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By Thais Cristina da Costa Caldas, Carlos Mauricio Fontes Vieira, Alline Sardinha Cordeiro Morais, Sergio Neves Monteiro

"This work has as its objective to evaluate the effect of the incorporation of a glass powder waste obtained from discarded and Hg-cleaned fluorescent lamp into clayey ceramics used to fabricate bricks and roofing tiles. Formulations were prepared with incorporation of the waste in amounts up to 10 wt.% into the clayey body. Rectangular specimens were prepared by uniaxial mold-press at 20 MPa to fire at 850 and 1050°C. The physical and mechanical properties evaluated were: linear shrinkage, water absorption and flexural rupture strength. The microstructure of the fired ceramics was evaluated by optical microscopy. The results showed that the waste incorporation significantly improved the evaluated properties mainly at 1050°C.IntroductionFluorescent lamps use mercury as a main component for its operation. This metal is potentially toxic and can contaminate soils, animals and water bodies. The problem is aggravated if considerations are made with respect to the amount of lamps that are commercialized and discharged in emergent countries like Brazil [ 1].By using appropriate recycling processes applied to discharging fluorescent lamps it is possible to reuse most constituents of these lamps into new productive processes. A study has shown that one million common fluorescent lamps can generate 900,000 tubes of clean glass [2]. Moreover, this Hg-cleaned gloss may be recycled in different products.In fact, to recovery and recycle all materials that constitute the lamp instead of discharging them. This action protects the soil avoiding the formation of environmental passives [3]. It is also relevant to mention that the glass from fluorescent lamps is 100% recyclable while its permanence in the environment would correspond to very long time pollution, since its decomposition time is undetermined [4]."

Jan 1, 2011

By M. Pesowski

"Certain environmental problems can substantially alter the physical properties of the subsurface. In such cases, geophysical methods can be used to map the distribution of subsurface contamination or buried wastes prior to drilling or sampling. For example, inorganic contamination by acids, bases, salts, or metallic ions can be detected by instruments that measure ground conductivity; metallic objects such as buried drums, pipelines, etc. can be located by magnetic survey, and radioactive mine waste can be mapped by radiometric techniques. Geophysical methods can also be used to characterize site geology. If carried out prior to development, they can assist in identifying areas of high- and low permeability and sources of natural contamination. The methods can also be used to establish baseline values and to locate stable areas for development of environmentally sensitive facilities. Application of geophysical methods to environmental problems is illustrated with examples from base-metal mines, uranium operations, and potash and oil-sands operations. Particular attention is given to the problem of acid mine drainage. =IntroductionGeophysical methods have been used for many years by the mining industry in exploration and geotechnical investigations. The basic techniques for mapping variations in physical properties of the subsurface have been adapted to meet the special needs of resource exploration and development in the coal, potash , oil sands, industrial minerals, precious metals, and base-metal industries. Now the mining industry is facing another challenge: to operate the mining cycle, from discovery to closure, with minimum impact on the environment. This involves the rehabilitation of abandoned mining sites, the minimization and effective containment of pollutants at operating and developing sites, and the longterm containment and monitoring of sites after mine closures.Some of the most difficult aspects of environmental control and monitoring relate to the location of buried waste and contaminated fluids in the subsurface. As in the search for buried ore deposits or in geotechnical investigations, geophysics can be a valuable aid in subsur face environmental investigations. Investigations can be remedial , involving the location or monitoring of existing problems, or preventative, where problem areas are identified or background values are established before site development. In either case, geophysical methods should not be considered as a substitute for drilling. Geophysical interpretations in general do not provide the detail required for a complete environmental or geotechnical investigation. They are most useful as rapid reconnaissance methods for targeting subsequent drilling or for interpreting subsurface condit ions away from drill holes. Table I lists the common geophysical methods and the physical properties to which they are sensitive."

Jan 1, 1993

By G H. Park, Y J. Jun, J H. Park

The carbon solubility of the CaO-Al2O3-FeO-SiO2-MgO slag, the main system formed in the Ruhrstahl-Heraeus (RH) vacuum degasser, was measured at 1873 K to understand the effect of slag compositions on the carbon contamination in the ultra-low carbon (ULC) steels. The stable form of carbon was demonstrated to be carbonate by plotting the log [(wt%C)/aC] ratio against the log p(O2) which ranged -11 < log p(O2,atm) < -9. The carbon solubility of the CaO-Al2O3-FeO-SiO2-MgO slag can be estimated using thermodynamic model. The distribution ratio of carbon increased with increasing concentration of FeO due to the FeO reduction reaction and increased basicity of slag. The carbonate capacity of the CaO-Al2O3-FeO-SiO2-MgO slag can be expressed as a linear function of the activity of lime and the optical basicity.

Jun 19, 2024

By L. C. Skinner

THE Coal Hydrogenation Demonstration Plant at Louisiana, Missouri, was completed early in the year 1949. It has operated more or less continuously since completion except for the time required for making necessary inspections, repairs, and alterations between runs. Operations have included a short vapor-phase run on North Dakota lignite-tar distillate oil in 1949, followed in 1950 by four comparatively short exploratory liquid-phase runs and one vapor-phase run on Rock Springs [ ]

Jan 1, 1953

By Robert D. Perry

This report describes methods of reclaiming abandoned or inactive tailings ponds and dams. The investigated sites were selected tailings deposits adjacent to metal mines in the southwestern United States and the Pacific Northwest. The basic data developed for each site consisted of the following: a review of existing literature: a site visit that included sampling of the tailings and surrounding materials; laboratory and engineering studies; and development of reclamation plans. Laboratory tests determined the gold and silver content of each tailings deposit and the chemistry of the tailings and surrounding materials. Reclamation plans that include approximate costs were developed for five tailings deposit sites. These ranged in size from 52,000 to 103,000,000 tons. Our conclusions on the remining potential of each site are based on the tailings assay and other technical data. This study concludes that remining as a reclamation tool is feasible at certain sites. Included in this report is a remining program as part of the overall reclamation plan for two sites. Our preliminary results indicate that remining as a reclamation tool is feasible for only one of them.

Jan 1, 1981

By Lucien Eaton

This paper describing the mining practices at Mine No. 1, Menominee Range, Mich., is one of a. series being prepared by the Bureau of Mines on mining practices, methods, and costs in the various mining districts of the United States. It is felt that the publication of this information will be of interest and value to the mining industry at large and especially to operators whose mining conditions are similar to those described. ACKNOWLEDGMENTS The author is indebted to the superintendent, engineer, and mining captain of Mine No. 1 for much of the information presented.

Jan 1, 1929

By B. M. Larsen, K. Heindlhofer

THIS paper describes a relatively simple electrical apparatus that, through the close analogy between the flow of heat and of electricity, enables one to solve quickly and with satisfactory accuracy many complex problems in heat flow. This device, developed in 1935, has proved especially useful in the solution of certain practical problems relating to the design and efficiency of regenerators for an open-hearth furnace or coke oven, yielding within a few hours information that would take weeks or even months to acquire by mathematical1.2 or experimental3 methods of comparable accuracy. Its description now is prompted by growing interest in such analogues, as shown by several recent papers.4.5 The analogy between flow of heat and of electricity appears to have been recognized first by Maxwell who, in his famous Treatise on Electricity and Magnetism (1881) says: The analogy between the theory of the conduction of electricity and that of the conduction of heat is at first sight almost complete. If we can take two systems geometrically similar, and such that the conductivity. for heat at any part of the first is proportional to the conductivity for electricity at-the corresponding part of the second, and if we also make the temperature of any part of the first proportional to the electric potential at the corresponding point of the second, then the flow of heat across any area of the first will be proportional to the flow of electricity across the corresponding area of the second. .. Thus, in the illustration we have given, in which flow of electricity corresponds to flow of heat, the electric potential to temperature, electricity tends to flow from places of high to places of low potential, exactly as heat tends to flow from places of high to places of low. temperature He noted, however, that this analogy is restricted: ... there is, however, one remarkable difference between the phenomena of electricity and those of heat. Suspend a conducting body within a closed conducting vessel by a silk thread, and charge the vessel with electricity. The potential of the vessel and of all within it will be instantly raised, but however long and however powerfully the vessel be electrified, and whether the body within be allowed to come in contact with the vessel, or not, no signs of electrification will appear within the vessel, nor will the body within show any electrical effect when taken out. But if the vessel is raised to a high temperature, the body within will rise to the same temperature, but only after a considerable time, and if it is then taken out it will be found hot, and will remain so till it has continued to emit heat for some time. The difference between the phenomena consists in the fact that bodies are capable of absorbing and emitting heat, whereas they have no corresponding property with respect to electricity. According to this statement the application of the analogy would be limited to problems of steady flow that do not involve heat-capacity effects. In spite of this

Jan 1, 1945

By Larry F. Brown

Mining has been the mainstay of the Woods Creek Valley for more than a century. The head of the valley is at the Continental Divide, about 50 miles west of Denver, Colorado. First, it was the quest for gold and silver that drew people to the valley. Then, when molybdenum was classified as a strategic metal by the U. S. Government during World War I, it was the valley&apos;s molybdenum mineralization which attracted the most attention. Molybdenum is used primarily as an alloying material in superior grades of steel. Circumstances responsible for providing the label "Urad" are unknown, but Urad is variously reported to be an acronym for "Uranium Research and Development" or "Uranium Research of America Division". The search for uranium was fruitless as no ore grade uranium exists in this area. The moly orebody was first developed and mined by the Primos Exploration Company from 1914 to 1919. During World War II, the mine was purchased by the government and turned over to the Molybdenum Corporation of America to operate. In 1963 AMAX Inc. purchased the property for $2 million. After spending nearly $30 million for exploration and development, AMAX put the mine into production again in 1967.

Jan 1, 1984

By S. P. Holt

The Salt Chuck mine is on the east bank of the Salt Chuck, a salt-water inlet at the head of Kasaan Bay, Prince Edward Island, Southeestern Alaska. The deposit was worked at intervals from 1905 until. 1941. Early ship-ments of hand-sorted ore are reported to have assayed about 4 percent copper, 0.15 ounce gold, and 0.15 ounce silver. The total mine production up to 1941 is reported to have been 326,000 tons containing 6,200,000 pounds of copper. During December 1942 the Bureau of Mines cut a 15-foot channel sample on the surface and channel samples from headings on the 300-foot level. In July 1943 a development project was started. Thirteen diamond-drill holes totaling 1,550 linear feet were drilled from underground stations on the 200- foot and 300-foot levels.

Jan 1, 1948

By Shen Zhengchang, Dong Ganguo, Chen Dong, Zhang Ming

"It is advantageous to process low grade ores with large scale flotation cells. Large-scale flotation cells have been enhanced with effective volume scale-up. In this paper, the latest and largest flotation cell with effective volume of 680 m3 in China is investigated. The hydrodynamics and flotation kinetics characteristics are conducted using CFD simulation. The similar circulating flow is formed compared to the previous BGRIMM (Beijing General Research Institute of Mining and Metallurgy) flotation cell and it is a suitable fluid dynamics environment. It is demonstrated that the flotation cell produces good gas dispersion and solid suspension. It is indicated that kinetic eddy dissipation plays a key role on collision kernel and collision probability profile. The higher collision probability profile appears at the impeller and stator regions aiding good metallurgical performances. The properties of the large-scale flotation cell are assessed using hydrodynamic numbers. The variation of hydrodynamic numbers such as the power number Np, the Froude number Fr, the air flow number Na, etc with flotation cell volumes show similar properties to previous flotation cells proven to be good in engineering applications. This research would aid structure optimization of the 680 m3 flotation cell.INTRODUCTIONFroth flotation is one of the mains method used in the mineral industry, which is used to process the most of metallic minerals. The proportion of low grade ores has increased with the minerals exploited around world. The increased capacity of concentrators demands large-scale flotation cells. Therefore, flotation equipment has seen a significant increase in size, for which large-scale flotation cells have prominent advantages in improving metallurgical performances, reducing area of plant blueprint printer, lowering the power consumption of the unit ore, decreasing labor cost and overall capital cost. Since the end of 1940’s, flotation cell sizes have continuously increased. To the end of 1990’s, flotation cells with the effective volume of 200 m3 were developed. In the last two decades, flotation cells have achieved a dramatic increase in size. In 2003, an industrial experiment on 257 m3 Smart Cell flotation cells was carried out in Minera Los-Pelambres, Chile. In 2007, the first 300 m3 Tank Cell flotation cell was designed and obtained industrial application in Macraes gold ore, New Zealand. And 320 m3 BGRIMM flotation cells are also in good operation in Toromocho Copper Mine, Peru and Wunugetushan Copper Mine, China. However, flotation cells are conventionally designed using empirically derived relations and geometric similarity. The continual scale-up of flotation cells is still a significant developing process. A 500 m3 Tank Cell was designed for the industrial experiment in Finland and a 620 m3 Tank Cell have also been completed the design. A 660 m3 Super Cell also was manufactured for the industrial experiment released in IMPC 2014. So, the flotation cells with volume exceeding 600 m3 become a pioneering research field for researchers worldwide."

Jan 1, 2016

By E. Nurminen

Thermal transport properties of copper flash smelting flue dust have been investigated. Such values of the dust are needed to correctly model the process and to optimize its heat recovery performance. Dust accretions on heat recovery boiler walls may have a significant influence on the boilers heat transfer efficiency. Measurements of the thermal transport properties have been made for industrial flue dust and for pure sulphate components. The measurements have been conducted at temperatures up to 400 °C and the effect of porosity on these properties has also been investigated. The results indicate that the flue dust and the sulphate components are effective thermal insulators and the dust build-up on the boiler walls is likely to greatly decrease the heat transfer efficiency of the boiler.

Jan 1, 2007

By M. Cross

Heap leaching presents a complex physico-chemical process to model and a significant challenge to develop a comprehensive model enabling reliable predictions of heap behavior over the long term. A computational modeling framework is described for the analysis of multi-phase flows in reactive porous media suitable for tracking metals recovery, for example, in heap leaching and environmental recovery processes. This modeling framework employs appropriately formulated, parameterized, and solution procedures to capture: 1) liquid and gas flow through heterogeneous porous media subject to variably saturated flow conditions, 2) the complex and dynamically changing nature of the porous media structure, 3) the transport of reactants and products of reaction, 4) the simultaneous mass and heat transfer, and 5) the role of bacteria as a catalyst for reactions. A second class of challenges to accurately model heap processes is to identify and then capture all the process data to characterize the reactivity of particular ores, the mine planning for the construction of the heap, leach schedules, meteorological data, etc. The objective of this paper is to outline these challenges and to describe a modeling framework that can cope with arbitrarily complex geometries and provide tools for rapid and accurate process assessment.

Jan 1, 2006

By Aline Silva Magalhães

Os aços com médio teor manganês são uma classe da terceira geração de aços avançados de alta resistência (AHSS), combinam propriedades mecânicas como ductilidade e resistência mecânica e são assistidos pelo efeito TRIP, características determinantes para sua aplicação na indústria automobilística. Convencionalmente, tais ligas são produzidas por meio de laminação a quente e a frio, seguidas de recozimento intercrítico. No entanto, o trabalho a morno têm ganhado interesse com o intuito de reduzir custos e tempo operacionais. O objetivo deste trabalho foi comparar a influência da laminação a quente e a morno por meio de análises de microscopia óptica, eletrônica de varredura, difração de raios x, microdureza Vickers e técnicas de EBSD em um aço 8Mn- 0,08C. Observou-se uma microestrutura mais refinada e deformada no material laminado a morno com um maior percentual de austenita retida, o que derivou uma menor dureza. Na amostra laminada a quente, o valor médio de dureza evidenciou uma microestrutura martensítica de baixo teor de carbono. Em relação à textura verificou-se uma maior intensidade de componentes da fibra a na amostra laminada a morno devido a um maior grau de encruamento neste processamento termomecânico.

Aug 17, 2017

The removal of tritium from tritiated water (-0.5 µCiIL) was studied by metallothermic reduction using aluminum. The influence of the three variables namely the aluminum powder amount, the NaOH concentration and the reaction time has been studied on the tritium activity reduction. The experimental results and statistical analysis showed that more than 85% of tritium can be removed from the tritiated water. Further work on the tritium recovery as well as efforts to totally decontaminate water by incorporating a cryogenic concept is currently pursued.

Jan 1, 1998

By Chris Sammon

The Block 75 portion of the City Creek redevelopment project in Salt Lake City required multiple shoring walls surrounding the 6 acre site constructed to depths ranging from sixty-five to ninety feet below original street grade. Shoring for the project was challenging due to site soils consisting of cobbles, sands and gravels, interlayered lakebed silty clay and fine sandy silt with incised stream deposits of silty/clayey sand and gravels combined with a high groundwater table. Moreover, several abutting structures each with a unique foundation system would be directly or indirectly supported by the shoring system. Three sections of interest are the shoring walls constructed at Main Street, Deseret Trust Building and Eagle Gate Tower. Main Street shoring extended to as much as sixty-five feet below street grade and utilized existing basement walls anchored in place in the upper zones with soil nail walls with pre-installed vertical elements for face stabilization below. Data are presented which illustrates the effect dewatering had on the settlement of the Main Street Shoring. The Deseret Trust Tower shoring supported a 12 story, historical masonry building. Site conditions dictated a separate design for the east side and the north side of the building allowing comparison of relative performance between these walls. Settlements of this structure were controlled by installing micropiles through the 90 year old structures spread footings. Shoring for the Eagle Gate Tower was to be constructed immediately adjacent to a mat supported 22 story high rise structure. This shoring system combined secant piles, ground anchors and incorporated existing abandoned-in-place pipe piles with infilling high pressure jet grouting to create a cutoff wall and eliminate the adverse impacts of dewatering below this sensitive foundation.

Jan 1, 2010

MR. SHUBART: Mr. Miller&apos;s paper mentioned the two processes that seemed to be a success, the Smith process and the Piron process. I suppose the main difference is this, that Smith&apos;s process is to furnish domestic fuel and the by-products while the Piron process that Ford is installing is for fuel for power plants. I would like to ask Mr. Miller something about the commercial cost of the process. With the briquette you must make it cheap enough to sell. What are the commercial possibilities of Smith&apos;s briquette? MR. MILLER: It is pretty hard to say what the cost would be at this time, owing to the fact that slack has advanced double, or even more at the time I was in New York with the plant, but at that time it was costing $1.10 for the operation. You can add to that, of course, the cost of the coke. One dollar and ten cents was the entire cost of plant operation. It takes about one and one-half tons of coal to make a ton of briquettes. One dollar and ten cents takes care of all the material, cost, labor, handling, etc. Labor was much cheaper then. I would say it would cost about $2.20 now. The cost of coal is what you can buy it for on the market. I don&apos;t think, however, that the carbocoal process will ever meet with any great favor for the simple reason that it is really a prepared fancy fuel. It is going to be nice for people in offices where they want a grate or for families where they want a nice clean fuel. It leaves no stain on the fingers, no odor to it. It seems in carbonizing coal we change the carbon molecule. For instance, we are all familiar with the diamond. It is carbon, yet it requires a tremendous heat to burn a common little diamond. But you can set a piece of charcoal afire, which is also carbon, with a match. The molecular form has been changed in carbonizing coal, i. e., it is larger. Carbocoal will fire very readily, it can be started with a piece&apos; of paper. I think the Piron process will be the process, i. e., to simply take out the tars and light oils, then fire direct-have the distillate plants right on the job. CHAIR: Can Mr. Shubart tell us something of the mechanical part of the Piron process? MR. SHUBART: The Piron process is of interest because Mr. Ford is taking it up. He has made so few mechanical mistakes it makes us feel that it is a success. Piron is a chemist of high accomplishment and reputation. The thing about the proces is its simplicity. Mr. Smith&apos;s is a very elaborate process, but Piron has gotten around all that. Piron feeds the raw coal in at about one-half inch mesh or smaller. He feeds it into a retort about 55 feet long, 16 feet wide over all. He has a hearth about 6 feet wide and the length of the retort. The base of the hearth that carries the coal is a conveyor, a flat cast iron conveyor, a very massive affair, very accurately made, so that there is no loss of coal. Between the upper and lower strands of the &apos; conveyor is a bath of molten lead which gives an accurate control of temperature. For best results he must have temperature of not under 800 F., not over 1,300 degrees F., about 1,100 or 1,200 F. seems to be ideal for getting greatest yield of oils and the best tars and other by-products. This lead bath has a system of flues running through it that

Jan 1, 1923

By Charles R. Marek

There is an ever-increasing need for quality construction materials to provide the necessary housing and transportation facilities required for the protection and movement of people and goods. By the year 2000, requirements for housing in the United States will have doubled due to population growth. Requirements for transportation facilities in this same period will also have increased substantially. Further, all existing facilities for both housing and transportation will require substantial maintenance of one form or another. Aggregate is the basic material of the construction industry. There is some occurrence of aggregate source material in virtually every state of the United States, and in every country in the world. United States reserves of commercially useable aggregate have never been systematically estimated and are probably so vast as to be incalculable.1 However, in many areas its existence is largely negated by inaccessibility. Often it is lodged deeply or intricately in the earth or it is too distant from markets to offer a desirable "return on investment" under the present economic structure. Other factors that prevent its utility are the occurrence of small scattered deposits that individually are too small to justify the necessary capital investment for exploitation and collectively are too widely disseminated; also, the aggregate nay be deficient in certain desired chemical or physical qualitites.1

Jan 1, 1974

By E. Ghali, J. F. Dorion

This paper presents the results of on-going investigations on the influence of corrosion on the performance of support systems in selected underground gold mines. Rock support is exposed to various conditions that can be aggressive. Samples of corroded support were analysed using SEM and photomicrography to determine the main corrosion forms. Tests are on-going in controlled corrosion chambers to qualify and quantify the impact of rock and minerals particles on steel corrosion. As more data become available these relationships can lead to useful information on the choice of support systems and reliable estimates of their longevity.

Jan 1, 2011

By C G. Robinson, B. K. Loveday, J. C. Paynter

"A method of optimizing the design of a processing plant has been developed which minimizes capital and operating costs for average stripping ratios and ore characteristics. Models were developed to describe the operating characteristics and costs involved in various operations such as up-grading, leaching and solid-liquid separation.The options available in up-grading policy and the relation between the cut-off grade and the costs incurred subsequently in the treatment of the ore formed the basis of the optimization. To arrive at an optimum plant configuration and a set of operating parameters, the interrelation between grinding size, leaching temperature, leaching time, and various plant recycle options was investigated."

Jan 1, 2014

By F. Kongoli

A computerized thermophysicochemical database is being developed for various processes involved in nickel smelting and converting. This database includes optimized models for slag, matte, liquid and solid alloys in the multicomponent system(s) as applied to batch and continuous nickel smelting and converting processes. This database can be used to quantify the multicomponent and multiphase slag/matte/alloy/gas equilibria, liquidus and solidus surface, tie-lines, solubility and/or losses of nickel and other components in the slag, distribution coefficients, components activities, heat and mass balance, etc. The database also includes optimized models for the viscosity of the slags associated with any of the above processes. Both databases are coupled and this constitutes a very effective method to quantify the effect of each component on several parameters of the smelting and converting processes and to diffuse the confusion that exists in the literature. Several application examples have been given to demonstrate the usefulness of this database for quantitative prediction of the thermophysicochemical properties of the phases involved in actual or developing processes, even in the areas where experiments are difficult or impossible. The considerable cost reduction that results ftom the use of this database as compared to other methods in the improvement of existing technologies or in the development of new ones is discussed along with continuing new developments of this database.

Jan 1, 2002