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"A fire design innovation of the concrete lining of the Ohio River Bridges East End Crossing Tunnel has been developed. As a result from a fire suppression and tunnel ventilation system, the project design Heat Release Rate (HRR) was able to be constrained from 300 MW to about 50 MW. With this reduced HRR, concrete lining without passive fire protection may be acceptable, if the tunnel concrete lining will not result in explosive spalling during the designed fire event. Concrete explosive spalling test was proposed to verify this assumption. Since no standard concrete fire explosive spalling testing procedure exists, a project specific testing procedure was developed and fire tests conducted. From fire test results, it is concluded that the proposed tunnel concrete lining, in conjunction with the proposed fire suppressing and ventilation system, will not experience explosive spalling and does not require a passive fire protection system. INTRODUCTION The Ohio River Bridge East End Crossing Tunnel is part of a Public Private Partnership project, which connects transportation network between Louisville, Kentucky and southern Indiana. Located in Louisville, Kentucky, the twin-tube highway tunnel provides northbound and southbound lanes of the Kentucky approach to a new bridge across the Ohio River. Tunnel lengths are approximately 1,675-ft and 1,685 for the northbound tube and the southbound tube, respectively. Connected by two cross-passages, both tubes have a roadway width of 40-ft, for 3-lane traffic, and a vertical clearance of 26.5-ft.The Tunnel was constructed by drill and blast method with shotcrete and rock dowels as initial ground supports. The final tunnel lining consists of 16 inches cast-in-place concrete lining and 20 inches invert slab, with a waterproofing system around the tunnel perimeter. Two (2) tunnel side drains and one (1) invert drain were provided for each tube. This paper describes the rational in assessing fire design requirements of the tunnel final concrete lining, to answer the question whether a passive fire protection system is needed or not."

Jan 1, 2016

By José Roberto de Olveira, Anna Paula Littig Berger, Caio Vaccari Silva, Victor Bridi Telles, Felipe Fardin Grillo, José Roberto de Oliveira

No presente trabalho foi proposto uma análise da eficiência de desfosforação de uma mistura padrão M1 e outras cinco misturas, onde foi realizada variação da massa de mistura adicionada ao sistema (60,70 e 80g), temperatura de trabalho (1350ºC e 1350ºC ajustada) e metodologia de adição. Os testes experimentais foram realizados a uma temperatura de 1400°C, com agitação de 450 RPM, em um forno de resistência. Para a análise das propriedades da escória, foram realizadas simulações através do software de termodinâmica computacional FactSage 7.2 e análises de imagens obtidas da superfície do cadinho ao final dos experimentos no software Quantikov. A mistura M1 apresentou melhor desempenho do que as misturas em todas as situações estudadas, sendo observado que melhores condições experimentais foram a utilização de 70g de mistura, a uma temperatura de 1400ºC, com a metodologia padrão de adição de toda a massa da mistura no início do experimento.

Oct 1, 2019

By Robert C. Pease

Siskon Gold has started gold production at the San Juan deposit in northern California. The mine is located about 27 km (17 miles) north of Nevada City, CA (Fig. 1). It is scheduled to be-come the largest underground gold mine in California. It is situated in the western foothills of the Sierra Nevada Mountains in the Mother Lode gold belt. The property consists of 8 km2 (2,000 acres) of patented land. It is situated in a topographically high area known as San Juan Ridge, which is 213 m (700 ft) above and between the Middle Yuba and South Yuba rivers. The elevation is between 790 and 914 m (2,600 and 3,000ft) above sea level. Annual precipitation averages 1,346mm (53 in.). Most of that falls between November and April.

Jan 1, 1996

The following paper outlines the types of employment immediately available to graduates following their university degree, a discussion on mine manager requirements, mentions career advancement and time frames to achieve this as well as providing some key information regarding student vacation work. The author hopes to educate present graduates, as well as inform students of characteristics to develop the most opportunities in life.

Jan 1, 2006

By C. Steve Albrecht

The primary objective of this study is to "evaluate the influences of different equipment systems on prime farmland subsoil compaction due to surface mining in the Midwest." The study is centered on four mine sites each utilizing a different combination of equipment for soil removal and replacement. Subsoil compaction is the primary focus of this research effort. Primarily owing to physical location, it is difficult to alleviate the increased compaction directly below the topsoil in reclaimed soils. Different equipment combinations cause varied effects when soils are replaced during surface mining activities. By collecting field data within a statistical framework, the effects of different equipment combinations on subsoil compaction can be evaluated and conclusions drawn. This research effort evaluates a comparison of natural and replaced soils by moist bulk density data. This comparison centers on changes in bulk density and texture to a depth of 48 inches. For each study site a complete case study is provided for use in data correlation and interpretation. Basis for this research effort centers on four (4) major experiment designs: o Comparison of soil bulk density values for three distinct equipment systems evaluated on the same general soil types (i.e. scrapers, bucket-wheel excavators and end-dump haulback); o Evaluation of the effects of soil replacement in repeated lifts using scrapers; o Presentation of bulk density values representing soil compaction for four (4) equipment systems (i.e. bucket-wheel excavators, draglines, scrapers and end-dump haul back) on four separate mine sites in the midwest; o A prediction analysis model is developed for subsoil bulk density following reclamation based on equipment characteristics and a statistical evaluation of texture. The soil data base of information includes data from the 1982 Bureau of Mines study entitled, "Impact of Surface Mining on Soil Compaction in the Midwest" as well as data from this research project. The final report is synthesized through an analysis of field data, statistical analysis and literature review. The final report focuses on the interpretation of results for practical application by government and industry.

Jan 1, 1984

By H. M. Thorne

The oil-shale deposits of the Puertollano basin in the Spanish province of Ciudad Real appear to have been give little consideration in discussions of oil-shale resources throughout the world. A small, integrated oil-shale operation has been conducted at Puertollano since about 1922 by a French company, Sociedad Mimora y Metalurgica de Penarroya, hereinafter referred to as "Penarroya", but only within recent years have the potentialities of the Spanish oil-shale deposits been recognized. Empresa Nacional "Calvo Sotelo" do Combustibles y Lubricantes, hereinafter designated as "Calvo Sotelo," which was created in 1942 by the National Industrial Institute of Spain to produce liquid fuels from oil shales, has made marked progress in the design and construction of a complete oil-shale plant at Puertollano. Penarroya is mainly a coal-mining company, and the oil-shale operations were on a small scale of approximately 220 tons a day in October 1947. It is an integrated operation comprising oil-shale mining and retorting and shale-oil refining. Motor gasoline, Diesel fuel oil, light burner fuel oil, lubricants, paraffin wax, cresols, and ammonium sulfate are manufactured.

Jan 1, 1950

By H. R. Peiffer

Recently artin has indicated that the recovery of resistivity at 145°C following elongation of molybdenum at room temperature was the result of the annihilation of vacancies. The activation energy for this process was, according to Martin, 1.26 ev. This energy seems to be a reasonable one for the activation energy for the diffusion of vacancies in molybdenum. However, impurity atoms such as carbon, nitrogen, and oxygen4 have an activation energy for diffusion in molybdenum of the same order of magnitude (i.e., 1.45, 1.15, and 2.09 ev, respectively). Cottrell and Churchman have already correlated the return of impurity atoms to dislocations in cold-worked iron with the return of the upper and lower yield point. According to cottrel16 the diffusion of carbon atoms to dislocations results in the return of the yield point. As the carbon atoms become trapped by dislocations, Bhatia has shown that a decrease in the electrical resistivity is to be expected. Cottrell and Churchman were able to correlate experimentally the decrease in electrical resistivity with the return of the yield point. Since one would expect strain aging to occur in molybdenum, an experiment was performed to determine whether the resistivity recovery at 150°C for molybdenum cold-worked at room temperature can be correlated with the return of an upper and lower yield point. For this experiment 3/16-in. tensile bars of Climax molybdenum, 99.961 pct pure, were used. The specimens were annealed at 1000° C for 1 hr in an argon atmosphere and then were elongated up to 10 pct on a Baldwin-Lima-Hamilton FGT

Jan 1, 1959

By H. De Cizancourt

The Pechelbronn (Alsace) field is the only important French producing field. During 1934, development was carried on as in previous years. The total output of this field reached 553,575 bbl. in 1934, showing a slight decrease from the 1933 figures. Of the total, 315,000 bbl. (56 per cent) was extracted by drilling, while 238,875 bbl. (46 per cent) was obtained by means of shafts and galleries. Exploration of deep Jurassic and Triassic horizons was still in progress at the end of 1934. A deep well reached the Upper Triassic at a depth of 34 m. (2736 ft.). (Information kindly supplied by M. S. Mena, Directeur Technique.) As mentioned before, the small Gabian field (Herault) is gradually being exhausted. No drilling operations were undertaken in 1934, the small production being restricted to the pumping of old wells. Two exploration wells, noted as "drilling" at the end of 1933, were completed in 1934; viz., Lavelanet (Ariége) at 3785 ft. and Santenay (Niévre) at 2578 feet. French Possessions Algeria.—No drilling at Tliouanet. Out of a total of 100 wells drilled in the area, only 8 are still producing. No exploration work is reported during 1934 in Algeria. Tunisia.—Two wells completed; one well drilling at the end of 1934. A total of 11 wells is reported to have been drilled before the beginning of 1935; out of these, 8 were completed before the present program was begun. Morocco.—Exploration work progressed actively last year. The outstanding event was the coming in of Ts. 26 well at 1243 ft. This well took fire, therefore great difficulties were encountered in the accurate measurement of initial production; the figure of 1500 bbl. of oil given here is a near estimate. Oil flowed accompanied by a great amount of water. The apparent decrease of drilling operations in 1934 is explained by the increase in field activities after the results of Ts. 26 were known;

Jan 1, 1935

By Carl L. Bieniewski

In a Bureau of Mines supply evaluation, the known uranium resources in the United States are estimated to have a total recoverable uranium oxide (U3O8) content of 3,132,400 tons at prices up to $69.32 per pound. Only those resources were evaluated for which sufficient quantity data are available and process technology exists for recovering uranium. A total of 160,800 tons of U3O8 is available at $8 per pound from ore deposits presently mined and an additional 244,700 tons available at prices up to $30 per pound from similar but usually lower grade deposits. A total of 2,726,900 tons of U3O8 is available from four other resources: copper leach solutions, wet-process phosphoric acid, Florida phosphate rock Leached zone, and Chattanooga Shale. These resources contain from 30,000 tons of recoverable U30, at a price of $7.52 per pound as a byproduct of copper leach solutions to 2,557,300 tons at a price of $69.32 per pound from Chattanooga Shale.

Jan 1, 1971

"Mechanical alloying (MA) synthesizing technology and thennohydrogen processing (THP) were utilized to produce nanocrystalline Ti-MMC's reinforced by TiB intermetallic compound by using TiH2-B powder mixtures. Powders MA'ed up to 8 hours were examined by X-ray diffraction and SEM study. All MA'ed powders afterwards were HIP'ed at 700, 800 and 950EC for 1 hour. Detailed XRD, SEM and TEM study of the samples were carried out to determine the structure and micrography of the Ti-TiB MMC material processed by MA+THP approach followed by HIP'ing at high temperatures.IntroductionThe fiber reinforced titanium base composites [1,2] which possess a great resistance to high temperature have been investigated. In these studies fibers of C and SiC were used as reinforcing materials. However, these fibers react with Ti-matrix at elevated temperature resulting in product formation at the interface between the matrix and the fiber. Because of the chemical reactions, strength of the product MMC material diminishes.In conventional techniques of whisker reinforced composite material production, the mixtures of matrix metal powders and dispersed fibers are consolidated by hot pressing, HIP and/or hot extrusion. These techniques, however, have some shortcomings. Hard and brittle fibers could be broken during mixing cycle of the processing. Consolidation techniques could also be the cause for fiber breakdown. Attaining of the uniform dispersion of fibers into the metal matrix is not an easy process. The chemical reactions at elevated temperature exposures in the interface between the matrix material and fiber reinforcement cause product formations leading to poor mechanical properties."

Jan 1, 1998

By A Parbhakar-Fox, S C. Dominy

The prediction of acid and metalliferous drainage (AMD) from mine waste materials is critically important during all stages of the mine value chain. However, to determine such geoenvironmental characteristics static and kinetic testing of individual waste units must be performed on representative samples. The importance of sample selection cannot be underestimated; it is the single most critical aspect of any geoenvironmental investigation. Poor sampling techniques and inadequate sample selection will contribute to excessive variance, difficulties in interpretation and incorrect assessment. By undertaking mesotextural characterisation based on hyperspectral mineralogical data (with sulfur assay data if available), opportunities to improve sampling strategies are presented. Such data will inform the selection of samples for low-cost total sulfur, paste pH and geoenvironmental logging, which collectively will allow for accurate AMD forecasting and improved sampling practices to be achieved. Once sampled, robust quality assurance/quality control (QA/QC) protocols must be developed where the use of international certified reference standards become obligatory. This is currently not practised, resulting in inter-laboratory discrepancies when undertaking waste classification. Further improvements in geoenvironmental characterisation testing lies in the adoption of blended static testing protocols, whereby blends of waste materials can be efficiently tested so as to give an early forecast as to whether they will produce acidic or metal-laden drainage. Such information is integral in developing a waste schedule that will allow for a non-acid forming waste landform to be constructed right from the start of the operational phase. Ultimately, improvements in this discipline lie in technological innovations with regards to mineralogical characterisation, and by offering geoscience and minerals engineering students a competent education in the discipline. Collectively, this will empower a step-change in AMD prediction and waste handling, and will make the realisation of the United Nations Sustainable Development Goals a reality, rather than a dream.CITATION:Parbhakar-Fox, A and Dominy, S C, 2017. Sampling and blending in geoenvironmental campaigns – current practice and future opportunities, in Proceedings Eighth World Conference on Sampling and Blending , pp 45–54 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

By Peter B. Knuckey

1, Introduction Location Kalengwa mine is located in the North Western Province of Zambia, 402 kilometre by unpaved road to the west of Kitwe, which is roughly in the centre of the Zambian Copperbelt, well known as one of the world's centres of copper mining. Its position is illustrated on the map of Africa in Figure 1 and on the map of Zambia in Figure 2. It is a mine of Roan Consolidated Mines Limited whose other properties, Mufulira, Luanshya, Chambishi and Chibuluma Mines, are all located on the Copperbelt. It is managed by the Chibuluma Division of the company. The rate of production from Kalengwa will vary from 12 000 to 17 000 tonnes of saleable copper a year over the next six years. Kalengwa did not exist as a place until the first prospecting parties and later the mine became established and the early working population was recruited entirely from small villages in the surrounding area as much as thirty miles away. The mining area consists of fourteen mining locations amounting to 3.35 square kilometres and the land may be used for any purpose connected with mining, including housing, wood cutting and other utilities. The whole area is, except for minor undulations, a fairly flat plateau with main rivers running from north to south and flood basins known as "dambos" located in a general east west direction. Vegetation is, with the exception of the grassy dambos, temperate forest with relatively light undergrowth. Game of great variety is prolific, as is the associated tsetse fly.

Jan 1, 1971

By John C. Kleiber

From time to time since the initial installation of an experimental flotation section in 1940 (reference A), Permanente Cement Company has made efforts to beneficiate the low-grade limestone fraction which occurs in its deposit at Permanente, California, The encouraging results outlined in this paper are the result of Permanente's latest effort. This paper discusses the factors governing the selection of the flowsheet with particular reference to marketability of the sand tailing by-product. The process flow is outlined in detail, and operating statistics of the plant are presented. Finally, the problems encountered in the operation of Permanente's beneficiation plant are discussed as well as solutions sought and found.

Jan 1, 1964

By Filipe Sathler

Mediante efeitos de sazonalidades do mercado Siderúrgico, períodos de crise, aliados às necessidades de reparos de equipamentos, os Altos Fornos são, eventualmente, submetidos ao desligamento. O procedimento específico mais utilizado é o Blowdown, com o abaixamento de carga até nível de ventaneiras, facilitando posterior limpeza e reparo. Para sucesso deste procedimento, é essencial um planejamento adequado das atividades. Informações técnicas e experiências operacionais permitiram o embasamento teórico e a execução do Blowdown do Alto Forno 03 da ArcelorMittal FCSA (Tubarão). Como preparação, foi efetuado o aumento do fluxo periférico (remoção de cascão) e o aumento da permeabilidade do Cadinho (maior circulação de líquidos, limpeza e drenagem). Realizou-se também a preparação de equipamentos específicos e controle dos parâmetros operacionais. O abaixamento de carga foi devidamente realizado conforme planejado, até o nível de ventaneiras e permitindo paredes internas livres de cascões.

Aug 16, 2017

The Anglo Platinum Mogalakwena North concentrator was one of the first three hard rock mineral processing applications to utilise a HPGR circuit in preference to a SAG milling circuit. This was driven by the extreme competence of the ore that had given rise to throughput issues on the original South Plant. Despite more than adequate capacity and performance of the individual comminution units, the circuit has struggled to obtain full design capacity. A thorough review of the integrated performance of the circuit revealed a wide range of bottlenecks and underutilised parts of the circuit arising from design issues. Interestingly, the major opportunities lie in materials handling issues and mismatch of loads about the circuit. This paper presents the high-level outcomes and the associated opportunities, and is pertinent to all HPGR circuit designs.

Jan 1, 2012

By Herbert Clark Hoover, Lou Henry Hoover

QUESTIONS of assaying were explained in the last Book, and I have now come to a greater task, that is, to the description of how we extract the metals. First of all I will explain the method of preparing the ore1 ; for since Nature usually creates metals in an impure state, mixed with earth, stones, and solidified juices, it is necessary to separate most of these impurities from the ores as far as can be, before they are smelted, and therefore I will now describe the methods by which the ores are sorted, broken with hammers, burnt, crushed with stamps, ground into powder, sifted, washed, roasted, and calcineda.

Jan 1, 1950

By R. Kossowsky

Structural changes in Be-Cu, Be-Ni. Be - Ag, and Be-Fc alloys pressurized in a solid medium were invesligated by resistivity measurements , X-ray diffrac lion in situ and metallogvaphic examination. Some limited tests in liquid medium were also conducted. Good correlation was oblained between diauges of slope of relative resistance us pressure and changes in diffraction pattern. Metallographic examination rez:ealed that the copper, silver, and nickel alloys lwiu heauily due to the applicalion of pressure at room temperature. Using polarized light technique {1012}, {1011}, and possible {1010} twinning planes were identified. At eleuated temperature twinning was moslly confined to the {1012} planes. Although twin-ning could be promoted by application of hydroslutic pvessure (liquid medium), it was strongly enhanced by the pvesence of a nonhydvostatic shear component due to pressurizalion in a solid medium. It was further obserced that a decrease in grain size inlnibiled twinnitzg activily. A great deal of effort has been expended in recent years to render beryllium useful for structural applications. Efforts were concentrated towards a possible phase change and to promoting other than basal deformation modes. Quenching experiments to obtain the high-temperature bcc phase have failed,' nor were alloying additions successful in improving ductility of the brittle hcp phase.2 Herman et a1.3 have reported a new {1011} twinning mode in a Be-4.4 wt pct Cu alloy oriented for a C axis compression sustaining loads to 440,000 psi. A new approach using high-pressure techniques was undertaken at Curtiss-Wright, Wright Aeronautical Division Laboratories. Marder4 reported a 25 pct decrease in relative resistance of commercially pure beryllium at 92 kbar. He proposed that this discontinuity corresponded to the bcc phase found at high temperature; however, X-ray diffraction in silu did not confirm a phase transition.5 contre6 has recently shown that the bcc transition in pure beryllium is lowered to 800°C at 80 kbar accompanied by a 50 pct increase in relative resistance. The purpose of this paper is to report on one phase of an investigation of the effects of high pressures and temperatures in beryllium alloys, namely, twinning behavior in Be-Ni, Be-Cu, Be-Fe, and Be-Ag alloys pressurized to nearly 100 kbar and temperatures up to 200°C. EXPERIMENTAL METHODS Material was obtained from Nuclear Metals, Inc., in the form of a 1.5-mm-diam wire extruded in stainless-steel cladding at 1600° F. Nominal composition of the alloys is listed in Table I, and the major impurities are are given in Table 11. Pressures to 100 kbar* were ob- tained using a National Bureau of Standards type 100/400 ton tetrahedral unit supplied by Barogenics, Inc. This type of apparatus contains a retaining sleeve with a conically tapered internal surface and four pressure-intensifying anvil assemblies with tungsten carbide tips. The 10-mm-long specimen fits into a pyro-

Jan 1, 1968

By A. U. Miller

Since coal -mining records have been kept , reports of all mining States show that each year the lives of many workers have been sacrificed in the production of coal , and Illinois has contributed its share , Illinois reports for the 50 years 1882 to 1932 , inclusive , show that 6,673 men were killed -- 6,121 underground , 340 in the shaft , and 212 on the surface . Of the fatalities underground , 3,116 were caused by falls of roof or sides , 1,111 by haulage , 630 by explosives , 577 by gas explosions , 139 by electricity, and 548 by other causes ; 166 of the shaft fatalities were caused by falling down the shaft , 143 by the cage , and 31 by other causes ; 108 of the surface fatalities were caused by railroad cars , 46 by machinery , and 58 by other causes . Most of those engaged in mining are still of the opinion that it is an extremely hazardous occupation and that it is practically impossible to operate without accidents ; however , students of safety in mining now believe that with the proper attention to accident prevention mining may be conducted with little , if any , greater accident rate than that of other supposedly hazardous industries . There is no mystery connected with accidents in mining ; reports show that the majority are due to two main causes , falls of roof and sides and haulage . Mining companies in Illinois , as well as in other States , have proved in the past few years that the hazards of mining , like those of other industries , can be controlled to a large extent and the mines operated with few if any accidents , provided a great enough effort is made by employer and worker . Although the past accident rate of Illinois may compare favorably with that of other mining States it is higher than it should be ; the fact that 6,673 men (an average of 133.46 per year) were killed in and around the mines of the State between 1882- and 1932 indicates that accident prevention should receive more consideration in the future than in the past .

Nov 1, 1934

This Bureau of Mines report is devoted to descriptions of systems that provide in-mine wired telephone service. Although they may incorporate other features, each system described functions to allow one telephone to selectively access another telephone. Except for the paper on Conventional Telephone Equipment, the equipment described is newly developed and specifically designed to satisfy the requirements of underground mine communications.

Jan 1, 1977

By A. Ignatieff

"Demonstrations of Automatic Coal Burning EquipmentAT THE 1951 and 1952 Annual Coal Research Conferences sponsored by the Dominion Coal Board and attended by delegates from the Dominion and Provincial governments as well as industry, the importance ,of encouraging the co-operative interest of Canadian coal and equipment industries in •promoting the use of equipment types best suited to burn given Canadian coals was emphasized. It. was suggested that this idea •be enlarged upon at forthcoming C.I.M. meetings that would be .attended largely by coal mining engineers.With this in view, a Domestic Heating Forum (1) was featured in the Coal Division programme at the 1951 Annual Western Meeting of the Institute in Calgary, and a much more ambitious programme, highlighted by live demonstrations, was •staged at the combined Annual Western Meeting and Fourth Meeting of District 4 held in Winnipeg in October 1952.With the excellent co-operation of a number of equipment manufacturers and coal companies, and with facilities kindly provided •by the University •of Manitoba authorities, burning demonstrations were• arranged in the Agricultural Engineering Building, on October l 7th. These demonstrations were a fitting sequel to the Coal Division sessions held in the Royal Alexandra Hotel on October 16th, at which the combustion of coal was specially featured in a series of papers by prominent Canadian and United States specialists.The primary purpose of the demonstrations was to •show that all coal, regardless •of rank, can be satisfactorily used provided that proper application is made with equipment suited to its purpose."

Jan 1, 1953