a high degree of spallability are: (1) Large linear thermal expansion at temperatures below 700º C. (2) High thermal diffusivity at temperatures below 400º C. (3) Equigranular interlocking structure with little or no fine-grained clay or mica alteration products. (4) No significant amounts of soft, low-melting, or elastic minerals or materials which yield after thermal decomposition.

Jan 7, 1969

By John T. Schamaun

Recent applications of explosives and blasting agents to rubble rock have led to requirements for more elaborate design and analysis methods. In most blasting uses, it is necessary not only to fracture the rock, but also to move the broken rubble in a predictable manner. Many in situ extraction techniques require rubblization to take place in a confined region where rock motion is a predominate factor in creating a permeable broken bed. In this paper, two analytical methods are presented which describe the large rubble motion during blasting. These methods provide the blast designer with a tool for evaluation and further refinement of blasting patterns and timing sequences. In both these methods, the rock medium is represented by a series of discrete, discontinuous regions. The use of discontinuous techniques rather than the classical continuum methods, results in better approximations to the rubble motion. These regions are set in motion by pressure loads from the explosive. The motion of these regions is then calculated numerically using interaction laws between regions in contact. The basis for these models or methods is presented along with the background for selecting explosive pressure loads and rock mass material behavior. Typical examples, including both cratering and bench blasting geometries, are discussed which illustrate the use of these models to predict rubble motion. Such engineering representations appear to provide a practical method for use in predicting rubble motion and a tool for design evaluation of blasting in confined geometries.

Jan 1, 1984

By Walter W. Lilly, Issa S. Oweis

Application of rock engineering in geotechnial consulting practice considered herein is in areas of: (a) bedrock verification for foundation support, (b) bearing capacity and settlements, and (c) excavations. A routine geotechnical investigation usually provides data on depth to rock, rock classification, and rock quality. In cases of rock outcrop, such outcrops are mapped for geologic structures and rock mass description. In addition, the regional geology and the general aspects of the groundwater regime are usually known from either published literature or previous experience. The predominant technique for ground and site investigation are usually drilling and geologic reconnaissance. Other techniques involving seismic and geophysical soundings, borehole camera, and oriented cores are used by by no means routine. Performing laboratory strength and compressibility tests is often made to be considered as routine. The use of the point load test is gaining increasing use in the United States and would, perhaps, become a routine field or laboratory test due to its simplicity and, more importantly, its relatively low cost. The purpose of this paper is to describe cases where mostly routine investigation and testing were used to arrive at engineering decisions. Bearing Capacity and Settlements The allowable bearing values for foundation support on rock is usually dictated by local building codes which presumably should reflect local experience. The interpretation of the code, however, can present a problem, especially if the interpretation is made by a designer under the delusion of knowledge in rock engineering. For

Jan 1, 1982