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By James W. Martin, Robert R. Faddick

INTRODUCTION Virtually every sector of society in our country feels the impact of tunnels, either through the transportation of water, commodities, or people. The economic implications are staggering. The Committee on Rapid Excavation (1) reported that during the near future, 1968-1975, underground excavation activity will comprise 946 miles of tunnels (subways: 85 miles; underground urban highways: 123 miles; intercity highway tunnels: 210 miles; water supply tunnels: 528 miles) and 5,119 million tons of crude ore; metals: 874 million tons; nonmetals: 899 million tons; and coal: 3,346 million tons. It is estimated that the cumulative demand for underground excavation in the decade 1970-1979 will be 13 billion dollars for construction-oriented demand and 16 billion dollars for mining-oriented demand. The respective figures for the decade 1980-1989 are estimated at 22 billion dollars and 18 billion dollars. Of the many advantages claimed for tunnels (2, 3, 4, 5) the environmental considerations are becoming increasingly important. Transportation tunnels particularly for rapid transit systems, offer reductions in noise pollution and air pollution while improving aesthetics and optimizing land use (fewer problems of right-of-way and disruption of utilities). Considerable interest has been shown recently in sub-surface construction and mining (6, 7, 8). Recognizing the future demands for tunnels has led to considerable study of methods to improve rates of tunnel advance per day, safety, and the overall economics. The search for higher rates of advance has Led away from what has heap termed conventional methods (drilling

Jan 1, 1974

By Henry N. Doyle

One can hardly discuss coal pneumoconiosis unless it is placed in the context of the total pneumoconiosis problem in the mining industry. However, it might be well if first we defined a few terms, since it has been my experience that the use of the word pneumoconiosis frequently causes con- fusion among those who are not familiar with the term. Pneumoconiosis comes from two Greek words meaning lung and dust. Hence, the word pneumoconiosis simply means dusty lung, or dust on the lung. There are many forms of the disease, some of which are disabling and some are not. Among the many dusts which cause pneumoconiosis might be included silica, asbestos, coal, talc, iron ore, and many other mineral dusts. Silicosis is a specific form of pneumoconiosis. It is caused by the inhalation of excessive amounts of silicon dioxide in the form of crystalline quartz. The disease is manifested by nodulation of the lungs which is apparent on an X-ray film. Continued exposure to silicon dioxide causes the nodules to grow and ultimately large areas of the lung become scar tissue which pre- vents the lung from performing its physiologic function. In its more advanced stages, there is a significant loss of pulmonary function which accounts for

Jan 1, 1966

By D. J. Burdon, Anthony Caplan

"(1) The radiological appearances of pneumokoniosis on the Kolar Gold Field is described in detail. The characteristic abnormality is the. presence of a diffuse, fine annular and punctate mottling. (2) The frequency of symptoms could not be determined with any degree of accuracy, but it is believed that symptoms are absent and there is no incapacity until profuse radiological mottling is present, i.e., after long exposure to dust. (3) There is an increased predisposition to tuberculosis, which, if it occurs, affects the prognosismost unfavourably.(4) Pathological examination shows that the radiological mottling is due to the presence inthe lung of numerous small dust-cdll aggregates (up to T5 mm. in dia.) deposited around the smaller bronchioles and blood-vessels.(5) The dust-cell aggregates are relatively acellular but when tuberculosis is superadded thereis an excessive cellular and fibrotic reaction.(6) The difficulties of defining the radiological and pathological appearances of early pneumokoniosisare discussed.(7) The incidence of pneumokoniosis in 7,653 workmen with 5 or more years’ undergroundservice was 43-75%, but it is suggested that in future the incidence will be appreciably lower.(8) The methods of- dust production and the chemistry of mine dust are described. It isshown that the free silica-content of air-borne mine -dust is relatively low.(9) The aetiology'of the pneumokoniotic lesion is discussed."

Jan 1, 1947

By Jean-Michel M. Rendu

Increasingly, geologists use geostatistical methods to evaluate drilling programs. The complexity of the methods varies with the nature of the available sample information, the objective of the statistical analysis and the geologist's experience. Occasionally, estimating the average sample grade is all that is required. In other instances a semivariogram calculation may be considered. If sufficient data is available, the geologist may wish to estimate blocks or panels of complex shape, using the kriging method of evaluation. Historically, the use of geostatistics by geologists has been limited by a number of factors, most significant being the difficulty in accessing and using computer programs needed to complete the necessary studies. Geologists are often working in remote areas from which electronic communication is unreliable, if not impossible. Even when access to computer programs is technically possible, the costs incurred in accessing and using these programs are often considered prohibitive. In many instances using the programs requires an understanding of computer systems far beyond that which a field geologist can justifiably be interested in acquiring and maintaining.

Jan 1, 1984

By José Carlos D’Abreu, Luiz Cláudio Pinto Oliveira

Os pós ou lamas de aciaria gerados nos sistemas de despoeiramento dos gases de exaustão do conversor LD têm papel relevante entre os coprodutos siderúrgicos devido às suas significativas gerações, dificuldades no manuseio e acondicionamento e expressivo custo para processamento e/ou disposição. Em contrapartida, o elevado teor de ferro que possuem lhes garantem um potencial de substituição dos materiais primários nos processos metalúrgicos. Um método desenvolvido para a reciclagem do pó de aciaria LD foi a aglomeração a frio via briquetagem, para utilização como refrigerante no conversor LD. O efeito refrigerante do minério de ferro é cerca de três vezes superior ao da sucata de aço. Os briquetes de pó de aciaria LD contém ferro em diferentes estágios de oxidação e assim, seu poder refrigerante se situa em uma condição intermediária. Neste trabalho são avaliados, teórica e operacionalmente, o efeito refrigerante dos briquetes de pó de aciaria em comparação com outros refrigerantes. Considerando que a sucata tem um poder refrigerante de 340 kcal/kg, constatou-se que o poder refrigerante dos briquetes é cerca de 1,8 vezes superior ao da sucata e o poder refrigerante das pelotas é 2,8 vezes superior ao da sucata.

Nov 3, 2019

By S Arai

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Podiform chromitites are commonly found in the Moho transition zone to the mantle section of ophiolites, but have been very rarely found from the current ocean floor, even though some ophiolites are considered as a slice of oceanic lithosphere. One of the factors controlling podiform chromitite formation is the chemistry of host mantle peridotite; an intermediately refractory harzburgite is the optimum host for chromitites. This harzburgite represents the most common lithology of the oceanic lithosphere, where the peridotite-melt reaction, which is another condition, is possibly common there. The oceanic lithosphere mantle is thus a good host for podiform chromitites. The apparent rarity of documented oceanic chromitites is solely due to under-sampling of mantle materials from the fast-spreading ridge and the segment centre of slow-spreading ridges. Some ophiolitic chromitites formed not from genuine mid-ocean-ridge basalt (MORB) but from wet MORB due to the situation of typical ophiolites, which formed not at ordinary mid-ocean ridges but at supra-subduction zone spreading centres.CITATION:Arai, S, 2015. Podiform chromitites do form beneath mid-ocean ridges , in Proceedings PACRIM 2015 Congress, pp 465–468 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

?Podolsky Water treatment plant discharges to Norman North bog which drains into Whistle / Post Creek watershed and into Wanapitei Lake ?Whistle Mine closed and reclaimed but continues to treat and discharge water to Whistle Creek

May 1, 2009

The Pogo Mine, near Delta Junction, Alaska is a new 2500 STPD gold operation. The control system of the mine and milling operations are a hybrid of DCS (Distributed Control System) control and PLC (Programming Logic Controller) control. A DeltaV DCS system serves as the main control and operation platform while the PLCs operate a multitude of vendor specific packages. The communication backbone of the DCS system is a hybrid of star and ring fiber optic topology, which provides reliability and flexibility. The communication between the DCS and PLCs is typically facilitated by serial communication. This communication insures the integrity of the whole control system.

Jan 1, 2008

By Alan Probert

IN his inaugural address in 1949, President Truman made a policy declaration which launched the foreign technical assistance program known to the world as Point Four. Congress passed Public Law 535 defining the scope of the program and holding activities to certain limitations. It also provided $34.5 million for the first fiscal year. The Technical Cooperation Administration was established within the Department of State to coordinate and direct a program to include "economic, engineering, medical, educational, agricultural, fishery, mineral and fiscal surveys, demonstration, training and similar projects." The mineral programs of Point Four have been staffed and managed by two agencies of the Department of Interior, the Geological Survey and the Bureau of Mines. The Geological Survey is concerned primarily with water-supply problems, the discovery of mineral deposits, and the determination of habit, shape, and grade of mineral deposits. The Bureau of Mines is concerned with determining the commercial potentialities of mineral deposits, mineral technology, and the production and distribution of mineral commodities. Mineral projects comprised only 1 pet of the first year's budget. In spite of the relatively insignificant expenditure compared to those for food, agriculture, and health, a commendable record has been achieved.

Jan 1, 1952

By D. E. Ranta, William B. Ryan, Ronald W. May

The Lower Cretaceous McMurray Formation in northern Alberta contains bituminous sands interbedded with other sediments which form the reject encountered during mining operations. Grade prediction is based on a combination of geological interpretation, computer modelling and past mining experience. In addition to estimates for ore, an accurate estimate of "waste" or "reject," are required for Mine Planning. This study investigates the ability of point-kriging using geostatistics, to augment the existing data base of drill-holes in a study area on Syncrude's leases. This approach enables the assessment of potential "worst" case - "best" case scenarios within the context of Mine Planning.

Jan 1, 1992

By Ronald W. May

The Lower Cretaceous McMurray Formation in northern Alberta contains bituminous sands interbedded with other sediments which form the reject encountered during mining operations. Grade prediction is based on a combination of geological interpretation, computer modelling and past mining experience. In addition to estimates for ore, an accurate estimate of "waste" or "reject," are required for Mine Planning. This study investigates the ability of point-kriging using geostatistics, to augment the existing data base of drill-holes in a study area on Syncrude's leases. This approach enables the assessment of potential "worst" case - "best" case scenarios within the context of Mine Planning.

Jan 1, 1985

By Xizhen J

Point load testing for irregular rock specimens was studied to determine the relationship between tensile and compressive strengths, drill penetration rate and other rotary drilling parameters. The DH-l type point load tester was developed and more than 2 000 irregular specimens of over 60 kinds of rock from 16 mines and quarries were tested. The effects of size, shape and number of samples on the point load strength index were investigated, using regression analysis. Experiments were carried out to investigate the relationship between point load strength index and uniaxial compressive strength on 29 kinds of rock. The relationship between these values and the drill penetration rate for rotary and percussion drills is discussed.

Jan 1, 1986

By Donald R. Reichmuth

Most brittle solids are relatively weak in tension and this weakness can be very significant in determining their performance in structures and excavations. Consequently, accurate knowledge of the tensile strength of brittle materials has long been recognized as important. In the past, measurements of the tensile strength of materials such as concrete, ceramics, and particularly rock have been hindered by problems encountered in fabricating test specimens and in accurately loading them. These difficulties have resulted in a scarcity of published tensile strength data. This can be readily seen in tabulations such as Wuerker's "Annotated Tables of Strength and Elastic Properties of Rocks."1 There are now three distinct approaches being used to determine the tensile strength of brittle materials. These are shown schematically in Fig. 1. The first method consists of simply pulling the specimen apart by applying an axial load. Although this procedure is the easiest to understand, the technical problems encountered during testing are numerous. Specimens cannot be readily fabricated into dumbbell-shaped specimen* like those customarily used for testing inetals. Cylindrical specimens cannot be loaded in jaw-clamps because adverse stress conditions arise at the clamping points, which causes unreliable results. An innovation developed by Niles Grosvenor at the Colorado School of Mines, in which the load is applied through steel-end caps glued to the ends of the specimens, has considerable merit, hut the samples are costly to prepare.2 All tests using a direct pull are further handicapped by the possibility of small amounts of bending being present, the specimen's surface condition, and

Jan 1, 1968

By Reichmuth, Donald R.

Most brittle solids are relatively weak in tension and this weakness can be very significant in determining their performance in structures and excavations. Consequently, accurate knowledge of the tensile strength of brittle materials has long been recognized as important. In the past, measurements of the tensile strength of materials such as concrete, ceramics, and particularly rock have been hindered by problems encountered in fabricating test specimens and in accurately loading them. These difficulties have resulted in a scarcity of published tensile strength data. This can be readily seen in tabulations such as Wuerker's "Annotated Tables of Strength and Elastic Properties of Rocks.

Jan 1, 1968

By C. A. Young, H-H. Huang, L. G. Twidwell

Solid particles, especially oxides/hydroxides, develop an electrical charge on their surface when submerged in aqueous solution. Parks was able to relate PZC (point of zero charge) of an oxide to its minimum solubility and isoelectric point. Dzombak has compiled an extensive database for adsorption reactions on ferrihydrite surfaces using the double layer theory. The equilibrium calculational program, STABCAL has been used to extend the considerations of Parks and Stumm. The PZC for many hydroxides, complex oxides, and non-oxides have been investigated and the results are reported in the literature. Removal of arsenic and metals by adsorption on ferrihydrite as the substrate has been computed using ST ABCAL and the computational results are compared to experimental data. Absorbents other than ferrihydrite such as aluminum hydroxide are also discussed.

Jan 1, 2005

By R. G. K. Morrison

As mines grow deeper, the problem of ground control becomes one of increasing importance. The literature on the subject has grown extensively in the past few years, but is still far from conclusive. Detailed and precise observations are on record covering most phases of the problem, and control measures have progressed to the point where, in a large measure, they are effective. The success of methods to date must be attributed to the efforts which have been exerted to reduce convergence of stope walls and to the realization that a regular progression of stope faces approaching longwall has a beneficial effect. This paper attempts to explain the relationship between these two factors and the general problem of ground control. The problem at present lacks the co-ordination of the practical with the scientific outlook, but fortunately as time goes on there are indications that our scientific friends are becoming more interested and more familiar with the practical issues involved. Opinions vary widely regarding the mechanism of the problem and there are several schools of thought, two only of which will be discussed. One associates the incidence of rock-bursts with the stresses built up by a sagging hanging-wall, while the other takes the view that stresses primarily responsible for the sagging hanging-wall are also the cause of rock-bursts. The first group starts its reasoning from the convergence of the walls, probably the most conspicuous feature of deep mining, and works back to the conclusion that rock-bursts are in sorne way due to the breaking up of the sagging layers. The second group begins with the stress zone apparent around excavations at depth and follows mathematical conceptions based on certain assumptions which, in the absolute sense, are known to be inaccurate, but which are justified by the similarity between the conclusions reached and the results obtained in practice. This reasoning is followed to the point where rock-bursts result from the failure, under stress, of rock in situ, quite independent of wall convergence.

Jan 1, 1939

Amongst the unavoidable studies of the mining engineer who desires to reach the maximum efficiency, is the subject of patents. With the fundamental principles of the patent laws of this and other leading countries he should of course befamiliar, but still more should he keep abreast of that practical knowledge which will enable him to act or advise wisely when the patenting of a new invention, or the sale, purchasing, or adoption of a new patented machine or process becomes amatter for consideration. As every engineer worthy of the name is an inventor and more particularly every mining engineer he has a direct interest in watching the progress of legislation and administration concerning patent monopolies.His worldly prospects may indeed, to a considerable extent, depend upon the defeat of bad patent laws and the removal of incompetent officials, or the appointment of better ones. Better patent administration is always in Australia a valid requirement, and until engineers generally take up and press the demand, bad administration is likely to continue. Even though every engineer is not a patentee, nevertheless his interests in patents must always be direct and powerful, and ignorance or apathy in regard thereto must inevitably injure either his own interests or those of his employer. When we consider the tens of thousands of mines scattered through Australia alone, on everyone of which there is expensivepatented machinery, and when we consider the thousands of...

Jan 1, 1901

By Maxine Wiber, Ross D. Gallinger, Brain A. Lewis

Poirier was an underground copper and zinc mine located in Northern Quebec that operated between 1965 and 1975. There are 5 million tonnes of acid-generating tailings, which have contributed acidity and metals to the Kananewesig and Kistabiche Creeks. The final closure plan incorporates the placement of all reactive material into the tails basin, installation of a geomembrane liner over the tailings deposit and a one metre soil layer to protect the liner. The environmental effect of the residual seepage was assessed from an ecological risk perspective. The Reclamation Plan has been accepted, and work commenced in 1998 to restore the site.

Jan 1, 2000

By SeyedBijan Mahbaz

Development of Geomechanical Earth Models (GEM) is a prerequisite to reservoir management, involving issues such as stress path analysis, prediction of induced seismicity and sanding initiation, and coupled flow-stress modeling that leads to more realistic predictions of oil rates and rock response. Part of GEM development is the stipulation of the 3-D lithostratigraphic disposition (geometry) which is used to choose the geomechanical units. The digital geological model is then populated with quantitative and semi-quantitative data on rock properties, fluid properties, saturations, initial conditions (p, T, [_]) and other information. Both fluid and solid properties are needed this requires integration of geomechanics skills with geophysical and rock physics skills, and this article deals with a subset of this integration process, with an example from two wells in southwest Iran.Rock physics approaches are used to predict reservoir rock and fluid properties with wellbore and 3-D seismic data, which are also used to interpolate rock mechanics properties to the inter-well regions. The first step in a generic rock physics approach is diagnostic and involves the introduction of a suitable Rock Physics model.Acoustic impedance (AI), shear impedance (SI), and density (_) are the fundamental rock properties usually derived using AVO equations, and these parameters, along with attenuation coefficients, can then be correlated to static rock mechanics properties that define deformability and perhaps even strength. In this study, Poisson Impedance is introduced as a new seismic attribute used for lithology and fluid differentiation in the FahliyanFormation (reservoir rock) in two oil wells in the southwest of Iran. To do this, a novel rock physics model was developed for this naturally fractured carbonate reservoir.Currently, these data are also being used to correlate to a limited rock mechanics data base to develop a more extensive GEM to serve as input to more general geomechanical and reservoir modeling tasks.

Jun 1, 2012

By David M. Cregger

The performance of the nation's first geologic repository for Commercial High Level Waste will be evaluated in a variety of ways which will involve the use of the state-of-the-art thermomechanical computer codes. Elastic properties of the host rock and the materials surrounding the repository are required for this numerical modeling effort to assess both near- and far-field effects. Only limited laboratory testing is possible, however, making it extremely beneficial to expand the data base by calculating dynamic elastic properties from available geophysical well logs. Elastic theory dictates that for an isotropic solid there are only two independent variables in addition to mass density, namely the compressional velocity, the shear velocity, and Poisson's Ratio. Compressional velocity and density are readily measured by geophysical well logs or in the lab; the crux of the solution requires measuring or determining either the shear velocity or Poisson's Ratio. Examination of acoustic propagated shear waves measured during confined compression testing demonstrates that Poisson's Ratio is a fundamental lithology-dependent parameter. Once a rock mass is appropriately classified, application of the laboratory derived dynamic Poisson's Ratio will yield a continuous and reasonable in situ modulus from acoustic and density logs. For preliminary characterization and assessment of the mechanical properties of rocks within the subsurface, and for studies of rock quality, this method is sufficiently accurate. The general availability of acoustic and density logs from wells logged for other purposes has made the application of this method desirable.

Jan 1, 1984