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By Brad Simser

Several case histories from Glencore’s Sudbury Operations show how passive seismic monitoring data is used for geotechnical decision making. The data comes from three different seismic arrays monitoring two open stoping deposits, and a narrow vein cut and fill/blasthole operation. Mining depths range between 1000 to 1680m below surface. The deposits are hosted in hard igneous rocks typical of the Sudbury basin, with characteristically high horizontal stress (approximately 1.8 times the depth of overburden). Rockbursting is the main geotechnical risk, due to the strong brittle nature of the rock and local high mining extraction. Fault related seismicity includes both fault slip events, and the stress channelling effect as the mining front approaches a major fault structure. Planar data trends generally line up with known faults and often indicate early stage fault activation. The structures are risk ranked based on their seismic response. This has been particularly useful at the Nickel Rim South Mine (NRS) where the structural fabric (jointing and small-scale faulting) is generally parallel to the more through going faults. The persistence of structures is difficult to measure, and the NRS faults generally have low offsets and thin gouge. The visual difference between the more persistent structures that occasionally generate large seismic events (up Mw 2.9 to date) and localised joints/slips is often minor. The seismic monitoring data clearly shows the more active structures. This information is highlighted on mine plans to help guide enhanced ground support and seismic re-entry protocol barricade locations. Pillar loading/yielding is a key element to the blasthole operations where a primary/secondary mining sequence is used. The secondary pillars are mined in a yielded state with just-in-time development. An example of the seismic signature of a secondary stope is shown with emphasis on the need for high location accuracy given the stope widths of 12.5 to 15m. The ratio of the shear wave energy to primary wave energy (Es/Ep) has long been used as a method to estimate source mechanisms; the higher the ratio, the more likely the event is fault slip versus rock fracturing. Data sets are filtered on Es/Ep ratios to highlight both fault slip populations and stress fracturing mechanisms. Examples of seismic data quality checks, high stress development, and re-entry protocols are also shown in the case histories.

Apr 26, 2022

By Richard J. Lewandowski

Corrosion and product contamination have been difficult problems for extractive metallurgy industries in the U.S. because of the highly active chemicals used. During the past twelve years, other industries, particularly the chemical and paper segments, began to combat this problem with some degree of success using newer materials of construction, including reinforced plastics. These materials are made by combining a corrosion resistant thermosetting resin with a glass fiber reinforcing material and are used to con¬struct hoods, stacks, blowers, tanks, towers, pipe, and equipment of the most complex configurations. For service in contact with aggressive chemicals, the equipment is most often fabricated with the bisphenol-A fumarate polyester resins because of their resistance to corrosive attack. Data from both laboratory work and case histories of field applications are presented-for many common chemicals found in extractive processes. Information is also presented concerning design standards and recommended construction procedures

Jan 1, 1970

By Virendra Singh

The load settlement behaviour of single pile or pile group may be obtained using computer based methods such as the finite or boundary element techniques. An alternative method of obtaining the vertical soil stresses adjacent to the Pile is presented Based on calculated stresses consolidation settlement for Piles foundation is obtained. This approach may be computationally more attractive than the more general finite or boundary element techniques.

Jan 1, 1996

By K. K. Kershner

To meet an increasing demand for high-purity cobalt, the Bureau of Mines has conducted investigations for producing this metal. Cobalt having a purity of 99.95 percent or higher is needed to determine heats of formation, corrosion resistances, phase diagrams, and other basic properties of the element and its compounds. This grade of cobalt may be used for preparing radioactive metal. As a result of its investigations a detailed procedure, which is of practical significance to the production of high-purity cobalt, has been developed by the Bureau for purifying cobalt solutions and for electrolytic deposition of the metal. Cobalt metal, which had a purity of 99.99 percent with reference to metallic contaminations, was deposited electrolytically. Qualitative spectrographic analysis showed only traces of calcium, copper, iron, magnesium, nickel, and zinc.

Jan 1, 1956

Past President Robert L. Hair, General Superintendent, Coal Mines, Colorado Fuel & Iron Corporation, Pueblo, Colorado, opened the meeting at 10:00 a.m. "I will now call the Fifty-Third Regular Meeting of the Institute to order this morning and welcome the members and the guests. I'm on the program to introduce John Peperakis, President of the Institute for this year. I regret to announce that Mr. Peperakis received word this morning of an emergency at his mine and left to attend to this. We hope it is of a minor nature and he will return. (Editor's Note: Please refer to the index for printed text of the President's address which he had intended delivering, had he not been called away.) However, in the meantime, Robert von Storch has graciously consented to act as president until John Peperakis returns. "I needn't tell you who he is. Robert M. von Storch is General Superintendent of Coal Mines and Quarries, Columbia-Geneva Steel Division, United States Steel Corporation, Columbia, Utah. I now present Bob von Storch." Mr. von Storch: "As most of you know, the Rocky Mountain Coal Mining Institute cannot compare to the Mining Congress, as it is not a professional organization. It represents the coal operators in New Mexico, Utah, Colorado, Montana and Wyoming. We have a group of volunteers to put this together and use this occasion to get together and exchange ideas.

Jan 1, 1957

By B. H. Kim, S. K. Chung

RMR, Rock Mass Rating, is one of the famous rock classifications. However, RMR was proposed empirically and absolutely depends on the experience of engineer. Therefore, engineering verification is needed for RMR system itself. In this study, the factor analysis and the multiple regressions were performed in order to evaluate the validity of rating factor of RMR. Also numerical analysis was carried out using the FLAC based on Taguchi method, a kind of robust designs, in order to examine the support of tunnel corresponding to the revaluated RMR. As the result of the analysis new RMR was proposed with five minimized factors of intact rock strength, RQD, spacing, persistence and roughness of discontinuities. RMR est un des procédés de la classification du roc qui sont généralement utilisés. Mais RMR s'appuie sur l'expérience et se absolument soumet à l'expérience d'ingénieur. Il est donc nécessaire de vér- ifier techniquement sur le système de RMR. Dans cet étude, on met à exécution l'analyse du facteur et la régression multiple pour évaluer la convenance de la cause de classification de RMR. De même, pour évaluer le support du tunnel selon RMR réestimé, on a exécuté l'analyse de la valeur numérique par FLAC qui se base sur la lois de Taguchi, laquelle est une sorte de système du plan robuste. Selon le résultat de la régression multiple, il est proposé de nouvel RMR à partir de l’intensité de roc intact, RQD, l'espacement, la persistance et la rugosité RMR ist eine der weit benutzten klassifikationen fuer die felsenstuecke. Da aber RMR erfahrungs- maessig ist und ueberwiegend von der persoenlichen Erfahrung eines Ingenieurs entschieden ist, ist es mit Sicherheit notwendig, das RMR-system selbst technisch zu ueberpruefen. In diesem studium waren die faktorenanalyse und mehrfachregressionanalyse durchgefuehrt, um die gerechtigkeit der klassifikationenfaktoren von RMR zu bewerten. Ferner war noch eine numerische analyse mit ben- utzung von FLAC aufgrund der Taguchi-methode, eine art technik der robust design, eingefuehrt, um die tunnelstuetze infolge der neubewertung von RMR unterzusuchen. Gemaess der mehrfach regression analyse wurde eine neue RMR, die sich aus 5-eingeschraenkten faktoren wie intact rock strength, RQD, spacing, persistence und roughness von discontinuities zusammensetzen, in vorsch- lag gebracht

Jan 1, 2003

By J. K. Brooke

Fluorine is a lively element in both its chemical and economic behavior. It was not isolated as an element until 1886 by Moissan. However, its principal source to this day, fluorspar, was known and its special merits recognized long before that time. Our own mining brother, Agricola, is credited with having named fluorite, the mineral name, in 1546 from the Latin, "fluere", to flow. It made things melt and was already being used as a flux. Because fluorspar has been found as a relatively common gangue mineral in metal ore veins, it has long attracted the attention of geological thinkers seeking to, explain the whys and wherefores of veins. Fluorine has been thought of as one of the principal mineralizers, holding metals in ascending vein solutions for deposition close enough to the eventual surface to be accessible for profitable mining.

Jan 1, 1964

By Robert B. Bittner

The Sutong Bridge across the lower Yangtze River in China will have, when completed, the longest span (1,088 m) and the highest towers (306 m) of any cable stayed span in the world. The foundations for this record setting span will also be record setting. They are located in water depths exceeding 30 m with maximum flows exceeding 3 m/sec. The soil at the site of the main pylons consists of layers of silty sands and silty clays extending to bed rock at 270 m below river elevation. This paper describes the innovative methods used by the team of foundation designers and constructors to support this record setting bridge at this very challenging site. This paper covers three specific topics related to the foundations of the Sutong Bridge: ? Design and construction of the 131 drilled shaft (2.8/2.5 m diameter and 114/117 m long) under each of the two main pylons, including the post-grouting of all drilled shaft tips. ? Design and construction of the scour protection for the two main pylons, ? Construction methods used to construct the waterline pile caps (113.8 m by 48.1 m by 13.3 m deep) under each pylon.

Jan 1, 2013

The Mascot-Jefferson City zinc mining district in eastern Tennessee has been a major zinc producer for over 60 years. The district lies within the Tennessee division of the Appalachian Valley and is underlain by folded and faulted Paleozoic rocks. The local formations are composed of limestones and dolomites with occasional shales, and sand- stones, and thin and scattered chert nodules. The regional structure of the district is unique in that it is complicated by irregular, distorted, and broken anticlines, synclines, domes, and major and minor post-ore folding and faulting.

Jan 5, 1976

By C. E. "Sam" Lovewell

In approaching a discussion of production of cement, I hope I won't be like the porter in the bank who was asked if he could give some details on the rediscount rate. He replied, "Boss, when I said hello, I told you all I know." Need for change every so often is illustrated by the story of the little boy four years old who had not spoken a word in those four years. One morning he said, "This damned oat meal is burned'." His Dad was amazed and said, "Son, how come you haven't said a word for four years and now out of a clear, blue sky you say, "The oat meal is burned." Johnny said, "Well, up to now everything has been all right." Not being a mining engineer myself, and my subject not dealing with mining engineering directly, I can only hope that you will agree that the subject has current relevancy by the feet that it can materially improve our environment by putting to good use a potential environmental polluter; namely, fly ash. The profitable utilization of fly ash can reduce cost of use of coal as an energy source. Therefore, it behooves us all to explore to the greatest depth, the pluses and minuses occasioned by its use wherever possible. My particular subject and my particular interest lie in its utilization as a blend in the production of Type IP Portland-Pozzolan Cement meeting requirements of ASTM C-595, Type IP.

Jan 1, 1974

By D. S. Burgess

A commercially available Halon 1301 extinguisher has been evaluated as part of an explosion-suppression system for use in coal mines. Studies were made both of the dispersion pattern of the Halon 1301 at an initial pressure of 280 psig, and of the efficacy of this suppressant against 9.5 percent methane-air flames. These flames were quenched successfully only when the suppressant was applied before the fireball diameter exceeded 18 inches.

Jan 1, 1971

By Kyle Apple

The following is a case study of how LuckStone Corporation improved their blast monitoring and documentation program. A number of resources already at their disposal have been utilized to improve the body of data collected from each blast. The tools being used include GPS, aerial photos, and a user-friendly push button format excel spreadsheet. The data collected include product by product records of materials used, distances to all concerned neighbors, seismograph data, etc: The spreadsheet has been designed to perform an ongoing analysis of blasting trends. The program has been carried out at a corporate level and is in use by blasters at each location. This paper addresses the advantages and drawbacks of this program. It also addresses the ways in which the various tools were integrated, Discussed as well is the need for simplicity when bringing “new” technology to the field and the steps taken in familiarizing the end user to changes.

Jan 1, 2001

By J. P. H. Steele, T. Vincent, C. Debrunner, M. Whitehorn

For a variety of reasons, the need for automation of underground mining equipment is growing dramatically, e.g., improved safety and health, availability of labor, deeper mines, and desire for more focused excavation. While there has been tremendous progress made in this direction, much needs to be done to reach the holy grail of an autonomous mining machine. This paper reviews a number of technological developments and presents research and development needs for future development. A report on our current project for the Western Mining Resource Center at CSM is included.

Jan 1, 2000

Two examples of risk assessment and risk management in action are discussed. The first is in a management context in relation to Kingsgate Consolidated LtdÆs Chatree operation in Thailand. Kingsgate has conducted an over-riding risk management program to assess and manage risk across its complete business from the Sydney and Bangkok offices through to the Chatree Mine and the companyÆs exploration group. This example addresses how Kingsgate has applied risk management, particularly to the process operation, and the benefits that have been gained. The second is in an operational context in relation to Minara Resources LtdÆs Murrin Murrin operation in Western Australia. The subject is the methodology and outcomes of a risk assessment across the Murrin Murrin operation specifically to identify and assess risks with potential impacts from $1 M to $7 M. This section of the paper then shows how the outcomes of the risk assessment were integrated into MinaraÆs strategic plan to debottleneck the plant and increase nickel production.

Jan 1, 2004

By S Q. Zhao, J H. Wei, Z X Zhao, S N. Liang

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The degree of regional denudation is one of the most important factors for judging the preservation potential of ore deposits as it can be used in a predictive manner to help guide exploration. There are many methods available to judge the denudation degrees of mineral deposits. These include regional geochemical assessment methods, the characterisation of primary lithogeochemical halos, the thermoelectricity of pyrite and apatite fission-track methods. Each method has its specific principles, application scopes, limitations and successful cases. Based on previous studies, this paper discusses the research progress on assessments of ore deposit denudation in China and provides a summary and discussion of various methods that can be employed.CITATION:Liang, S N, Wei, J H, Zhao, Z X and Zhao, S Q, 2015. Review on the ore deposit denudation degree, in Proceedings PACRIM 2015 Congress, pp 65–68 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By P. K. Naik, S. C. Das

Leaching studies of low-grade manganese ore containing 31.77% Mn and 23.71 % Fe from Nishikhal, India, were carried out using pyritiferous lignite as a reductant in sulfuric acid medium. The variables studied were quantity of lignite, sulfuric acid concentration and temperature. Regression equations for the extraction of manganese and potassium were determined from 23 full factorial design data. The experimental conditions for the extraction of manganese were optimized using the steepest-ascent method. It was found that 99.03% of the manganese could be extracted in three hours with an ore to lignite ratio of 1:1.8, a sulfuric acid concentration of 1.9 M and a temperature of 99°C. Key words: Leaching, Manganese ore, Lignite, Statistical design

Jan 1, 2003

By P. B. Baxendell

The appraial of producing properties and profitability ntzalysis of a proposed capital expenditure are based on the same principles. In both problems a projection of future cash income is. cornpared to one or more capital expenditures. Several different methods have been in use either to compute a price to obtain a given earning power on the investment or to compute the earning power which will result from a given capital expenditure. One of these, the "Average Annual Rate of Return" method, computes in a simple manner the ratio of the present value of the future earnings after amortization to the present value of the undepreciated balances of the investment over the life of a project. This method, not well known generally, appears to have some rather unique advantages in reducing the computation work required, eliminating trial-and-error solutions, and providing a more accurate answer when applied to oil industry investments subject to the unit-of-production basis of amortization. Its derivation is given and its versatility demonstrated in the solution of certain everyday investment problems. A number of charts, useful in applying this method to profitability analysis and appraisal work, are provided. The current trend in the market values of producing properties is shown. INTRODUCTION Making sound capital expenditure decisions requires an objective means of measuring the productivity of individual investment proposals. Since the best measure of the economic worth of such proposals is their ability to produce profits, it is common practice to grade proposed capital expenditures according to their annual earning power as a percentage of the outstanding capital. The same principles which govern the determination of the rate of return of proposed capital expenditures also apply generally to the problem of determining the appraisal value or purchase price of income-producing oil and gas properties. Both problems are of prime importance in the producing phase of the oil business, where management is faced daily with decisions to drill or not to drill certain development wells, or with the determination of the appraisal value of producing properties. The common feature in both problems is that a projection of future cash income is compared with a known or estimated capital investment to determine itsiearning power or annual rate of return. In the case of development drilling, the cost of the proposed well can usually be estimated with a fair degree of accuracy and the problem consists of finding the rate of return on the invested capital. In the case of appraising producing properties, on the other hand, the desired rate of return is usually known in advance and the problem consists of determining the purchase price which, for the given income projection, results in the fequired rate of return. Certain accounting procedures common to the oil and gas producing business make these two problems and their solutions somewhat different from corresponding problems in other industries, and, in certain ways, simpler. The main difference is in the amortization policy which, for oil and gas production, is frequently on a unit-of-production basis, compared to the amortization on a time basis used in many other industries. The purpose of this paper is to discuss briefly the various methods currently in use for the measurement of productivity of invested capital in producing properties and, in more detail, the derivation and application of what will be called the "Average Annual Rate of Return Method". This rather interesting and not too well known method has some very definite advantages in the solution of many problems common to the oil industry. For the sake of simplicity, federal income tax considerations have been disregarded in the examples used, since they do not affect the principles involved. The use of the production payment route in the sale or purchase of producing properties, which has been amply covered in many other publications, has also not been included in this analysis. METHODS FOK MEASUKING THE EARNING POWER OF INVESTED CAPITAL, Of the many different methods used to measure the earning power of invested capital, four are applicable to oil or gas production ventures. Depending on whether these four methods utilize one or two interest rates, and whether a fixed amortization pattern is used, they may be classified as follows.

By David A. Thomas, Eugene S. Meieran

MECHAMCAL, electrical, and other property measurements are often more easily made on wires than on sheets. In order to carry out transmission electron microscopy on the same material used for property determinations, we have developed a method for preparing thin foil specimens of wires. The technique was developed for 0.030 in. diam tungsten wires, and is a modification of the thinning techniques used by Wilsdorf, et al 1 A length of wire is first ground to about 0.010 in. thick by mounting the wire in low melting temperature wax, hand grinding a longitudinal flat, removing and reversing the wire in the mount, and then grinding a second parallel flat. The 0.030 in. wide and 0.010 in. thick strip is cut into 1/8 in. lengths to fit in the specimen holder of the electron microscope. Next the specimen is gripped in platinum-tipped tweezers (the anode) and placed 2 mm below a hol- low copper cathode with a 0.010 in. ID nozzle. Electrolyte, 10 pct NaOH, flows by gravity feed through the nozzle onto the specimen, as shown in Fig. l(a). Polishing is carried out until a shallow impression is made on one surface, and then the specimen is turned over and the opposite surface indented. The metal between the two impressions should be about half the specimen thickness, as is shown by the heavy line in the cross section in Fig. l(b). The entire specimen is then electropolishedin 2 pct NaOH until a hole appears at the location of the indentations. The apparatus is shown in Fig. 2, and is essentially the same as that used by Wilsdorf et al. at The Franklin Institute. Light is reflected by a mirror onto the bottom surface of the specimen! which is viewed by a stereoscopic microscope placed above it. Polishing is carried out until light is seen, indicating that a hole has formed, and then immediately stopped. The specimen is washed in water. alcohol, and ether, and is then ready for examination. The specimen should be reversed in its platinum clip during electropolishing to insure equal polishing on both sides of the impression. For tungsten, indenting at 120 v and 0.04 amp takes less than 1 min, and final polishing, at 10 v and 1 amp, less than 5 min. The portion of the specimen available for transmission microscopy surrounds the hole, as is seen by the dashed lines in Fig. l(b). Slight electroetch-ing accompanying electropolishing reveals the mi-crostructure, as seen in Fig. 3(a) by light microscopy. Low-magnification electron microscopy, as in Fig. 3(b), enables the same areas and grains to be viewed and identified when subsequently examined at high magnification. Fig. 4 is a typical structure of

Jan 1, 1963

By R. C. Amero

FULLERS earth is a general name applied to claylike minerals that have high natural ad-sorptive powers. They are usually distinguished from ordinary clays by a higher content of combined moisture and a lower apparent density. The definition is based on the ancient use of the material for fulling, or cleansing woolen cloth of oil and grease; a more modern definition should mention the ability to decolorize oil and should differentiate between fullers earth, which is naturally active, and certain bentonites which only develop decolorizing power after being leached with strong mineral acids. The distinction between fullers earth and activable bentonite is not a sharp one, since all types of intermediate clays can be found that are more or less naturally active, yet more or less responsive to acid treatment. The differences seem to depend somewhat on the amount of leaching that has been effected by natural ground waters. Physical Properties The principal mineral constituent of activable bentonite is montmorillonite, a hydrous aluminum silicate to which the following formula is generally assigned: Al,Si,O,, (OH), • 12H,O Fullers earth, as well as bentonite, is usually composed of some variety of montmorillonite, but in the United States the largest tonnage of fullers earth is mined from deposits of attapulgite. Attapul- gite is a clay mineral composed of monoclinic crystals of colloidal size, having a fibrous shape similar to that of asbestos. A sectional model of the attapulgite "molecule" is shown in Fig. 1. A single unit is about 18.0 A wide and 12.9 A high. The length of the molecule is variable, but this same molecular pattern is repeated to form needlework crystals, rather than flakes, as is characteristic of the montmorillonite crystals. Attapulgite has been assigned the following formula,' although actually, the magnesia has been largely replaced by alumina: (0%) . (OH), • Mg, . Si, • Olp . 4H20. The fibrous nature of the mineral is clearly shown in the electron micrograph, Fig. 2. Although the deposits contain 5 to 30 pct quartz and carbonate minerals, impurities in the commercial products are held at a low level, principally by selective mining on the basis of oil decolorizing efficiency. The particle size distribution of this fullers earth has been estimated from settling rates, using sodium citrate as a dispersing agent.' Since Stokes' law only applies to spherical particles, the equivalent particle diameter calculated below is probably more nearly an index of diameter rather than length of the needlelike crystals: Eqnivalent Arbitrary Particle Distribution, Size Diameter Pci Classil3catian 0.05 mm 0.80 0.80 pct sand 0.05-0.02 mm 10.96 0.02-0.01 mm 9.65 42.10 pct silt 0.01-0.005 mm 11.40 0.005-0.002 mm 10.09 2-0.5 micron 10.61 0.5-0.2 micron 29.09 56.58 pct clay 0.2-0.05 micron 14.86 0.05 micron 1.96 The differential thermal analysis shown in Fig. 3 is unique and supports the theory that this is a distinct mineral species.' ~ Other general properties of the mineral as shown in Table I.

Jan 1, 1952

By A. Mainza, A. Mabentsela

A finite element model of a 5 m radius DC arc ilmenite furnace in idling mode was used to test the notion that the slag solidifies when it comes in to contact with colder pig iron, thus constituting the initial step in the formation of solid slag at the slag-pig iron interface. It was found that a slag that is 150°C hotter than the pig iron does not solidify at the interface. The 150°C temperature difference between the slag and pig iron is a result of solid slag at the slag-pig iron interface, not the other way around as suggested in the literature. Calculations show that the thickness of the frozen slag at the slag-pig iron interface is 1.7 cm for the furnace used. It is proposed that slag solidification begins with the slow co-current flow of molten slag and pig iron in the outer parts of the furnace. This provides enough time for molten slag to interact with molten pig iron without solidifying. As the reduction products form due to reduction of the slag by carbon in the pig iron, the slag solidifies. This approach negates the need for the slag to solidify by merely coming into contact with an inherently colder pig iron. Making use of a low thermal contact conductance between the slag and pig iron was found to be sufficient to numerically capture the presence of solid slag at the slag-pig iron interface and to preserve the 150C difference between the slag and pig iron phase.

Mar 30, 2023