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By William L. Crentz

In the past, Westmoreland County together with Fayette County produced about one-third of the bituminous coal mined in Pennsylvania. The Pittsburgh bed in Westmoreland County has furnished enormous quantities of coal to the by-product and beehive ovens, gas-manufacturing plants, and general industrial manufacturers over a wide area until about 20 years ago. Little attention was paid to the thinner beds because of the superior quality of the Pittsburgh. The approaching exhaustion of Pittsburgh coal will require accelerated-exploitation of these coals if Westmoreland County is to continue as an important source of bituminous coal, Much of the Pittsburgh coal in Westmoreland County is low-sulfur and requires no mechanical cleaning for the preparation of a metallurgical fuel. Even those areas where the sulfur percentage increased to a maximum of about 2 percent, a relatively easy washing operation usually produced a cleaned coal, which found ready acceptance by the coke industry. Davis reported the remaining recoverable reserves of the .Pittsburgh bed in Westmoreland County to be 255,439,000 tons as of January 1, 1937. Since that date, more than 100,000,000 tons of Pittsburgh coal has been extracted so that the time is not too distant when this important coal bed will be depleted. A study of the Pittsburgh bed in Westmoreland -County has not been made a part of this report as the remaining reserves of the coal can be used in coke making with a, minimum of preparation. The production from the Upper 'Freeport bed will increase as the supply of coal from the Pittsburgh bed diminishes, and as of the present time it supplies a substantial proportion of the county's coal output.

Jan 1, 1951

By William Gleason

"It is safe to say that the coal industry, in the United States and globally, is currently suffering through one of the hardest times in its history.A perfect storm of competition, changing energy demands, politics and public perceptions have collided, inflicting significant harm to the industry that many say is irreparable. This, in turn, has led to massive job losses in some regions, heavy cuts in production and even bankruptcy filings from two of the largest coal mining companies in the nation.Cheaper natural gas can certainly take a large share of the blame for the struggle of coal, as utility companies switch from coal to natural gas for power generation. According to the U.S. Energy Information Administration (EIA) the amount of coal used for electricity generation in the United States is at a 45-year low.November 2015 marked the fifth consecutive month that natural gas was the leading source of power generation in the United States. EIA said generators produced 101,866 thousand megawatt hours (MWh) of electricity with gas in November versus just 87,789 thousand MWh with coal, the lowest monthly level since May 1980 when monthly coal use was 84,884 thousand MWh.According to Robert Godby, director of the Center for Energy Economics and Public Policy at the University of Wyoming, there are a number of factors playing a role in the decline of coal, but he points to the advances in fracking as the tipping point.“A lot of people will argue that regulation is the cause of the decline, and it has played a part, for sure, but the story of the recent past is more about what competition has done to the energy market,” Godby told Mining Engineering. “The war on coal was originally declared by natural gas in 2008.”The price of natural gas, which was at $13 per million Btu before the gas fracking boom, has fallen to as low as $1.68 in December 2015. Likewise, Godby said the cost of wind generation is now lower than the cost of generation from coal and the cost of solar generation is coming down as well. In addition to that, the demand for energy has changed in the past five years with more efficiencies in everything from building design to lightbulbs."

Jan 1, 2015

By R. W. Raymond

(Pittsburg Meeting, March, 1910.) IN the long list of our illustrious and lamented dead, there are names which recall personality as well as career and achievement; social as well as scientific merit; devotion to the Institute itself as well as to some one of the professions which it represents. These men we remember because they did not forget us; besides our pride in their wider work and fame, we are proud of what they did with and through us; especially do we rejoice if our early recognition of them opened the way to a recognition by the world; and in their departure we claim to sorrow, not merely as members of an appreciative public, but also as. bereaved personal friends. In common with thousands, we regret our loss, but we do not regret only-we mourn and miss. To this group of those whose death has brought to us the double sense. of public and private grief belonged our strong, bright, dear brother, in whose memory this inadequate tribute is offered. Charles Benjamin Dudley was born July 14, 1842, at Oxford, Chenango county, N. Y. He came on both sides of New England blood, his father being from New Hampshire and his mother from Connecticut. Emigrating from the rocky hills of their native States, they. settled upon the more fertile soil of what was then regarded as the West, and, with thousands of other pilgrim sons, imitating the pilgrim fathers, contributed to the foundation of new commonwealths. The Empire State owes much to this element of its population. Dudley's early education was obtained, like that of the sons of the pioneers generally, by attending the village school and academy in the autumn and winter, while he worked upon the farm during the rest of the year. But his ambition looked forward to a college-course; and this was almost within his reach when a passion still stronger took possession of him. The out-

Jun 1, 1910

By P. deH. Eastcott

The paper summarizes a slide presentation made during the CIM Mechanical-Electrical Operators' Conference, held at Sudbury. Ontario, January 25-27, 1977. Its scope has been limited to a few specific aspects of modern Canadian hoisting plant practice that are likely to be of interest to operating personnel. It is intended to serve as a brief review of established methods discuss in more detail the present state-of-the-art and suggest trends that will appear as products during the next few years.

Jan 1, 1977

By M. T. Ityokumbul

The use of yield index, the product of the yield and gangue rejection, for the optimization of separation processes is presented. The characteristics of the yield index are contrasted with separation efficiency calculations and applied to laboratory froth flotation and washability data. Data from continuous froth flotation tests conducted to "optimize" froth flotation using process optimization software were also evaluated with the yield index procedure.

Jan 1, 1997

By C. M. Harrer

Reconnaissance investigations were made of 129 iron occurrences in Arizona to determine their extent, attitude, and potential; character samples were analyzed to determine their quality and impurities; and pioneer metallurgical investigations were made on character samples to present their metallurgical problems. Some factors influencing past and potential western iron markets are discussed. The location, features, qualities, extent, and potential of iron occurrences and some associative resources--limestone and dolomite, coal, petroleum and natural gas, power, and water are discussed. The most abundant iron minerals are magnetite and hematite. The higher grade deposits are extensive contact-metamorphic or pyrometasomatic replacements of calcareous Paleozoic to Proterozoic rocks associated with intrusives. Large low-grade deposits of great potential are present as Precambrian taconite, semitaconite-, and jaspilite-like iron formations of magnetite-hematite. Iron occurs also as low-grade concentrations of magnetite in extensive alluvial deposits. Nonferrous metallurgical slags, nearly 100 million tons, are considered a potential source of iron. Various accessory elements are associated with the iron minerals and these pose metallurgical and economic problems.

Jan 1, 1964

By C. M. Harrer

Reconnaissance investigations were made of 129 iron occurrences in Arizona to determine their extent, attitude, and potential; character samples were analyzed to determine their quality and impurities; and pioneer metallurgical investigations were made on character samples to present their metallurgical problems. Some factors influencing past and potential western iron markets are discussed. The location, features, qualities, extent, and potential of iron occurrences and some associative resources--limestone and dolomite, coal, petroleum and natural gas, power, and water are discussed. The most abundant iron minerals are magnetite and hematite. The higher grade deposits are extensive contact-metamorphic or pyrometasomatic replacements of calcareous Paleozoic to Proterozoic rocks associated with intrusives. Large low-grade deposits of great potential are present as Precambrian taconite, semitaconite-, and jaspilite-like iron formations of magnetite-hematite. Iron occurs also as low-grade concentrations of magnetite in extensive alluvial deposits. Nonferrous metallurgical slags, nearly 100 million tons, are considered a potential source of iron. Various accessory elements are associated with the iron minerals and these pose metallurgical and economic problems.

Jan 1, 1964

Jan 1, 1948

Jan 1, 1948

By J. C. Gathje

Newmont acquired the Phoenix Project through the acquisition of Battle Mountain Gold in 2000. Shortly after the acquisition, Newmont Metallurgical Services (NMS) and Nevada Operations began development work on a process to Pressure Oxidize (PDX) precious metal rich copper concentrates from Phoenix using the Lone Tree PDX facilities at Valmy, Nevada. The high precious metals content of the Phoenix concentrate - Au up to -300 g/t and especially Ag, up to -1700 g/t - led Newmont to the development of a High Temperature PDX process that achieves high cyanide leach recovery of Au and Ag, from the PDX solids, without the requirement for a messy and expensive "lime boil" or sulphate destruction process. Base metals content in Phoenix concentrates range from: 15-25 % for Cu, 1-10 % for Zn and 0-2 % for Pb. Excellent solution extraction of Cu and Zn is achieved while Pb is precipitated in the PDX residue. In addition to achieving high Au and Ag recovery this process produces very clean PDX discharge liquors that require minimum effort to remove contaminant metals and PDX solids that have superior settling and filtration characteristics. All of these factors contribute to lower capital and operating costs for the overall process. This paper describes the laboratory and PDX pilot plant developments for this process.

Jan 1, 2004

By Alexandre Aparecida Morais

No processo de lingotamento contínuo de placas, o controle de fluxo de aço líquido entre o distribuidor e os moldes pode ser realizado através de tampão refratário ou válvula gaveta. Quando se usa o controle via tampão refratário, aproveita-se o mesmo para reter um volume mínimo de aço no distribuidor, visando efetuar a partida do veio. Este volume de aço é importante para evitar o congelamento da primeira porção de aço e prevenir o arraste de impurezas existentes no fundo do distribuidor para o molde. Já quando se usa o controle via válvula gaveta, para acumular o volume de aço necessário, utiliza-se de outros “artifícios”, como o uso de anteparos metálicos em forma de bujões, cuja eficiência é limitada. Visando melhorar o desempenho de partida das máquinas com controle de fluxo de aço distribuidor-molde, via válvula gaveta, desenvolveu-se o chamado tampão flutuante de fibra cerâmica, cujas funções principais são: equalizar o nível de aço para proporcionar uma partida normal e impedir que impurezas arrastadas pela primeira porção de aço, se dirijam para os veios. Este trabalho mostra o desenvolvimento pioneiro desta técnica para distribuidores de aços planos na ArcelorMittal Tubarão.

Jul 30, 2018

By Alfred Boyles

"HEREDITY"' in cast iron has been a subject of much discussion. Numerous experimenters have found that the properties of gray iron may vary greatly without corresponding variations in composition or thermal treatment. The main structural difference in such cases is in the size and distribution of the graphite flakes and the explanations given usually attribute this difference to some chemical element not shown by ordinary analysis or to some physical factor, such as inclusions in the melt. It cannot be said that any of these theories is completely satisfactory. Much remains to be learned about cast iron and for this reason a study of the material was undertaken as a part of the program of fundamental research at Battelle Memorial Institute. A review of the literature indicated that very little systematic work had been done on the mecha-nism of freezing in cast iron. The experiments described below are largely concerned with that problem.

Jan 1, 1937

By Duane A. Smith

Introduction From the days of the Spanish in the eighteenth century, Colorado's San Juan mining district has attracted miners and public interest. The Spanish left behind names - San Juans, La Plata, Animas, legends of lost mines, and the remains of a few scattered mining operations. They came, but did not stay. Again in 1860-61, as a spinoff of the Pike's Peak gold rush, prospectors climbed the mountains and descended into the canyons searching for gold. They found some, not enough to convince them to remain and confront the isolation, often hostile environment and the Utes, who rightfully felt this to be their home. Not until the 1870s did miners come to stay. In their wake little camps grew in the high valleys and squeezed into narrow canyons. Nowhere else in Colorado were there more rugged mountains, a higher average elevation, nor a climate that one old Swede said was "three months of mighty late fall and nine months of winter." The San Juans proved eventually to be a mineral treasure chest. At the moment, however, the prospectors sought gold. Then they discovered silver deposits and the first rush was on. It got started just in time to be completely overcome by the Leadville excitement. At Leadville, investors almost fell over themselves to buy claims and stock in the hopes of becoming another millionaire like Leadville's own Horace Tabor. The San Juaners could only look from the sidelines and speculate how it might have been had fate been kinder. Fate was seldom kind, as these pioneers quickly discovered. From the mid-1870s on, the San Juaners wrestled with some major problems. And the fate of their district rode in the balance. The problems they faced were similar to those of other Colorado districts, compounded by their geographic isolation. Every mining district needed the best transportation system available, experienced investors combined with sound investment, and mineral reserves to develop. The San Juans offered the last in abundance. It was hoped the first two would appear. Railroads - much needed transportation link Nothing was more desired than railroad connections, the penultimate nineteenth century form of transportation. Colorado's own, the Denver & Rio Grande, resolved the issue with its mountain-hugging narrow gauge. As early as the mid-1870s, the D&RG dreamed of tapping this potentially lucrative market in southwestern Colorado. A national economic depression and then the Leadville silver excitement prevented immediate construction. Not until 1879-80 did survey crews start work.

Jan 2, 1988

By Bharat Garg

The coking coal or clean coal from raw material division, Tata Steel Ltd. is a prime source of energy for inhouse steel making. Coal reserves of semi soft coking coal at West Bokaro is beneficiated by dense media cyclone and froth flotation processes to produce clean coal. In dense media cyclone process two byproducts-middling and rejects are also produced along with clean coal. With the growing demand for clean coal, it becomes imperative to maximize the recovery of clean coal in beneficiation processes. This will help, not only in reduction in cost of production, but also in raw resource conservation, and proper utilization. In this context, a case study was conducted at West Bokaro to identify opportunities for clean coal recovery from by-products. This paper mainly discusses the process for recovery of clean coal from byproducts and study of further liberation of clean coal from byproducts for economic consideration.

Sep 1, 2012

By Robert C. Johnson

Water-swelling fluormicas and fluormontmorillonoids were synthesized and described. They were found predominantly in the system Mg0 - MgF2 - Si02, with varying amounts of Li+ or Na+, Some water-swelling synthetic minerals were prepared with only strontium or lead in the twelvefold position, Water- swelling compounds containing either K+ or Ba+ were not found. The synthesized water-swelling products were shown by electron microscopy, X-ray diffraction, and chemical analysis to be typically two-silica-layer, platy compounds, Except for the complete substitution of fluoride for hydroxyl, the compounds were similar to the natural micas or montmorillonites. The stability and properties of the compounds were further established by electrodialysis, by differential thermal analysis, and by anion and cation exchange methods. Fluoride in the interlayer positions was nonexchangeable except through decomposition of the product. Exchanging the sodium or the lithium of the synthetic fluormicas or fluormontmorillonoids with potassium ion, particularly those derived from KOH provided a product from which a completely inorganic paper of extraordinary flexibility was fabricated. This paper had excellent mechanical and electrical properties except for water adsorption and a high power factor. Neither of these problems was solved during this investigation. However, papers with dielectric strength from 1,500 to 5,000 volts per mil were readily fabricated, particularly from the lithium containing fluormicas or fluormontmorill onoids.

Jan 1, 1963

By X. Shi

Magnesium, the lightest structural metal, has not yet been considered as a serious contestant for automotive use due to its weaknesses in corrosion. Electroless nickel-boron alloys are well known for their corrosion resistance and hardness. An electroless nickel-boron layer was successfully deposited first on the chemical conversion pre-treated AZ31 alloy and also on the Ni-P coating which was deposited on the conversion coating. The electroless bath contained nickel sulphate and dimethylamine borane (DMAB) as main salts and the samples were activated by a 5 g/L AgNO3 solution before the electroless plating process. The presence of the conversion coating between the nickel coating and the AZ31 substrate acted as a barrier and prevented corrosion of the alloy. The morphology of the nickel-boron layer was studied using SEM. The crystal structure and the composition were examined by EDS and the hardness was measured. The corrosion behaviour of the nickel-boron layer deposited on the conversion coating and on the Ni-P coating was studied using potentiodynamic polarization in a 0.5M NaC1 solution. A saturated standard calomel electrode was used as a reference electrode. The results show that the nickel-boron coatings had a significantly better corrosion resistance than the AZ31.

Jan 1, 2006

By Thomas T., Read

THROUGHOUT the Colonial era, Philadelphia was easily , the leading city of North America, and it still held that position at the end of the period, with a population of about 25,000, though closely pressed by Boston, which had slightly over 20,000, and New York, which had nearly as many. It was the center of a region in which mineral industry was important. Thomas Rutter's bloomery, built in the Schuylkill valley in 1716, was quickly followed by many others, and during the Colonial period at least 20 blast furnaces, 45 forges, and iron- works of other types were built in eastern Pennsylvania, which easily led all the other colonies in iron manufacture. During the Revolutionary period others were erected as far west as Fort Loudon, in the Cumberland c alley.^ After 1800 the rapid development of the anthracite mining industry profoundly affected Philadelphia's, development, since transportation of the coal was then necessarily by water, and the streams of the anthracite . regions mostly flowed into either the Schuylkill or the Delaware Rivers. With an abundant near-by supply of coal and iron, with the seat of government, which had been there since 1774, and with a National Bank established there in 1791, one would have seemed safe in prophesying, at the beginning of the nineteenth century, that Philadelphia would permanently remain the leading city of the United States. Education in Philadelphia was at first wholly in the hands of the Quakers, who had established a "Public School" there in 1689, but in November 1739 George Whitefield, who had created a sensation in England by his preaching, though only 24 years old, passed through Philadelphia on his way to Georgia to found an orphan school there. He preached a series of sermons in Christ Church that were so disturbing to the established church that on Nov. 25 the Rev..Richard Peters (who was also Provincial

Jan 1, 1941

By C. D. Taylor, A. L. Mazzella, A. L. Martikainen

In fluctuating airflow, continuous air velocity recording is the most reliable method of air velocity measurement. It allows for fast recognition of changes and the calculation of long-term averages. Also, it enables the mine operator to identify when the airflow has decreased to a point requiring action. Using ultrasonic anemometers provides an accurate option for continuous air velocity monitoring. This paper provides information about the effect of common obstructions in underground mining on air velocity readings. Stationary and moving obstructions are used to represent workers and equipment that would cause discrepancies in measured airflow. Also, it is important to know how large of a sample size is required to ensure reasonable accuracy of results. Statistical analysis is used to evaluate the required sample size. The sampling procedure is further studied by comparing two different sample rates. The results show that obstructions provide noticeable differences in air velocity measurements. Also, movement of obstructions can be recognized from changes in results. Surprisingly small sample sizes provide reliable air velocity information. Standard sample rates are found to be suitable for the underground environment.

Jan 1, 2011

By James D. Cooper

COMBINED tonnage or natural abrasive materials sold or used in the United States in 1962 was 10 percent greater than that of 1961 and value was 9 percent higher. Production of crude artificial abrasives in the United States and Canada was up 14 percent in volume and 9 percent in value. Value of grinding-wheel sales increased 13 percent, and the value of coated-abrasives sales was up 10 percent. The value of imports and reexports declined, while the value or exports increased. [ ]

Jan 1, 1963

By P. K. Kaiser, S. M. Maloney, S. P. Singh

"Corrosion of underground support measures constitutes a concern to industry in both safety and economic terms. It also represents a potential market for corrosion resistant materials such as stainless steel.In order to assess the market potential for a stainless steel friction rock bolt, a review of current corrosion processes and remedial or preventative measures in the underground environment was undertaken. This was supplemented by distribution to industry of a detailed questionnaire, concerning the magnitude and extent of support corrosion and the costs of current support measures, and by visits to selected sites. Following data synthesis, support costs were established and the economic benefit of stainless steel rock bolts evaluated.Stainless steel rock bolts can be an effective cost reducing measure in unscreened areas requiring frequent reconditioning. Their benefit is rapidly diminished, however, if only partial reconditioning is required, the reconditioning interval is long or if screening is required.While most industry personnel are receptive to the application of stainless steel support measures, the localization of corrosion problems and the potential high cost of this type of support are barriers to its widespread implementation. They have potential for use in extreme environments. However, this relatively small market may not be economically viable.IntroductionFriction rock bolts are the simplest of all interior rock fixtures. The friction resistance to sliding of the rock on the bolt is generated by a radial pressure against the borehole wall over the length of the bolt. Two types of friction rock bolts are currently marketed, the Split Set and the Swellex.Unlike conventional point anchor bolts, friction rock stabilizers may move relative to the rock strata and maintain their capacity even if rock shifts, a condition that sometimes loosens or breaks conventional bolts. Ease of installation, effectiveness in jointed as well as weaker rock, and the possibility of having relatively long bolts are a few of the many advantages which generate considerable interest in the application of friction rock bolts (Wijk and Skogberg, 1982). However, due to their thin-walled construction and large surface area, frictional rock stabilizers are more susceptible than conventional bolts to damage by corrosion. For this reason, they are normally not recommended for long-term use (Jolly and Neumeier, 1987).In light of the above discussion; the Nickel Development Institute commissioned a study by the Geomechanics Research Centre with the objective of generating a credible database for the assessment of the feasibility of a stainless steel friction bolt system in corrosive ground and mine environments."

Jan 1, 1990