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By S. Devereaux, P. Gover, S. Everett

Having real-time data of blast furnace burden profile with respect to burden height and temperature is critical to making informed decisions on blast furnace operation. Given the high temperature and gaseous environment within the blast furnace shaft, traditional instrumentation has been limited at providing the level of real-time feedback information needed to optimize blast furnace operations. Infrared thermal imagery technology provides non-contact temperature measurement across the entire burden profile, allowing for better understanding of the dynamic movement of the burden within the blast furnace shaft. This technology increases blast furnace performance by improving the decision-making process for hour by hour operations. This paper will discuss the development of incorporating infrared thermal imagery technology into the operating strategy of a lead blast furnace.

Jan 1, 2015

By D Chalmers

"There is a tendency to treat mine roadways with fan installations as leak proof systems. Morecomplex ventilation arrangements are being installed in coal mines out of necessity or designand these can introduce additional hazards. This paper explores the leakage paths that can existaround fans and in particular the hazards these leakage paths may generate around undergroundfan installations. The behaviour or these leakage paths in the event of a fan failure has also beenexplored. Early detection of spontaneous combustion is essential, so understanding the leakage behaviour around fans especially boosters or main fans installed underground will assist in sett ing up monitoring locations in the correct places. If this behaviour is not fully understood then monitoring may be placed incorrectly, or trends may not be picked up until it is too late."

Jun 1, 2012

By Gabriel Voicu, Marc Bardoux, Ross Stevenson, Nuno Machado, Jean Lafrance

"Abstract - Paleoproterozoic gold is found in two different volcano-sedimentary sequences and intrusive bodies separated by 600 km within the Guiana Shield. The 2148 Ma St-Élie granite intruded volcanic-arc sequences of the Paramaca Group, whereas the 2096 Ma Omai stock penetrated backarc/ island-arc sequences of the Barama-Mazaruni Group. Positive ?Nd values suggest that both suites lack Archean crustal contaminants, which is consistent with an origin in an oceanic arc setting.The St-Élie deposit is characterized by quartz-dominant vein systems with minor metallic minerals, represented chiefly by pyrrhotite and pyrite. Biotite, calcite, and chlorite are the main gangue minerals. The alteration haloes at St-Élie feature a strong potassic zone, which is absent at Omai. The ore-controlling structures are ductile and the vein emplacement is related mainly to contemporaneous, high-angle ductile shear zones. The St-Élie deposit formed at temperatures >350°C. The stable isotopes values are compatible with a magmatic or metamorphic source.The Omai deposit is characterized by quartz-dominant vein systems with minor metallic minerals, represented mainly by pyrite. Ankerite, scheelite, albite, and chlorite are common gangue minerals. The vein emplacement is syn- to post-deformation and it is related mainly to brittle shear zones with low-angle, stockwork networks and breccia zones. The Omai deposit formed in a temperature range between 250°C and 170°C, much lower than the St-Élie deposit. The stable isotope values are compatible with mixing between deep-seated fluids of metamorphic or magmatic origin with surface- derived fluids.These differences between St-Élie and Omai are interpreted in terms of their depth of formation. Alteration patterns, structural elements, and paragenetic assemblages indicate that the gold at St-Élie was most probably emplaced at a mesozonal depth, whereas the Omai setting yields evidence for epizonal conditions."

Jan 1, 1999

By J. G. Trowell, D. T. Magee

"IntroductionMANITOBA'S first recoverable oil was from the California Standard Daly 15-18 well in Lsd. 15, Sec. 18, Twp. 10, Range 27, W.P.M., completed early in 1951. This well also gave the first indications of commercial production in the Williston basin, which is centred in North Dakota and extends into southeastern Saskatchewan and southwestern Manitoba. Subsequent drilling in the Manitoba portion of the basin has revealed the presence of oil in more or less commercial quantities at various points in an area approximately four townships in width and eleven townships in length.Although completions are becoming fairlly widespread in the area,, the greatest activity is in the Virden district, with the focal point in the Daly field, approximately eight miles west •of Virden. This paper will deal with the various techniques used in the Daly field, where •completion problems have •been unusually troublesome. Techniques evolved there have already been used with success at other points in southwestern Manitoba.Daly FieldGeneralTo date, all production has been from the Mississippian limestone, which is encountered •at depths ranging from 2,300 to 2,500 feet. Pay thickness is •of the order of 100 feet. Core analyses indicate average porosity .of about 9 per cent but permeabilities, for the most part, are extremely low."

Jan 1, 1953

By Mohammad Djavid

The one-pass tunneling pipe jacking method has often been the most schedule and cost efficient method for the pipe line installation. The main challenges in jacking pipes larger than 108 inches and for longer runs are: transportation and logistics, requiring high jacking forces, keeping line and grades, control of ground surface settlement, providing adequate external lubrication, and the potential of damaging the joints and pipe spigots. In recent years, 144" diameter pipes have been jacked for short runs of up to only 300 feet. In this article design and construction of installation of up to 1,000 linear feet run of 144-inch internal diameter, reinforced concrete pipes without intermediate jacking station in Chicago O?Hare International Airport are discussed. The article also presents discussions regarding the subsurface saturated silt formation, shallow cover, dewatering, jacking and receiving shafts, jacking forces, lubrication and settlement data.

Jan 1, 2008

By Robert Anderson

ROUGHLY, a crack in a casting may be considered, for the moment, to be due to fracture of the alloy resulting from the stress set up by the contraction in volume on passing from the liquid to the solid state. Cracks may be external or surface, internal or deep-seated, or incipient or so-called strain cracks. Draws may appear as depressions, unevenness, and "pinching in" of the surface of a casting. Roughly, draws are due to contraction in volume and are governed largely by the same factors as cracks. A casting may be cracked, however, without being drawn. Shrinkage is a foundry term; it connotes the contraction in volume of a metal or alloy on passing from the liquid to the solid state. Pattern-makers' shrinkage is the total contraction in volume (including liquid, solidification, and solid shrinkage) that occurs when an alloy is poured into a mold. The contraction in volume of aluminum is one of the principal factors affecting the occurrence of cracks, as will be shown later, and the question of shrinkage and its control requires careful study in any treatment of cracking in castings. In the case of, sand and die castings, cracks have been attributed to a number of causes, but in the case of most light aluminum alloys, they are due to the large contraction in volume on freezing and the lack of its regulation or control. The most important factors are: (1) Contraction in volume; (2) composition of alloy; (3) quality of melting charge; (4) design of casting; (5) method of molding; (6) hardness of ramming; (7) method of gating; (8) hardness and characteristics of cores; (9) chills; (10) risers; (11) melting temperatures; (12) furnace used for melting; (13) pouring tempera-tures; (14) inclusions in alloys; (15) hot shortness of alloys; and (16) physical properties of alloys at high temperatures. Of these, the first, second, third, and eleventh to sixteenth involve ascertainable metallurgical facts; the remainder are largely matters of opinion, judgment and technical knowledge of men experienced in the production of castings.

Jan 10, 1921

By Warren D. Longwill

The Bureau of Mines inventoried Federal lands in the State of Oregon and classified them in detail, section by section, according to their availability for mineral exploration and development as affected by legal status and agency management practices. The Bureau determined areas of the State having past mineral production and/or known metallic mineral resources and areas favorable for coal, oil, gas, and geothermal resources, and prepared maps that spatially compare the availability of Federal mineral land with these mineral areas to demonstrate the extent of restrictions to mineral entry. Oregon contains 62.1 million acres, of which 33.9 million acres or 55% is Federal mineral land. About 2.3 million acres of Federal land is favorable for selected metallic mineral deposits, of which 64% is available, 13% is restricted, and 23% is unavailable. Of the 21.1 million acres of Federal leasable land favorable for oil and gas, 68% is available, 11 % is restricted, and 21 % is unavailable. Of the 146,720 acres favorable for coal, approximately 71% is available, 13% is restricted, and 16% is unavailable. Federal leasable land favorable for geothermal resources amounts to 458,968 acres, of which 42% is available, 34% is restricted, and 24% is unavailable.

Jan 1, 1988

By A. C. Veatch

Jan 1, 1921

By X-F Zhao, J-W Li, L-P Zeng

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The formation of Kiruna-type deposits has been ascribed to either immiscible iron phosphate melt separated from silicic magma or precipitation from magmatic-hydrothermal fluids. The early Cretaceous Ningwu volcanic basin in Eastern China contains tens of Kiruna-type iron deposits. The orebodies are mainly hosted within the top zones of subvolcanic dioritic intrusions and along the contacts between these intrusions and adjacent volcanic rocks/strata.The orebodies are commonly associated with widespread brecciation and wall rock replacement. Magnetite formation was closely associated with extensive hydrothermal alteration that may extend kilometres, with both vertical and horizontal zonation. Field and textural data indicate that magnetite formed slightly later than albitisation but coeval with apatite and actinolite. Elemental analysis of magnetite and apatite from ores shows distinct features to those as igneous accessary minerals in the host dioritic intrusions, suggesting a genetic relationship to magmatic-hydrothermal processes. Magnetites have elevated TiO2 (up to 5 wt per cent) and V2O3 (up to 0.7 wt per cent), which implies that they are derived from incipient high-temperature magmatic fluids. It is concluded that the Kiruna-type deposits in the Ningwu basin most likely formed from high-temperature magmatic-hydrothermal fluids. The emplacement of dioritic intrusions into a subvolcanic setting likely plays a critical role in the development of Kiruna-type deposits.CITATION:Zhao, X-F, Zeng, L-P and Li, J-W, 2015. Kiruna-type iron deposits in the Mesozoic Ningwu volcanic basin, Eastern China – origin and relationship to subvolcanic dioritic intrusions, in Proceedings PACRIM 2015 Congress, pp 657–662 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By Martin J. Pedley

The use of soil nailing has grown steadily in the UK over the last 15 years and it has recently become more popular in the Republic of Ireland. This paper presents three soil nailing temporary works case histories where the technique has been used to support steep excavations in difficult ground conditions. It demonstrates the effectiveness of soil nailing when applied in appropriate conditions. Details of design methods and construction techniques are described and those aspects of soil nailing that will benefit from further study and development are identified.

Jan 1, 2000

By M. J. Miller, N. Ripepi, M. Karmis, J. M. Conrad

Unmineable coal seams present an opportunity to sequester carbon dioxide emissions from power plants, while enhancing the recovery of coalbed methane. Injected carbon dioxide is adsorbed and stored on the coal surface while releasing methane that can be commercially recovered. Carbon sequestration, therefore, allows the utilization of unexploited mineral resources while reducing “greenhouse” gas emissions. This paper presents the feasibility, efficiency and enhanced recovery potential of coalbed methane production using carbon dioxide sequestration in the Central Appalachian Basin. The focus of research is on geological characterization of unmineable coal seams in Central Appalachia and the corresponding carbon dioxide storage capacity. Virginia Tech and Marshall Miller & Associates, Inc. conducted this research under the Department of Energy’s Southeast Regional Carbon Sequestration Partnership program.

Jan 1, 2006

By S. E. Bronisz, R. E. Tate

s-plutonium samples possessing a strong growth texture have been produced by allowing them to transform under pressure from p to a. A fiber texture with [010] parallel to the pressure axis results. The textured samples are expected to be useful in determining the effects of crystallographic orientation on the physical properties of a plutonium, and initial results of measurements of resistivity and mechanical properties are described. THE crystal structure of a plutonium1 is mono-clinic, P21/m, and many of the metal's properties should reflect the crystallographic anisotropy. Unfortunately, it has not yet been possible to grow useful sizes of single crystals of a plutonium. Therefore, few of plutonium's orientation-sensitive properties have been determined as a function of crystallographic orientation. One way to gain information about at least some of the orientation-dependent properties is to study a highly textured sample. Such samples have been produced by cold rolling a plutonium,2 but they are necessarily very small in one dimension. We have now successfully used two other techniques to produce highly textured samples, not limited to small thicknesses. METHODS OF PRODUCING PREFERRED ORIENTATION The texture is produced by causing the plutonium to transform from ß to a while under pressure. It was observed by Gardner3 that applying a compres-sive load during the transformation resulted in the formation of columnar grains of a plutonium, and Cramer4 observed a similar structure in some diffusion couples rolled in the P phase. Neither of these workers, however, investigated the subject beyond these observations. The more flexible of the two methods developed is that of compressive loading. The technique is to enclose a sample of plutonium in a die assembly before applying the load. It is possible, of course, to dispense with the die and simply press the sample between two platens. In this case, however, the unrestrained sample deforms during the pressing, making it difficult to maintain the load and to control the final sample thickness. This compressive loading technique has been used on specimens ranging from 1/4 to 3 in. diameter, with height-to-diameter ratios ranging from 5 : l to 1:6. The procedure begins with loading the sample, a right cylinder of a plutonium, into the pressing die. Plastic deformation of the sample while it is being pressed is minimized by machining the sample so that its diameter is nearly the same as that of the die barrel. Then the loaded die assembly is placed in a vacuum pressing can that fits on a hydraulic press. After a vacuum is achieved the die assembly is heated to 180°C and equilibrated. The load is then applied and the specimen and die are allowed to cool to about 40° to 50°C before the pressure is removed. The resulting sample is composed of rod-shaped a -plutonium grains, the rod axes being parallel to the cylinder axis and the pressing direction. Photomicrographs of the oriented structure are shown in Fig. 1. Although most of the specimen is composed of grains whose rod axes are parallel to the cylinder axis, a thin, peripheral layer consists of rod-shaped grains whose rod axes are perpendicular to the cylinder axis. Presumably, the highly plastic nature of p plutonium leads to approximately hydrostatic conditions during the initial stages of the P — a transformation under pressure. At this time, the grains in the peripheral layer would have grown parallel to the local force direction. During the latter stages of the transformation, the accompanying volume contraction would have eliminated the radial forces, leaving only the axial force and resulting in the growth of the observed structure. The growth texture did not form without the application of pressure. Attempts were made to produce the texture by repeating the standard temperature cycle without

Jan 1, 1965

By Daniel Murray

"ACCIDENT PREVENTION in and around coal mines presents many problems of a type which are not encountered in any other industry. This is particularly true of the coal mines in Nova Scotia, where the underground workings are very extensive and the area of exposure to workmen is very great.Roof conditions at the coal faces and in the waste change very rapidly, almost from hour to hour, and it is at these places that the greatest dangers exist and where most mine accidents occur. It is only natural, therefore, that our attention, as far as accident prevention is concerned, should be concentrated •at the coal faces and in the waste, especially in mines where the longwall system is used in the operation •of the seam.It has been said that no hard and fast rules can be set down for timbering at the coal faces and in the waste in the coal mines in this area. We do not subscribe to this theory, however, for the following reasons:On the longwall faces in No. 18 Colliery of the Dominion Coal Company, Limited, where the 'Dosco Miner' has been in operation and where there is a very rigid system of timbering and roof supports, which is strictly followed, only one compensable accident has occurred on those faces from May 2ndJ 1950, to the time of writing this paper, February 3rd, 1953.The 'Dosco Miner' has worked on four different longwall faces in this mine and has mined and loaded some hundreds of thousands of tons of coal."

Jan 1, 1953

By A. Ennen, R. Wagner, B. Orberger, J. -M. Milazzo, N. Uhlmann, J. Banchet, J. Lucic, N. Wörlein, M. Firsching, J. L. Dubos, C. Bauer

The residues from mining and processing ores can often be considered as secondary raw materials. However, the material is only available in the form of fine particles (< 3 mm). In order to recycle these wastes, it is necessary to agglomerate it for transportation prior to reprocessing. The resulting agglomerates need to mechanically resist the stress of transportation and loading into the furnace. X-ray computed tomography (CT) is an established method for characterisation of internal structures in material science. This non-destructive technique can provide information on size and distribution of particles and grains. However, the information is not limited to the size, but also can yield structural features like orientation and position of cracks and fractures, which are important features indicating potential for deteriorating the agglomerates. Furthermore, deduced features such as contact conditions of inclusions or boundary surfaces can also be calculated. We studied binder-free tablets of manganese-oxyhydroxide, bentonite, kaolinite and slag powder using micro-CT. Inclusions of highly absorbing particles were identified using a watershed transformation with automatic segmentation by Otsu thresholding. Subsequently, the resulting data was analysed regarding their volume percentage, distribution in size and location within the sample. For the slag agglomerates, the volume fraction of iron could be determined. Furthermore, visible cracks were investigated with the goal to determine the long-term durability. It was shown that the data provided by micro-CT is reliable and helpful for the characterisation of industrial waste agglomerates. Keywords: X-ray, computed tomography, micro-CT, agglomerates, manganese fines, slags, kaolinite, bentonite

Jan 1, 2020

By C. P. Mangelsdorf

The roof truss as a means of secondary or supplemental mine roof support has enjoyed increasing acceptance in recent years, particularly in bituminous coal mines. In those entries where long life is required or doubtful performance from other forms of support seems likely, trusses in many cases have provided the necessary protection for continuing operations. Although relatively expensive and time-consuming in their installation, trusses, particularly with the new resin point anchor system, appear to be justifying their higher premium. It seems inevitable that techniques and equipment for installing them within the cycle will soon be developed. The actual mechanism by which trusses contribute to the stability of a roof is, as yet, poorly understood, and it may be that more than a single mechanism is involved. There are, however, a number of useful observations which can be made concerning the structural behavior of the truss itself, based solely on the mechanics of rigid and deformable bodies. The purpose of this article is to present some of these observations, particularly relating to friction in the system. A few speculations concerning the roof must, of course, be made. From a knowledge of the structural behavior, some insight into the truss-roof interaction may be gained. The concept of the truss is quite simple. As shown in [Fig. 1], it consists of two inclined chords (usually at 45&apos;) anchored in holes drilled in the roof over the ribs. A horizontal chord is formed connecting the exposed ends of the inclined chords, either with a third piece or by bending extensions of the inclined chords until they meet in the middle. A distinction can be made between active and passive chords of a truss depending upon the manner of installation. If the inclined chords are fully grouted and the horizontal chord is merely attached to them, it may reasonably be assumed that no significant forces exist in the truss until the roof begins to work. Such would be a completely passive system. On the other hand, if the inclined chords are anchored only at their upper extremities and the horizontal chord is formed in such a way that all three chords can be pretensioned to a significant portion of their tensile strengths then the truss may be regarded as fully active. Combinations of active and passive chords are also possible. * The discussion here is confined to the fully active truss such as the Birmingham steel rod system or the Galis wire rope truss. In both cases, pretensioning is accomplished by tightening of the horizontal chord, some of which tension is transferred to the in-

Jan 1, 1981

By R. E. Ray, J. W. Stevenson, J. A. Berry

Conventional concrete block plastered with a cementitious coating is the most common material used in the construction of permanent stoppings to direct airflow in underground mines in the US. All mines experience various degrees of strata convergence depending on depth of overburden, geological conditions, and type of roof support employed. Strata convergence will cause cracks and joint openings in masonry stoppings, resulting insignificant air leakage losses. Where strata convergence is severe, complete structural failure of the stopping can ultimately occur. Reconstruction of damaged or destroyed stoppings adds expensive overhead to mining operations, and even greater expenses are incurred from the additional fan horsepower required to overcome leakage losses. Ideally, a stopping should maintain high resistance to airflow while yielding to strata convergence. By properly incorporating a polyisocyanurate rigid foam material within the masonry block structure, stopping service life can be increased in mines experiencing strata convergence problems such as floor heave, roof loading, and lateral rib movement.

Jan 1, 1986

By F. J. J. van Loo, A. A. Kodentsov, J. A. van Beek, M. R. Rijnders

"A periodic layered morphology of the reaction zone has been observed in several annealed solid/solid diffusion couples, including metal/metal and metal/ceramic couples. This morphology is characterized by a regular array of alternating layers, which are either single-phase layers or bands of particles embedded in an intermetallic matrix phase. A description of several systems showing periodic layer formation is given. It is shown that the periodic layered structure with the single phase layers and the one with the bands of particles have a different mechanism of formation.IntroductionSolid state reactions in ternary systems can produce a variety of reaction zone morphologies if there are two or more reaction products. Three types of morphology have been described in detail: 1) simple layered; 2) isolated precipitates in a singlephase layer; 3) interpenetrating columnar (lamellar) or interwoven structure. Understanding the factors that govern the formation of different morphologies is of importance in many fields of engineering. For solid state displacement reactions the conditions governing the formation of these morphologies are well understood [1-4]. For example, the development of a layered or aggregate reaction zone depends on the relative diffusivities of the components through the reaction products.This paper is concerned with the periodic layered morphology which has been observed in various solid state systems. We consider this to be a fourth type of reaction layer morphology. Two manifestations of periodic layered morphology may be distinguished. One form consists of regularly spaced layers of particles of one reaction product embedded in a matrix phase (another reaction product). The other form consists of single-phase layers embedded in a matrix phase. It will be shown that each manifestation has its own mechanism of formation. In section A we consider a system (Ag/Ti-foil/Si) in which periodic layer formation will be explained as a special case of the Liesegang phenomenon. In section B we consider systems where the periodic layered structure has a different origin."

Jan 1, 1996

By Penrose E. K

With the exception of occasional periods, when up to 80% of oxidized ore was treated, the G.M.K. plant treated all sulphide ore until October, 1939. The treatment was, briefly, as follows:The ore was ground to approximately 17% plus 200 mesh Tyler and agitated in cyanide solution, after straking. After agitation, the pulp passed through two stages of counter-current decantation washing in Dorr thickeners and was filtered once, to complete the precyanidation stage.The precyanide filter cake was repulped with flotation circuit solution and floated in a Denver Sub A flotation machine, consisting of twelve cells. The concentrates were roasted, cyanided and filtered four times before disposal to the&apos; dam. The flotation tailings were thickened to conserve water and pumped away to a separate dam.The average results of flotation operations for the six months before October, 1939, are shown in Table 1.

Jan 1, 1942

By A Duran

When dealing with rocks in the geotechnical profession, a common activity involves providing an estimate of the intact strength. The tactile approach and descriptions of strength that apply to soils is well documented, can be readily checked through the use of a pocket penetrometer and are known to provide reliable estimates of strength. Moreover, although different soil strength classification systems are present, the bounds between classification classes are compatible across almost all documented classification systems. However, this is not the case for rock strength materials. There are numerous systems within the literature, some with different concepts, and almost all have different bounds to each strength classification. In this paper, the author presents seven classification systems for estimating intact rock strength and highlights issues in their implementation. Example cases are presented to discuss the typical concerns confronting field strength estimates.CITATION:Duran, A, 2014. Comparison of field estimated strengths, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 101–106 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

By K. Oraee

Mining Ventures are considered as high risk projects and therefore managing the risks is inevitable. Risk assessment is an important part of the complex process of risk management, hence applying appropriated and practical methods for ranking the risks associated with projects, can help to perform a better risk management. In this research the applicability of using Techniques for Order Preference by Similarity to Ideal Solution (TOPSIS) method for risk ranking in an underground mine, extracting by block caving method, was studied. Via this method, the risk associated with reserve estimation ranked as the first while in conventional method (P-I Matrix method) located in the sixteenth. Also there were significant differences in ranks of the other risks. Considering the more criteria, with different weights, in comparison with conventional methods, the results comprised from TOPSIS method are more reliable. By implementing this method risks are ranked better and more realistic and consequently then will be managed more efficient.

Jan 1, 2011