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The measurement of coal porosity with different gases

Rodrigues, C. F.; Lemos de Sousa, M. J.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2002 Português
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37.14%
Sorption processes can be used to study different characteristics of coal properties, such as gas content (coalbed methane potential of a deposit), gas diffusion, porosity, internal surface area, etc. Coal microstructure (porosity system) is relevant for gas flow behaviour in coal and, consequently, directly influences gas recovery from the coalbed. This paper addresses the determination of coal porosity (namely micro- and macroporosity) in relation to the molecular size of different gases. Experiments entailed a sorption process, which includes the direct method of determining the ‘‘void volume’’ of samples using different gases (helium, nitrogen, carbon dioxide, and methane). Because gas behaviour depends on pressure and temperature conditions, it is critical, in each case, to know the gas characteristics, especially the compressibility factor. The experimental conditions of the sorption process were as follows: temperature in the bath 35 ºC; sample with moisture equal to or greater than the moisture-holding capacity (MHC), particle size of sample less than 212 mm, and mass ca. 100 g. The present investigation was designed to confirm that when performing measurements of the coal void volume with helium and nitrogen, there are only small and insignificant changes in the volume determinations. Inducing great shrinkage and swelling effects in the coal molecular structure...

Avaliação ecotoxicológica dos percolados das colunas de cinza de carvão e de solos com cinza de carvão utilizando Lactuca sativa e Daphnia similis como organismos teste; Ecotoxicological evaluation of leachates from columns of coal fly ash and soil with coal fly ash using Lactuca sativa and Daphnia similis as test organism

Castro, Flávia Junqueira de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 22/02/2013 Português
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37.14%
As cinzas resultantes da queima de carvão por usinas termelétricas tem sido uma fonte de contaminação constante devido a seu descarte sobre o solo de forma inadequada. Os elementos tóxicos presentes na cinza de carvão quando lixiviados da cinza para o solo podem ficar biodisponíveis e serem absorvidos por plantas, consumidos por animais ou ainda transportados para diversas matrizes ambientais, tais como, águas subterrâneas e águas superficiais. Ensaio de germinação e desenvolvimento das radículas de Lactuca sativa e ensaio de toxicidade aguda com Daphnia similis foram realizados para avaliar a toxicidade dos percolados de colunas de cinza de carvão e de solo com cinza de carvão. De acordo com os valores obtidos por meio dos ensaios de germinação e desenvolvimento das radículas de L. sativa foram observados efeitos tóxicos à germinação das sementes de L. sativa nos percolados da coluna de cinza de carvão. Os valores médios de CI50(120h) destes percolados variaram de 27,6 a 90,6% e os valores do índice de germinação (IG) variaram de 6,7 a 40,8. Nos ensaios de toxicidade aguda com os organismos teste D. similis também foram observados efeitos tóxicos à mobilidade e/ou sobrevivência dos organismos expostos aos percolados da coluna de cinza de carvão. Os valores obtidos para CE50(48h) nestes percolados variaram de 25...

Estudo experimental de briquetes autorredutores e auto-aglomerantes de minério de ferro e carvão fóssil.; Experimental study of self-reducing self-agglomerated iron ore and brown coal briquettes.

Tanaka, Marcio Toshio
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 27/03/2014 Português
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37.14%
Este trabalho consiste no estudo da obtenção de aglomerados autorredutores na forma de briquetes a frio tratados termicamente, utilizando minério de ferro e carvão fóssil como matérias-primas. Esta promissora tecnologia tem como premissa a utilização da termo-plasticidade do carvão fóssil para conferir resistência e promover a auto-aglomeração. A obtenção de briquetes dá-se através de três etapas: condicionamento da mistura, briquetagem a frio e tratamento térmico. Os finos de carvão e minério são misturados e homogeneizados. A mistura, então, passa por processo de briquetagem a frio para compactação, promove o aumento de contato entre as partículas de carvão e minério. Finalmente tratamento térmico é realizado para obter a forma de um corpo sólido e coeso de auto-aglomerado autorredutor. O objetivo deste trabalho é determinar as melhores condições de obtenção de briquetes através do estudo de variáveis ao longo do processo de fabricação, utilizando a resistência mecânica como parâmetro. As variáveis estudadas são: granulometria do carvão, envelhecimento do carvão, percentual de carvão na mistura, adição de aglomerantes, pressão de compactação na briquetagem e temperatura de tratamento térmico. Os resultados obtidos neste estudo indicam que estas variáveis afetam significativamente a resistência mecânica. Utilizando-se o carvão Chipanga...

Thermal analysis evaluation of the reactivity of coal mixtures for injection in the blast furnace

Gomes, Maria de Lourdes Ilha; Osorio, Eduardo; Vilela, Antonio Cezar Faria
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Artigo de Revista Científica Formato: application/pdf
Português
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37.14%
Pulverized Coal Injection (PCI) is an important standard technology replacing coke partially by pulverized coal into the blast furnace that allows a significant reduction of hot metal costs and environmental impact, contributing to a decrease of coke requirements for ironmaking. Coals typically used in this process in Brazil are, at current time, exclusively imported from many countries, although economic important coal-measures occur in the southern part of the country. The Brazilian coals have a low rank, higher contents of inert components, proportioning nocoking properties and an expected high reactivity. Due to these caractheristics, these coals could be used for injection in the blast furnaces in order to decrease the dependency on high cost imported coals. The efficiency in the combustion and the coal reactivity are considered important parameters in the blast furnace, since a larger amount of char (unburned coal) causes severe problems to the furnace operation. The aim of the present work is to compare the reactivity of a south Brazilian coal, obtained from Faxinal mine, with two imported coals and the blends of the Brazilian coal with the imported ones. The reactivity of these coals and their blends were evaluated in a thermogravimetric analyzer. In the experiments...

A Strategy for Coal Bed Methane and Coal Mine Methane Development and Utilization in China

Energy Sector Management Assistance Program
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Português
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37.25%
China is short of clean energy, particularly conventional natural gas. The proven per capital natural gas reserve is only 1/12th of the world average. However, China has large coal bed methane (CBM) resources with development potential which can be recovered from surface boreholes independent of mining and in advance of mining, and also captured as a part of underground coal mining operations. However, in order to meet its targets, the government must improve the administrative framework for CBM resource management, introduce more effective CBM or coal mine methane (CMM) development incentives, raise the technical capacity of the mining sector, expand gas pipeline infrastructure and promote gas markets in coal mining areas. In order to significantly reduce methane emission from coal mines and better exploit the gas recoverable from coal seams, the government should introduce measures to: strengthen the CBM/CMM policy, legal and regulatory framework to improve resource management; improve CMM availability and quality so more can be utilized; enhance incentives to promote expansion of CBM/CMM exploitation and destruction of surplus drained CMM; and Promote development of regional development strategies to take advantage of specific local advantages.

Poland : Reform and Restructuring of the Hard Coal Sector 1998-2006 and Future Prospects

Strongman, John; Palac, Roman; Eftimie, Adriana
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Português
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37.26%
Poland has by far the highest hard coal production of any country in the European Union and hard coal will continue to play a crucial role regarding energy security for Poland. Most importantly, hard coal can reduce both the price and supply risks for Poland associated with oil and gas imports. Poland has a number of low cost mines with good quality coal where production can be expanded so that it is feasible for coal to meet domestic demand without requiring operating support from the state budget and if the remaining restructuring of the coal mining sector is completed successfully, the sector can again become an important driver for economic development of Silesia rather than a liability. While heavy industries such as hard coal and steel will remain core industries for Silesia, they are unlikely to be sources of increased employment in future. The growth sectors for Silesia are to be found in higher technology (including coal-based technologies) and service industries. The next few years, while EU funds are available...

Technology Assessment of Clean Coal Technologies for China : Volume 2. Environmental and Energy Efficiency Improvements for Non-power Uses of Coal

World Bank
Fonte: Washington, DC Publicador: Washington, DC
Português
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37.24%
Analysts expect China to continue improving the efficiency of energy production and use, thereby decoupling the traditional relationship between gross domestic product (GDP) and energy consumption. Environmentally acceptable economic growth is closely linked with further improvements in the overall efficiency of energy use. Both of these goals will require a continued increase in the use of coal to produce electricity, along with a more deliberate and rapid transition from direct coal combustion to the use of electricity and other cleaner coal-based fuel sources, especially for cooking, space heating, and industrial furnaces. The opportunity for environmental improvement in conjunction with economic growth lies in the wise adoption of clean coal technologies (CCT) for both the electric power and non-power sectors. This report presents CCT options for the power sector that can help China achieve these twin goals. The CCT options are: 1) air pollution controls for particulates, sulphur dioxide, and nitrous oxide; and 2) advanced electricity generation technologies--supercritical pulverized-coal boilers...

Technology Assessment of Clean Coal Technologies for China : Volume 3. Environmental Compliance in the Energy Sector

World Bank
Fonte: Washington, DC Publicador: Washington, DC
Português
Relevância na Pesquisa
37.15%
Analysts expect China to continue improving the efficiency of energy production and use, thereby decoupling the traditional relationship between gross domestic product (GDP) and energy consumption. Environmentally acceptable economic growth is closely linked with further improvements in the overall efficiency of energy use. Both of these goals will require a continued increase in the use of coal to produce electricity, along with a more deliberate and rapid transition from direct coal combustion to the use of electricity and other cleaner coal-based fuel sources, especially for cooking, space heating, and industrial furnaces. The opportunity for environmental improvement in conjunction with economic growth lies in the wise adoption of clean coal technologies (CCT) for both the electric power and non-power sectors. This report presents CCT options for the power sector that can help China achieve these twin goals. The CCT options are: 1) air pollution controls for particulates, sulphur dioxide, and nitrous oxide; and 2) advanced electricity generation technologies--supercritical pulverized-coal boilers...

Rheological characterisation of low-rank coal ash at high temperatures.

Tonmukayakul, Narongsak
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2004 Português
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37.18%
Ash deposition is a problem in power generation when coal with high ash and alkali contents are utilised. The problem is more severe in fluidised bed combustion where the ash deposition can causes agglomeration of the bed material, may lead to defluidisation of the unit. The successful operation of fluid bed combustion with coal high in ash and alkali content will depend on the ability to control ash deposition. The rheological properties of coal ash under furnace conditions are important in controlling the stickiness and mobility of the molten ash deposition. Therefore, a good knowledge of the rheological properties of coal will improve the understanding of the mechanisms associated with ash deposition, and may assist in controlling the deposition and agglomeration of fluid bed material. At present, a good deal of information about coal ash rheology under conditions similar to those found in fluidised bed combustion is not known, and greater understanding is required. This is primarily due to a lack of reliable instruments and measurement techniques. In this work, a new high temperature rheometer has been developed based on the principle concepts of visco metric flow. The developed rheometer allows fundamental rheological properties...

Quantitative in-situ measurements of sodium release during the combustion of single coal particles using planar laser induced fluorescence.

van Eyk, Philip Joseph
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2011 Português
Relevância na Pesquisa
37.18%
The release of sodium from low rank coal during combustion is known to be an important factor in the phenomena of fouling and corrosion in industrial boilers. Although much is known about the gas phase chemistry of sodium compounds, and the likely sequence of events that lead to fouling and corrosion, very little fundamental work has been undertaken on the release of sodium from the coal particle as it is combusted. The principal objective of this study was to perform detailed quantitative measurements and mathematical modelling of sodium release during combustion of single brown coal particles. Planar Laser Induced Fluorescence (PLIF) was applied for the in-situ measurement of the atomic sodium concentration field in the plume of single Loy Yang brown coal particles. Laser absorption measurements at the sodium D1 line (589.59 nm) were utilised to calibrate PLIF measurements of atomic sodium in a purpose designed flat flame environment. Detailed measurements of atomic sodium in the plume of single combusting brown coal particles of varying amounts and forms of sodium and of varying particle sizes were then undertaken. A run-of-mine Loy Yang brown coal sample and two samples that were processed using Mechanical/Thermal Expression (MTE)...

Temperature effect on methane sorption and diffusion in coal: application for thermal recovery from coal seam gas reservoirs

Salmachi, A.; Haghighi, M.
Fonte: Australian Petroleum Production and Exploration Association Publicador: Australian Petroleum Production and Exploration Association
Tipo: Artigo de Revista Científica
Publicado em //2012 Português
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37.17%
Investigating the effects of in situ thermal treatment on coal seams requires adequate knowledge of gas sorption and its kinet¬ics in coal at various temperatures. Methane sorption onto two Australian coal samples (high-volatile bituminous) at dry state and different temperatures was measured. Methane adsorption isotherms were measured at pressures up to 7 MPa by the gas ad¬sorption manometric method. Adsorption isotherms data at two temperatures were used to investigate the effects of in situ thermal treatment on critical desorption pressure, ultimate gas recovery and the diffusion coefficient in coal. An increase of experimental temperature from 308 to 348 K resulted in a 50% reduction in the adsorption affinity of the coal sample and an insignificant reduction in the saturation capacity of the isotherms. At higher ex¬perimental temperatures, Langmuir isotherms exhibit downward shift with the initial gas content of the coal seam being constant, resulting in critical gas desorption pressure increase. According to the measured Langmuir isotherms at different temperatures, an increase in reservoir temperature by 1 K leads to a 2% and 1.2% increase in total recovery for the tested coal seams. Gas left in the coal seam at the abandonment pressure can only be recovered at a higher reservoir temperature. Diffusion coefficients of coal seam samples were calculated for different experimental temperatures. Fractional uptakes of the first coal sample show a good agreement with the results obtained using the unipore diffusion model with the diffusion coefficient to be 4.7 × 10–12 m2/s at 348 K. For the second coal sample...

The Availibility of the Danville Coal Member for Mining in Indiana

Conolly, Carol L.; Zlotin, Alex
Fonte: Indiana Geological Survey Publicador: Indiana Geological Survey
Tipo: Relatório Formato: 5087737 bytes; application/pdf
Português
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Indiana Geological Survey Open-File Study 2000-1; This study assesses the resources of the Danville Coal Member in Indiana and identifies those resources that have the most favorable geologic and land use characteristics for mining. The tonnage of original coal in place, remaining coal after mining, coal unlikely to be mined due to geologic and land use factors, and available coal resources were calculated for the Danville Coal in Indiana. The geologic and land use factors which restrict the mining of the Danville Coal were identified through interviews with geologists and mining engineers mining the Danville Coal in Indiana and Illinois. These restrictions were applied to the tonnage of remaining Danville Coal resources in order to calculate the tonnage of available resources. The original, remaining, and available coal resources are reported in terms of potential method of mining, "surface" or "underground," coal thickness, "14-28 inches," "28-42 inches," or "greater than 42 inches," and overburden thickness, "0-200 feet," and "greater than 100 feet." Coal that lies between depths of 100 and 200 feet is considered minable by both surface and underground methods. Additionally, the resources are categorized by three levels of geologic assurance or reliability. The reliability categories express the degree of reliability of the resource estimate based on the density of coal thickness data points that are used to derive the resource estimate. The three reliability categories are: measured (0-0.5 miles from the data point)...

Coal Reserve Assessment and Database Development of the Danville and Springfield Coal Members in Indiana: Final Report

Conolly, Carol L.; Rupp, John A.
Fonte: Indiana Geological Survey Publicador: Indiana Geological Survey
Tipo: Relatório Formato: 4291706 bytes; application/pdf
Português
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37.16%
Indiana Geological Survey Open-File Study 2001-1; This study assesses the coal resources of the Danville and Springfield Coal Members (Dugger and Petersburg Formations, respectively) in Indiana and provides new estimates of the tonnage of coal in the following categories as of January 1, 2000: original resources in place, resources remaining after mining, identified resources, demonstrated reserve base, accessible reserve base, and estimated recoverable reserves. In addition, the sulfur, heat, and ash content of the Danville and Springfield Coals were mapped in order to allocate indicated reserves, demonstrated reserve base, accessible reserve base, and estimated recoverable reserves according to specified categories of sulfur, heat, and ash content. The resources and reserves categories are defined based upon criteria for minimum coal thickness, overburden thickness, and reliability category. Three reliability categories are used to express the relative degree of geologic assurance or reliability of the resource estimate based upon the density of coal thickness data points that are used to derive the resource estimate. The reliability categories are: measured (0-0.5 miles from the data point), indicated (0.5-2.0 miles), and inferred (2.0-4.0 miles). The geologic and land use factors which limit the mining of the Danville and Springfield Coal were identified through interviews with geologists and mining engineers from companies mining these coals in Indiana and Illinois. These factors were mapped and then applied to the tonnage of demonstrated reserve base in order to calculate the tonnage of accessible reserve base. Recovery-rate factors for surface and underground mining (80% and 50%...

Directory of Coal Mines and Producers in Indiana–2002

Weber, Licia A.; Carpenter, Jeanne A.; Shaffer, Kathryn R.; Irwin, Paul N.
Fonte: Indiana Geological Survey Publicador: Indiana Geological Survey
Tipo: Livro Formato: 11479588 bytes; application/pdf
Português
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Indiana Geological Survey Directory 12-02; The Directory of Coal Mines and Producers in Indiana–2002 is a compilation of information related to actively permitted coal mines and producers in Indiana. For 20 years, the Indiana Geological Survey (IGS) has published similar directories as a service to clients interested in coal, including property owners, environmental consultants, coal companies, potential investors, coal consumers, and regulatory agencies. This directory includes index maps of the Illinois Basin and southwestern Indiana, as well as county overview maps and coal production tables for each county having mines with active permits. In addition, a detailed map of each mine shows mined-out areas, as well as locations of active pits, mine offices, and local roads. Detailed maps of each mine are accompanied by tabular information including mine location, mine type, operation dates, mining status, coals mined, ownership information, contact personnel, addresses, phone numbers, and production data. Mine data were collected from coal companies and the Indiana Department of Natural Resources, Division of Reclamation (DOR) between March and November 2001. This directory contains information related to mines that were active or idle...

The health impacts of coalmining operations and coal combustion on geographically proximate communities

Barnes, Mallory
Fonte: Universidade Nacional da Austrália Publicador: Universidade Nacional da Austrália
Tipo: Relatório
Português
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37.18%
The objective is to how coalmining operations and coal combustion (herein coal operations) impact upon the health of communities that are in close geographical proximity to these operations. Although coal operations emit a medley of toxic gases, only the effect of Particulate Matter (PM) will be assessed in depth because of its overbearing impact on public health compared to other gases, it's superabundance in areas proximal to coal operations, its amenability to reduction initiatives and_ the size of the social benefit gained from reduction. The air quality of four regional communities - Mackay (Qld) Moranbah (Qld), The Upper Hunter Valley (NSW) and Latrobe Valley (Vic) - was compared to the major urban centres. All communities are in coal mining or coal combustion hubs. Literature review An overwhelming body of literature supports the association between elevated PM and increase population morbidity and mortality. A panoply of independent, epidemiological studies consistently demonstrate about a 1% increase in population mortality with every 1 Oμm/m3 short term increase in PM10. Increases in PM2.5 are more lethal, but far less is understood about it. Both forms of PM have a stronger association with respiratory and cardiovascular disease and mortality than any other kind. Long term exposures were more harmful. Very little study has been done in Australia or overseas...

Coal Industry Restructuring in Ukraine : The Politics of Coal Mining and Budget Crises

Lovei, Laszlo
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Tipo: Publications & Research :: Viewpoint; Publications & Research
Português
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37.15%
Restructuring Ukraine's coal industry has been even more difficult and politicized than reforming its electricity and gas industries. Coal reform has divided Parliament and the government into two camps - one supporting populist policies and the other supporting fiscal realism - and the balance of power between these camps has changed frequently. Despite mounting financial losses, coal miners and managers have blocked attempts to rationalize production and employment practices. The government has, however, managed to close several highly uneconomic mines. Speeding up mine closures seems to be the only way to arrest the accumulation of payment arrears - nearly US$4billion (including wages) by mid-1998 -- and of payments due for coal supplies - more than US$1.5billion by mid-1998.

Biogeochemical Transformations of Trace Element Pollutants During Coal Combustion Product Disposal

Schwartz, Grace Ellen
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Dissertação
Publicado em //2015 Português
Relevância na Pesquisa
37.26%

Coal fired power plants generate approximately 45% of the electricity produced in the United States every year, and each year, over 100 million tons of coal ash are produced as a by-product of electricity generation. Coal ash is a solid waste made up principally of bottom ash, fly ash, and flue gas desulfurization materials. The chemical composition of coal ash varies depending on the feed coal source, combustion parameters, and the presence and type of air pollution control devices that remove contaminants from the flue gas into the solid waste stream. Although a significant portion of coal ash waste is recycled, the majority of coal ash is disposed in landfills and holding ponds. Coal ash impoundments have a long history of environmental degradation, which includes: contaminant leaching into groundwater, the discharge of contaminant-laden effluent into surface waters, and catastrophic impoundment failures and ash spills. Despite these known problems, coal ash is not considered a hazardous waste, and thus is not subject to stringent disposal requirements. The current coal ash management system is based on risk assessments of coal ash that do not include environmental parameters that have a profound impact on coal ash contaminant mobility...

The coal cycle: small scale illegal coal supply in eastern India

Lahiri-Dutt, Kuntala; Williams, David
Fonte: TERI Press Publicador: TERI Press
Tipo: Artigo de Revista Científica
Português
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37.18%
A characteristic of the Jharia-Raniganj coalfields area is the sight of bicycles carrying sacks of coal, the bike being used as an inanimate packhorse with men pushing them along the roads connecting the mines with the neighbouring towns instead of pedalling. This is one tiny part of an extensive illegal coal supply network involving millions of tonnes annually. Who are these coal cycle wallahs, how much coal do they carry, where does the coal come from, and where does it go? Our objective here is to provide an estimate of one part of the 'black' (or illegal) coal economy in one part of the coal-producing tracts of India by describing the nature and extent of the supply of coal (or coke) provided by bicycles. We recognize that it is indeed a rather tiny part of the entire gamut of illegal coal mining, transportation, and distribution network that is in place in the colliery tracts of India. This paper examines this cycle distribution network and provides an estimate of the amount of coal supplied in this manner throughout the eastern Indian coalfields of Jharkhand and West Bengal. This estimate is based on recent field surveys of the amount of coal loaded onto cycles for transport to a particular town, assuming demand was local- and urban-population driven. The study was supported by previous experience in the field and by interviews with key informants. At the end...

Representation of coal and coal derivatives in process modelling

Theron,J.A.; le Roux,E.
Fonte: Journal of the Southern African Institute of Mining and Metallurgy Publicador: Journal of the Southern African Institute of Mining and Metallurgy
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/05/2015 Português
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37.19%
This paper provides guidelines on performing mass and energy balance modelling involving coal and coal derivatives. Usually, the inputs to a pyrometallurgical process would be specified in terms of elements and compounds. Reliable thermochemical data is more widely available for species involving uniquely defined, relatively smaller molecules. However, in the case of coal, the molecules are extremely large and not uniquely defined. Consequently, modelling processes involving coal and its derivatives involve several potential pitfalls. These are outlined in the present paper. It was found that coal proximate analysis should not be regarded as absolute; it could vary with several parameters, including heating rate. For modelling, the use of ultimate analyses should be considered a preferable option to proximate analyses, where 'fixed carbon' and 'volatiles' are not defined in terms of chemical composition. Significant errors could be incurred if the larger molecules are neglected during calculation of the calorific value (CV) of coal gas (the gas liberated when coal is heated in the absence of oxygen). For elemental analysis determination, the oxygen content (which is calculated by balance) should be checked to ensure it is within the expected range. For representation of sulphur in coal...

Techno-economic impact of optimized low-grade thermal coal export production through beneficiation modelling

Bergh,J.P.; Falcon,R.M.S.; Falcon,L.M.
Fonte: Journal of the Southern African Institute of Mining and Metallurgy Publicador: Journal of the Southern African Institute of Mining and Metallurgy
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/11/2013 Português
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37.15%
The advent of low-quality export coal demand has brought a new range of possibilities to the South African coal industry. Products that traditionally were only of value to the domestic or combustion industry sectors now have the potential to be exported, with only minor amounts of upgrading required through beneficiation. Comparatively high steam-coal export prices can be obtained for low-quality export coal, which enhances the economic feasibility of expanding low-quality thermal coal exports. There are, however, increasing concerns about the feasibility of lower quality thermal coal exports and the broader implications. These concerns relate to the environmental impact of low-quality thermal coal production for export and the inherent threat to the security of domestic thermal coal supply in South Africa. Against this background, this paper serves to explain the extended value chain in the production of export coal. The technical and economic advantages and disadvantages of low-grade exports versus coal production for domestic use are evaluated. The value chain estimation is calculated by the beneficiation modelling and characterization of two coals. Based on the value estimation, the low-grade export production scenario, and finally the modelling of potential pollutant distribution...