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By S. Norman Kesten

The Galena mine is located astride the Polaris fault in the Coeur d'Alene district of northern Idaho. The surface installations are about a mile up Lake Gulch, the mouth of which is about 2.4 km (1 112 miles) west of the old town of Wallace. The mine had its beginnings when the first claims were located in the early boom days of the district in the 1880s and when the first underground ore bodies were opened up in 1917. During the ensuing 14 years, ore was mined from which were recovered 5.4 Mkg (12 million lb) of lead and almost 14.2 Mg (112 million oz) of silver. Workings consisted principally of a vertical shaft from surface to the 800 level and an offset underground shaft to the 1600 level, together with extensive lateral openings. High-grade silver-copper ore was discovered near the Silver Standard fault in the Sunshine mine, a few miles to the west, on the 1700 level in 1930. By 1937, the Sunshine and adjacent mines were producing silver-copper ore on a regular basis. In 1943 additional ore of a similar type was found along the Chester fault, to the east of the principal Sunshine workings. The interest of American Smelting and Refining Co. (renamed ASARCO in 1975) was aroused and the company's geologists determined that the Galena mine, idle since 1931, provided a geological environment in which similar ore might be found. After negotiations were initiated with the owners of the property, Callahan Zinc-Lead Co., the property in question was deeded to Callahan's wholly owned subsidiary, Vulcan Silver-Lead.

Jan 1, 1990

By E. P. Youngman

This paper is one of a series of digests of foreign mining legislation and court decisions that is being prepared in advance of a general report relative to the right of American citizens to explore for minerals and to own and operate mines in various foreign countries. This interpretation of the mining laws of British Honduras has been prepared from the best available information in Washington and is released subject to amplification or correction, if necessary, by United States foreign-service officers. INTRODUCTION The mining law governing all mineral substances other than oil is ordinance No. 7 of 1927 (Minerals Ordinance, 1927), passed by the Legislative Council on March 25, 1927. The accompanying regulations, No. 3 of 1932 (General Minerals Regulations, 1932), made under the authority of section 66 of the minerals ordinance, were made by the Governor in Council on December 23, 1931.

Jan 1, 1934

By Alan Galley, Tom Hynes, Michel Plouffe

"Mining in Canada’s economy• Employs 320,000+ workers; Wages 30-60% above other sectors• Operates 220 producing mines, 33 smelters and refineries• Paid $8.4B in taxes and royalties to governments in 2010• Invests about $30B in capital projects annually • Largest private employer of Aboriginal Canadians 2• Core supplier to clean-technology sectors• Attracted 18% of world exploration spending in 2010• Efficient TSX processes - 1400 mining companies listed, ~50% of mineral projects are outside Canada• Estimated 1000 Canadian companies in 100 countries• Minerals account for 21% by value of Canada’s goods exports• Top 5 World Producer in uranium, potash, nickel, platinum, aluminum, diamonds, zinc, met coal"

Jan 1, 2012

By Alicia O&apos, Overbeck, Reardon

DIFFIDENTLY, because don'ts are rarely greeted with cheers; humbly, because I, myself, have never lined up with the irreproachables, I venture on the subject of manners for the mining camp matron. Mining camps can be divided roughly into two types-the large, opulent settlement that blooms like the rose about a strong mine in full operation; and the puny group of adobe huts, or calamina shacks, or even canvas tents flung down in the wilderness to shelter the gay pioneers of a shining prospect or the shattered survivors of a lost hope. Of the first, I know nothing; but in the second, I have spent some of my best years, and from its curious code of morals and manners, its comic hates and its unreasoning loves, its high impatience and its engulfing kindness, I have charted the narrow .and pitted path which must be trod by the woman who would success¬fully live therein.

Jan 1, 1936

Surface mining and reclamation of a southeastern Ohio site with sandstone-shale overburden resulted in (as compared to premining levels): 1) runoff volumes and peak rates that increased by a factor of from 2 to 10 during mining and after reclamation, 2) destruction of the "aquifer" perched on the underclay of the mined coal bed and gradual, but, as yet incomplete redevelopment of this aquifer after reclamation, 3) no immediate effect on another, lower perched "aquifer", 4) up to 100 times greater sediment concentrations in runoff. Results were influenced by increasing annual precipitation amounts through the period of record; 1978, 1979, and 1980 (postreclamation years) experienced precipitation amounts approaching or exceeding long-term normalcy for the area. Part of the reason that the site produced more runoff after reclamation than before mining is that the premine condition was one of an open, porous soil under woodland, while the postreclamation condition was one of a compacted, bulldozed soil. Sediment concentration results were influenced by failure of the postreclamation erosion control system and by a series of detention reservoirs above the stream monitoring station.

Jan 1, 1983

By A. Baldwin

Reports technical progress in designing four machines to be used in mining coal underground, applying innovative concepts at the design stage (instead of add-ons). A study phase was followed by design activity, including calculations supporting the designs. Scale models of three machines were built, and a full-scale mock-up of the conventional loader was used to measure human factors parameters.

Jan 1, 1976

By Michael Rieber

A new mode of coal transportation based on the principles of pneumatic conveying has been recently, proposed by Soo, et al. [5]. Pneumatic transport is not a novel concept and commercial experience with pneumatic pipelines for short haul distances is plentiful. The list of applications is long and includes transporting ores, chemicals and pharmaceutical products, agricultural products, and domestic and industrial wastes. The study by Soo, et al. [5] updated an earlier one [l0] and presented the most recent economic evaluation of pneumatic transportation of coal. Their preliminary study concluded that there are immediate advantages for short-distance transport (less than 100 miles) and that it is both technologically and economically feasible. That study also concludes that pneumatic transport has a higher potential and more promising profitability in long-distance applications than rail if new track and roadbed must be built. Some of the advantages of long and short distance pneumatic pipeline transport of coal compared to rail and slurry transport are: 1) Replacement of diesel fuel consumed by unit trains, as the pipeline can be powered by coal-generated electricity; 2) Reduction of the skilled-labor costs required for upgrading and maintaining railroads; 3) Elimination of signaling, rerouting and overpass costs due to increased rail traffic on' mainline trackage;

Jan 1, 1977

THERE are three objectives in translation of works of this character : to give a faithful, literal translation of the author's statements ; to give these in a manner which will interest the reader ; and to preserve, so far as is possible, the style of the original text. The task has been doubly difficult in this work because, in using Latin, the author availed himself of a medium which had ceased to expand a thousand years before his subject had in many particulars come into being ; in consequence he was in difficulties with a large number of ideas for which there were no corresponding words in the vocabulary at his command, and instead of adopting into the text his native German terms, he coined several hundred Latin expressions to answer his needs. It is upon this rock that most former attempts at translation have been wrecked. Except for a very small number, we believe we have been able to discover the intended meaning of such expressions from a study of the context, assisted by a very incomplete glossary prepared by the author himself, and by an exhaustive investigation into the literature of these subjects during the sixteenth and seventeenth centuries. That discovery in this particular has been only gradual and obtained after much labour, may be indicated by the fact that the entire text has been re-typewritten three times since the original, and some parts more often ; and further, that the printer's proof has been thrice revised. We have found some English equivalent, more or less satisfactory, for practically all such terms, except those of weights, the varieties of veins, and a few minerals. In the matter of weights we have introduced the original Latin, because it is impossible to give true equivalents and avoid the fractions of reduction ; and further, as explained in the Appendix on Weights it is impossible to say in many cases what scale the Author had in mind. The English nomenclature to be adopted has given great difficulty, for various reasons ; among them, that many methods and processes described have never been practised in English-speaking mining communities, and so had no representatives in our vocabulary, and we considered the introduction of German terms undesirable ; other methods and processes have become obsolete and their descriptive terms with them, yet we wished to avoid the introduction of obsolete or unusual English ; but of the greatest importance of all has been the necessity to avoid rigorously such modern technical terms as would imply a greater scientific understanding than the period possessed. Agricola's Latin, while mostly free from mediaeval corruption, is somewhat tainted with German construction. Moreover some portions have not

Jan 1, 1950

By David A. Hall

We present an analysis of the propagation in a uniform tunnel of semi -circular cross section that contains two axial conductors. In particular, we show that, even if one of these conductors has high ohmic loss, one of the two propagating modes has relatively low attenuation. This corresponds to the situation where an unloaded dedicated wire is used to improve radio frequency communication in a mine tunnel that contains a heavily loaded trolley wire.

Jan 1, 1978

By G. Roger Miller, Kristine M. Krajnak, Stephen S. Leonard, Stacey Waugh

Repeated exposure to hand-arm vibration through the use of vibrating hand tools can result in the development of the disorder known as hand-arm vibration syndrome (HAVS; (1,3)). One of the hallmark symptoms of HAVS is cold-induced peripheral vasospasms that result in finger blanching (4). Although the vascular and neural pathology associated with vasospasms has been described, little is known about cellular mechanisms leading to this damage (4). To understand how vibration may alter vascular and neural physiology and anatomy, rats were exposed to a single bout of tail vibration and the molecular responses of neural and vascular tissues were measured to determine if there are immediate or sustained affects of vibration that may underlie longer term changes in physiology. Methods Experiment 1. Male Sprague Dawley rats (n = 32, 6 weeks of age) were housed in AAALAC accredited facilities. All procedures were approved by the NIOSH Animal Care and Use Committee and were in compliance with the CDC guidelines for care and use of laboratory animals. Vibration exposures were performed by restraining rats in Broome-style restrainers, and securing their tails to a vibration platform using 6 mm wide straps that were placed over the tail every 3 cm. Restraint control rats were treated in the same manner, except that the tail platform was mounted on isolation blocks and not on a shaker. The vibration exposure was 125 Hz, 49 m/s2, for 4 h. Rats were euthanized with an overdose of pentobarbital (100 mg/kg) 1 h or 24 hours after the exposure. RTqPCR was used to measure transcript levels for endothelin 1 (ET-1), the 3 forms of nitric oxide synthetase (NOS) NOS-1, NOS-2, NOS-3 and norepinephrine receptor subtypes 1D, 2A, 2C, in artery tissue, and to measure calcitonin gene-related peptide (CGRP) and nitric oxide synthase-1 (NOS-1) in ventral nerves. Data were analyzed using 2-way ANOVAs. Experiment 2. Male Sprague Dawley rats (n =24, 6 weeks of age) were maintained as described above. Animals were exposed to a single bout of restraint or vibration. Another group of animals served as cage controls. All animals were euthanized 24 h after the exposure, and tail arteries were isolated and frozen. Reactive oxygen species ROS) were measured using electron spin resonance spectroscopy (ESR). Arteries were homogenized over ice in 1 ml of PBS with protease inhibitor cocktail, using a tissue tearer (Biospecs Products Inc. Racine, WI USA). The sample was split into two 0.5 ml samples. One set had PBS and the spin label hydroxyl-TEMPO [0.1 mM] added while the other set had hydroxyl-TEMPO [1.0 mM] plus the specific hydroxyl radical scavenger, dimethylthiourea (DMTU), added to confirm the presence of the hydroxyl radical. Samples were vortexed and then placed in a flat cell for ESR analysis. The ESR spectrometer settings were: receiver gain, 6.32 x 102; time constant, 0.02 s; modulation amplitude, 1.0 G; scan time, 20 sec; magnetic field, 3490 ± 100 G (2). Data were analyzed using 1-way ANOVAs.

Jan 6, 2006

By G. T. Austin

This is an overview of the gemstone industry with special attention on particular states within the united states. The U.S. Bureau of Mines, Department of the Interior compiled and analyzed the information contained in this report. The report should be viewed as a current "still photograph" of a dynamic system. The information presented on a specific gemstone or for a specific state can and will change with time. This overview presents historical and reference information on the principal gemstones and their production in certain states. The report is not a definitive work on gemstones within the select states or United states.

Jan 1, 1995

By Ronald L. Gibbs

IN THE BEGINNING Contrary to popular myth, the personal computer can trace its roots back to a time before 1981 and the IBM PC. The seeds of the personal computer revolution were probably founded in 1975 with the release of the Altair (kit) personal computer, first advertised in Popular Electronics. June of 1975 marked the beginning of the Homebrew Computer Club in San Francisco. The founding membership list of the Homebrew Club now reads like a "Who's Who" of those involved in the early development of the personal computer industry. The Apple I computer was created by Steve Wozniak in early 1976 from the newly manufactured MOS Technology 6502 chip. It had 4,000 bytes (4K) of Random Access Memory (RAM] memory, a revolutionary amount of memory in 1976. Another early pioneer, the Commodore Pet computer, was another 6502 machine, but with 8K of memory. Tandy Corporation made its name in the hobby industry with leather kits. They embarked on a new path with the production of the TRS-80 line of personal computers. Most were based on the Z-80 chip, but again, were memory limited. A number of other Z-80 based systems followed later, including the Osbourne and the KayPro Computers. These systems were based on the Digital Research CP/M operating system and had a maximum of 64,000 bytes of memory (64K). The Apple I1 Computer appeared in 1977. Newer models of the original Commodore Pet and an Atari computer followed. These machines were also limited to 64K of memory addressing, and the early models typically shipped with only 16K, 32K, or 48K of memory. The Z-80 and the 6502 were the first truly commercialized CPU chips touting boxes with key- boards, monitors (sometimes a TV), and the ability to expand (peripheral slots for serial communications, centronics parallel communications, etc.1. They all shared one technology, audio tape as a storage media. The use of a portable tape recorder provided inexpensive, if not always reliable, magnetic storage. The tape recorders were typically finicky and required patience to use. Adjustments to the volume control were often needed to find "just-the-right" setting for loading or saving information. This kept the personal computer from being accepted in many markets, and gave it a reputation as a hobbyist or experimenters' toy. In early 1979, Steve Wozniak finished the design of a floppy disk drive and controller. This was a revolutionary design which reduced the "then" standard number of controller chips from fifty-plus, to just eight. With the advent of an affordable floppy disk drive mechanism, the personal computer was about to gain respectability. From a business standpoint, it was now possible to save and reliably retrieve business information. It also provided a superior means of distribution for commercially created software. Commercial software became a commodity rather than an oddity.

Jan 1, 1993

By D. E. Wakefeld

"My first reaction to Joanna LaForte’s discussion paper is that she has quite properly assumed that I would like the process of equitable participation between aboriginal landowners and mining companies to be a fast process. On the other hand, I have been a business lawyer long enough to know that the past experiences of the parties will have a significant effect on how they will proceed at any one time.In my article, I was trying to convey the importance of responding to the wishes, aspirations and fears of aboriginal communities in Arctic regions without land settlements. I agree that if it is necessary to wait for governments, the process will be quite slow. My article did point out that often aboriginal communities and mining companies who have become comfort-able that a project is in their mutual interest regard the government(s) involved as their common enemy. I agree that the education and training of aboriginals should “expedite the negotiations and end the power struggles equitably”. Also, I did not mean to suggest that the elders distrust of changes in traditional land use was solely due to concern for alienation and separation from their offspring; however, I suspect it is one reason for their caution. I also agree with this author that establishing opportunities that enable the young aboriginal community members to remain in the north and avoid the problems that await them in southern urban culture should be a common concern of the mineral developer and the Arctic aboriginal community.When this author suggests I am “overly concerned about how much land the aboriginals will control, how educated they may become, how ignorant they are of mining procedures, how objections from aboriginals will escalate expenses, etc.”, she attributes to me as “concerns” matters that were intended to be general information for my readers. My references to the increased land holdings and the improvement in education of aboriginal peoples was intended to deter mining companies from any attempt to be inequitable in their dealings with aboriginal communities."

Jan 1, 1996

By R. J. Charles

F. C. Bond: This is an outstanding paper on comminution theory and represents a considerable advance in mathematical formulation. It clears the way for a discussion that should ultimately decide whether the work index should be considered as a parameter according to the Third Theory or as a constant. In the empirical differential equation dE = —Cdx/x [1] either Corn must be treated as a variable to satisfy known crushing and grinding conditions. The author has chosen the exponent n as the variable, with C as a constant. According to the Third Theory, in the general case n is a constant equal to 3/2, and C is a variable related to the work index Wi. If x is placed equal to P (the size in microns which 80 pct of the product passes) and F is the size 80 pct of the feed passes, then C equals 5 W1, and dE = 5 -5 Widx/x = 10 Wi 10 Wi w = vP vF which is the basic equation of the Third Theory. It is apparent that this integration involves the error of treating the parameter Wi as a constant, just as the author's treatment involves the error of integrating his variable n as a constant. These errors are probably relatively unimportant, considering the small range of the variables. When more is known about the factors contained in the work index, Eq. 1 can be revised as a partial differential equation. The Third Theory exponent of 1/2, or n = 3/2 in the Charles' differential equation (Eq. l), was not chosen primarily because it is the average between the Kick and Rittinger exponents; this may be merely fortuitous, since it is illogical to define truth as the average between two errors. It was first discovered from the study of a large mass of crushing and grinding data and confirmed by laboratory testing. The general correspondence of the Third Theory equation to actual crushing and grinding results over the entire size reduction range argues strongly that a fundamental phenomenon is involved. The a posteriori theoretical explanation of the constant Third Theory exponent is that the work done in breaking rock is proportional to the length of the crack tips formed. Compressive force applied to the rock results in deformation and strain energy. When this locally exceeds the breaking strength a crack tip forms, the surrounding strain energy flows to the crack tip and extends it to split the rock, with release of the energy as heat. Under rapid impact the crack tip may form before the strain has reached equilibrium, resulting in less energy expenditure and probably a coarser product. In any case, the elastic limit of a brittle material is practically the same as its breaking strength, and the work necessary to form the crack tip is the work required to break. The crack length of a ton of broken rock cannot be measured directly. However, the particle shapes of feed and product are similar, and the crack length is considered equal to the square root of one half of the new surface area formed. It is, therefore, proportional to 1/vD, where D is the equivalent product particle diameter. This is the basis of the Third Theory equation. Many secondary factors can be imposed upon the crack length breakage. These may cause the Third Theory work index to increase or decrease somewhat as the product size becomes finer. The work index is properly a parameter rather than a constant, making it an increasingly valuable practical criterion of the work input required in crushing and grinding.

Jan 1, 1959

By J. Clark

The objective of this study has been to determine the state of the art in underground, thin-seam-mining systems, to identify new technology and procedures that would reduce the hazards of thin-seam mining and to recommend areas for further research. The study was carried out in two phases, the first of these being devoted to a survey of authoritative literature. Subsequently, the practices adopted in the various mining countries were analysed and comparisons made to identify machines and methods with the potential for application in the USA. Published figures on US bituminous coal reserves show the high proportion contained in thin seams and US accident statistics demonstrate that the risk is greater in thin-seam operations. A comparison has been made with the experiences of foreign operations. The Phase 11 study proceeded along two separate avenues to examine the distinctive problems associated with seam thicknesses above and below 30 in. Current systems of mining appropriate to seams greater than 30 in were elaborated and compared by means of a simulation exercise in terms of safety, production and cost. For seams below 30 in, less conventional systems, some presently disused, were studied and their potential evaluated; the research and development work necessary to make them viable has been indicated.

Jan 1, 1980

By E. F. Koppe

The Upper Freeport coal in the Freeport and New Kensington quadrangles, Pennsylvania, varies from a bony streak to a thick coal deposit often exceeding ninety inches, the "Double" or "Thick Freeport". Distinctive basal partings, a central bone layer, and a canneloid top bench may be present. The appearance of a sandstone roof, sandstone rolls, and bony coal at the top of the main coal bench can be anticipated in thin Freeport areas when basal partings are absent. When the two basal partings are present, a shale roof is normal. These effects are correlated with the original topography upon which the coal was deposited. The original depositional high areas tend to coincide with present structural highs. Preliminary data indicate that coal quality, in part, is affected by the deposi-tional setting. In "high" areas, a tendency exists for the main coal bench to contain higher percentages of fusain and mineral matter. Within limits, some-what higher ash fusion temperatures appear to correlate with paleotopographic highs. As a result of these findings, critical examination of the paleotopography and related sediments is indicated in other areas and other coals. The Upper Freeport coal is quite variable both in thickness and composition in the Freeport and New Kensington quadrangles of Pennsylvania (Figure 1). The coal horizon in these quadrangles is marked either by a thin carbonaceous shale bed or by a single bed containing a variable number of partings (binders). The complex coal zone known locally as the "Double" or "Thick Freeport" contains the Upper Freeport Coal Bed at the base; but in addition, it has an overlying bone layer and an upper coal bed occasionally capped with a canneloid layer. The "Thick Freeport" often exceeds 90 inches in thickness, whereas the normal Upper Freeport coal usually varies between 34 and 50 inches.

Jan 1, 1961

By Y. M. Jiang

A users friendly PC Computer Program has been developed to implement a systematic design of the powered support. The required input data are: (1) thickness, RQD, and compressive strength of the immediate roof; (2) mining height; and (3) type, thickness, and tensile strength of the main roof. Several important parameters for support selection under a given geological condition are generated through the implementation of the program, including type of support most favorable for the geologic condition, minimum inclination angle of the legs with respect to the horizontal axis, suitable setting load ratio of the front to rear leg for the 4-leg supports, optimum setting load, and support capacity.

Jan 1, 1989

By D. R. Rathburn

Jan 1, 1962

By K. Zenger, J. Kaartinen, J. Huuskonen, S. Torttila, S. Lähteenmäki, J. Pietilä

"Pyhäsalmi Mine in Finland has a long history of continuous process development. The concentrator processes Cu-Zn-sulphide ore with high recoveries. An on-line flotation simulator has been developed to maintain and further improve the flotation performance. Consisting of a flotation kinetic dynamic model, and interconnected with process control software, the simulator can be used for training new control room operators in various scenarios. For daily operation, the model parameters are continuously adapted to take into account the changing process conditions. On-line simulator tracking the process can provide the process operator new information in several ways: a) values of unmeasured process variables are obtained by displaying the corresponding simulator values, b) predictions of future process states and outputs are calculated and displayed, c) information of changing process parameters can be used as an indicator of e.g. change in the processed ore type. This paper describes the adaptive simulation system and its usage at the Pyhäsalmi concentrator.IntroductionPyhäsalmi massive sulphide orebody is located in central Finland. Operation of the mine started in 1962 and it is currently producing copper (Cu), zinc (Zn) and sulphur (S) concentrates. The concentrator control and optimization system has a long history of successful continuous development during the past decades (see e.g. Huuskonen & Moilanen, 2010). An on-stream analyzer has been a part of the automatic process control since 1968 (Lähteenmäki, Miettunen & Saloheimo, 1999). First control algorithms based on a flotation mathematical model were developed in 1971 (Koivistoinen & Miettunen, 1985). In 1990’s the development of a froth machine vision systems started (Kaartinen, 2009; Kaartinen, Roine & Hätönen, 2009). More recently Pyhäsalmi Mine Oy has been involved with several national development projects dealing with particle size distribution measurements (Kaartinen & Tolonen, 2008), spectral analysis of flotation slurries (Haavisto, Kaartinen & Hyötyniemi, 2008), and dynamic simulation of flotation processes. The latter topic is further elaborated in this paper."

Jan 1, 2015

This paper presents the near-field rock damage owing to production blasting in limestone quarry in the western region of Japan. The study's purpose is to learn the mechanism of crack development due to blast vibration. In this study, blast vibration's magnitude was expressed with peak particle velocity (PPV) which was obtained based on seismographs recorded database. In attempt to pursue a research's purpose of this study, there were two considerable interests: near-field blast vibration propagation and prediction, and crack observed and prediction. Furthermore, with regards to considerable interest of the study, there were three essential aspects which were challenged, such as: monitoring and interpretation of seismic wave propagation in a rock mass near large explosive charge of production blast scale, measurement of blast rock damage in adjacent to blasthole, and determine critical value of PPV which may produce significant rock damage. In order to determine precision critical PPV, understanding correlation between rock damage with vibration level is firstly important to be done. This paper also discusses how to measure, detect and quantify near-field blast vibration and blast rock damage in adjacent to blasthole.

Dec 6, 2010