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By James P. Savely, Victor L. Kastner

Inspiration Consolidated Copper Company is currently mining in four pit areas; Live Oak, Red Hill, Thornton and Joe Bush Extension, near Globe, Arizona. Small satellite orebodies lying outside the main pits have been mined out in a series of small open pits. Major slope instability has affected production in every pit. Some consequences of the instability have been; (1) Serious interruption of mining plans, which resulted in deferred ore production, lost ore, reduced mining rates and increased stripping requirements. (2) Forced replacement of crushing facilities. (3) Serious effects on other production facilities. The introduction of a slope stability monitoring and control function as an integral part of mine planning has been successful in reducing the impact of these failures and will eventually result in economic pit design based on probabilistic slope analysis. This case history presents a brief review of the problems associated with slope instability at Inspiration's mines followed by a more detailed report on one specific failure area in the Thornton pit where the use of horizontal drain holes for slope stabilization appears to be successful. Relationships between slope movement rate, rainfall, and mining activity are shown.

Jan 1, 1983

By George Rice

THE A.I.M.E. Ground Movement and Subsidence Committee, pro-posed in 1920, held its first technical meeting in February 1923, under the able chairmanship of Mr. H. G. Moulton. The following list of papers and discussions, indicating the scope of the problems and relation to various conditions and method of mining, were given at that meeting by the distinguished mining engineers: J. Parke Channing, on Subsidence at Miami, Arizona; Howard N. Eavenson, on Mining an Upper Bitu-minous Seam after a Lower Seam Has Been Extracted; J. J. Rutledge, on Subsidence in Two Oklahoma Coal Mines; Benjamin F. Tillson, on Caving Cracks at the Franklin Mine, New Jersey; Dr. F. W. McNair, on the Dome Theory; William Kelly, on disadvantageous effects in Mining and Back-filling Working Upward a Steep-Pitching Iron-ore Bed; Eli T. Conner, on the good results of Back-Filling by Hydraulic Means in Preventing Destructive Subsidence in the Anthracite District; Thomas H. Claggett, on the merit of Systematic Pillar Drawing in Preventing Cracks in an Upper Seam; Henry H. Otto, successful results in the anthracite district in Mining Lower Seams before Upper Seams; Douglas Bunting, on Leading Factors Incident to Successful Mining of an Overlying Seam; Edwin Ludlow, on there being "less damage to buildings when there was complete removal of coal with complete packing than when room and pillar is used without extracting the pillars"; Edward O'Toole on "bumps" in eastern Kentucky mines, which he thought were the result of geologic stresses: H. A. Buehler, on Upheaval of Surface in an Illinois Case in Advance of the Face; and R. Dawson Hall, on The Mechanics of Subsidence from Mining. The author of this paper discussed various Winds of problems of ground movement and subsidence in both metal mining and coal mining; the production of great landslides by workings near an outcrop, as at Turtle Mountain, Alberta, Canada; and general

Jan 1, 1939

By George Rice

THE A.I.M.E. Ground Movement and Subsidence Committee, pro-posed in 1920, held its first technical meeting in February 1923, under the able chairmanship of Mr. H. G. Moulton. The following list of papers and discussions, indicating the scope of the problems and relation to various conditions and method of mining, were given at that meeting by the distinguished mining engineers: J. Parke Channing, on Subsidence at Miami, Arizona; Howard N. Eavenson, on Mining an Upper Bitu-minous Seam after a Lower Seam Has Been Extracted; J. J. Rutledge, on Subsidence in Two Oklahoma Coal Mines; Benjamin F. Tillson, on Caving Cracks at the Franklin Mine, New Jersey; Dr. F. W. McNair, on the Dome Theory; William Kelly, on disadvantageous effects in Mining and Back-filling Working Upward a Steep-Fitching Iron-ore Bed; Eli T. Conner, on the good results of Back-Filling by Hydraulic Means in Preventing Destructive Subsidence in the Anthracite District; Thomas H. Claggett, on the merit of Systematic Pillar Drawing in Preventing Cracks in an Upper Seam; Henry H. Otto, successful results in the anthracite district in Mining Lower Seams before Upper Seams; Douglas Bunting, on Leading Factors Incident to Successful Mining of an Overlying Seam; Edwin Ludlow, on there being "less damage to buildings when there was complete removal of coal with complete packing than when room and pillar is used without extracting the pillars"; Edward O'Toole on "bumps" in eastern Kentucky mines, which he thought were the result of geologic stresses: H. A. Buehler, on Upheaval of Surface in an Illinois Case in Advance of the Face; and R. Dawson Hall, on The Mechanics of Subsidence from Mining. The author of this paper discussed various kinds of problems of ground movement and subsidence in both metal mining and coal mining; the production of great landslides by workings near an outcrop, as at Turtle Mountain, Alberta, Canada; and general

Jan 1, 1939

By E. C. IBBOTSON

THIS process was reported upon by the Canadian Commission in 1904, and much detailed information was also given in a paper by Chief Engineer V. Engelhardt.1 Believing that some of the latest particulars of the process will be of interest, I submit the following data. At Gysinge in Sweden during the year ending May 31, 1906, from a fixed furnace giving 1 ton (2,240 lb.) of steel per tap, there were produced 950 tons of tool-steel and special steel ingots. . In carbon and iron tool-steels all the usual tempers were made. The bulk of this steel was made from charges composed of about 80 per cent of Swedish white pig-iron and 20 per cent. of steel-scrap. The percentage of carbon was regulated by the addition of briquettes. Other charges were made from Swedish white iron and steel-scrap. The average time taken per charge, for the year, when adding briquettes, was 7* hr., and the electric energy consumed was 1,128 units (kilowatt-hours) per ton. The average time per charge for white-iron and scrap charges was 5.5 hr., and the electric energy consumed was 886 units per ton. These consumptions include all time and energy lost from various causes, such as bad water-supply, ice, etc. It is quite ordinary practice to complete the charges with briquettes in 6.5 hr., and without briquettes in 5 hr., as shown by the following typical charges White pig-iron, 1,457; steel-scrap, 439; briquettes, 220; ferrosilicon (50 per cent. of silicon), 17 ; ferromanganese (80 per cent. of manganese), 15 lb. ; and aluminum, 1 oz.=

Nov 1, 1906

By P. B. Knuckey, D. Littleford

The Kalengwa mine, situated in a remote area of Zambia in Central Africa, has presented some unique problems to the planners engaged in developing the deposit. This small, high grade copper deposit contains some 1,688,000 tons of ore at a grade of 9.3% contained copper. Of this 362,000 tons is classified as high grade ore at 27.2% Cu, the coarse fraction of which can be fed directly to converters; 733,000 is classed as intermediate grade ore averaging 6.3% Cu, and 593,000 tons classed as low grade ore containing 2.1% Cu. The geology of the deposit and the establishment of the mining operation is fully described. A concentrator is being built at Kalengwa to treat the high grade fine product, intermediate, and low grade ore, whilst the coarse high grade ore will be trucked to the Copperbelt smelters for direct smelting. Details of metallurgical processing are given. The decision to truck the coarse high grade ore to the smelters on the Copperbelt necessitated the construction of a new 200-mile road, the setting up of a fleet of heavy ore transport trucks and associated equipment. The remoteness of the area from established communication facilities on the Copperbelt necessitated the provision of radio communications between Kalengwa and the head office at Kalulushi, and the establishment of a regular mine air service. The paper also describes the training of an unsophisticated local population in the operation of heavy plant and machinery, the establishment of the township, and the provision of health services.

Jan 1, 1972

By M. R. Daly

In a recent paper on Geologic Structure in the Cushing Oil and Gas Field, Oklahoma,l Carl H. Beal has pointed out some interesting peculiarities in the distribution of the hydrocarbons and the disposition of the "planes of separation" between the oil and the water (water surfaces). Mr. Beal's principal statements on this matter may be, summarized as follows: I. In every important dome in the Cushing field, which has not been complicated by folding along its sides, the oil area in each of the three oil and gas sands studied (Layton, Wheeler and Bartlesville) apparently extends farther down on the long axis of the dome than it does on the steeper sides. The result is that water is encountered at a lesser depth below datum plane (sea level) on the steep sides of the dome than along the ends where the beds are more gently tilted. II. In the Layton and Wheeler sands (to which the detailed study of water surfaces has been almost entirely confined), the water surface is not level, but dips at a gentle angle (maximum dip 100 ft. to the mile) away from the center of the structure. This inclination existed prior to development, and it has been rendered greater by the rapid extraction of oil and gas. To these statements, the following observations are added: The dominant structural feature in the Cushing field is a broad north and south anticlinal fold, along whose axis the domes are distributed (Fig. 1, p. 897), and the more important oil areas in each sand lie on the west side of the field. In many cases, gas has been forced to the east side of the structure, sometimes as far as the water line. From the distribution of the oil and gas bodies, Mr. Beal concludes that the hydrocarbons in this region probably migrated from the west or the northwest. It seems as if these different features would be susceptible of some

Jan 1, 1918

By William Schriever

The flow of a gas-free liquid through a spherical-grain sand has been investigated by S1ichter.l By theoretical considerations involving a rather large number of approximations he arrives at the following flow-formula: V = CPd2At NLB{1 - m) where V is the volume of liquid delivered in time t through a cylindrical column of sand of length L and cross-sectional area A by a pressure-drop P when the sand grains of diameter d are packed to a porosity m and the coefficient of viscosity of the liquid is n. C and B are constants which were determined from geometrical relations; B was in reality a function of . Values of B(l — m) for various values of m were given in a table. In the same Annual Report of the U. S. Geological Survey, King reported the results of his experiments on the flow of water through porous media. He found that there was a departure of about 86 per cent. from a linear relationship between rate of flow and pressure, for a specimen of Dunnville sandstone for pressure drops not exceeding 60 cm. of mercury. The specimen was approximately 4 cm. in diameter and 5.1 cm. in length. Over the same range of pressure he found a departure of 45 per cent. for a specimen of Madison sandstone. For unconsolidated sands he found departures as great as 49 per cent. for pressure drops of 70 cm. of mercury; for pressure drops not exceeding a few inches of water he obtained a close approximation to a linear relation. He also investi-

Jan 1, 1930

By C. G. Rhodes, D. Kramer

High-field critical transport current density (J) measurements at 4.2 °K as a Junction of applied magnetic field (H) were made on samples of cold-rolled and annealed columbium with H parallel to J. Microscopic examination of the samples revealed a well-defined planar fiber structure produced by the cold rolling. J was found to he lower when fibers are parallel to the direction of magnetic field penetration than when they are perpendicular. This effect may he a consequence of the interaction of flux movement with fiber boundaries. THE severe changes in microstructure brought about by cold working superconductors leads to profound changes in their superconducting behavior. In particular, the ability of a superconductor to carry a transport current with zero resistance (the maximum value of this current density will be called "J" in the presence of large external magnetic fields (to be referred to as "H") is greatly influenced by the microstructure. In the case of columbium, LeBlanc and Little1 and Autler et a1.2 have observed an increase in J due to cold work. LeBlanc and Little also observed an anisotropy in J in cold-rolled columbium strips, which Hake et al.3-6 have shown to depend upon the angle between H (H ? J) and the rolling plane. An increase in J due to cold work has been found in a variety of high-field superconducting alloys3'4'7-9 as has the anisotropy effect.10 First explanations of why cold work raised J invoked the idea that dislocations carried the high-field supercurrents,8,11 since cold working drastically increases the dislocation density and presumably the number of supercurrent paths. However, recent ideas on the nature of high-field superconductivity together with new experimental evidence reveal that the bulk of certain superconductors can remain superconducting in high fields while carrying high transport currents. These later developments have been discussed by Berlin-court and Hake12 and a comprehensive review has been prepared by Berlincourt.13 According to the ideas of Gorter14 and Anderson,15 one would expect that the influence of microstructure on high-field supercurrent density will depend on tine interaction between microstructure and penetrating flux and on the direction of the Lorentz

Jan 1, 1965

By J. J. Thomas, J. H. Nead

This investigation was undertaken to determine, if possible, the relation between static and dynamic tensile tests as measured by the work required to break test specimens slowly, in a tensile testing machine, and rapidly, by means of a falling weight. It was hoped that the investigation would throw some light on the role played by ductility under different rates of application of load. In problems of design, it is usually assumed that the moduli of elasticity of all steels are equal; viz., about 30,000,000. The stress-strain diagram within the elastic limit is a straight line, as shown in Fig. 1, where OA is the curve of a hard steel and OB that of a soft steel. If the modulus of elasticity is constant, as assumed, the slope of the line OC

Jan 1, 1922

By E. Cortese

Phosphate occurs in many places in Egypt, in two main zones: one in Upper Egypt, along the Nile Valley, principally on the right side, and one near the Red Sea coast. In the Nile zone, the principal layers of phosphate rock are to be found: in the mountains east of Mahamid (right side of the valley); in the hills near Sibaiya, also called Sebaieh (both sides); in the hills of Agula, Hagaza and Gurn (right side); and further on, along the camel road leading from Kena to Kosseir, a few miles east of Legheita's Oasis. Following that track, after having crossed the watershed, underlain by rocks like granite, serpentine, porphyry, and diabase, one comes again to the Cretaceous formation containing considerable quantities of phosphate, at Gebel Duwi, Gebel Nakheil, and Gebel Kosseir El Kadim, not far from the coast. More to the north, in the hills near Safaga Bay (Um El Uettat El Wasif) is another rich bed of the same formation. There are reports of phosphate existing near Suez and in the Sinai peninsula, and possibly some other zones can be traced or discovered in the future. The mines are well developed on the right bank of the Nile at Sharawna (near Sebaieh Station) and along the Red Sea coast, at Safaga and near Kosseir. Prospecting work has been done at Gebel Duwi, Gebel Gurn, Agula, Hagaza, and near Mahamid. The phosphatic formation in Egypt is quite variable, not only from place to place, but even within small areas. The phosphate is all of Cretaceous age, as is proved by the fossils found in it. It is considered to belong to the Campanian or, more appropriately, to the Maestrichtian series. The principal fossils are: Alectryonia Villei Coq. sp.; Roudereia Aures-sensis Coq. sp. = R. Drui Mun. Chalm.; Trigonoarca multidentata, Newton.; Cardita libyca, Zittel; Libycoceras Ismaely, Zittel; Nautilus sp.; Ancystrodon libycum Dam.; Corax pristodontus Ag.; Lamma biauriculata Zittel sp. Above the Maestrichtian beds, we have the Danian series, unconform-ably covered by Lower Eocene beds. Under the phosphate is a grayish marly clay, and beneath this, bluish-gray scaly shales resting on the Nubian sandstone (Santonian).

Jan 1, 1918

By J. H. Nead, J. J. Thomas

This investigation was undertaken to determine, if possible, the relation between static and dynamic tensile tests as measured by the work required to break test specimens slowly, in a tensile testing machine, and rapidly, by means of a falling weight. It was hoped that the investigation would throw some light on the role played by ductility under different rates of application of load. In problems of design, it is usually assumed that the moduli of elasticity of all steels are equal; viz., about 30,000,000. The stress-strain diagram within the elastic limit is a straight line, as shown in Fig. 1, where OA is the curve of a hard steel and OB that of a soft steel. If the modulus of elasticity is constant, as assumed, the slope of the line OC

Jan 1, 1922

By Frances H. Clark

IN wartime, the fabrication and use of metals assumes increased importance, for a modern war of sizable proportions cannot be undertaken with- out a vast supply of this material. Light alloys of aluminum and magnesium, which were comparatively unknown in the last war, will play an important role in this one. Due to research on a vast scale in the interim of years, industry is today well equipped to fabricate metals on an enormous scale. Research for the past year has been most productive and a comprehensive survey in the space of this article would be impossible. It is hoped that the stressing of a few items here and there out of a great quantity of able work will indicate in a small way the advances made within recent times. Specific references to the literature will be omitted at the Editor's re- quest but some authors of papers that I have found of special interest are mentioned.

Jan 1, 1940

By Norman Weiss

IF we were to measure progress this year in terms of large new mills and discoveries of fundamental significance we should certainly be disappointed. Outside of the uranium field there was little of a spectacular nature. San Manuel and Reserve completed their first year of operation; Erie approached readiness; the Toquepala project in southern Peru broke ground and gained speed. Important mill enlargements occurred at Inspiration, Anaconda, Ray, and Climax Molybdenum. A 3000-ton copper concentrator was completed at Pima, near Tucson. The Republic Mill of Marquette Iron Mining Co. started up in April. Abroad, the great developments in the African Copper Belt can be likened to the rapid growth of the porphyry coppers in this country. Fundamental research was confined nearly entirely to iron ore flotation and recovery of metal values from leach solutions, particularly uranium. The large number of review articles this year reflected a desire to take stock and consolidate past gains before taking the next bold steps. Undoubtedly a shortage of competent young engineers and technicians is stunting the natural growth of theoretical investigation in the field of minerals beneficiation, as well as the conversion of ideas into action. We find our small stock of talented young scientists concentrated in a few centers of erudition because there are not enough to diffuse through the industry. It is safe to say that among mine administrators and managers there is more interest in the education, training, and welfare of the young engineer than ever before.

Jan 2, 1957

By Joseph Kaye Wood

A metal is said to be overstrained when it is deformed beyond the elastic limit at a temperature well below the critical range, as in cold working. Quantitatively, overstrain might be considered as that part of the total elastic deformation of the piece of metal, left over after the external load is removed, that added to the permanent deformation due to plastic action will give the total permanent deformation. Ordinarily the effects of this phenomenon, which vary with the internal residual stress probably in accordance with Hooke's law, are more noticeable when the yield point of the metal is exceeded, but they probably also exist to a smaller degree when the load is just large enough to cause the least amount of permanent set. These effects, which we recognize as the result of overstrain, are as follows: 1. An apparent increase of the elastic limit in tension and a decrease of the elastic limit in compression, provided the external load is tensile. The reverse is true when the load is compressive. 2. An elastic after-effeet in which time and temperature are important factors. 3. A state of imperfect elasticity in which Hooke's straight line becomes slightly curved, giving rise to an hysteresis loop. 4. In addition to the apparent increase in the elastic limit, such properties as the hardness, ultimate strength, and resistance to fatigue failure are increased, provided the overstraining has not been carried far enough to make the metal brittle. 5. Correspondingly the ultimate elongation, reduction in area, magnetic quality, ratio of endurance limit (fatigue breaking stress) to elastic limit, and resistance to season cracking (in certain copper alloys) are decreased. The question naturally arises: how do these changes in the properties of a metal resulting from overstrain influence our method of design? The fact that most of the desirable qualities are increased makes overstraining a favorable process, from an engineering standpoint; but on the other hand, the loss of such qualities as perfect elasticity and complete

Jan 1, 1924

By Charles M. Rolker

The main tin-producing regions of the world are known to be England, Australia and the Dutch East Indian possessions, chiefly Banca and Billiton. During recent years, the tin of the Malay Peninsula, exported from Penang and Singapore, has been coming prominently to the front. France, Austria, Hungary, Germany, Spain, South America, Russia and China still present insignificant figures. The conspicuous part which the Dutch possessions in the Indian Archipelago have taken in supplying the world with tin, is well known. Tin was discovered in Banca as early as 1710, and has been produced there ever since; but the supply has been most important since Banca came fully into the possession of Holland, in 1821. In Billiton and the adjoining island of Singkep, the existence of tin was known prior to 1822.* The Lingganese knew of its existence in the valley of Embalong, from creeks and streams in the neighborhood of Tima and Simper hills, on Billiton and also on Singkep island, but the prevailing superstition that tin-mining brought misfortune, influenced them to let this industry lie idle. The attempts of the Dutch government to test this question were lukewarm, perhaps by reason of the fear of reducing, through new discoveries, the price of Banca tin, and the island was abandoned in 1826, leaving only a military post. In 1850, Dr. Crookewit, a chemist and naturalist, was sent out to verify the rumors that tin existed in Billiton. His report was unfavorable; but in 1851 Mr. C. De Groot, a mining engineer, found tin readily, and the active work on Billiton dates from that time. Less than 600 tons were produced during the first ten years, and 3000 tons in the next decade. Billiton tin-mining is done by

Jan 1, 1892

By Louis D. Huntoon

The Porcupine gold area, located on the Hudson Bay slope of northern Ontario, has produced over $100,000,000 in gold and has paid more than $28,000,000 in dividends, since the first real production in 1912. The character of the ore has been studied by the geologists of the Bureau of Mines of Ontario, the geological staffs of the operating mines, and engineers commissioned to examine properties there. What information the Government has is free to everybody; the geological staffs of the several properties also give to the visiting engineer what information regarding ore deposition they possess, and the author wishes to express his indebtedness to the geologists of the Ontario Bureau of Mines and the staffs of the operating mines for their free discussion of geological questions. This paper is based on the examination of several properties, various petrographic reports, not only on specimens from Porcupine but from elsewhere in northern Ontario, and interviews with Government and mine staff geologists. The petrographic work has been done by Prof. R. J. Colony, of Columbia University. Geological History The geological history of the district may be summarized as follows: The outpouring of great floods of lava accompanied by beds of tuff, flow following flow; the contacts of different flows can be seen in various parts of the camp. This period mas followed by an uplift and the production of the Temiskaming sediments by erosion. Later, dynamic action turned the sediments and underlying lavas on edge; this was followed by the intrusion of igneous rocks—in the Porcupine area the quartz porphyry, which is of such great importance in connection with the gold deposits. Doctor Burrows says: "The intrusions of quartz porphyry have in some way influenced the deposition or location of the gold but it is not likely the porphyry has been the source of the gold-bearing solutions." This statement of Doctor Burrows I indorse. The formation of non-gold bearing quartz veins followed the intrusion of the porphyry. These veins occur along or near the contact of

Jan 1, 1923

By Louis D. Huntoon

The Porcupine gold area, located on the Hudson Bay slope of northern Ontario, has produced over $100,000,000 in gold and has paid more than $28,000,000 in dividends, since the first real production in 1912. The character of the ore has been studied by the geologists of the Bureau of Mines of Ontario, the geological staffs of the operating mines, and engineers commissioned to examine properties there. What information the Government has is free to everybody; the geological staffs of the several properties also give to the visiting engineer what information regarding ore deposition they possess, and the author wishes to express his indebtedness to the geologists of the Ontario Bureau of Mines and the staffs of the operating mines for their free discussion of geological questions. This paper is based on the examination of several properties, various petrographic reports, not only on specimens from Porcupine but from elsewhere in northern Ontario, and interviews with Government and mine staff geologists. The petrographic work has been done by Prof. R. J. Colony, of Columbia University. Geological History The geological history of the district may be summarized as follows: The outpouring of great floods of lava accompanied by beds of tuff, flow following flow; the contacts of different flows can be seen in various parts of the camp. This period mas followed by an uplift and the production of the Temiskaming sediments by erosion. Later, dynamic action turned the sediments and underlying lavas on edge; this was followed by the intrusion of igneous rocks—in the Porcupine area the quartz porphyry, which is of such great importance in connection with the gold deposits. Doctor Burrows says: "The intrusions of quartz porphyry have in some way influenced the deposition or location of the gold but it is not likely the porphyry has been the source of the gold-bearing solutions." This statement of Doctor Burrows I indorse. The formation of non-gold bearing quartz veins followed the intrusion of the porphyry. These veins occur along or near the contact of

Jan 1, 1923

By E. G. Williams

Manganese-ore has been found upon the Isthmus of Panama throughout' a region of nearly three hundred square miles, over the greater part of which, however, it is known only in small bodies without commercial value. Only six mines, controlled by two companies, have actually shipped ore, although a large area has been taken up in miningelaims. The ore-bearing region extends along the coast of the Carib. bean Sea, beginning on the west near Puerto Bello and extending easterly about 35 miles toward Point San Blas. Ore has been discovered in the interior, at a maximum distance of about 10 m. from the coast. Fig. 1 is a map of a portion of the Isthmus

Jan 1, 1903

By Peter N. Blakey, Thiann R. Yu, Douglas O. Tansey

A flexible, efficient, and relatively low-cost drilling and blasting operation has evolved at Texasgulf Canada, Ltd.'s Kidd Creek underground mine. Located 32 km (20 miles) north of historic Timmins, Ontario, the underground operation utilizes a sublevel open stoping method developed with large-diameter blastholes. Over the years, Kidd Creek engineers have experimented with various drill-and-blast techniques, leading to the present-day practice. Continuing work is being conducted to further mechanize the blasting operation.

Jan 6, 1976

By H. K. Birnbaum

The termination of a twin lamella in the interior of a crystal requires accommodation of the strains at the tip of the twin which result from coherency of the twin and matrix. In zinc and magnesium crystals,

Jan 1, 1960