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By Joel F. Flurnerfelt

Molten Al and Al alloys containing si, Mn, Ti, and y have been lanced with nitrogen-bearing gases. These lancing experiments provided the means for observing what phases form during exposure to nitrogen-bearing gases for finite periods of time, <2 minutes, at high temperatures, >1290oC. The experiments were conducted in sn induction heated drop tube furnace apparatus. The overall premise of these experiments was to select those Al alloys and gas compositions that show promise of forming secondary dispersoid phases, particularly AIN, in the Al matrix. The alloys selected will be atomized using gas atomization reaction synthesis (GARS) using the most favorable conditions. In this case, the chosen Al alloy will be atomized with a nitrogen-bearing gas, such that the Al and gaseous nitrogen species react to form a dispersoid phase within each powder particle. The powder particles that result from this "aggressive" GARS-process would be essentially Al metal-matrix composites within a uniform distribution of dispersoids. To date, only high-purity Al has been atomized using a mild GARS reaction. This work is funded by the Materials Science Division of DOE-BES under contract number W-7405-Eng-82.

Jan 1, 1996

By E. Chin

The domination of Bangladesh&apos;s mineral industry by natural gas was in for some possibly significant changes. A modest flow of crude oil was struck in a gas development well in the northeastern corner of the country. This was the first commercial flow of crude oil in Bangladesh. All crude oil was being imported, which cost a significant proportion of the nation&apos;s foreign exchange earnings. The development of an oilfield producing only a few thousand barrels per day would be a welcome help to the economy. Additional exploration at a 1985 coal discovery in the northwest indicated a considerable reserve of good-quality coal at a depth suitable for mining. If the coal is mined, it would be a boon to the local economy because natural gas was not available in the area.

Jan 1, 1988

By C. Özgen Karacan

Gob gas ventholes (GGV) are used to control methane inflows into a longwall operation by capturing it within the overlying fractured strata before it enters the work environment. Thus, it is important to understand the effects of various factors, such as drilling parameters, location of borehole, applied vacuum by exhausters and mining/panel parameters in order to be able to evaluate the performance of GGVs and to predict their effectiveness in controlling methane emissions. However, a practical model for this purpose currently does not exist. In this paper, we analyzed the total gas flow rates and methane percentages from 10 GGVs located on three adjacent panels operated in Pittsburgh coalbed in Southwestern Pennsylvania section of Northern Appalachian basin. The ventholes were drilled from different surface elevations and were located at varying distances from the start-up ends of the panels and from the tailgate entries. Exhauster pressures, casing diameters, location of longwall face and mining rates and production data were also recorded. These data were incorporated into a multilayer-perceptron (MLP) type artificial neural network (ANN) to model venthole production. The results showed that the two-hidden layer model predicted total production and the methane content of the GGVs with more than 90% accuracy. The ANN model was further used to conduct sensitivity analyses about the mean of the input variables to determine the effect of each input variable on the predicted production performance of GGVs.

Jan 1, 2009

By Y. C. Kim, F. Szidarovsky

The technique of linear kriging as a grade estimation method of mining blocks is reason¬ably established in the mining industry. During the kriging process, negative kriging weights ([]i) are sometimes encountered. Due to negative kriging weights, negative block grades may be obtained in some extreme situations, which makes no practical sense. To guarantee nonnegative weights, an additional constraint is required in the kriging system of equations. Unfortunately, the nonnegative weight constraint results in a set of nonlinear system of equations. In this paper, a derivation of the resulting set of nonlinear equations is presented and a numerical algorithm is developed for the solution of the equations. Because the algorithm developed does not remove negative weights arbitrarily, optimal nonnegative weights are always guaranteed. Results obtained using the developed algorithm were compared with those using the standard linear kriging, in terms of computer, time and the estimation results. Both the computer time and the kriging variance were found to be higher with nonnegative constraint, as expected. However, some systematic pattern was observed in the kriged values (i.e., over-or underestimation) with or without the nonnegative constraint. The study also demonstrated when one should generally expect negative kriging weights in practice, and what practical impact the negative weights can have on the kriging estimates.

Jan 1, 1987

Bolivia, due to its turbulent past with a history of constant military coups, has given an image of complete instability to the foreign investor. The effects of this have been several fold, the major one resulting in a complete lack of exploration in modern terms since their revolution in 1952. What was overlooked by the foreign investor was the fact that revolution produced Agrarian Reform which is the foundation of the stability which Bolivia enjoys today. Another factor that is overlooked is the fact that its past history is one of vast mining fortunes having being made. Their political problems resulted in economic chaos in 1985 with an annual inflation rate of 26,000 percent. This resulted in the collapse of the government but the democratic process continued. Then came the so-called"South American Miracle" in 1986 when the government of Dr. Paz Estenssoro enacted an extremely harsh austerity program which consisted of the abolition of wage and price controls, the abolition of monopolies, the right to hire and fire, the weekly auctions of dollars and the free convertibility of currency which yielded a stable government with 8 percent inflation. This was followed by massive personnel reductions in the various mines and other industries.

Jan 1, 1991

The sixth University of Stelenbosch (US)/University of Cape Town (UCT) Minerals Processing Symposium was held at the University of Cape Town on Friday, 7th August, 1987, and was sponsored by The South African Institute of Mining and Metallurgy (SAIMM). Once again the Symposium attracted a large number of delegates from the mining, metallurgical, and chemical industries. Uranium and electricity A symposium on &apos;Uranium and Electricity- The Complete Nuclear Fuel Cycle&apos; will be held in Saskatoon, Canada, during 18th to 20th September, 1988. The Symposium is sponsored by the Canadian Nuclear Society. Electric steel The Institute of Metals, organizers of the 3rd European Electric Steel Congress, have announced that this important international event will take place in October 1989 at the Bournemouth International Centre.

Jan 1, 1987

By David Branch, Martin J. White, Faramarz P. Hassani

The work presented in this paper is part of an overall research programme into the problem of stability of main access roadways driven in Coal Measure strata. Data about the post-failure behaviour of rocks are generally of a qualitative rather than quantitative nature. This investigation represents the initial part of a long-term research project aimed at quantifying the post-failure properties of Coal Measure rocks and to investigate their effects on tunnel stability. The results of tests conducted to evaluate the post-failure strength characteristics of Coal Measure rocks under uniaxial and triaxial stress conditions are presented. Empirical failure models are proposed to define the triaxial intact and residual failure properties of these rock types. The application of such data to closure prediction techniques of underground excavations are outlined and discussed.

Jan 1, 1984

By N. Barton, E. Quadros

This paper addresses the prediction of groutable joint apertures, grout penetration limitations, and possible grout take volumes per cubic metre of rock, as a result of 5 to 10 MPa pre-injection pressures ahead of tunnels. Joints are obviously opened more than in the preceding Lugeon tests, and many rock mass properties can apparently be improved if stable micro-cement based materials are used. Cet article concerne la prédiction des ouvertures des fractures injectables, les limites de pénétration du coulis et les volumes injectés par mètre cube, d’après les résultats des injections à l’avant tête des tunnels sous pressions de 5 à 10 MPa. Evidemment les joints s’ouvrent plus que dans les essais Lugeon précédents. Maintes propriétés du massif peuvent apparemment être améliorés si l’on emploi des coulis a base de micro-ciment stable. Die Publikation widmet sich der Prognose injizierbarer Kluftöffnungen, Grenzwerte für Injektionsreichweiten und erreichbarer Injektionsvolumen pro Kubikmeter injizierter Fels, durch die Anwendung von 5 bis 10 MPa Vorinjektionsdrücken vor der Tunnelfront.Die Klüfte werden offensichtlich weiter geöffnet als in den vorhergegangenen Lugeon Versuchen und mehrere Felsparameter können durch die Verwendung von stabilisierten Micro-Zement basierten Injektionsmaterialien verbessert werden.

Jan 1, 2003

"Nestling in a little valley, right under the shadow of the rugged peaks of the Rocky Mountains and just over the great Continental Divide on the Pacific Slope, are Columbia Gardens, Butte's one rare beauty spot. Here purling brooks, fed from springs of snow-water course through the grounds to lend their aid later in making the great Columbia River. It is a question which has done more to make this oasis the charming place it is, nature or man, for both appear to have put forth their best efforts. The inspiring scenery surrounding the gardens is found in close association with the consummate art of the trained landscape gardener. The most delicate flowers, nurtured in large greenhouses, in the pleasant months of early spring and summer are transplanted into outdoor beds and in many instances woven, as it were, into beautiful designs. Green trees and grass on every side rest the tired eyes.Butte owes this delightful breathing spot to former Senator W. A. Clark, who owns and maintains it. A decade ago there were five large smelters belching forth their obnoxious fumes upon the city, making it impossible for vegetation to flourish within the confines of the town, a condition which fortunately no longer prevails. Primarily with a view of furnishing the children with a healthy playground, other than the muddy or dusty streets, Mr. Clark bought and developed the land upon which these grounds are situated. Upon numerous days in each month during the summer season, when school no longer demands attendance, his street railway carries the little folks to and from this ideal spot, free of all charge. ""Children's Day"" at the gardens presents a scene of life and happiness which once seen can never be forgot."

Jan 1, 1913

A 2-year moratorium on accreditation of curricula bearing new designations has been declared by Engineers&apos; Council for Professional Development at its Executive Committee meeting on July 29, 1952. Reason: a more definitive description of what the contents of a curriculum should include to be appropriately designated as "engineering" is needed. This action was brought on by the Committee of Evaluation of the American Society of Engineering Education which had become perturbed over the extension of the name "engineering" to numerous fringe curricula. The 2-year period will permit time for the Committee on Evaluation to study the question and make a recommendation for further action by ECPD. ECPD action also provided that the following curricula should only be given provisional accreditation for one year upon either inspection or reinspection; such provisional accreditation to be extended annually for not more than two successive years pending the report: Engineering Physics, Engineering Mechanics, Geological Engineering, Geophysical Engineering, and Textile Engineering. There are 22 such curricula now accredited.

Jan 1, 1952

As a leading global company in the mining sector, we are committed to sustainable development. To this end, we invest in the responsible, integrated management of economic, environmental and social issues. Vale?s objective is for our businesses to produce local, regional and global prosperity, enabling the construction of a positive legacy throughout the lifecycle of our activities. This covers everything from talking with stakeholders and preventing failures to complying with legislation, paying constant attention to environmental issues and respecting ethics in business. Keywords: sustainable development

Sep 1, 2012

By William B. Potter

We have come together on this occasion, as so often before the members of the Institute have met in friendly council, to hear and discuss whatever investigation, observation, and experience during the past months may have developed of value or interest to the many departments of knowledge and practice represented in this association. The member, possessed of the true scientific spirit which this Institute is especially intended to foster, brings here the results of his experience and study unrestrained by fear of giving undue advantage to competitor or rival. He appreciates, moreover, the responsibilities of membership and his duty to the cause, and how much is to be gained by himself from the keen but friendly criticism of his fellow-workers and even by the suggestions that may come of shrewd question or chance remark from those who labor in other but related fields.

Jan 1, 1889

By W. G. Payne, A. C. Richardson, B. L. Gandrud

"INTRODUCTION The Connellsville mine of the Yolande Coal & Coke Co. is in the southwestern part of Jefferson County, Ala., about 30 miles southwest of Birmingham. The mine is on the Blue Creek bed, which is about 6 feet thick and dips at a angle of 18º. The bed is worked by the room-and-pillar method and is mined by both machine and hand methods. The Blue Creek bed at this point yields a high ash, low-volatile coal with excellent coking properties. Because of its exceptionally low volatile content and high coking strength, this coal is excellent for blending with Alabama coals of higher volatile content and weaker coking properties to form blends suitable for production of metallurgical coke.A sample of washed coal taken during this investigation gave the following analysis on an as received"" basis: Moisture, 8.3 per cent; volatile matter-, 20.2 per cent; ash, 8.0 per cent; fixed carbon, 63.5 per cent. The high ash content of this coal limits the quantity which can be utilized when low-ash coke is required. In the Birmingham district it is usually difficult to sell as coking coal a product that contains more than 8.0 per cent ash. To produce a. coal with this ash content at Connellsville presents a somewhat difficult washing problem. This paper gives the results of an investigation that was conducted by the Southern Experiment Station of the U. S. Bureau of Mines in cooperation with the University of Alabama and the Yolane Coal & Coke Co. for the purpose of determining the washing characteristics of the coal and the possibility of reducing its ash content on coal-washing tables.The practice at the Connellsville washery at the time of beginning this investigation was to crush the run-of-mine coal to pass a 1 1/2-inch round-hole screen and to treat the satire output on two primary, 3-compartment jigs. A. middling product was recovered from the primary jigs which was re-treated on a single-compartment rougher jig. This system yields a product of acceptable ash content, but the yield is low and the loss of good coal in the refuse is high."

Feb 1, 1933

By W. G. Huang

To recover the coal resources of high-sulphur anthracite in Jincheng Mining Area, underground coal gasification (UCG) of No. 15 seam in Fenghuangshan Coal Mine was proposed. The feasibility of the project was confirmed by investigations of occurrence conditions, coal properties, and roof conditions, as well as experimental studies and theoretical analysis. It was found that UCG technology is appropriate to be adopted in the mining of the No. 15 seam, due to the stable rock conditions, simple geological structure and hydrogeology, the high carbon content of the coal, non-cohesiveness, medium-thermal stability, high ash fusion temperature, and weak reactivity with CO2. Further factors are the characteristics of the immediate roof, which consists of 9.11 m of limestone and mudstone with a compact structure and low permeability, and 4.27 m of dominantly mudstone with low permeability.

Jan 1, 2012

By A Havenga, F, J Hough, R Grobbelaar

After the closure of mines they naturally start to fill up with water. As a result, hydraulic gradients develop between adjacent mines and different hydraulic water pressures are exerted onto peripheral areas or compartments within mines. This results in water flow between mines, or onto the surface. This flow is referred to as intermine flow. The geometry of the collieries in the central Witbank Coalfield make intermine flow possible in several areas. Since the Department of Water Affairs and Forestry declared intermine flow as one of its greatest concerns for granting closure to South African mines, much research into this phenomenon has been undertaken. The importance of the quantification lies in the DepartmentÆs goal of sustainable water management, and the possible long-term financial implications these flows could have for individual mines. The challenges of determining intermine flow are numerous, and attention is focused on the identification of areas where these flows can take place. Detailed mining plans on a regional scale are required, and detailed coal-seam floor data are combined to provide targets for possible interaction between these mines. The quantification of these flows is problematic due to the uncertainties regarding geometrical configurations and the variation in site-specific hydraulic characteristics of the coal and overlying lithilogical layers. To this end, use has been made of several analytic solutions and numerical flow modelling. Stage curves (volume versus elevation curves) for the opencast and underground workings have been calculated and first-order estimates for intermine flow or decant from these areas have been determined. The numerical modelling methodology entailed a down-scaling approach, starting with a broad regional model covering the entire area, followed by modelling the interactions between interconnected mines and finally looking in detail at the major areas of interaction. By considering different scenarios within the context of these flows, possible management options for intermine flow can be evaluated in terms of volumes and qualities that might emanate in the post-closure phases. Challenges for the future include obtaining site-specific information on the groundwater hydraulics and acceptable ranges for model parameters, and verifying model results over time.

Jan 1, 2003

By R. C. A. Minnitt, A. Akpabio

This study presents a rigorous comparison between ordinary kriging and commonly used machine learning algorithms, those being, linear regression, support vector regression, decision trees, random forests (RF), and k-nearest neighbours for spatial interpolation of platinum grade estimates in a complex ore body within the Bushveld Igneous Complex. Using only X and Y coordinates as predictors, both ordinary kriging and machine learning models were evaluated at point and block supports under traditional and spatial block cross validation frameworks. While naive validation results suggested superior performance for k-nearest neighbour and random forest (R² = 0.92 and 0.86, respectively), these were revealed to be overly optimistic under spatial dependence. Spatial block cross validation results demonstrated substantial declines in model performance, with R² often falling below zero, particularly for decision trees and k-nearest neighbour, indicating strong overfitting and limited generalisability. Ordinary kriging exhibited more stable, albeit modest, performance under spatial validation, reflecting its strength in geostatistical interpolation when contextual geological variables are unavailable. The study underscores the critical importance of spatially aware validation in resource estimation and highlights that machine learning models constrained to spatial coordinates behave as interpolators rather than true learners of geological variability. Recommendations are provided for future work incorporating geological information to enhance predictive robustness.

Mar 30, 2026

By James M. Krese

The West Kentucky Division of Island Creek Coal Company, which is a wholly owned subsidiary of Occidental Petroleum Corporation, operates the new Hamilton Mine. It is located six miles West of Morganfield, Kentucky, in the Northwest section of Union County, adjacent to the Ohio River in Lock 50. On July 15, 1968, a unique new coal conveying system was put in operation. This system consists of eight conveyor units carrying coal from the bottom of the mine slope ultimately to barges on the Ohio River. It is over two miles in length and has a total of 3175 connected horsepower. The river loading conveyor is the longest 72" wide conveyor in operation in this country.

Jan 1, 1969

By Keith Whiting

The Van Stone zinc-lead mine is located in northeastern Washing- ton in Stevens County. It is about 24 km (15 miles) south of the Canadian border and 48 km (30 miles) west of the Idaho line. The deposits occur in late Cambrian age limestones and dolomites of the Metaline Formation. The bedding controls the trend of the zones containing the lenses of zinc-lead mineralization. The Van Stone property and vicinity is almost entirely covered with glacial drift averaging perhaps 6 m (20 ft) in thickness. Outcrops are very sparse. Outcropping gossan with zinc mineralization was first discovered by George Van Stone in 19 13, in what is now known as the South Ore Zone. Only minor trenching was done at that time. The property was idle until the mid- 1920s when Hecla Mining Co. drove several short adits and performed minor diamond drilling. In 1938, Willow Creek Mines of Nevada Inc. acquired the Van Stone plus adjacent parcels and commenced drilling on the known South Ore Zone. In the course of an expanded drilling program, the nonoutcropping North Ore Zone was discovered and was drilled out along a N30°E strike for about 305 m (1000 ft), beyond which point no mineralization was intersected.

Jan 1, 1991

This paper will first discuss the fundamental requirements for reliable discharge of backfill by gravity alone at high per cent solids. This discussion will include brief mention of the underlying principles of saturated solids flow contrasted to that of stirred tank or dilute discharge systems. Here the need to possess full knowledge of the flow properties of the stored material will be highlighted. In addition proper account must be made of the silo overflow weir and settling capacity to match plant throughput. Here opportunity will be taken to highlight the complexity of this multi-phase flow situation as well as the general yet paramount requirements for reliable solids flow. It will be shown that by proper attention to the multi-phase considerations gravity discharge of slurries as a consolidated bed with minimal water content is possible. Such high solids discharge results in greatly reduced demand for process water. In addition pumping costs are reduced as is the delay time associated with the mine drainage operation. Confirmation of successful applications will be highlighted by reference to several recent case studies. In the concluding phase mention will be made of the key yet very simple and effective operation techniques which enhance reliable discharge. The simplicity and reliability of properly designed gravity discharge backfill tank systems suggests increased application of this technology by the mining industry.

Jan 1, 1998

By A. Bouillot, G. W. Luxbacher

In a reserve assessment in areas where multiple coal seams lie above drainage or outcrop and where mining options include contour, auger, mountaintop removal and underground methods, the mining technique (or techniques) selected are heavily dependent on both economic and technologic factors. Rapid and accurate calculations utilizing digital terrain modeling, structure isopacs and including factors such as minimum seam heights, reject limits and coal quality are of vital importance in mine planning. The ability to forecast mine development in a "what if" fashion is a powerful tool that now demands computer resources to reduce these time-consuming, often repetitive calculations. Island Creek Coal and Occidental Systems have developed a minicomputer based engineering workstation for local digitizing, plotting, and volumetric calculations to move the computing function from the computer room (with time sharing on a mainframe computer) into a more interactive environment, resulting in a gain in efficiency and productivity for the mine planning process. The workstation is connected to Occidental&apos;s mainframe computers allowing data transfer to the host for "CPU-intensive" calculations. This paper reviews the system configuration and describes the operations required for a typical mine planning application.

Jan 1, 1983