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By Warwick Bullen

A hypothetical economic model has been developed for diamond projects in the Canadian Arctic using data from recent exploration and mining projects. The model reflects economic conditions as it applies to the diamond mining industry in the Canadian Arctic at the present time. The economic model captures pre-production expenditures, production data, and post-production costs. Before- and after-tax cash flows are derived from the data along with the relevant economic criteria. From the corporate perspective, the model provides guidance as to the minimum size and/or in-situ value per tonne requirements of targets being sought in order to ensure economic success and probable exploration and development expenditures. From the government perspective, the model provides an indication of income and mining tax revenues that can be expected from a particular diamond project. The model shows, on average, diamond projects in the Canadian Arctic are expensive to explore for and develop, but are economically robust. They generate great economic return for mining companies and significant amounts of tax revenue for governments. The fact that diamonds can be transported directly from the mine site by air makes them particularly attractive targets for mining companies that operate in the Canadian Arctic.

Apr 1, 2005

By J. P. Capp

This experiment, one of a series on underground gasification of coal, was an investigation by the Federal Bureau of Mines of hydraulic fracturing as a means of increasing the air acceptance of a coalbed to permit introducing combustion air and removing product gases. Specific objectives of the investigation included: (1) Fracturing a coalbed; (2) determining the distance the coal was physically affected; (3) ascertaining the effect of the fracture on air acceptance of the coalbed; and (4) gasifying the coal. The coal was fractured with a fluid consisting of 15,000 lb. of sand mixed with 10,000 gal. of fuel oil and 5,000 gal. of kerosine, injected at pressures up to 900 p.s.i.g. and rates up to 425 g.p.m. The oil served as the fracturing medium, and the sand as a propping agent to hold the fracture open. From the fracture point, (the place in the bed where the fluid was injected), the fracture extended 200 ft. or more along the face cleats, somewhat less along the butt. cleats, and was confined to the coalbed. At the fracture point, the bed accepted about 500 std. c.f.m. of air, which was an etghtyfold increase. Fracture effects were extensive, as airflow was noted from old mine workings and outcrops 600 to 800 ft. from the fracture point. It is probable the actual fracture was much less than 600 ft. and that normal coalbed permeability beyond the fracture limits was responsible for this flow. This indicated that effects of the fracture extended beyond the area of coal physically affected. Although no attempt was made to gasify coal more than 200 ft. away, these effects plus the natural permeability of the bed likely would permit combustion beyond the outer limit of the fracture. As these experiments continued for more than 2 years, and greater air acceptance due to the fracture was observed at the beginning of each test, it is apparent that the effects of the fracturing persist for a considerable time.

Jan 1, 1960

By William L. Crentz

Floyd County, KY., contains sizable deposits of high volatile bituminous coal. Some of the coals have been blended with higher-rank coals and used in the manufacture of high-quality metallurgical coke. The Upper Elkhorn No. 3, Upper Elkhorn No. 2, and Upper Elkhorn No. 1 beds produce the bulk of the present output in the county and contain the main known reserves of coal. Little information is available concerning the quality and extent of the deposits underlying the Upper Elkhorn No. 1 bed, although small operations in the past have worked a bed that is reported to be; the Lower Elkhorn. Undoubtedly, these lower beds occur in Floyd County, but depth Will preclude their development into a major source of fuel as long as large deposits of more-accessible coal are available. More is known of the occurrence of the beds above the Upper Elkhorn No. 3 owing to sporadic mining ventures in the upper measures. Many of the coal samples from beds above the Upper Elkhown No. 3. were collected in mines that had been abandoned. Almost all of the present production of Floyd County coal is taken from the Upper Elkhorn beds, and it is unlikely that their dominant position as coal producers will be challenged in the near future. Table 1 shows the coal production of the county by beds, during 1950.

Jan 1, 1952

By A. J. Romeo

The Old Hickory heavy mineral ore body, which lies within the Fall Zone of south central Virginia, has been mined since 1997. There are many differences in this deposit when compared to humate-laden mineral sands mines of southern Georgia and Florida. These differences include an abundance of kaolin-rich clayey sands, highly concentrated and iron-colored heavy mineral sand units, and a base of mineralization that is undulating. For these reasons, the selective approach of dry mining with track excavators is ideal. Grade control in this deposit uses traditional panning techniques and requires an intimate working knowledge of near-by drilling data. Mine geologists train equipment operators to recognize the base of mineralization by such characteristics as a stark color change, significant changes in grain size, and/or considerable, recognizable shifts in the concentration of heavy minerals. The regular pattern of mine site drilling does not always prepare the geologist and digging crews for occurrences of near-vertical contacts between the saprolite basement and the ore sands. These deformed areas, combined with undulating and pinching ore zones, require close monitoring and flexibility by the geologist and the mine operators.

Jan 1, 2005

By Washington Luiz Mafra

Every year the conventional direct reduction processes ? Midrex and HYL III ? increased their market share in the world steel production, even though they are only economically feasible in countries where natural gas is available at competitive prices. In this context, the new Midrex projects are based on large reactors (Megamod - 1.5 to 1.8 Mt/y of DRI), reduction temperatures of the metallic burden up to 850oC, with bustle gas temperatures between 960oC e 1050oC. Thus, the requirements of metallic burden performance, as well as the evaluating methods, usually based on ISO standards, need to be reviewed. It is well known that the standards usually applied to quality evaluation do not reflect the performance of metallic burden inside the reactors. This paper describes the different methods of evaluating the disintegration under reduction of DR pellets based on ISO 11257 standard. This is the most important method used by pellet producers and customers for evaluating DR feedstocks. The different methodologies tested to evaluate the disintegration under reduction had varying results, evidencing the relevance of the method and the quality of the pellet. Nevertheless, validating the method in an industrial reactor is still fundamental.

May 1, 2007

By T. W. Johnson

One of the common methods of increasing recovery of oil from partly depleted oil sands is to inject natural gas, air, or air-gas mixtures into the sand, thereby supplying energy to move oil into the well bore. Where natural gas is not available, air or an air-gas mixture is used as the repressuring medium. Air-gas mixtures are obtained from the casing-heads of oil-producing wells in the areas repressured with air or air-gas mixtures and consist usually of varying amounts of the hydrocarbon gases, nitrogen, oxygen, and carbon dioxide. Laboratory experiments have been conducted by the Bureau of Mines to determine the effect of air on crude oils.4/ In these experiments the crude oils were oxidized by the air, and the degree of oxidation depended not only upon the chemical composition of the crude oil but also upon the duration and method of contact between the oil and air, the temperature of the fluids and the concentration of the oxygen. When the crude oils were oxidized the following results and changes in the oils were obtained:

Jan 1, 1937

By T. W. Johnson

One of the common methods of increasing recovery of oil from partly depleted oil sands is to inject natural gas, air, or air-gas mixtures into the sand, thereby supplying energy to move oil. into the well bore. Where natural gas is not available, air or an air-gas mixture is used as the repressuring medium. Air-gas mixtures are obtained from the casingheads of oil-producing wells in the areas repressured with air or air-gas mixtures and consist usually of varying amounts of the hydrocarbon gases, nitrogen, oxygen, and carbon dioxide. Laboratory experiments have been conducted by the Bureau of Mines to determine the effect of air on crude oils.4/ In these experiments the crude oils were oxidized by the air, and the degree of oxidation depended not only upon the chemical composition of the crude oil but also upon the duration and method of contact between the oil and air, the temperature of the fluids and the concentration of the oxygen. When the crude oils were oxidized the following results and changes in the oils were obtained:

Jan 1, 1937

By A. L. Engel

[Thi;. re:9ort presents re3ults of investigations of problema a3signed as ore-testing projects to the Ore-Dressing Section, t.fetal1urgica.l Div:biion, of the Bureau of Ii.fines at the .fississippi?Valley E>"'1lcrimcnt Station in rtolla, Ho., durine the fiscal year ended June 30, 1940.]

Jan 1, 1941

By A. L. Engel

[This report presents results of investigations of problems assigned as ore-testing projects to the Ore-Dressing Section, Metallurgical Division, of the Bureau of Mines at the Mississippi Valley Experiment Station in Rolla, Mo., during the fiscal year ended June 30, 1940.]

Jan 1, 1941

By W. N. Hamilton

British Columbia is geologically favourable for a rich variety of industrial mineral occurrences. Some have been produced for years, others overlooked until recently. Major production occurs for asbestos, gypsum, limestone, magnesite, silica and sulfur; lesser production for a dozen others. For several of the minerals, potential is much greater than existing production. New production opportunities exist also for diamonds, niobium and REE minerals, fluorspar, kyanite, nepheline syenite, talc, and several others. Alberta, though geologically less diverse, also has many industrial minerals. Limestone, salt and sulfur have the major production; clay and shale, silica, sodium sulfate and a few others lesser production. Opportunities exist for expanded production, and for new production in heavy (Ti -Zr) minerals, formation brines (Ca-Mg-I-Li), and gypsum.

Jan 1, 1987

By B. H. Eccleston, R. F. Kendall, D. E. Hirsch, Norman G. Foster

The mass spectra of 23 alkylthiophenes are presented , including 21 that have not been previously reported . Correlations between mass spectra and the structure of the thiophene homologs are discussed . Comparisons with , and corroboration of , earlier workers ' correlations and predictions are made . Several additional correlations are reported to enable the spectroscopist to identify the substituents on alkyl - substituted thiophenes , and the relationship of the mono - substituted and 2,5 - disubstituted alkylthiophenes is discussed in detail .

Jan 1, 1964

By Henry P. Cole

A comprehensive review of published research was carried out to identify methods for teaching and assessing critical but nonroutine skills needed for coping with emergency situations. Specific methods for assessing critical skills proficiency in aviation, medicine, organization management, the military, and other industrial/technical workplaces are described. The potential application of these methods for teaching and assessing (1) critical first aid and (2) self-rescue and escape skills to underground coal miners in annual refresher training is explored. Research and development activities that may improve mine health and safety training are suggested. Most of these research and development activities were completed later in the project. This additional work is reported in the project technical report #2 and the final report. The research reported in the present document was completed in 1984 -85. Many of the initial findings reported in this document are updated in the later project final report.

Jan 1, 1988

By M Sandy, P Bamford

The Challenger Gold deposit was discovered in 1995 by Dominion Mining Ltd in a remote western area of the Gawler Craton in South Australia. Mine development commenced in 2002 with initial production from an open pit supplemented by ore from a very small adjacent auxiliary pit. Development of the underground mine commenced in 2004. The orebody plunge of just less than 30 degrees requires careful attention to mine design. Production from the M1 orebody, with less than 800 ounces per vertical metre (ovm) and very limited æsurgeÆ capacity, requires careful scheduling and implementation to ensure continuity of ore feed for milling. Initial production results from underground stopes included more dilution than anticipated. The narrow, high-grade zones proved to have much more complex geometry than early interpretations had indicated. Greatly improved understanding of the mineralisation controls resulted in important changes being made to the underground mine design and method. Coupled with careful control of development and drilling and blasting practices, this resulted in an immediate reduction in dilution and high recoveries of the resource. The benefits of these changes flowed through in the 2005/06 financial year, resulting in a 150 per cent increase in gold production to 108 080 oz and a sharp reduction in cash operating costs to A$280/oz. This was followed in 2006/07 with production of 108 91 oz of gold at an operating cost of $309/oz and in 2007/08 with 109 326 oz of gold at $367/oz. Production to June 2008 has been mainly from the M1 orebody, with the lowest stoping to date on the 580 m Level (615 m below surface) above development mining on the 520 Level. The rate of vertical advance of mining this orebody has averaged 150 vertical metres per year. The increased current combined JORC compliant resource and reserve position of over one million ounces, now includes the M2 and M3 orebodies with a current total average gold inventory up to 1400 - 1500 ovm. Exploration has intersected other shoots and all shoots are open at depth. The adjacent M2 and M3 orebodies are being developed for stoping. The narrow width of these zones from 1 m up to 4 m will require continued focus on ore zone definition, accurate development and careful drill and blast practice. In addition, to minimise cost increases in the current period of rapidly escalating labour, equipment, consumables and energy costs, high productivities will need to be maintained to allow the established rapid mining advance to continue at low unit costs.

Jan 1, 2008

By J. L. Morning

During recent years, the Bureau of Mines has conducted an extensive investigation of the materials for making iron and steel. This work includes iron ore concentration, agglomeration, direct reduction of iron ores and concentrates, the production of pure manganese, chromium, and cobalt by electrolytic processes, the production of ferroalloys from low-grade domestic ores, and the development of special alloys to utilize these products. As a part of this general program, a Congressional appropriation allowed the con¬struction of an electric-furnace, semicommercial, ingot-producing plant at Shasta Dam near Redding, Calif. The primary objectives of the pilot plant were to determine the costs and operating problems involved in the production of steel and ferrous alloys in which sponge iron was used as melting stock, and to determine the physical properties of the materials produced. The pilot-plant equipment and the results of sponge iron-melting tests in the basic lined, electric arc furnace have been reported in previous publications.3/4/

Jan 1, 1953

By G. D. Markland

The Moose Mountain mine is located in a belt of Precambrian volcanic rocks situated 20 miles north of Sudbury, Ontario. It was the first iron mining operation in the Archean iron-formations of the Canadian Shield. The ore is believed to have been formed in an environment of active volcanism, being part of a pyroclastic and volcanic series where only the iron-formation and chert qualify as chemical sediments. The volcanic environment, subsequent regional tectonics and metamorphism produced orebodies which differ from the main sedimentary iron ranges of the world in such features as continuity, grade, structure and metallurgical characteristics. The orebodies occur as relatively small lenses which have been complexly folded, faulted and intruded by acidic and basic dykes.

Feb 1, 1966

By Earl F. Hastings

The Pilgrim mine, operated by the Pioneer Gold Mining Co., is 9-1/2 miles west of Chloride in the Pilgrim mining district on the eastern slope of the Black Mountains, or River Range, Mohave County, Ariz. In March 1937, 100 tons of gold ore per day were being mined and milled at the property by a total force of 5i men. Climatic conditions allow year-round operations. Due to present activity in the county there is an ample supply of labor for the requirements of the mine. The Pilgrim is the only producing property within s radius of 6 miles; recently, however, the South Pilgrim Mining Co. has launched a development campaign on claims that adjoin the Pioneer Co. property to the south.

Jan 1, 1937

By C Carbonneau

In order to successfully produce columbium pyrochlore concentrates, St. Lawrence Columbium and Metals Corporation had to face two principal problems met in several new operations but possibly made more acute than usual owing to the newness of the project. 1.-The ore is particularly complex, as it is made up of an elaborate intermingling of carbonates and discontinuous ultra-alkaline rock bodies of various ages and types in which no less than seventy mineral have been re-ported. Obvious petrographic or structural controls are lacking. Ore boundaries have to be defined on the basis of assay results and the determination of several minerals which occur in trace amounts. 2.-The pyrochlore concentrates produced had to com-ply with a set of stringent specifications. This fact, combined with the low Cb205 content of the ore, necessitated the use of a beneficiation process that would have to operate at a concentration ratio greater than 100:1. A brief description of the mill circuit is given. Mill stability was obtained through extensive mineralogical study of the mill feed coupled with close geological and engineering control of the mining operations.

Jan 1, 1965

By B. D. Nash

The object of this research was to investigate the technical feasibility of preparing chromium metal by the thermal decomposition of bisbenzene chromium. Bisbenzene chromium, a pi-bonded sandwich type organometallic compound, was thermally decomposed under reduced pressure to form a metal plate on a heated substrate. Metal recovery was close to 100 percent of theoretical, with deposition rates up to 20.8 mg/hr/cm2. Metal purity was dependent not only upon the purity of the starting material, but also upon the sublimation rate of bisbenzene chromium. Total detectable metallic impurities ranged from a low of 18 ppm to several hundred ppm. In general, metallic impurities were less than 100 ppm. Carbon, the major nonmetallic impurity, ranged from less than 0.3 percent to more than 10 percent. The carbon contamination is most likely a result of the decomposition of the organic portion of bisbenzene chromium. An unusual property of some of the deposits was their outstanding corrosion resistance. Unlike pure electrolytic chromium, which dissolves readily, these deposits were insoluble in hot mineral acids.

Jan 1, 1968

By Emily Adelsohn, Robert Winn, Anthony Iannacchione

"Over 600 longwall panels have been mined in Pennsylvania in the last 50 years. Of those 600 panels, 25 panels undermined interstate highways. Despite this quantity of panels, much is still unknown regarding the detailed effects of undermining highways. The Gateway Mine, the Emerald Mine, and the Cumberland Mine undermined I-79 with 17 panels between 1982–1989 and 2003–2008, respectively; mine Eighty-Four undermined I-70 with 4 panels between 1987–2000.Through the examination of the panels that undermined I-70 and I-79, it is possible to determine which factors have most impacted the highway alignments. In some locations, the highway intersects with panels at angles ranging from 45 to 80 degrees, and at others, it runs between two panels, which simulates the effect of gateroads on the subsidence. The panels width to overburden ratio varies between 0.64 and 1.7, meaning that the interstates were influenced by both subcritical and supercritical subsidence basins. The face advance rates and overburden depths also vary between the panels.Unfortunately, specific information detailing highway impacts associated with unique characteristics of the subsidence basins are limited. However, using the profile function model and influence function model within the Surface Deformation Prediction System (SDPS), the effects of overburden, panel size, and orientation of the road to highway can be indirectly assessed by profile and influence models of subsidence basin formation.INTRODUCTIONCoal mining has been an integral part of Pennsylvania’s history. Room-and-pillar mines have been active since the late-1700s when coal was extracted from outcrops. By 1830, the city of Pittsburgh alone consumed more than 400 tons of bituminous coal each day for domestic and industrial use (PADEP, 2019). In the late 1960s, the face of mining in Pennsylvania changed with the development of full extraction longwall mines. Since that development, over 600 longwall panels have been mined in the Pittsburgh Coalbed in Pennsylvania alone (PADEP, 2019).As longwall mining and other forms of full extraction mining have increased in popularity, the amount of planned subsidence impacting the surface has also increased. The stresses and strains induced by longwall subsidence can cause damage to the surface as well any structures, water supplies, or water bodies that lie above the panel. Since the behavior of soils and structures vary, one way to study the surface effects of longwall mining is to analyze the impact on flat, rigid, pavement surfaces. Examining factors that vary the impact of subsidence with respect to highway alignment can demonstrate the favorable orientation of an alignment to avoid or mitigate damage and critical impact zones in a subsidence basin."

Jan 1, 2019

By Simón D. Strauss

Dada la demanda de los recursos minerales en las industrias productoras de metales, surgió el temor de un posible desabastecimiento de los mismos. Sin embargo, el abastecimento potencial de minerales y metales básicos es tan vasto que se satisfacen todas las demandas. En este sentido, el presente trabajo describe una visión panorámica sobre el proceso de la demanda mineral desde fines de la Segunda Guerra Mundial hasta el año de 1978. La revisión considera el proceso de demanda en cuatro zonas principales: Estados Unidos, los otros países industrializados con economías de mercado, los países socialistas con economías centradas y los países en desarrollo del Tercer mundo. Asimismo, se remarcan las posibilidades de fuentes de desarrollo de los países latinoamericanos en torno al mercado mineral a través de una financiamiento adecuado y de la habilidad y conocimientos tecnológico de sus líderes para formar parte de una sociedad industrializada.

Nov 20, 1978