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By E. E. De Beer

This paper describes a method for the determination of the settlement of an individual H-bearing pile, based on the results of CPT-tests. As implied by the nature of the problem, no analysis performed on one pile can be regarded as generally valid for a whole piling foundation project because, even on one site, the pile behaviour varies from one pile to another. Consequently, no precise mathematical analysis has been established; the proposed procedure represents a simple model for the determination of the probable settlement behaviour of an H-pile under a compressive load. Prior to the settlement computations, the rupture load and the resistance distribution along the pile have to be determined. Since the method for the determination of the H-pile bearing capacity from the results of CPT tests has been described elsewhere (de Beer, 1971, 72; de Beer et al., 1982; Arbed, 1985), no details will be given in this paper. The proposed method is valid for both uniform and non-uniform H-piles. The computed results have been satisfactorely compared to the static loading tests performed on different types of piles in clayey and sandy soils during an ECSC research program on H-bearing piles (1983-1987).

Jan 1, 1987

By R. A. Turpin

Bethlehem Steel's Research Department is developing a set of computer programs as mine-planning tools for Bethlehem's coal mines. Several of these computer programs have been completed and have been in routine use by Bethlehem Mines personnel since early 1975. The production scheduling and ventilation planning programs have been installed on an interactive time-sharing computer. The use of time sharing allows mines in remote locations to access these planning tools through standard phone lines and low-cost computer terminals. The capabilities of the interactive production scheduling and ventilation planning programs are briefly described. The advantages of implementing them using time sharing are discussed. A case study illustrates some of the benefits that planning based on the use of these programs has already provided.

Jan 1, 1977

By G. C. Hall, B. E. Hobbs

Giant gold deposits are considered products of crustal-scale systems. Reduced fluids stored in mid to lower crustal reservoirs were discharged into mid to upper crustal sites of deposition. Elements of the architecture include crustal-scale structures, reduced packages of rock and regional seals. Gas-rich aqueous fluids were common but non-aqueous fluids may have been significant in the deeper parts of the systems. Fluid fluxes in over pressured domains were maintained by porosity waves. Abnormal heat input from the mantle may not be required once the systems were perturbed. Fluid-mixing and hypogene enrichment were probably the most significant precipitation processes.

Jan 1, 1999

By Eugene McAuliffe

The term "mechanical mining" carries an ambiguity which justifies a preliminary word of explanation. . All mining activity conducted in this day is more or less mechanical; that is to say, power expressed in the form of electricity, steam or compressed air is used in some portion of practically every mining activity of consequence. "Mechanical loading" is more nearly correct than "mechanical mining" in reference to present practice. The first substantial effort made in the direction of mechanical mining, subsequent to the application of steam for hoisting and underground pumping purposes, was that of substituting for hand labor undercutting and shearing by power-driven machines. The undercutting of coal by hand represented at one time the most arduous task confronting the miner. Occupying a kneeling position in the thicker beds, or lying on his side in the thinner coal, the task was tedious and exhausting. The first attempt to substitute crude air-driven, and later electrically driven, "punchers," as the percussion type of machine was called, met with much the same opposition on the part of the workers as was expressed by workers in the other industries when any innovation, whether labor-saving or otherwise, was introduced. We should not be too critical of this attitude of mind shown by the mine workers. The peculiarly isolated character of the work carried on in semidarkness by a class of men who to a large extent lived and held themselves aloof from the other branches of society led long ago to the development of a craft consciousness which they have found difficult to surrender. It was not until 1891 that a definite record of the results obtained by the use of undercutting machines of all types was made available, the quantity undercut in that year totaling 6,211,732 tons of bituminous coal from all American mines. The volume of bituminous coal undercut by machines in 1928 totaled 369,687,007 tons, or 73.8 per cent. of the nation's production. In the light of this experience, we can properly feel that the work of introducing the coal-loading machine as a substitute for hand shoveling is making substantial progress.

Jan 1, 1931

By Ta M. Li

A change in priorities is perhaps the underlying motivation reflective of governments and people in the Far East nations of the Philippines, Indonesia, and Thailand. While in the past, local governments have focused on feeding their large populations, the transfer of modern technology to the agricultural sector has produced record crop years in many of these countries. As a result, agricultural objectives have become more manageable, prompting governments to shift priorities to the accelerated development of their industrial sectors. The basis of any sustained industrialization program, the governments concede, is the development of a vibrant minerals sector.

Jan 8, 1979

By Raymond C. Voige

"The use of current electronic technology in the design of new underground mine communications equipment is providing improved and expanded voice communications which can, in turn, contribute to improved productivity and safety. A review of equipment that is now available or under development Includes the following categories:WIRED SYSTEMSI.Pager phones with selective calling, audible and visual alerting and message indicator.2. Mufti-conversation pager phones that use multiwire cable ormultiplexing techniques.WIRELESS SYSTEMSLow-and medium-frequency inductive systems utilizing ""near"" magnetic fields for both vehicular and personal communications.Wired SystemsCommunication systems in underground mines have evolved slowly in many parts of the world. For many years, magnetotype telephones were the only means of communication from one mine level to another and to the surface. These units were located near the shaft and communications to the working areas were limited."

Jan 1, 1981

By W. F. Carew, F. A. Crossley

The stress for rupture in 500 hr at 1000° F has been reported to be about 13,000 psi higher for Widmanstitten than for equiaxed microstructures for the Ti-7A1-3Mo alloy.1,2 Also, limited data indicated Widmanstatten and equiaxed micro-structures to have approximately the same creep resistance at 1000°F.' Recently, data have been obtained which show Widmanstatten structures to be significantly more creep resistant than equiaxed structures at 1000°F, see Fig. 1. These data represent several ingots and several heat treatments of the solution treat and age type. The thermal history and tensile properties corresponding to the creep data are given in Table I. The creep data were taken from creep-rupture tests. The associ- ated rupture data are given in Table 11. It may be noted that total creep deformations are considerably greater for equiaxed structures. Previous evaluations of stability indicated that all of the structures tested are stable with respect to exposure to stress at elevated temperature.1,2 For a minimum creep rate of 10-4 in. per in. per hr the difference in stress levels is indicated to be about 17,000 psi. Holden,et found an irreversible contraction upon heating three a-ß titanium alloys in the equiaxed condition above their ß-transus temperatures. The alloys were: Ti-6Al-4V, Ti-155 A (5Al-1.3Cr-1.5Fe-1.2Mo), and C-130 AM (44-4Mn). The net contractions in length between the original equiaxed and the final Widmanstatten structures measured at room temperature were: 0.4, 0.4, and 0.7 pct, respectively. The greater creep and rupture resistance of the WidmanstStten structure of the Ti-7Al-3Mo alloy may be associated with the phenomenon

Jan 1, 1959

The physical phenomena which influence gas flow in the bosh and hearth of a blast furnace are discussed including the hold-up of slag as a mechanism which can result in a flooding condition. An equation is defined which describes the limitation to wind volume arising from the flooding condition. Implications of the various factors influencing bosh and hearth gas flow on furnace operation are discussed. Coke quality is shown to be the most important factor in the aerodynamics of these zones and coke requirements are defined for the Port Kembla No. 5 BF which has an inner volume of 2670 m3.

Jan 1, 1975

By C. H. Manney

This report deals with the feasibility of the use of vocoders as an integral part of a mine electromagnetic voice communication system. Limitations imposed by the nature of the transmission path, background noise and equipment are examined. Some properties of vocoders and apparent advantages of the use of vocoders in a mine communication are discussed. The conclusion is reached that the man-made noise level will ultimately determine the workability of such a system.

Jan 1, 1972

By Lonie W. M

The rapid development of the Australian steel industry over the past twenty years has greatly increased the demand for coking coal from the collieries owned by the Broken Hill Proprietary Co. Ltd. and Australian Iron & Steel Ltd. This in turn has called for an intensive and continuous programme of colliery expansion and new colliery development, along with the reorganization and modernization of existing collieries.This paper presents a general description of the factors involved and the techniques used in planning modern colliery development for the steel industry.PRELIMINARY GEOLOGICAL INVESTIGATIONSIn any colliery development, preliminary geological investigations require a detailed and practical knowledge of the geology and characteristics of the coal-field as a whole. In the early stages of the investigations, probably the most valuable information is obtained from outside the particular area under review, rather than within it, and unless the geology of the coal-field is understood, the projection of the known information into the unknown area cannot be carried out with certainty.Because development of the coal seams from the outcrops has been an apparently simple matter and not subject to the risks involved in deep mine development, the geology of the New South Wales. coal-fields has not received the attention that major mineral resources warrant.Only the most accessible regions of the coal measures have been generally prospected, while the potential areas remain...

Jan 1, 1957

By Frank J. Weibelt

In accordance with provisions of the Strategic Minerals Act of 1939, the Bureau of Mines surveyed the chromite occurrences in California. The Seiad Creek deposit afforded excellent opportunity for developing reserves that could be used by the nation in case of critical shortages of the mineral. Subsequently an exploration and development program was undertaken in April 1941, which was concluded in October of the same year. Work included road construction, diamond drilling, drifting and crosscutting, surface trenching, and sampling.

Jan 1, 1949

By Kefton H. Teague

Attempts to locate domestic supplies of sillimanite have been un- successful until recently. This paper describes recent discoveries of sillimanite-bearing schists in the Southeastern States, with emphasis on geology of the deposits, mineral composition, origin, and reserves. Statements concerning possible methods of mining, milling, and utilization of sillimanite are given. Results from refractory tests on a laboratory scale are summarized.

Jan 7, 1950

By Koehler Stout

Many hydraulic backfills are deposited at low density and provide less than optimum support strength to stope walls. This laboratory study shove that fill strength can be considerably increased. Placement methods used to increase the fill strength were the head, vibratory, cementation, double-planed (dblplod), and combinations of these methods. An experimental facility van designed to study the placement cathode and resultant strengths of the fills. Physical property tests made on the fills included laboratory penetration and vane shear plus several supplementary tests, such as grain size distribution and relative density. Test results were compared to fills planed by conventional methods and to those results reported by other investigators. When compared to fills placed by conventional methods, the penetration modulus was increased by 4.3 tines when the uncemented-vibrated-head concept was used and 71 times when the cemented-vibrated-head-dblplod concept was used. Apparently, hydraulically fill strength can be substantially increased. Conceptual mining plans are also included on suggested ways of placing and using high-modulus backfills.

Jan 1, 1979

By L. F. Mondolfo, B. E. Sundquist

The undercooling associated with the nucleation of the secondary phase from the liquid by the solid primary phase was studied in sixty binary alloys by means of a hot-stage microscope. It was found that in a system of a and ß, a usually nucleates ß at low undercoolings, but ß does not nucleate a, except possibly at undercoolings approaching homogeneous nucleation. This behavior can be explained in terms of relative interfacial energies and shows that crystallographic disregistry is only a minor factor in heterogeneous nucleation from metallic liquids. PREVIOUS experimental work1-6 on nucleation of solids from liquids has shown that normally nucleation is heterogeneous, and that small solid particles present in the liquid are responsible for the nucleation. These experiments and the theory that has evolved from them have made apparent that there is a "characteristic undercooling" associated with the nucleation of the solid from a given liquid by a given impurity. Little is known, however, about the chemical and structural relationships between the nucleating agent and nucleated solid that control the effectiveness of the nucleating agent in catalyzing the nucleation, as measured by the required undercooling. A review of the literature has yielded seventeen undercoolingsL-6 for the nucleation of solid from liquid metals by "known" nucleating agents. All values come from experiments in which the metal studied was divided into a number of particles (10 to 300 pin diam.) much larger than the number of extraneous impurity particles so as to obtain a large number of particles free of foreign nucleating catalysts. Known nucleating agents are then introduced by coating the droplets with particles or a thin film of the catalyst. Six of the seventeen undercooling values referred to cases where, for various reasons, the identity of the nucleating species was not at all certain. Another six cases involved nucleating agents with a crystal structure that was not known. Four other cases involved undercoolings listed as greater than or equal to undercoolings which were very likely those for homogeneous nucleation. One investigation3 involved adding to droplets powdered oxides, carbides, and so forth that were doubtlessly covered with adsorbed oxide or nitride films. The highly variable nature of these films resulted in highly variable undercooling (as was also found in preliminary work in this investigation). It is apparent that the information on heterogeneous nucleation in liquid metals is too limited to give rise to any definite conclusions on the nature of the catalytic process. With these problems in mind a new method was

Jan 1, 1962

By Willard P. Ward

It is the object of the present paper to bring to the notice of members of this Institute, the results of experiments made during the past six months in the manufacture of the alloys of iron and manganese in the blast-furnace. The ores at hand and available for the purpose were brown hematites, containing but a very small percentage of manganese, and various manganese ores containing a small percentage of iron. It is hardly necessary here to call attention to the statements regarding the production of iron-manganese alloys from such ores, which are given by all the well-recognized authorities on metallurgy. Suffice it to say, in a few words, that they hold that the operation is practically impossible, and that in the use of oxides of iron and manganese, mechanically intermixed in the same ore, much difficulty has been found in producing spiegeleisen. Spathic ores, containing manganese chemically combined, are alone recommended for the production of spiegel, and even then it is said that well-managed furnaces produce only about 75 to 80 per cent. of spiegel, the balance of the production being white laminated pig or gray iron.

By J. B. Pullen

THE United Verde mine is in the north central part of Arizona, on the. north-easterly slope of the Black Hills, near the town of Jerome. Ore was first discovered in the district about 1875, and the first mining claims were located by M. A. Ruffner and associates in 1877. In 1888 the late Senator William A. Clark secured control of the property and under his ownership it developed into one of the country's most important copper producers. The property was sold to the Phelps Dodge Corporation in 1935, and since then has been under this Corporation's management. Except for shutdowns caused by general world-market conditions, production has been continuous from 189o to date. GEOLOGY The mineralized zone ranges in area from approximately 12 acres to less than 5 acres. All mineralization occurs in the pre-Cambrian intrusives. The first intrusion, according to geologic records, was the quartz porphyry, which later was intruded by augite diorite. Following the diorite intrusion through a series of intrusions of lesser magnitude, a pipelike mass of massive sulphide, quartz and rock was formed. The diorite forms the hanging wall of this mass, and the porphyry the footwall. Between the footwall and the sulphide a band of chlorite schist was formed, probably owing to metamorphic conditions. Commercial ore occurs along the contact of the schist and sulphide extending into the sulphide, sometimes entirely through the schist, and fingering out into the porphyry. The ore deposit was formed by replacement similar to deposits formed in limestone areas. Faulting and deformation occurred in pre-Cambrian times and again in the Tertiary period, removing approximately 2000 ft. from the top of the main United Verde ore body, forming the United Verde Extension ore body, the only other major ore body in the district. Major development work has shown that the sulphide mass extends to the 3300-ft. level, and diamond drilling below this level has indicated that the mass might extend below the 3700-ft. level, but in a diminished quantity. While many copper minerals exist in the mine, the chief commercial mineral is chalcopyrite. A plan and vertical section of the mineralized zone showing the principal geological features is shown in Figs. I and 2. GENERAL DESCRIPTION AND PHYSICAL CONDITION OF MINE After over 50 years of active production, ore still exists on almost every level of the mine. This condition is due to many causes -mine fires, which broke out as early as 1894, caused the abandonment of certain areas; subsidence and ground movements retarded the cleaning up of others. Furthermore, in the early days there was such an abundance of ore that when mining became difficult it was a simple matter to replace the production by going to a deeper level. Several attempts were made to recover the ore in the fire zone, both by glory-holing

Jan 1, 1941

By Robertson A. D C, Cranfield L. C, Murray C. G

Most base and precious metal mineralisation in the Gympie Province is genetically linked to intrusion of branitoids of Late Permian to Late Triassic age. Most lodes are hydrothermal quartz and quartz-calcite veins at intrusive contacts, within either the granitoids themselves or the country rocks, and commonly associated with dykes. Other types of intrusive related deposits are disseminated porphyry type Cu, base metals in skarns, and Mo in quartz pipes and veins. Although the Late Permian-Late Triassic granitic intrusives can be subdivided in terms of age, it is not yet possible to relate deposits of particular metals or styles to granites of a specific age on a regional scale.Some significant mineralisation is not associated with granitic intrusions. This includes the Gympie goldfield, by far the largest known deposit within the Gympie Province. Gold occurs in quartz veins crosscutting Early Permian volcaniclastic sediments and also in NW striking fault zones. The source of the mineralisation is unknown. Gold and silver also occur in epithermal, disseminated and breccia hosted deposits within Late Triassic continental volcanics. Epithermal Hg mineralisation at Kilkivan may be related to Early-Middle Triassic volcanics.

Jan 1, 1990

7253. Arkhangelsky, A. D. Geological Results of the General Magnetometric and Gravimetric Surveys of the U.S.S.R. (in Russian). Internat. Geol. Cong., Rep. of the 17th Sess., Moscow-Leningrad, 1937, vol. 1, Moscow, 1939, pp. 241-250. Geophysical methods have been used in the U.S.S.R. to study geological problems. Such is the case of the general magnetometric and gravimetric surveys made jointly by the Main Physical Observatory, Main Office of Geodesy and Cartography, Institute of Terrestrial Magnetism, and Main Office of Geophysical Prospecting. Some institutions supplied the data, others processed them. Geological interpretation was made by the author. (1) Regional magnetic anomalies in the plains of the U.S.S.R. are traceable to the folded substratum overlain by sedimentary rocks; these anomalies promise to yield data characterizing the substratum in respect to strike and depth. Anomalies in European U.S.S.R. suggest that the pre-Cambrian -substratum of the East European plateau consists of elements of different ages. In the most ancient of them, the main strike of the folding is almost latitudinal; in the younger ones, the folding is oriented in the meridian. (2) The Faye and Bouguer gravity anomalies are caused primarily by differences in the density of rocks composing the upper crust and by unknown processes producing changes of density at depth; these processes are not connected with isosiatic movements. The anomalies in the European and adjoining Asiatic U.S.S.R. promise to indicate the volume of the pre-Cambrian massif of the east-European plateau and to clarify the interrelations between the Ural, Tian-Shan, and Donetz Basin folding systems, as well as between the Dnieper-Donetz depression and the mid-European depression. - V. S.

Jan 1, 1944

The application of cheap robust microprocessor based units to achieve monitoring and control in an underground mining environment is described. The functional layout of the programmable controller and the methods of multiplexing and processing information from local and remote sources are examined as are features for refrigeration plant control.High noise immunity communication to a remote micro computer uses existing telephone lines and enables display and print of essential data. The development of this system then leads to applications in monitoring compressed air, ore transport and underground fires.In conclusion, the problems of data presentation to different levels of management and the future philosophy of a central multi-reporting system are discussed.

Jan 1, 1985

Diamond drilling was first carried out at Norseman in the Princess Royal Mine, early in this century. Little concentl'ated drilling was done from then until Western Mining Corporation commenced drilling in 1934. Since then Central Norseman Gold Corporation N.L. has continually employed diamond drilling in exploration of the field. After 1946 the advantage was seen of applying broad pattern surface drilling at Norseman in the reef exploration. In 1953, as a result of the steeply rising cost of drilling and the time taken to penetrate surface material by light equipment, heavier drills and new rigs were introduced. The surface drilling programmes called for a greater monthly or annual footage and to satisfy this new techniques were introduced. The Mitchell-21 machines were discarded and A-3000 machines were installed, firstly under a 48 ft. fixed tower, then mounted on a truck with a 20 ft. tower, and finally on a truck carrying a 40 ft. tower. With the mobile units a compressed air compressor is attached. By use of compressed air with either the Reed roller or Hawthorne bit, rate of penetration of overburden is greatly increased. The mobility of the truck mounted machines has greatly reduced the time required to move from one hole to another, and the use of heavier machines on a three shift per day basis has considerably increased the footage per shift. The general result is an increase to 1,500 ft. of drilling per month per machine, while costs have been greatly reduced in spite of increased wages and diamond prices.The underground drilling technique is described. Analysis of performance has not been made because the drillers performance is subject to shaft routine and service.INTRODUCTIONGold was first discovered at Dundas in 1894, and at Norseman, 14 miles north, in 1895. From that tirpe until 1935 mining activity fluctuated. Following the mining revival in 1935, production in the field has remained comparatively stable. This stability in part has been due to the broader scale of operations of Central Norseman Gold Corporation N.L., and in these operations diamond drilling has played an increasingly important role.

Jan 1, 1956