Co-combustion of waste materials using fluidized bed technology

Energy Technology Data Exchange (ETDEWEB)

M. Lopes; I. Gulyurtlu; P. Abelha; T. Crujeira; D. Boavida; I. Cabrita [INETI-DEECA, Lisbon (Portugal)

2004-07-01

There is growing interest in using renewable fuels in order to sustain the CO{sub 2} accumulation. Several waste materials can be used as coal substitutes as long as they contain significant combustible matter, as for example MSW and sewage sludge. Besides the outcome of the energetic valorization of such materials, combustion must be regarded as a pre-treatment process, contributing to the safe management of wastes. Landfilling is an expensive management option and requires a previous destruction of the organic matter present in residues, since its degradation generates greenhouse gases and produces acidic organic leachates. Fluidized bed combustion is a promising technology for the use of mixtures of coal and combustible wastes. This paper presents INETI's experience in the co-combustion of coal with this kind of residues performed in a pilot fluidized bed. Both the RDF (from MSW and sewage sludge) and sewage sludge combustion problems were addressed, relating the gaseous emissions, the behaviour of metals and the leachability of ashes and a comparison was made between co-combustion and mono-combustion in order to verify the influence of the utilization of coal. 9 refs., 1 fig., 3 tabs.

Radioactivity of combustion residues from coal-fired power stations

International Nuclear Information System (INIS)

Vom Berg, W.; Puch, K.H.

1996-01-01

Each year in Germany, about 18 mill. t of combustion residues are produced from the combustion of bituminous coal and lignite. They are utilized to a great extent in the construction industry and in mining. During the combustion of coal, the radio-nuclides remain predominantly in the ash. The radionuclide concentration in lignite ash is within the range of that in natural soil. The combustion residues of bituminous coal contain radio-nuclides of a similar order of magnitude as also can occur in natural rock. The utilization of combustion residues in construction materials makes a negligible contribution to radiation exposure through retention in buildings. (orig.) [de

Effects of backing board materials on wood combustion performance

Science.gov (United States)

Mathew J. Hagge; Kenneth M. Bryden; Mark A. Dietenberger

2004-01-01

Cone calorimeter tests show that backing board materials do not affect the ignition time, initial heat release rate, or the total heat released of combustion for redwood slabs. However, it has been observed that backing board materials alter combustion performance by altering the secondary heat release peak observed when the pyrolysis reaction front nears the unheated...

Acid mine drainage abatement resulting from pressure grouting of buried bituminous mine spoils

International Nuclear Information System (INIS)

Scheetz, B.; Silsbee, M.; Schueck, J.

1998-01-01

A 37 acre surface coal mine located in Clinton County, PA, USA, was mined and reclaimed between 1974 and 1977. Buried pyrite-rich pit floor cleanings and tipple refuse were found to be producing severe acid mine drainage. The pyritic material is located in discrete piles or pods in the backfill. The pods and the resulting contaminant plumes were initially defined using geophysical techniques and confirmed by drilling. The approach taken was to use a cementitious grout, composed of fluidized bed combustion ash and water, which would be placed in a manner which would prevent water and oxygen from contacting the pyritic materials. Statistically significant water quality improvements have been noted as a result of the grouting. After four years of post-grouting monitoring, reductions in concentrations of most of the mine drainage parameters range from 40 to 90%. 12 refs., 1 fig., 4 tabs

Determination of combustible volatile matter in coal mine roadway dusts by backscatter of x-rays from a radioisotope source

International Nuclear Information System (INIS)

Ailwood, C.R.; Bunch, K.; Fookes, R.A.; Gravitis, V.L.; Watt, J.S.

1977-01-01

The combustible volatile matter in coal mine roadway dusts (CVM) has been determined using x-ray backscatter techniques. The correlation between x-ray and chemical techniques is reasonably good for the 92 samples from collieries on the Bulli seam, and the maximum error expected at the maximum level of 11.5 weight per cent CVM permitted in the N.S.W. Coal Mines Regulation Act, 1912, as amended, is about +- 2.5 weight per cent. This x-ray technique can be used only when the combustible volatile content of the coal matter (CVM) varies within a limited range, and a separate calibration is required for each coal seam. Portable equipment based on a radioisotope x-ray source and digital ratemeter makes possible simple and rapid analysis, and with adaptation to use in coal mines should lead to much more comprehensive testing of roadways and hence improved overall prevention of coal dust explosions. (author)

Combustion synthesis of inorganic materials; Muki zairyo no nensho gose

Energy Technology Data Exchange (ETDEWEB)

Oyanagi, M. [Ryukoku University, Kyoto (Japan)

1999-11-01

Combustion synthesis of porous titan carbide is outlined. In combustion synthesis, exothermic chain reaction, which is induced by igniting at one point of the simple substance mixture, propagates the combustion wave, and the compound is synthesized, which can be sintered by it. By this method, to this day intermetallic compounds, ceramics and high melting point composite materials have been synthesized, and synthetics can be made compact by adding pressure during or just after the reaction. Recently, applying the induction heating jointly, preheating before the reaction and heat treatment after the reaction can be controlled, accordingly, many high melting point inorganic compounds and composite materials can be made by combustion synthesis under pressure. (NEDO)

Sulfur Release from Cement Raw Materials during Solid Fuel Combustion

DEFF Research Database (Denmark)

Nielsen, Anders Rooma; Larsen, Morten B.; Glarborg, Peter

2011-01-01

During combustion of solid fuels in the material inlet end of cement rotary kilns, local reducing conditions can occur and cause decomposition of sulfates from cement raw materials. Decomposition of sulfates is problematic because it increases the gas-phase SO2 concentration, which may cause...... deposit formation in the kiln system. SO2 release from cement raw materials during combustion of solid fuels has been studied experimentally in a high temperature rotary drum. The fuels were tire rubber, pine wood, petcoke, sewage sludge, and polypropylene. The SO2 release from the raw materials...

Design of material management system of mining group based on Hadoop

Science.gov (United States)

Xia, Zhiyuan; Tan, Zhuoying; Qi, Kuan; Li, Wen

2018-01-01

Under the background of persistent slowdown in mining market at present, improving the management level in mining group has become the key link to improve the economic benefit of the mine. According to the practical material management in mining group, three core components of Hadoop are applied: distributed file system HDFS, distributed computing framework Map/Reduce and distributed database HBase. Material management system of mining group based on Hadoop is constructed with the three core components of Hadoop and SSH framework technology. This system was found to strengthen collaboration between mining group and affiliated companies, and then the problems such as inefficient management, server pressure, hardware equipment performance deficiencies that exist in traditional mining material-management system are solved, and then mining group materials management is optimized, the cost of mining management is saved, the enterprise profit is increased.

Environmental remediation with products of fluidized bed combustion

International Nuclear Information System (INIS)

Kim, A.G.

1999-01-01

Commercialization of fluidized bed combustion (FBC) technology could be enhanced by increased utilization of FBC products (ash). In the US, coal combustion products (CCP) are not hazardous under RCRA and are regulated as residual waste by the states. The composition of CCP from fluidized beds is primarily determined by the inorganic constituents in coal, the sorbent reaction products and the unreacted sorbent. The combustion system and the inclusion of other fuels may also affect the chemical composition, physical properties and leaching behavior. The alkalinity of the FBC material, residual lime and pozzolanic properties are desirable characteristics for use in soil stabilization and mine reclamation. At reclaimed surface coal mines, placement of CCP is intended to reduce the amount of acid mine drainage (AMD) produced at such sites. Neutralization, inhibition of acid forming bacteria, encapsulation of the pyrite or water diversion are believed to be the mechanisms facilitated by the alkaline material. Comparison of water quality, before and after injection of a grout composed of FBC ash and water indicated small increases in pH and decreases in acidity at discharge points. The concentrations of calcium and magnesium in water samples generally increased compared to background levels. The average concentration of trace elements (arsenic, cobalt, copper, nickel and zinc) was slightly elevated in the injection areas, but in down dip and discharge water samples were comparable to background levels. Over a four year period, the average acidity in the injected area decreased by approximately 30%, a value similar to another site where a mixture of class F fly ash and cement was injected. Although coal mine remediation is a beneficial environmental use of FBC products, its effectiveness may be related to the amount of FBCB used and the method of emplacement

Environmental remediation with products of fluidized bed combustion

Energy Technology Data Exchange (ETDEWEB)

Kim, A.G.

1999-07-01

Commercialization of fluidized bed combustion (FBC) technology could be enhanced by increased utilization of FBC products (ash). In the US, coal combustion products (CCP) are not hazardous under RCRA and are regulated as residual waste by the states. The composition of CCP from fluidized beds is primarily determined by the inorganic constituents in coal, the sorbent reaction products and the unreacted sorbent. The combustion system and the inclusion of other fuels may also affect the chemical composition, physical properties and leaching behavior. The alkalinity of the FBC material, residual lime and pozzolanic properties are desirable characteristics for use in soil stabilization and mine reclamation. At reclaimed surface coal mines, placement of CCP is intended to reduce the amount of acid mine drainage (AMD) produced at such sites. Neutralization, inhibition of acid forming bacteria, encapsulation of the pyrite or water diversion are believed to be the mechanisms facilitated by the alkaline material. Comparison of water quality, before and after injection of a grout composed of FBC ash and water indicated small increases in pH and decreases in acidity at discharge points. The concentrations of calcium and magnesium in water samples generally increased compared to background levels. The average concentration of trace elements (arsenic, cobalt, copper, nickel and zinc) was slightly elevated in the injection areas, but in down dip and discharge water samples were comparable to background levels. Over a four year period, the average acidity in the injected area decreased by approximately 30%, a value similar to another site where a mixture of class F fly ash and cement was injected. Although coal mine remediation is a beneficial environmental use of FBC products, its effectiveness may be related to the amount of FBCB used and the method of emplacement.

Trace element emissions from spontaneous combustion of gob piles in coal mines, Shanxi, China

Science.gov (United States)

Zhao, Y.; Zhang, Jiahua; Chou, C.-L.; Li, Y.; Wang, Z.; Ge, Y.; Zheng, C.

2008-01-01

The emissions of potentially hazardous trace elements from spontaneous combustion of gob piles from coal mining in Shanxi Province, China, have been studied. More than ninety samples of solid waste from gob piles in Shanxi were collected and the contents of twenty potentially hazardous trace elements (Be, F, V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Sn, Sb, Hg, Tl, Pb, Th, and U) in these samples were determined. Trace element contents in solid waste samples showed wide ranges. As compared with the upper continental crust, the solid waste samples are significantly enriched in Se (20x) and Tl (12x) and are moderately enriched in F, As, Mo, Sn, Sb, Hg, Th, and U (2-5x). The solid waste samples are depleted in V, Cr, Mn, Co, Ni, Cu, and Zn. The solid waste samples are enriched in F, V, Mn, Cr, Co, Ni, Cu, Zn, Sb, Th, and U as compared with the Shanxi coals. Most trace elements are higher in the clinker than in the unburnt solid waste except F, Sn, and Hg. Trace element abundances are related to the ash content and composition of the samples. The content of F is negatively correlated with the ash content, while Pb is positively correlated with the ash. The concentrations of As, Mn, Zn, and Cd are highly positively correlated with Fe2O3 in the solid waste. The As content increases with increasing sulfur content in the solid waste. The trace element emissions are calculated for mass balance. The emission factors of trace elements during the spontaneous combustion of the gobs are determined and the trace element concentrations in the flue gas from the spontaneous combustion of solid waste are calculated. More than a half of F, Se, Hg and Pb are released to the atmosphere during spontaneous combustion. Some trace element concentrations in flue gas are higher than the national emission standards. Thus, gob piles from coal mining pose a serious environmental problem. ?? 2007 Elsevier B.V. All rights reserved.

Chemical Pollution from Combustion of Modern Spacecraft Materials

Science.gov (United States)

Mudgett, Paul D.

2013-01-01

Fire is one of the most critical contingencies in spacecraft and any closed environment including submarines. Currently, NASA uses particle based technology to detect fires and hand-held combustion product monitors to track the clean-up and restoration of habitable cabin environment after the fire is extinguished. In the future, chemical detection could augment particle detection to eliminate frequent nuisance false alarms triggered by dust. In the interest of understanding combustion from both particulate and chemical generation, NASA Centers have been collaborating on combustion studies at White Sands Test Facility using modern spacecraft materials as fuels, and both old and new technology to measure the chemical and particulate products of combustion. The tests attempted to study smoldering pyrolysis at relatively low temperatures without ignition to flaming conditions. This paper will summarize the results of two 1-week long tests undertaken in 2012, focusing on the chemical products of combustion. The results confirm the key chemical products are carbon monoxide (CO), hydrogen cyanide (HCN), hydrogen fluoride (HF) and hydrogen chloride (HCl), whose concentrations depend on the particular material and test conditions. For example, modern aerospace wire insulation produces significant concentration of HF, which persists in the test chamber longer than anticipated. These compounds are the analytical targets identified for the development of new tunable diode laser based hand-held monitors, to replace the aging electrochemical sensor based devices currently in use on the International Space Station.

Early detection of spontaneous combustion of coal in underground coal mines with development of an ethylene enriching system

Energy Technology Data Exchange (ETDEWEB)

Xie, Jun; Xue, Sheng [CSIRO Earth Science and Resource Engineering, Kenmore (Australia); Cheng, Weimin; Wang, Gang [Shandong University of Science and Technology, Qingdao (China)

2011-01-01

Spontaneous combustion of coal (sponcom) is a major hazard in underground coal mining operations. If not detected early and managed properly, it can seriously affect mine safety and productivity. Gaseous products of sponcom, such as carbon monoxide, ethylene and hydrogen, are commonly used in coal mines as indicators to reflect the state of the sponcom. Studies have shown that ethylene starts to occur when sponcom reaches a characteristic temperature. However, due to dilution of ventilation air and detection limits of the instruments used for gas analysis at coal mines, ethylene cannot be detected until the sponcom has developed past its early stage, missing an optimum opportunity for mine operators to control the hazard. To address the issue, an ethylene-enriching system, based on its physical adsorption and desorption properties, has been developed to increase detection sensitivity of the ethylene concentration in mine air by about 10 times. This system has successfully been applied in a number of underground coal mines in China to detect sponcom at its early stage and enable mine operators to take effective control measures. This paper describes the ethylene enriching system and its application. (author)

Weathering behaviour of overburden-coal ash blending in relation to overburden management for acid mine drainage prevention in coal surface mine

International Nuclear Information System (INIS)

Gautama, R.S.; Kusuma, G.J.; Lestari, I.; Anggana, R.P.

2010-01-01

Potentially acid forming (PAF) materials are encapsulated with non-acid forming materials (NAF) in order to prevent acid mine drainage (AMD) in surface coal mines. NAF compaction techniques with fly and bottom ashes from coal-fired power plants are used in mines with limited amounts of NAF materials. This study investigated the weathering behaviour of blended overburden and coal combustion ash in laboratory conditions. Free draining column leach tests were conducted on different blending schemes. The weathering process was simulated by spraying the samples with de-ionized water once per day. The leachates were then analyzed using X-ray diffraction and fluorescence analyses in order to identify the mineral composition of the samples over a 14 week period. Results of the study indicated that the weathering process plays a significant role in controlling infiltration rates, and may increase the capability of capping materials to prevent infiltration into PAF materials. Fly- and bottom-ash additions improved the performance of the encapsulation materials. 3 refs., 4 tabs., 2 figs.

Mine shaft fire and smoke protection systems - an update on hardware development and in-mine testing

International Nuclear Information System (INIS)

Johnson, G.A.

1982-01-01

In 1976, The Bureau of Mines developed a prototype system to sense and extinguish fires in shafts and shaft stations in underground metal and nonmetal mines. Subsequent work modified this technology to include fueling areas, spontaneous combustion zones and coal mines. This paper updates IC-8783 ''In-mine Fire Tests of Mine Shaft Fire and Smoke Protection Systems'', which was published in 1978 and summarized the design and in-mine, actual fire testing of the first prototype mine shaft fire and smoke protection system. This paper also updates related work from IC-8775 ''Spontaneous Oxidation and Combustion of Sulfide Ores in Underground Mines, (also published in 1978) and IC-8808 ''In-mine Evaluation of Underground Fire and Smoke Detectors'', (published in early 1979)

Applying Rock Engineering Systems (RES approach to Evaluate and Classify the Coal Spontaneous Combustion Potential in Eastern Alborz Coal Mines

Directory of Open Access Journals (Sweden)

Amir Saffari

2013-12-01

Full Text Available Subject analysis of the potential of spontaneous combustion in coal layers with analytical and numerical methods has been always considered as a difficult task because of the complexity of the coal behavior and the number of factors influencing it. Empirical methods, due to accounting for certain and specific factors, have not accuracy and efficiency for all positions. The Rock Engineering Systems (RES approach as a systematic method for analyzing and classifying is proposed in engineering projects. The present study is concerned with employing the RES approach to categorize coal spontaneous combustion in coal regions. Using this approach, the interaction of parameters affecting each other in an equal scale on the coal spontaneous combustion was evaluated. The Intrinsic, geological and mining characteristics of coal seams were studied in order to identifying important parameters. Then, the main stages of implementation of the RES method i.e. interaction matrix formation, coding matrix and forming a list category were performed. Later, an index of Coal Spontaneous Combustion Potential (CSCPi was determined to format the mathematical equation. Then, the obtained data related to the intrinsic, geological and mining, and special index were calculated for each layer in the case study (Pashkalat coal region, Iran. So, the study offers a perfect and comprehensive classification of the layers. Finally, by using the event of spontaneous combustion occurred in Pashkalat coal region, an initial validation for this systematic approach in the study area was conducted, which suggested relatively good concordance in Pashkalat coal region.

Effect of density on forward and upward smoldering combustion of cellulosic material

Science.gov (United States)

Veronica, Sherly; Putri, R. H.; Fitriani, F.; Ramadhan, M. L.; Riki, M.; Reynaldo, S.; Imran, F. A.; Nugroho, Yulianto S.

2017-03-01

Smoldering is a slow, flameless and the most persistent type of combustion. Wildland fire or ground fire is an example of smoldering combustion which has become one of the most important issue in Indonesia and no effective solution has been found to solve this phenomenon yet. The organic materials contained in peatland can potentially become a flammable fuel with the presence of a trigger for wildland fire. In this experimental work tobacco material was used to study smoldering phenomenon. The relation between material density with temperature distribution and mass loss rate are conducted in the experiment. The transmissivity of the smoke produced by the smoldering combustion will also be analyzed. Experiments are carried out for the material density ranging from 0.12 - 0.2 g/cm3. The result showed that smoldering combustion are affected by density, due to the allowance of airflow and heat propagation. The result showed that material bed with the lowest density of 0.12 g/cm3 has the slowest smoldering velocity and mass loss rate while the material bed with the highest density of 0.2 g/cm3 has the fastest smoldering velocity and mass loss rate. The smoke took a longer period time to reach the bed surface at higher bed density.

Application of the coal-mining waste in building ceramics production

Directory of Open Access Journals (Sweden)

Vaysman Yakov Iosifovich

Full Text Available In the process of construction ceramics production a substantial quantity of non-renewable natural resources - clays - are used. One of the ways of science development in building materials production is investigation of the possibility of regular materials production using technogenic waste. Application of coal-mining waste (technogenic raw material in charge composition for production of ceramic products provides rational use of fuel, contributes to implementation of resource saving technologies on construction materials production enterprises. Though science development on revealing new raw material sources should be conducted with account for safety, reliability, technical, ecological and economical sides of the problem, which is especially current. The article deals with the problem of coal-mining waste usage in building ceramics production instead of fresh primary component (clay, fluxes, thinning agents and combustible additives. The interdependence between the density and shrinkage of the ceramic products and the amount and quality of coal-mining waste in its composition was established. The optimal proportion of coal-mining waste and clay in building ceramics production was estimated.

Injection of alkaline ashes into underground coal mines for acid mine drainage abatement

International Nuclear Information System (INIS)

Aljoe, W.W.

1996-01-01

The injection of alkaline coal combustion waste products into abandoned underground coal mines for acid mine drainage (AMD) abatement has obvious conceptual appeal. This paper summarizes the findings of the baseline hydrogeologic and water quality evaluations at two sites--one in West Virginia and one in Maryland--where field demonstrations of the technique are being pursued in cooperative efforts among State and Federal agencies and/or private companies. The West Virginia site produces severe AMD from three to seven AMD sources that are spaced over about a 1.2 km stretch of the down-dip side of the mine workings. By completely filling the most problematic portion of the mine workings with coal combustion ashes, the State expects that the costs and problems associated with AMD treatment will be greatly reduced. At the Maryland site, it is expected that the AMD from a relatively small target mine will be eliminated completely by filling the entire mine void with a grout composed of a mixture of fly ash, fluidized-bed combustion ash, and flue gas desulfurization sludge. This project will also demonstrate the potential cost-effectiveness of the technique at other sites, both for the purpose of AMD remediation and control of land subsidence

Synthesis of functional materials in combustion reactions

Science.gov (United States)

Zhuravlev, V. D.; Bamburov, V. G.; Ermakova, L. V.; Lobachevskaya, N. I.

2015-12-01

The conditions for obtaining oxide compounds in combustion reactions of nitrates of metals with organic chelating-reducing agents such as amino acids, urea, and polyvinyl alcohol are reviewed. Changing the nature of internal fuels and the reducing agent-to-oxidizing agent ratio makes possible to modify the thermal regime of the process, fractal dimensionality, morphology, and dispersion of synthesized functional materials. This method can be used to synthesize simple and complex oxides, composites, and metal powders, as well as ceramics and coatings. The possibilities of synthesis in combustion reactions are illustrated by examples of αand γ-Al2O3, YSZ composites, uranium oxides, nickel powder, NiO and NiO: YSZ composite, TiO2, and manganites, cobaltites, and aluminates of rare earth elements.

Naturally occurring radioactive materials at New South Wales mines

International Nuclear Information System (INIS)

McLaughlin, Robert

2013-01-01

Until recently mines in New South Wales have been largely exempt from the provisions of the Radiation Control Act with respect to radioactive ore being mined and processed. Legislative changes and the national harmonisation efforts for mine safety regulation have drawn attention to the emerging issue of naturally occurring radioactive material (NORM). While mine operators are already obliged under their duty of care to manage this hazard, specific control measures are increasingly expected by the community and regulators. This applies throughout the whole mine life cycle from exploration right through to rehabilitation.

System catalytic neutralization control of combustion engines waste gases in mining technologies

Science.gov (United States)

Korshunov, G. I.; Solnitsev, R. I.

2017-10-01

The paper presents the problems solution of the atmospheric air pollution with the exhaust gases of the internal combustion engines, used in mining technologies. Such engines are used in excavators, bulldozers, dump trucks, diesel locomotives in loading and unloading processes and during transportation of minerals. NOx, CO, CH emissions as the waste gases occur during engine operation, the concentration of which must be reduced to the standard limits. The various methods and means are used for the problem solution, one of which is neutralization based on platinum catalysts. A mathematical model of a controlled catalytic neutralization system is proposed. The simulation results confirm the increase in efficiency at start-up and low engine load and the increase in the catalyst lifetime.

Combustible structural composites and methods of forming combustible structural composites

Science.gov (United States)

Daniels, Michael A.; Heaps, Ronald J.; Steffler, Eric D.; Swank, W. David

2013-04-02

Combustible structural composites and methods of forming same are disclosed. In an embodiment, a combustible structural composite includes combustible material comprising a fuel metal and a metal oxide. The fuel metal is present in the combustible material at a weight ratio from 1:9 to 1:1 of the fuel metal to the metal oxide. The fuel metal and the metal oxide are capable of exothermically reacting upon application of energy at or above a threshold value to support self-sustaining combustion of the combustible material within the combustible structural composite. Structural-reinforcing fibers are present in the composite at a weight ratio from 1:20 to 10:1 of the structural-reinforcing fibers to the combustible material. Other embodiments and aspects are disclosed.

Thermal conditions for stopping pyrolysis of forest combustible material and applications to firefighting

Directory of Open Access Journals (Sweden)

Zhdanova Alena O.

2017-01-01

Full Text Available Five models describing heat transfer during evaporation of the water sprayed over the forest to stop fires and to cool down the pyrolysis of the bio- top layer are established and investigated by a parametric approach. It aims to improve the understanding of the behaviour and the properties of the forest combustible material. A mathematical description of forest combustible material surfaces (needles of pine and fir-tree, leaves of birch is established. The characteristic time, td, to cool down the forest combustible material layer below the temperature of the onset of the pyrolysis is the important parameter investigated in the present work. The effective conditions were determined allowing to reach the shortest td and the lowest consumption of e. g. water to be dropped.

Fluidized bed combustion bottom ash: A better and alternative geo-material resource for construction.

Science.gov (United States)

Mandal, A K; Paramkusam, Bala Ramudu; Sinha, O P

2018-04-01

Though the majority of research on fly ash has proved its worth as a construction material, the utility of bottom ash is yet questionable due to its generation during the pulverized combustion process. The bottom ash produced during the fluidized bed combustion (FBC) process is attracting more attention due to the novelty of coal combustion technology. But, to establish its suitability as construction material, it is necessary to characterize it thoroughly with respect to the geotechnical as well as mineralogical points of view. For fulfilling these objectives, the present study mainly aims at characterizing the FBC bottom ash and its comparison with pulverized coal combustion (PCC) bottom ash, collected from the same origin of coal. Suitability of FBC bottom ash as a dike filter material in contrast to PCC bottom ash in replacing traditional filter material such as sand was also studied. The suitability criteria for utilization of both bottom ash and river sand as filter material on pond ash as a base material were evaluated, and both river sand and FBC bottom ash were found to be satisfactory. The study shows that FBC bottom ash is a better geo-material than PCC bottom ash, and it could be highly recommended as an alternative suitable filter material for constructing ash dikes in place of conventional sand.

Center for commercial applications of combustion in space (CCACS); A partnership for space commercialization at the Colorado School of Mines

Science.gov (United States)

Schowengerdt, F. D.; Kee, Bob; Linne, Mark; McKinnon, Tom; Moore, John; Parker, Terry; Readey, Dennis; Tilton, John E.; Helble, Joe

1997-01-01

The Center for Commercial Applications of Combustion in Space (CCACS) is a NASA/Industry/University consortium at the Colorado School of Mines (CSM). The mission of the Center is to assist industry in developing commercial products by conducting combustion research which takes advantage of the unique properties of space. By conducting experiments in near-zero gravity, convection and buoyancy effects can be minimized and new fundamental design-related knowledge can be gained which can be used to improve combustion-related products and processes on earth. Companies, government laboratories and universities most actively involved in CCACS at present include ABB Combustion, ADA Technologies, Advanced Refractory Technologies, Golden Technologies, Lockheed-Martin, Southwest Sciences, Space Systems/Lora, NASA-Lewis, JPL, the Baylor Dental School and the University of Connecticut. Products and processes of interest to the Center participants include industrial process combustors; catalytic combustion; Halon replacements; ceramic powders, whiskers and fibers; metal-matrix composites; NiTi for bone replacement; diamond coatings for oil-well drill bits; zeolites; imaging sensor arrays and other instrumentation for flame and particulate diagnostics. The center also assists member companies in marketing the resulting products and processes.

A cost-benefit analysis of landfill mining and material recycling in China

International Nuclear Information System (INIS)

Zhou, Chuanbin; Gong, Zhe; Hu, Junsong; Cao, Aixin; Liang, Hanwen

2015-01-01

Highlights: • Assessing the economic feasibility of landfill mining. • We applied a cost-benefit analysis model for landfill mining. • Four material cycling and energy recovery scenarios were designed. • We used net present value to evaluate the cost-benefit efficiency. - Abstract: Landfill mining is an environmentally-friendly technology that combines the concepts of material recycling and sustainable waste management, and it has received a great deal of worldwide attention because of its significant environmental and economic potential in material recycling, energy recovery, land reclamation and pollution prevention. This work applied a cost-benefit analysis model for assessing the economic feasibility, which is important for promoting landfill mining. The model includes eight indicators of costs and nine indicators of benefits. Four landfill mining scenarios were designed and analyzed based on field data. The economic feasibility of landfill mining was then evaluated by the indicator of net present value (NPV). According to our case study of a typical old landfill mining project in China (Yingchun landfill), rental of excavation and hauling equipment, waste processing and material transportation were the top three costs of landfill mining, accounting for 88.2% of the total cost, and the average cost per unit of stored waste was 12.7 USD ton −1 . The top three benefits of landfill mining were electricity generation by incineration, land reclamation and recycling soil-like materials. The NPV analysis of the four different scenarios indicated that the Yingchun landfill mining project could obtain a net positive benefit varying from 1.92 million USD to 16.63 million USD. However, the NPV was sensitive to the mode of land reuse, the availability of energy recovery facilities and the possibility of obtaining financial support by avoiding post-closure care

A cost-benefit analysis of landfill mining and material recycling in China

Energy Technology Data Exchange (ETDEWEB)

Zhou, Chuanbin, E-mail: cbzhou@rcees.ac.cn; Gong, Zhe; Hu, Junsong; Cao, Aixin; Liang, Hanwen

2015-01-15

Highlights: • Assessing the economic feasibility of landfill mining. • We applied a cost-benefit analysis model for landfill mining. • Four material cycling and energy recovery scenarios were designed. • We used net present value to evaluate the cost-benefit efficiency. - Abstract: Landfill mining is an environmentally-friendly technology that combines the concepts of material recycling and sustainable waste management, and it has received a great deal of worldwide attention because of its significant environmental and economic potential in material recycling, energy recovery, land reclamation and pollution prevention. This work applied a cost-benefit analysis model for assessing the economic feasibility, which is important for promoting landfill mining. The model includes eight indicators of costs and nine indicators of benefits. Four landfill mining scenarios were designed and analyzed based on field data. The economic feasibility of landfill mining was then evaluated by the indicator of net present value (NPV). According to our case study of a typical old landfill mining project in China (Yingchun landfill), rental of excavation and hauling equipment, waste processing and material transportation were the top three costs of landfill mining, accounting for 88.2% of the total cost, and the average cost per unit of stored waste was 12.7 USD ton{sup −1}. The top three benefits of landfill mining were electricity generation by incineration, land reclamation and recycling soil-like materials. The NPV analysis of the four different scenarios indicated that the Yingchun landfill mining project could obtain a net positive benefit varying from 1.92 million USD to 16.63 million USD. However, the NPV was sensitive to the mode of land reuse, the availability of energy recovery facilities and the possibility of obtaining financial support by avoiding post-closure care.

30 CFR 56.7807 - Flushing the combustion chamber.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Flushing the combustion chamber. 56.7807 Section 56.7807 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Rotary Jet Piercing Rotary Jet Piercing § 56.7807 Flushing the combustion chamber. The combustion chamber...

Role of coal combustion products in sustainable construction materials

Energy Technology Data Exchange (ETDEWEB)

Naik, T.R.; Siddique, R.; Vaniker, S. [University of Wisconsin-Milwaukee, Milwaukee, WI (USA). UWM Center for Products Utilization, College of Engineering and Applied Science

2003-07-01

The paper describes various coal combustion products, CCPs produced in the process of power generation. These include fly ash, bottom ash, boiler slag and flue gas desulfurization products. Typical test protocol used for testing, analysis and evaluation of CCPs, as well as the current best recycling use options for these materials are discussed. Materials, productions, properties, and potential applications in the manufacture of emerging materials for sustainable construction, as well as environmental impact are also briefly discussed. 47 refs., 16 figs., 8 tabs.

THE REACTION TO FIRE TEST FOR FIRE RETARDANT AND FOR COMBUSTIBLE MATERIAL

Directory of Open Access Journals (Sweden)

Adelaida FANFAROVÁ

2016-12-01

Full Text Available Currently the natural materials become popular building material for houses, buildings and recreational property. The risk of fires in residential timber construction or eco houses cannot be completely ruled out, therefore there is a need for proper and correct implementing preventive measures and application of all available solutions, which may reduce the risk of fire as far as possible, to slow down the combustion process, to protect the life of people, animals and also the building itself until arrival members of the Fire and Rescue Services. Fireproofing of combustible materials is a specific area of fire protection. For scientific research as well as for real-life practice, not only their structural and physical properties, but also fire-technical characteristics are really important. The present researchers mostly focus on fire-retardant treatment of wood that is why the authors of this contribution focused on a different combustible material. This research article presents the experimental testing and examination of the reaction to fire test of the selected thermal insulation of hemp fiber that was impregnated by the selected fire retardant in laboratory conditions.

Technique for in-place welding of aluminum backed up by a combustible material

Science.gov (United States)

Spagnuolo, A. C.

1971-01-01

Welding external aluminum jacket, tightly wrapped around inner layer of wood composition fiberboard, in oxygen free environment prevents combustion and subsequent damage to underlying fiberboard. Technique also applies to metal cutting in similar assemblies without disassembly to remove combustible materials from welding heat proximity.

Combustion synthesis of advanced materials. [using in-situ infiltration technique

Science.gov (United States)

Moore, J. J.; Feng, H. J.; Perkins, N.; Readey, D. W.

1992-01-01

The combustion synthesis of ceramic-metal composites using an in-situ liquid infiltration technique is described. The effect of varying the reactants and their stoichiometry to provide a range of reactant and product species i.e. solids, liquids and gases, with varying physical properties e.g. thermal conductivity, on the microstructure and morphology of synthesized products is also described. Alternatively, conducting the combustion synthesis reaction in a reactive gas environment is also discussed, in which advantages can be gained from the synergistic effects of combustion synthesis and vapor phase transport. In each case, the effect of the presence or absence of gravity (density) driven fluid flow and vapor transport is discussed as is the potential for producing new and perhaps unique materials by conducting these SHS reactions under microgravity conditions.

An Experimental Evaluation of the Weathering Effects on Mine Shaft Lining Materials

Directory of Open Access Journals (Sweden)

W. Yang

2017-01-01

Full Text Available Many shaft collapses are related to the deterioration and failure of the masonry shaft lining materials. In modern mine shaft, concrete is widely used to provide support. To analyse shafts stability, the properties of the lining need to be well defined. The behaviour of masonry and concrete can be considerably affected by long-term exposure to harsh mine water. This paper presents a study which focuses on the weathering effects of mine water on lining materials (brick, mortar, and concrete. To reproduce the weathering process, samples were placed into solutions of potable water, artificial mine water, and a more aggressive mine-water solution for just less than one year. Four phases of laboratory tests were conducted throughout the time period to assess the degradation of mechanical properties of the lining materials. Particular attention is given to the degradation of material strength and stiffness. Results indicate that the harsh acidic mine water has pronounced detrimental effects on the strength and stiffness of mortar. The weathering process is shown to have the most significant effect on the stiffness of concrete and mortar. It is also shown that the use of mass loss as an index for evaluation of mechanical properties may not be appropriate.

Safe Handling and Use of Flammable and Combustible Materials. Module SH-30. Safety and Health.

Science.gov (United States)

Center for Occupational Research and Development, Inc., Waco, TX.

This student module on safe handling and use of flammable and combustible materials is one of 50 modules concerned with job safety and health. This module introduces the student to the hazards of flammable and combustible materials and the measures necessary to control those hazards. Following the introduction, 14 objectives (each keyed to a page…

Mining of Radioactive Raw Materials as an Origin of the Nuclear Fuel Chain

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Bedřich Michálek

2007-01-01

Full Text Available The mining of radioactive raw materials may be considered as an origin of the nuclear fuel chain and thus determines the amount of radioactive wastes which have to be stored safety in the final stage of the fuel chain. The paper informs about the existing trends in mining of radioactive raw materials in the world, provides an overview of development in mining in the Czech Republic and of possibilities of future exploiting some uranium deposits. It points a possibility of non-traditional obtaining uranium from mine waters from underground uranium mines closed and flooded earlier.

Long-term behaviors of phosphate-based rapid repairing material for concrete shafts in coal mines.

Science.gov (United States)

Lei, Feng; Zhen-Ya, Zhang; Xiao-Dong, Wen; Chao, Xin; Dong-Yuan, Hu

2018-04-01

Concrete structures in shaft linings are apt to deteriorate prematurely and therefore prompt restoration is required. In considering this, desulphurization fly ash and machine-made tuff sand are employed to fabricate a phosphate-based rapid repairing material. The long-term efficiency of the material is evaluated based on combined factors, so drying shrinkage, interfacial bonding strength, corrosion resistance, and combustibility of the specimens are tested and researched in this paper. Experimental results showed that, under a dry circumstance, the material goes through a minor expansion at an early stage. It goes into a stage of rapid contraction after one day and a stable contraction after seven days. After 28 days, the total deformation is 67 micro-strains. On the other hand, the fabricated material manifests an excellent mechanical property. The one hour bending strength and compressive strength were 9.2 MPa and 32.6 MPa, respectively. A long-term mine water flushing simulation demonstrates that only 10% bending strength is lost and the corrosion resistance coefficient stays above 0.8, so a very good corrosion resistance is thus achieved. What is more, this repairing material retains its stability even at a high temperature of 1000°C, revealing its good thermo-stability. All these prominent properties make it a good prospective material for real restoration applications.

Suitability of dredged material for reclamation of surface-mined land. Final report

Energy Technology Data Exchange (ETDEWEB)

Harrison, W.; Van Luik, A.

1979-12-01

Eroding ridges of acidic coal-mine spoil in La Salle County, Illinois, were leveled to form a gently-sloped raised plateau. Four test plots were constructed: a control plot and three treatment plots that received a 0.9-m-thick cover of dredged material obtained from the Metropolitan Sanitary District of Greater Chicago. Two treatment plots received lime applications and all plots were seeded with a mixture of grasses. Pressure-vacuum soil water samplers were installed, in duplicate, at two levels in the control plot and at three levels in each treatment plot. The three levels in the treatment plots coincided with dredged material, the dredged-material mine-spoil interface, and the underlying mine spoil. Surface water, soil water, and groundwater were monitored for 29 water-quality parameters for one year. Rainfall, air temperature, runoff, and water-level elevation data were collected also. Detailed analysis of the data indicates that the dredged material used in this study does not adversely affect water quality; it supports abundant plant growth, lessens groundwater contamination, and controls acid runoff. The dredged material is judged to be a suitable material for use in reclamation of surface-mined land.

Filter materials for metal removal from mine drainage--a review.

Science.gov (United States)

Westholm, Lena Johansson; Repo, Eveliina; Sillanpää, Mika

2014-01-01

A large number of filter materials, organic and inorganic, for removal of heavy metals in mine drainage have been reviewed. Bark, chitin, chitosan, commercial ion exchangers, dairy manure compost, lignite, peat, rice husks, vegetal compost, and yeast are examples of organic materials, while bio-carbons, calcareous shale, dolomite, fly ash, limestone, olivine, steel slag materials and zeolites are examples of inorganic materials. The majority of these filter materials have been investigated in laboratory studies, based on various experimental set-ups (batch and/or column tests) and different conditions. A few materials, for instance steel slag materials, have also been subjects to field investigations under real-life conditions. The results from these investigations show that steel slag materials have the potential to remove heavy metals under different conditions. Ion exchange has been suggested as the major metal removal mechanisms not only for steel slag but also for lignite. Other suggested removal mechanisms have also been identified. Adsorption has been suggested important for activated carbon, precipitation for chitosan and sulphate reduction for olivine. General findings indicate that the results with regard to metal removal vary due to experimental set ups, composition of mine drainage and properties of filter materials and the discrepancies between studies renders normalisation of data difficult. However, the literature reveals that Fe, Zn, Pb, Hg and Al are removed to a large extent. Further investigations, especially under real-life conditions, are however necessary in order to find suitable filter materials for treatment of mine drainage.

Forming artificial soils from waste materials for mine site rehabilitation

Science.gov (United States)

Yellishetty, Mohan; Wong, Vanessa; Taylor, Michael; Li, Johnson

2014-05-01

Surface mining activities often produce large volumes of solid wastes which invariably requires the removal of significant quantities of waste rock (overburden). As mines expand, larger volumes of waste rock need to be moved which also require extensive areas for their safe disposal and containment. The erosion of these dumps may result in landform instability, which in turn may result in exposure of contaminants such as trace metals, elevated sediment delivery in adjacent waterways, and the subsequent degradation of downstream water quality. The management of solid waste materials from industrial operations is also a key component for a sustainable economy. For example, in addition to overburden, coal mines produce large amounts of waste in the form of fly ash while sewage treatment plants require disposal of large amounts of compost. Similarly, paper mills produce large volumes of alkaline rejected wood chip waste which is usually disposed of in landfill. These materials, therefore, presents a challenge in their use, and re-use in the rehabilitation of mine sites and provides a number of opportunities for innovative waste disposal. The combination of solid wastes sourced from mines, which are frequently nutrient poor and acidic, with nutrient-rich composted material produced from sewage treatment and alkaline wood chip waste has the potential to lead to a soil suitable for mine rehabilitation and successful seed germination and plant growth. This paper presents findings from two pilot projects which investigated the potential of artificial soils to support plant growth for mine site rehabilitation. We found that pH increased in all the artificial soil mixtures and were able to support plant establishment. Plant growth was greatest in those soils with the greatest proportion of compost due to the higher nutrient content. These pot trials suggest that the use of different waste streams to form an artificial soil can potentially be used in mine site rehabilitation

Occupational radiation protection in the mining and processing of raw materials

International Nuclear Information System (INIS)

2004-01-01

The mining and processing of uranium ore, thorium ore and other raw materials containing natural radionuclides are carried out in a number of Member States. There is a clear need to update the guidance on the radiation protection of the workers involved, and this Safety Guide provides such updated guidance. Material from two previous publications has been adapted for inclusion in this Safety Guide. These previous publications - Radiation Monitoring in the Mining and Milling of Radioactive Ores (Safety Series No. 95) and Radiation Protection of Workers in the Mining and Milling of Radioactive Ores (Safety Series No. 26, hereby superseded) - dealt principally with activities involving uranium ore and thorium ore. Activity concentrations of naturally occurring radionuclides are elevated in other mineral deposits such as heavy mineral sands and phosphate rock. Furthermore, high radon levels may be found in mines, irrespective of the activity concentrations of natural radionuclides in the raw material being extracted. In recognition of these circumstances, this Safety Guide is intended to apply also to the mining and processing of any raw material for which radiation protection measures need to be considered. The IAEA Safety Fundamentals publication on Radiation Protection and the Safety of Radiation Sources presents the principles, concepts and objectives of protection and safety. Safety requirements based on the objectives and principles specified in these Safety Fundamentals, including requirements for the protection of workers exposed to ionizing radiation, are established in the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (the Basic Safety Standards or Bss). These requirements also reflect the recommendations of the International Commission on Radiological Protection (ICRP). Safety Guides provide recommendations on the basis of international experience on the fulfilment of the requirements

Internet of Things Based Combustible Ice Safety Monitoring System Framework

Science.gov (United States)

Sun, Enji

2017-05-01

As the development of human society, more energy is requires to meet the need of human daily lives. New energies play a significant role in solving the problems of serious environmental pollution and resources exhaustion in the present world. Combustible ice is essentially frozen natural gas, which can literally be lit on fire bringing a whole new meaning to fire and ice with less pollutant. This paper analysed the advantages and risks on the uses of combustible ice. By compare to other kinds of alternative energies, the advantages of the uses of combustible ice were concluded. The combustible ice basic physical characters and safety risks were analysed. The developments troubles and key utilizations of combustible ice were predicted in the end. A real-time safety monitoring system framework based on the internet of things (IOT) was built to be applied in the future mining, which provide a brand new way to monitoring the combustible ice mining safety.

Fire safety requirements for electric cables and lines in deep coal mines

Energy Technology Data Exchange (ETDEWEB)

Herms, C D

1982-01-07

In the case of a mine fire, an additional hazard from combustible cable material is likely to arise only in those few areas of the mine where special circumstances might help the fire to spread along the cables. It is more important to preserve the functional integrity of cables in the outbye roads which are affected by fire gases then at the actual seat of the fire. Mine cables with better fire-resistant properties should be made from materials which do not propagate fires, do not release burning drops, develop the lowest possible fume density and/or will permanently resist gas temperatures of 200 to 300/sup 0/C. Fire test specifications should be defined for such special cables, based on corresponding draft VDE directives. In proposing these measures the proviso is made then improvement in safety can be clearly demonstrated.

Validation of new ceramic materials from tungsten mining wastes. Mechanical properties

International Nuclear Information System (INIS)

Duran Suarez, J. A.; Montoya Herrera, J.; Silva, A. P.; Peralbo Cano, R.; Castro-Gomes, J. P.

2014-01-01

New ceramic materials obtained from tungsten mining wastes, from region of Beira Interior in Portugal, with no commercial use, responsible for landscape and environmental problems are presented. These preshaped new ceramic products, prepared in a wide thermal range (800 degree centigrade to 1300 degree centigrade) was evaluated by mechanical test, but also was characterized the starting raw materials: tungsten wastes mining and industrial kaolin. Results, which also include a mineralogical characterization of ceramic products and morphologic evaluation of neoformed by scanning electron microscopy, show firstly, the feasibility of converting a large number of these wastes in marketable ceramics. Thanks to the experimentation carried out, the ability to generate ceramic materials is emphasized, without the presence of mineral clay, due to the particular composition of these waste of mining with content of acid, neutral and basic oxides. (Author)

Use of Thermoanalytic Methods in the Evaluation of Combusted Materials

Directory of Open Access Journals (Sweden)

František Krepelka

2006-12-01

Full Text Available The paper describes possibilities of using thermoanalytic methods for the evaluation and comparison of materials designed for a direct combustion. Differential thermal analysis (DTA and thermogravimetric analysis (TGA were both used in the evaluation. The paper includes a description of methods of data processing from analyses for the purposes of comparison of used materials regarding their heating values. The following materials were analysed in the experiments: wooden coal of objectional grain size, fly ash from heating plant exhaust funnels, dendromass waste: spruce sawdust, micro-briquettes of spruce sawdust and fly-ash combined.

Cermet materials prepared by combustion synthesis and metal infiltration

Science.gov (United States)

Holt, Joseph B.; Dunmead, Stephen D.; Halverson, Danny C.; Landingham, Richard L.

1991-01-01

Ceramic-metal composites (cermets) are made by a combination of self-propagating high temperature combustion synthesis and molten metal infiltration. Solid-gas, solid-solid and solid-liquid reactions of a powder compact produce a porous ceramic body which is infiltrated by molten metal to produce a composite body of higher density. AlN-Al and many other materials can be produced.

Material flow-based economic assessment of landfill mining processes.

Science.gov (United States)

Kieckhäfer, Karsten; Breitenstein, Anna; Spengler, Thomas S

2017-02-01

This paper provides an economic assessment of alternative processes for landfill mining compared to landfill aftercare with the goal of assisting landfill operators with the decision to choose between the two alternatives. A material flow-based assessment approach is developed and applied to a landfill in Germany. In addition to landfill aftercare, six alternative landfill mining processes are considered. These range from simple approaches where most of the material is incinerated or landfilled again to sophisticated technology combinations that allow for recovering highly differentiated products such as metals, plastics, glass, recycling sand, and gravel. For the alternatives, the net present value of all relevant cash flows associated with plant installation and operation, supply, recycling, and disposal of material flows, recovery of land and landfill airspace, as well as landfill closure and aftercare is computed with an extensive sensitivity analyses. The economic performance of landfill mining processes is found to be significantly influenced by the prices of thermal treatment (waste incineration as well as refuse-derived fuels incineration plant) and recovered land or airspace. The results indicate that the simple process alternatives have the highest economic potential, which contradicts the aim of recovering most of the resources. Copyright © 2016 Elsevier Ltd. All rights reserved.

12th US/North American mine ventilation symposium

Energy Technology Data Exchange (ETDEWEB)

Wallace, K.G. (ed.)

2008-07-01

Topics covered include: ventilation planning for metal/non-metal and coal mines, spontaneous combustion, heat and humidity, miner's act and mine seals, numerical modeling, coal mine methane, mine dust, tunnel ventilation, mine fans, diesel emissions control, mine fires, and general ventilation design and monitoring. The papers, talks and presentations are available for free download from the www.smenet.org site; printed copies of the proceedings are no longer available.

Mechanochemical modification of the composition and structure of plant raw materials to control the combustion of alternative fuel

Directory of Open Access Journals (Sweden)

Bychkov Aleksey

2017-01-01

Full Text Available The possibilities of mechanochemistry in processing of renewable lignocellulose raw material into solid kinds of biofuel are demonstrated in this work. A review of lignocellulose raw materials promising for our country is presented. These raw materials include wastes from agriculture and forestry, and the biomass of rapidly growing plants. The physicochemical properties of lignocellulose materials with different delignification degrees were modeled with the help of the artificial mixtures of plant raw material with purified cellulose and lignin. The data illustrating the effect of disperse state and lignin content on the reactivity of the material in subsequent combustion are presented. The tests at the combustion bench with the thermal power up to 5 MW allowed determining the optimal combustion parameters for the obtained biofuel in the autothermal mode.

3D modeling of surface quarries and deposits of mined materials and the monitoring of slopes

Directory of Open Access Journals (Sweden)

Ivan Maňas

2007-06-01

Full Text Available The application of computer technology by simulating opencast mining and deposits of raw materials. The mathematic principles of three-dimensional probabilistic models of raw materials deposits and a familiarization with the user interface software GEOLOGICKY MODEL. The principles of the simulation of opencast mines, generation intersections with models of raw materials deposits, computation of mining materials with the quality scaling,and the design of advanced mining with the software BANSKY MODEL.The monitoring the potential of dynamic movements’ of unstable slopes with the automatic total station and a following interpretation in general time intervals by means of the software MONITORING.

Working group report: methane emissions from fuel combustion and industrial processes

International Nuclear Information System (INIS)

Berdowski, J.J.M.; Beck, L.; Piccot, S.; Olivier, J.G.J.; Veldt, C.

1993-01-01

This paper lists the source categories which are currently recognised as minor sources of methane. These fall into five broad groups: stationary fuel combustion (residential combustion of fuels, solid waste incineration at home sites, on-site agricultural waste burning, industrial and utility combustion of coal, wood, oil and gas, commercial and industrial waste incineration); mobile fuel combustion; non-combustion industrial processes (primary metals production, chemical manufacturing processes, petroleum refining, commercial charcoal manufacturing waste treatments); minor energy production sources (storage and distribution of automotive fuels, geothermal energy production; peat mining operations, oil shale mining operations); and miscellaneous sources. The paper also presents a preliminary estimate of global methane emissions from these minor sources and the results of the working group's discussion on recommendations for the IPCC/OECD methodology and specific research needs. A list of control options for emissions from minor sources is provided. 2 tabs

Utilization of coal ash/coal combustion products for mine reclamation

International Nuclear Information System (INIS)

Dolence, R.C.; Giovannitti, E.

1997-01-01

Society's demand for an inexpensive fuel, combined with ignorance of the long term impacts, has left numerous scars on the Pennsylvania landscape. There are over 250,000 acres of abandoned surface mines with dangerous highwalls and water filled pits. About 2,400 miles of streams do not meet water quality standards because of drainage from abandoned mines. There are uncounted households without an adequate water supply due to past mining practices. Mine fires and mine subsidence plague many Pennsylvania communities. The estimated cost to reclaim these past scars is over $15 billion. The beneficial use of coal ash in Pennsylvania for mine reclamation and mine drainage pollution abatement projects increased during the past ten years. The increase is primarily due to procedural and regulatory changes by the Department of Environmental Protection (DEP). Prior to 1986, DEP required a mining permit and a separate waste disposal permit for the use of coal ash in backfilling and reclaiming a surface mine site. In order to eliminate the dual permitting requirements and promote mine reclamation, procedural changes now allow a single permit which authorize both mining and the use of coal ash in reclaiming active and abandoned pits. The actual ash placement, however, must be conducted in accordance with the technical specifications in the solid waste regulations

Considerations on valorization of biomass origin materials in co-combustion with coal in fluidized beds

Energy Technology Data Exchange (ETDEWEB)

I. Gulyurtlu; P. Abelha; H. Lopes; A. Crujeira; I. Cabrita [DEECA-INETI, Lisbon (Portugal)

2007-07-01

Co-combustion of biomass materials with coal is currently gaining increasing importance, in order to meet the targets on greenhouse gas emissions, defined in the Kyoto protocol. Co-firing of coal with biomass materials could be the short-term solution in reducing CO{sub 2} emissions from power stations. The work undertaken studied co-firing of meat and bone meal (MBM), olive cake and straw pellets with bituminous coals from Colombia (CC) and Poland (PC), which are commonly used in European power stations. The co-combustion studies were carried out on the pilot fluidized bed installation of INETI. Gaseous pollutants and solid concentration in flue gases and ashes from different locations were monitored. Results obtained indicate that the co-feeding of biomass materials did not present any problem and ensured stable combustion conditions and high efficiency. However, for temperatures above 800{sup o}C, bed agglomeration could be observed for all biomass species studied. Most of the combustion of biomass material, contrary to that of coal, was observed to take place in the riser where the temperature was as high as 150-250{sup o}C above that of the bed. SO{sub 2} and NOx levels were found to be lower. The emissions of dioxins could be considerable with fuels with high Cl as is the case with straw. However, mixing of fuels with high S content could lead to a strong reduction in dioxin emissions. Ashes produced from biomass combustion may be considered for further reutilization or landfilling. Other options depend on their characteristics, chemical composition and leaching behaviour. This was evaluated in this study.

Combustion modeling in waste tanks

International Nuclear Information System (INIS)

Mueller, C.; Unal, C.; Travis, J.R.; Forschungszentrum Karlsruhe

1997-01-01

This paper has two objectives. The first one is to repeat previous simulations of release and combustion of flammable gases in tank SY-101 at the Hanford reservation with the recently developed code GASFLOW-II. The GASFLOW-II results are compared with the results obtained with the HMS/TRAC code and show good agreement, especially for non-combustion cases. For combustion GASFLOW-II predicts a steeper pressure rise than HMS/TRAC. The second objective is to describe a so-called induction parameter model which was developed and implemented into GASFLOW-II and reassess previous calculations of Bureau of Mines experiments for hydrogen-air combustion. The pressure time history improves compared with the one-step model, and the time rate of pressure change is much closer to the experimental data

78 FR 79010 - Criteria to Certify Coal Mine Rescue Teams

Science.gov (United States)

2013-12-27

... coal requires more heat to combust; (3) anthracite dust does not propagate an explosion; and (4) there... to Certify Coal Mine Rescue Teams AGENCY: Mine Safety and Health Administration, Labor. ACTION... updated the coal mine rescue team certification criteria. The Mine Improvement and New Emergency Response...

Combustion

CERN Document Server

Glassman, Irvin

1997-01-01

This Third Edition of Glassman's classic text clearly defines the role of chemistry, physics, and fluid mechanics as applied to the complex topic of combustion. Glassman's insightful introductory text emphasizes underlying physical and chemical principles, and encompasses engine technology, fire safety, materials synthesis, detonation phenomena, hydrocarbon fuel oxidation mechanisms, and environmental considerations. Combustion has been rewritten to integrate the text, figures, and appendixes, detailing available combustion codes, making it not only an excellent introductory text but also an important reference source for professionals in the field. Key Features * Explains complex combustion phenomena with physical insight rather than extensive mathematics * Clarifies postulates in the text using extensive computational results in figures * Lists modern combustion programs indicating usage and availability * Relates combustion concepts to practical applications.

29 CFR 1910.107 - Spray finishing using flammable and combustible materials.

Science.gov (United States)

2010-07-01

... drying apparatus and electrical connections and wiring thereto shall not be located within spray... apparatus, the drying apparatus, and the ventilating system of the spray enclosure shall be equipped with... 29 Labor 5 2010-07-01 2010-07-01 false Spray finishing using flammable and combustible materials...

Quantitative analysis of raw materials mining of Sverdlovsk region in Russia

Science.gov (United States)

Tarasyev, Alexander M.; Vasilev, Julian; Turygina, Victoria F.

2016-06-01

The purpose of this article is to show the application of some qualitative methods for the analysis of a dataset for raw materials. The main approaches used are related to the correlation analysis and forecasting with trend lines. It is proved that the future mining of particular ores can be predicted on the basis of mathematical modeling. It is also shown that there exists a strong correlation between the mining of some specific raw materials. Some of the revealed correlations have meaningful explanations, and for others one should look for sophisticated interpretations. The applied approach can be used for forecasting of raw materials exploitation in various regions of Russia and in other countries.

Radiation situation during underground mineral raw materials mining

International Nuclear Information System (INIS)

Ogorodnikov, B.I.

2007-01-01

One studied the content and the ratio of 4 0 K, 226 Ra, 232 Th and 238 U natural radionuclides in the ores mined in Egypt, Iran, China and Turkey. It is shown that in some ores, for example, in the carbonaceous shale mined in China, in the Iranian bauxite and turquoise Ra eq is higher than 370 Bq/kg, that is, it is higher than the value recommended by the International Scientific Committee on Radiation Effect. The Chinese bituminous shale shows high content of 226 Ra, while 226 Ra/ 232 Th concentration ratio varies between 10 and 60 in contrast to that of other numerous mineral raw materials being close to 1-3. In a number of mines one recorded high concentrations of radon (higher than 300 Bq/m 3 ). Inhalation of such an air results in the essential internal irradiation. The average annual dose equivalents for miners may be higher than the maximum permissible value equal to 20 mSv/g [ru

Efficient Flame Detection and Early Warning Sensors on Combustible Materials Using Hierarchical Graphene Oxide/Silicone Coatings.

Science.gov (United States)

Wu, Qian; Gong, Li-Xiu; Li, Yang; Cao, Cheng-Fei; Tang, Long-Cheng; Wu, Lianbin; Zhao, Li; Zhang, Guo-Dong; Li, Shi-Neng; Gao, Jiefeng; Li, Yongjin; Mai, Yiu-Wing

2018-01-23

Design and development of smart sensors for rapid flame detection in postcombustion and early fire warning in precombustion situations are critically needed to improve the fire safety of combustible materials in many applications. Herein, we describe the fabrication of hierarchical coatings created by assembling a multilayered graphene oxide (GO)/silicone structure onto different combustible substrate materials. The resulting coatings exhibit distinct temperature-responsive electrical resistance change as efficient early warning sensors for detecting abnormal high environmental temperature, thus enabling fire prevention below the ignition temperature of combustible materials. After encountering a flame attack, we demonstrate extremely rapid flame detection response in 2-3 s and excellent flame self-extinguishing retardancy for the multilayered GO/silicone structure that can be synergistically transformed to a multiscale graphene/nanosilica protection layer. The hierarchical coatings developed are promising for fire prevention and protection applications in various critical fire risk and related perilous circumstances.

Combustion and Ignition Studies of Nanocomposite Energetic Materials

Science.gov (United States)

2010-12-14

Characterization of a gas burner to simulate a propellant flame and evaluate aluminum particle combustion,” M. Jackson, M. L. Pantoya and W. Gill, Combustion...of a gas burner to simulate a propellant flame and evaluate aluminum particle combustion,” M. Jackson, M. L. Pantoya and W. Gill, Combustion and...changes in parameters such as particle size. The LFA measures these properties for bulk powders, consolidated pellets or even liquid mediums and is

Application of a Novel Liquid Nitrogen Control Technique for Heat Stress and Fire Prevention in Underground Mines.

Science.gov (United States)

Shi, Bobo; Ma, Lingjun; Dong, Wei; Zhou, Fubao

2015-01-01

With the continually increasing mining depths, heat stress and spontaneous combustion hazards in high-temperature mines are becoming increasingly severe. Mining production risks from natural hazards and exposures to hot and humid environments can cause occupational diseases and other work-related injuries. Liquid nitrogen injection, an engineering control developed to reduce heat stress and spontaneous combustion hazards in mines, was successfully utilized for environmental cooling and combustion prevention in an underground mining site named "Y120205 Working Face" (Y120205 mine) of Yangchangwan colliery. Both localized humidities and temperatures within the Y120205 mine decreased significantly with liquid nitrogen injection. The maximum percentage drop in temperature and humidity of the Y120205 mine were 21.9% and 10.8%, respectively. The liquid nitrogen injection system has the advantages of economical price, process simplicity, energy savings and emission reduction. The optimized heat exchanger used in the liquid nitrogen injection process achieved superior air-cooling results, resulting in considerable economic benefits.

Combustion synthesis of TiC-based materials: Mechanisms, densification, and properties

International Nuclear Information System (INIS)

LaSalvia, J.C.; Meyers, M.A.

1995-01-01

The micromechanisms involved in the combustion synthesis of a Ti-C-Ni-Mo mixture resulting in the formation of a TiC-based composite were examined using the combustion wave quenching technique developed by Rogachev et al. At the micron level, the main reaction occurs at the interface between a Ti-Ni-C melt and C particles, resulting in the formation of a solid TiC x layer on the C particles. This layer undergoes a successive process of rapid growth and decomposition into TiC x spherules until all of the C particle is consumed. This mechanism is consistent with the apparent activation energy (E = 100 kJ/mol) for the process obtained from a macrokinetic investigation of the system. The apparent uniformity in size (d = 1 μm) of the TiC x spherules upon formation indicates a critical condition in the stability of the energetics involved in the process. These TiC x spherules undergo growth due to Ostwald ripening and coalescence mechanisms resulting in a final apparent size of 2.5 μm. For the compositions investigated, the addition of Mo did not affect either the micromechanisms or macrokinetics of the combustion synthesis process. Densification of the porous body after the combustion synthesis process can be carried out while it is still in a easily deformable state. The highly porous body is densified by a combination of fracture (communition), plastic deformation, and sintering. The mechanisms are identified for the case of combustion synthesized TiC. Mechanical properties and microstructures of a number of materials (e.g. TiC, TiB 2 , Al 2 O 3 -TiB 2 , TiB 2 -SiC, TiC-Ni-Mo) produced by combustion synthesis combined with a high-velocity forging step are reviewed

Nanoenhanced Materials for Reclamation of Mine Lands and Other Degraded Soils: A Review

Directory of Open Access Journals (Sweden)

Ruiqiang Liu

2012-01-01

Full Text Available Successful mine soil reclamation facilitates ecosystem recovery, minimizes adverse environmental impacts, creates additional lands for agricultural or forestry uses, and enhances the carbon (C sequestration. Nanoparticles with extremely high reactivity and deliverability can be applied as amendments to improve soil quality, mitigate soil contaminations, ensure safe land–application of the conventional amendment materials (e.g., manures and biosolids, and enhance soil erosion control. However, there is no report on using nanoenhanced materials for mine soil reclamation. Through reviewing the up-to-date research results on using environment-friendly nanoparticles for agricultural soil quality improvement and for contaminated soil remediation, this paper synthesizes that these nanomaterials with high potentials for mine soil reclamation include zeolites, zero-valent iron nanoparticles, iron oxide nanoparticles, phosphate-based nanoparticles, iron sulfide nanoparticles and C nanotubes. Transport of these particles in the environment and their possible ecotoxicological effects are also discussed. Additionally, this article proposes a practical and economical approach to applying nanotechnology for mine soil reclamation: adding small amounts of nanoparticles to the conventional soil amendment materials and then applying the mixtures for soil quality improvements. Hence the cost of using nanoparticles is reduced and the benefits of both nanoparticles and the conventional amendment materials are harnessed.

Growth of soil algae and cyanobacteria on gold mine tailings material

Directory of Open Access Journals (Sweden)

Tanya Seiderer

2017-11-01

Full Text Available The goal of revegetation of gold mine tailings storage facilities is to reduce aeolian pollution, nutrient leaching and erosion caused by exposure to wind and water. The establishment of biological soil crusts may prove to be a more cost-effective way to reach the same goal and the aim of this study was therefore to determine if it is possible to establish algae and cyanobacteria on gold mine tailings. Different treatments of Chlamydomonas, Microcoleus and Nostoc were inoculated on gold mine tailings in controlled conditions and algal growth was measured on all of the treatments after 6 weeks. Nostoc treatments had the highest chlorophyll-a concentrations and produced a surface crust, while Chlamydomonas treatments penetrated the tailings material and provided the strongest crust. The results were promising but more research is necessary to determine the best organism, or combination of organisms, to colonise mine tailings and to eventually produce biological crusts. Significance: Determination of the best organisms to colonise mine tailings and to produce biological crusts for the revegetation of gold mine tailings storage facilities.

Assessing the Impact of Removing Select Materials from Coal Mine Overburden, Central Appalachia Region, USA

Science.gov (United States)

The exposure of readily soluble components of overburden materials from surface coal mining to air and water results in mineral oxidation and carbonate mineral dissolution, thus increasing coal mine water conductivity. A conductivity benchmark of 300 µS/cm for mine water dischar...

Utilization of stabilized municipal waste combustion ash residues as construction material

International Nuclear Information System (INIS)

Shieh, C.S.

1992-01-01

Stabilized municipal waste combustion (MWC) ash residues were investigated for their potential as construction material that can be beneficially used in terrestrial and marine environments. End-use products, such as patio stones, brick pavers, solid blocks, and reef units, were fabricated and tested for their engineering and chemical characteristics. engineering feasibility and environmental acceptability of using stabilized ash residues as construction material are discussed in this paper. Ash samples were collected from two mass-burn facilities and one refuse derived fuel (RDF) facility in Florida

Characteristics of an open-cut coal mine fire pollution event

Science.gov (United States)

Reisen, Fabienne; Gillett, Rob; Choi, Jason; Fisher, Gavin; Torre, Paul

2017-02-01

On 9 February 2014, embers from a nearby grass/shrub fire spotted into an unused part of the Hazelwood open-cut brown coal mine located in the Latrobe Valley of Victoria, Australia and started a fire that spread rapidly and extensively throughout the mine under strong south-westerly winds and burned over a period of 45 days. The close proximity of the town to the coal mine and the low buoyancy of the smoke plume led to the accumulation of dense smoke levels in the township of Morwell (population of 14,000) particularly under south-westerly winds. A maximum daily PM2.5 concentration of 731 μg m-3 and 8-h CO concentration of 33 ppm were measured at Morwell South, the closest residential area located approximately 500 m from the mine. These concentrations were significantly higher than national air quality standards. Air quality monitoring undertaken in the Latrobe Valley showed that smoke from the Hazelwood mine fire affected a wide area, with particle air quality standards also exceeded in Traralgon (population of 25,000) located approximately 13 km from the mine. Pollutant levels were significantly elevated in February, decreased in March once the fire abated and then returned to background levels once the fire was declared safe at the end of March. While the smoke extent was of a similar order of magnitude to other major air pollution events worldwide, a closer look at emissions ratios showed that the open combustion of lignite brown coal in the Hazelwood mine was different to open combustion of biomass, including peat. It suggested that the dominant combustion process was char combustion. While particle and carbon monoxide monitoring started approximately 4 days after the fire commenced when smoke levels were very high, targeted monitoring of air toxics only began on 26 February (17 days after the fire) when smoke levels had subsided. Limited research on emission factors from open-cut coal mine fires make it difficult to assess the likely concentrations of air

The Use of Waste Materials in the Passive Remediation of Mine Water Polution

Science.gov (United States)

Batty, Lesley C.; Younger, Paul L.

2004-01-01

The contamination and resulting degradation of water courses by effluents from abandoned and active mines is a world-wide problem. Traditional methods of remediating the discharges from mines involve the addition of chemicals and the utilisation of artificial energy sources. Over the last 15-20 years passive treatment systems have been developed that harness natural chemical and biological processes to ameliorate the potentially toxic effects of such discharges. There are many different types of passive system, including compost wetlands, reducing and alkalinity producing systems (RAPS), permeable reactive barriers and inorganic media passive systems. Different waste materials can be utilised as reactive media within each of these systems, dependent upon the type of mine water and treatment technology. In many cases the reactivity of these recycled waste materials is key to the remedial performance of these systems. The materials used may be organic (e.g., composts) or inorganic (e.g., blast furnace slag) and where possible are sourced locally in order to minimise transport costs. The remediation of mine waters in itself can produce large quantities of waste products in the form of iron oxide sludge. Potential uses of this material in the production of pigments and in the treatment of phosphate contaminated waters is also currently under investigation. The exploitation of what are traditionally thought of as waste materials within treatment systems for polluted waters is an expanding technology which provides great scope for recycling.

Rehabilitation materials from surface- coal mines in western U.S.A. III. Relations between elements in mine soil and uptake by plants.

Science.gov (United States)

Severson, R.C.; Gough, L.P.

1984-01-01

Plant uptake of Cd, Co, Cu, Fe, Mn, Ni, Pb and Zn from mine soils was assessed using alfalfa Medicago sativa, sainfoin Onobrychis viciaefolia, smooth brome Bromus inermis, crested wheatgrass Agropyron cristatum, slender wheatgrass A. trachycaulum and intermediate wheatgrass A. intermedium; mine soil (cover-soil and spoil material) samples were collected from rehabilitated areas of 11 western US surface-coal mines in North Dakota, Montana, Wyoming and Colorado. Correlations between metals in plants and DTPA-extractable metals from mine soils were generally not statistically significant and showed no consistent patterns for a single metal or for a single plant species. Metal uptake by plants, relative to amounts in DTPA extracts of mine soil, was positively related to mine soil organic matter content or negatively related to mine soil pH. DTPA-extractable metal levels were significantly correlated with mine soil pH and organic-matter content.-from Authors

Naturally Occurring Radionuclides of Ash Produced by Coal Combustion. The Case of the Kardia Mine in Northern Greece

Science.gov (United States)

Fotakis, M.; Tsikritzis, L.; Tzimkas, N.; Kolovos, N.; Tsikritzi, R.

2008-08-01

West Macedonia Lignite Center (WMLC), located in Northwest Greece, releases into the atmosphere about 21,400 tons/year of fly ash through the stacks of four coal fired plants. The lignite ash contains naturally occurring radionuclides, which are deposited on the WMLC basin. This work investigates the natural radioactivity of twenty six ash samples, laboratory produced from combustion of lignite, which was sampled perpendicularly to the benches of the Kardia mine. The concentrations of radionuclides 40K, 235U, 238U, 226Ra, 228Ra and 232Th, were measured spectroscopically and found round one order of magnitude as high as those of lignite. Subsequently the Radionuclide Partitioning Coefficients of radionuclides were calculated and it was found that they are higher for 232Th, 228Ra and 40K, because the latter have closer affinity with the inorganic matrix of lignite. During combustion up to one third of the naturally occurring radioisotopes escape from the solid phase into the flue gases. With comparison to relative global data, the investigated ash has been found to have relatively high radioactivity, but the emissions of the WMLC radionuclides contribute only 0.03% to the mean annual absorbed dose.

Naturally Occurring Radionuclides of Ash Produced by Coal Combustion. The Case of the Kardia Mine in Northern Greece

International Nuclear Information System (INIS)

Fotakis, M.; Tsikritzis, L.; Tzimkas, N.; Kolovos, N.; Tsikritzi, R.

2008-01-01

West Macedonia Lignite Center (WMLC), located in Northwest Greece, releases into the atmosphere about 21,400 tons/year of fly ash through the stacks of four coal fired plants. The lignite ash contains naturally occurring radionuclides, which are deposited on the WMLC basin. This work investigates the natural radioactivity of twenty six ash samples, laboratory produced from combustion of lignite, which was sampled perpendicularly to the benches of the Kardia mine. The concentrations of radionuclides 40 K, 235 U, 238 U, 226 Ra, 228 Ra and 232 Th, were measured spectroscopically and found round one order of magnitude as high as those of lignite. Subsequently the Radionuclide Partitioning Coefficients of radionuclides were calculated and it was found that they are higher for 232 Th, 228 Ra and 40 K, because the latter have closer affinity with the inorganic matrix of lignite. During combustion up to one third of the naturally occurring radioisotopes escape from the solid phase into the flue gases. With comparison to relative global data, the investigated ash has been found to have relatively high radioactivity, but the emissions of the WMLC radionuclides contribute only 0.03% to the mean annual absorbed dose

Combustion of peanut shells in a cone-shaped bubbling fluidized-bed combustor using alumina as the bed material

International Nuclear Information System (INIS)

Arromdee, Porametr; Kuprianov, Vladimir I.

2012-01-01

Highlights: ► We propose burning of peanut shells in a conical fluidized bed using alumina sand. ► We examine hydrodynamic, combustion and emission characteristics of the reactor. ► High, over 99%, combustion efficiency is achievable. ► Emissions of CO and NO from the combustor meet the national emission limits. ► Composition of the bed material undergoes significant changes during the combustion. -- Abstract: This paper reports experimental studies on burning peanut shells in the conical fluidized-bed combustor using alumina sand as the fluidizing agent. Prior to combustion tests, hydrodynamic regimes and characteristics of a conical alumina–biomass bed were investigated under cold-state conditions for variable percentage of peanut shells in the mixture and static bed height. With selected particle sizes (300–500 μm) and static bed height (30 cm), alumina ensured bubbling fluidization regime of the bed at operating conditions specified for firing biomass. Combustion tests were performed at 60 kg/h and 45 kg/h fuel feed rates, while ranging excess air from 20% to 80% at a fixed combustor load. Temperature and gas concentrations (O 2 , CO, C x H y as CH 4 , and NO) were measured along radial and axial directions inside the reactor as well as at stack in order to characterize combustion and emission performance of the combustor for the ranges of operating conditions. For firing 60 kg/h peanut shells, excess air of 40% can be selected as an appropriate value ensuring high, about 99%, combustion efficiency and rather low emissions of CO and NO: 520 ppm and 125 ppm, respectively (both on a dry basis and at 6% O 2 ). With reducing combustor load, the combustion efficiency and emission characteristics were improved to a little extent. No evidence of bed agglomeration was found during 30-h combustion tests on this conical fluidized-bed combustor using alumina sand as the bed material. However, the timescale effect on the composition of the bed material was

Computational Fluid Dynamics Simulation of Oxygen Seepage in Coal Mine Goaf with Gas Drainage

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Guo-Qing Shi

2015-01-01

Full Text Available Mine fires mainly arise from spontaneous combustion of coal seams and are a global issue that has attracted increasing public attention. Particularly in china, the closure of coal workfaces because of spontaneous combustion has contributed to substantial economic loss. To reduce the occurrence of mine fires, the spontaneous coal combustion underground needs to be studied. In this paper, a computational fluid dynamics (CFD model was developed for coal spontaneous combustion under goaf gas drainage conditions. The CFD model was used to simulate the distribution of oxygen in the goaf at the workface in a fully mechanized cave mine. The goaf was treated as an anisotropic medium, and the effects of methane drainage and oxygen consumption on spontaneous combustion were considered. The simulation results matched observational data from a field study, which indicates CFD simulation is suitable for research on the distribution of oxygen in coalmines. The results also indicated that near the workface spontaneous combustion was more likely to take place in the upper part of the goaf than near the bottom, while further from workface the risk of spontaneous combustion was greater in the lower part of the goaf. These results can be used to develop firefighting approaches for coalmines.

Evaluation of coal combustion byproducts as soil liming materials - their influence on soil pH and enzyme activities

Energy Technology Data Exchange (ETDEWEB)

McCarty, G W; Siddaramappa, R; Wright, R J; Codling, E E; Gao, G

1994-03-01

To evaluate coal combustion byproducts as liming materials and address issues related to soil quality, the authors compared the influence of different amounts of four combustion byproducts (fly ash and bed ash from a fluidized bed combustion furnace, lime-injected multistage burner residue, and spray dryer residue) and CaCO[sub 3] on soil pH and activities of urease, phosphatase, arylsulfatase, and dehydrogenase in an acidic soil. Studies comparing the influence of the combustion byproducts and CaCO[sub 3] on soil pH showed that on weight basis of application, substantial differences were observed in the ability of these materials to influence soil pH but that such differences decreased markedly after the data were transformed to a CaCO[sub 3] equivalent basis of application. Analysis of covariance for these transformed data indicated that whereas the liming abilities of fly ash and CaCO[sub 3] were not significantly different when compared on the CaCO[sub 3] equivalent basis, those of bed ash, multistage burner residue, and spray dryer residue were less than that of CaCO[sub 3]. Studies comparing the influence of the byproducts and CaCO[sub 3] on soil enzyme activities showed that the effect of these liming materials on the enzyme activities studied was largely due to their influence on soil pH. These studies showed that the combustion byproducts tested functioned as soil liming materials in a manner similar to that of CaCO[sub 3] and seemed to have little adverse effect on soil quality.

Utilization and mitigation of VAM/CMM emissions by a catalytic combustion gas turbine

Energy Technology Data Exchange (ETDEWEB)

Tanaka, K.; Yoshino, Y.; Kashihara, H. [Kawasaki Heavy Industries Ltd., Hyougo (Japan); Kajita, S.

2013-07-01

A system configured with a catalytic combustion gas turbine generator unit is introduced. The system has been developed using technologies produced by Kawasaki Heavy Industries, Ltd., such as small gas turbines, recuperators and catalytic combustors, and catalytic oxidation units which use exhaust heat from gas turbines. The system combusts (oxidizes) ventilation air methane (less than 1% concentration) and low concentration coal mine methane (30% concentration or less) discharged as waste from coal mines. Thus, it cannot only reduce the consumption of high- quality fuel for power generation, but also mitigate greenhouse gas emissions.

The combustion heat of power producing shale based on individual deliveries for the years 1968 to 1981

Energy Technology Data Exchange (ETDEWEB)

Yyspuu, L M; Rayur, K W; Sits, Kh I

1983-01-01

The results are cited of a retrospective study of the specific combustion heat of power producing shale relative to the geological and mining technological conditions for nine mines and four open pits of the Baltic Sea Basin. In 1981 the maximal mean annual combustion heatQsigma-c of 12.44 megajoules per kilogram was held by the shales from the Tammiku mine, while the minimum of 10.12 megajoules per kilogram was held by the shales from the Leningradskaya mine. The results are used in a predictive evaluation of the heat creativity of the total fuel of the Baltic Sea region and the Estonian state regional electric power plants (GRES) for the coming years.

Dimensionless model to determine spontaneous combustion danger zone in the longwall gob

Institute of Scientific and Technical Information of China (English)

ZHANG Xin-hai; DENG Jun; WEN Hu

2011-01-01

According to spontaneous combustion propensity,the longwall gob is divided into three zones,including heat dissipation zone,self-heating zone and the choking zone.Only in the self-heating zone can temperature of coal rise due to oxidation.Studying the distribution of the “Three Zones” in gob is important for predicting and preventing spontaneous combustion in coalmine.In normal mining operations,temperature of coal is roughly constant.The process of mass transfer in the gob is considered to be steady.Based on mass conservation,gas species conservation,darcy' s law,Ficks law of diffusion and coal oxidation 1-grade reaction rule,governing equation for air leakage intensity and species concentration are deduced.With critical value of coal spontaneous combustion and the size of longwall workface as basic dimension,a dimensionless steady coupled model of air flow diffusion and chemical reaction in loose coal of Fully Mechanized Top-Coal Caving Mining Workface (FMTCCMW) is setup.By solving the model numerically,regulation of three zones' distribution and spontaneous combustion in the gob can be obtained.The results can be easily popularized to prediction of spontaneous combustion in other coalmines' longwall gob.

Stoichiometric calculations of combustion of Lakhra lignite

International Nuclear Information System (INIS)

Ali, I.; Ali, M.M.

2002-01-01

Lakhra coal field is largest productive coal field of Pakistan. About 1.5 millions tonne of this coal is, annually, mined and transported daily to various parts of the country in 500 trucks each of 10 tonnes of coal. The major consumers of this coal are brick kilns located in Sindh and Punjab. It is available at Rs. 500/- per tonne at mine head. A number of attempts were made for the production of power (electricity) by foreign companies. Feasibility studies were undertaken but no one set up power plant. It may be due to inferior quality of coal as it is lignitic in nature with high ash and sulfur contents. This coal is also, very sensitive to spontaneous combustion. Spontaneous combustion is the auto-ignition of coal at ambient conditions. Hence there are storage problems. In spite of these drawbacks, a 3(50) Mega Watt (3 units of each 50 mega watt power generation capacity) power plant, based on atmospheric fluidized bed combustion of coal technology (AFBC), was setup in early nineties. The performance of this plant remained poor. The main reasons might be poor quality of coal and limestone. Limestone is used with high sulfur Lakhra lignite, in fluidized bed combustor, to arrest sulfur of the coal, fixing sulfur as calcium sulfate to minimize hazardous emissions of sulfur dioxide (SO/sub 2/). Spontaneous combustion of Lakhra lignite is responsible for each fire of coal and conveyor belt etc. (author)

Validation of the Ventgraph program for use in metal/non-metal mines

Energy Technology Data Exchange (ETDEWEB)

Pritchard, C.J. [National Inst. for Occupational Safety and Health, Spokane, WA (United States)

2010-07-01

Ventgraph is a ventilation software developed by the Polish Academy of Sciences. It has features similar to other ventilation programs, such as network simulation and contaminant dispersal. Its additional capabilities include mine fire simulation, compressible flow modelling, and real-time on-screen visualization of mine ventilation and fire effects. For that reason, it has been widely used around the world for studying coal mine fires, fighting fires with inert gases, spontaneous combustion, and mine emergency exercises. Ventgraph has been used to a much lesser extent in metal/non-metal (M/NM) mines. The National Institute for Occupational Safety and Health has determined that the use of Ventgraph to hardrock mining methods would be beneficial for studying M/NM ventilation effects, mine evacuation training, risk analysis of potential mine ventilation changes, airborne contaminants, recirculation, and mine fires. Ventgraph was used to simulate the 1972 Sunshine Mine fire where 91 miners perished. The Sunshine Mine was chosen because of its deep, complex ventilation system. Calibration of Ventgraph's fire simulation module to known events of the fire showed close correlation to contaminant levels observed and real-time movement of fire combustion products through the mine. It was concluded that Ventgraph is a valuable tool for M/NM mine ventilation, fire, and evacuation planning. 13 refs., 3 figs.

Development and Sliding Wear Response of Epoxy Composites Filled with Coal Mine Overburden Material

Science.gov (United States)

Das, Prithika; Satapathy, Alok; Mishra, M. K.

2018-03-01

The paper reports on development and characterization of epoxy based composites filled with micro-sized mine overburden material. Coal mine overburden material is typically highly heterogeneous and is considered as waste material. For excavating each ton of coal, roughly 5 tons of overburden materials are removed and is dumped nearby occupying large space. Gainful utilization of this waste is a major challenge. In the present work, this material is used as filler materials in making a new class of epoxy matrix composites. Composites with different weight proportions of fillers (0, 10, 20, 30 and 40) wt. % are prepared by hand layup technique. Compression tests are performed as per corresponding ASTM standards to assess the compressive strength of these composites. Further, dry sliding tests are performed following ASTM G99 standards using a pin on disk machine. A design of experiment approach based on Taguchi’s L16 orthogonal arrays is adopted. Tests are performed at different sliding velocities for multiple sliding distances under varying normal loads. Specific wear rates of the composites under different test conditions are obtained. The analysis of the test results revealed that the filler content and the sliding velocity are the most predominant control factors affecting the wear rate. This work thus, opens up a new avenue for the value added utilization of coal mine overburden material.

Development of a new methodology for mitigating acid mine drainage (AMD) at reclaimed surface mines

International Nuclear Information System (INIS)

Ackman, T.E.; Kim, A.G.

1993-01-01

A 1.2 hectare (ha) experimental site located on a 14.5 ha reclaimed surface mine in Greene County, PA was injected with a 141 cubic meters (m 3 ) of fly ash and fluidized bed combustion (FBC) ash grout that included acid mine drainage (AMD) sludge. An evaluation of this AMD abatement approach by the Bureau of Mines found that the average net acidity and concentrations of several metal ions at the discharge seep and monitoring wells decreased after grouting. Changes in metal concentrations were assumed to be related to alkaline addition and/or encapsulation. Initial results indicate that this technique is potentially an effective AMD abatement method

Flow behavior and mobility of contaminated waste rock materials in the abandoned Imgi mine in Korea

Science.gov (United States)

Jeong, S. W.; Wu, Y.-H.; Cho, Y. C.; Ji, S. W.

2018-01-01

Incomplete mine reclamation can cause ecological and environmental impacts. This paper focuses on the geotechnical and rheological characteristics of waste rock materials, which are mainly composed of sand-size particles, potentially resulting in mass movement (e.g., slide or flow) and extensive acid mine drainage. To examine the potential for contaminant mobilization resulting from physicochemical processes in abandoned mines, a series of scenario-based debris flow simulations was conducted using Debris-2D to identify different hazard scenarios and volumes. The flow behavior of waste rock materials was examined using a ball-measuring rheometric apparatus, which can be adapted for large particle samples, such as debris flow. Bingham yield stresses determined in controlled shear rate mode were used as an input parameter in the debris flow modeling. The yield stresses ranged from 100 to 1000 Pa for shear rates ranging from 10- 5 to 102 s- 1. The results demonstrated that the lowest yield stress could result in high mobility of debris flow (e.g., runout distance > 700 m from the source area for 60 s); consequently, the material contaminants may easily reach the confluence of the Suyoung River through a mountain stream. When a fast slide or debris flow occurs at or near an abandoned mine area, it may result in extremely dynamic and destructive geomorphological changes. Even for the highest yield stress of debris flow simulation (i.e., τy = 2000 Pa), the released debris could flow into the mountain stream; therefore, people living near abandoned mines may become exposed to water pollution throughout the day. To maintain safety at and near abandoned mines, the physicochemical properties of waste materials should be monitored, and proper mitigation measures post-mining should be considered in terms of both their physical damage and chemical pollution potential.

Tube bundle system: for monitoring of coal mine atmosphere.

Science.gov (United States)

Zipf, R Karl; Marchewka, W; Mohamed, K; Addis, J; Karnack, F

2013-05-01

A tube bundle system (TBS) is a mechanical system for continuously drawing gas samples through tubes from multiple monitoring points located in an underground coal mine. The gas samples are drawn via vacuum pump to the surface and are typically analyzed for oxygen, methane, carbon dioxide and carbon monoxide. Results of the gas analyses are displayed and recorded for further analysis. Trends in the composition of the mine atmosphere, such as increasing methane or carbon monoxide concentration, can be detected early, permitting rapid intervention that prevents problems, such as a potentially explosive atmosphere behind seals, fire or spontaneous combustion. TBS is a well-developed technology and has been used in coal mines around the world for more than 50 years. Most longwall coal mines in Australia deploy a TBS, usually with 30 to 40 monitoring points as part of their atmospheric monitoring. The primary uses of a TBS are detecting spontaneous combustion and maintaining sealed areas inert. The TBS might also provide mine atmosphere gas composition data after a catastrophe occurs in an underground mine, if the sampling tubes are not damaged. TBSs are not an alternative to statutory gas and ventilation airflow monitoring by electronic sensors or people; rather, they are an option to consider in an overall mine atmosphere monitoring strategy. This paper describes the hardware, software and operation of a TBS and presents one example of typical data from a longwall coal mine.

Nanocrystals-based Macroporous Materials Synthesized by Freeze-drying Combustion

International Nuclear Information System (INIS)

Yan, Ruiqiang; Chen, Yu; Lin, Ye; Chen, Fanglin

2016-01-01

We present a novel freeze-drying combustion method for synthesis of macroporous powders with nano-network, using Sm 0.2 Ce 0.8 O 1.9 (SDC) as an example. The metal nitrate salt solution mixed with glycine is frozen to form homogeneous nitrate/glycine mixture and then freeze-dried through sublimation of ice crystals. Upon combustion of the freeze-dried mixture, SDC powders with macroporous microstructure consisting of 10–20 nm nanocrystals, high surface area and excellent sinterability are achieved. High resolution transmission electron microscopy (HRTEM) analysis indicates that nanodomains due to aggregation/segregation of dopants in the SDC powders obtained from freeze-drying combustion are much smaller than those in the SDC powders synthesized by the conventional nitrate solution combustion approach, demonstrating better elemental homogeneity and improved conductivity. Using low cost precursors and simple processing conditions, freeze-drying combustion can be a versatile method to synthesize nanocrystalline powders with excellent composition homogeneity for broad applications.

The reclamation of former coal mines and steelworks

International Nuclear Information System (INIS)

Richards, I.G.; Palmer, J.P.; Barratt, P.A.

1993-01-01

The book is a result of studies undertaken on behalf of the European Commission and examines the current 'state of the art' techniques for the restoration of despoiled lands arising from the coal and steel industries. Chapters are entitled: introduction; site assessment; investigation and treatment of mine workings and unstable ground; demolition and site clearance; colliery spoil heap characteristics; colliery spoil heap stability; colliery spoil heap combustion; colliery spoil washing; steel industry raw materials and wastes; coal carbonisation; treatment of contaminated soils; water quality; landform and earthworks; the establishment and care of vegetation; management of reclaimed land; a framework for site generation; and case studies. 266 refs

Fate of the naturally occurring radioactive materials during treatment of acid mine drainage with coal fly ash and aluminium hydroxide.

Science.gov (United States)

Madzivire, Godfrey; Maleka, Peane P; Vadapalli, Viswanath R K; Gitari, Wilson M; Lindsay, Robert; Petrik, Leslie F

2014-01-15

Mining of coal is very extensive and coal is mainly used to produce electricity. Coal power stations generate huge amounts of coal fly ash of which a small amount is used in the construction industry. Mining exposes pyrite containing rocks to H2O and O2. This results in the oxidation of FeS2 to form H2SO4. The acidic water, often termed acid mine drainage (AMD), causes dissolution of potentially toxic elements such as, Fe, Al, Mn and naturally occurring radioactive materials such as U and Th from the associated bedrock. This results in an outflow of AMD with high concentrations of sulphate ions, Fe, Al, Mn and naturally occurring radioactive materials. Treatment of AMD with coal fly ash has shown that good quality water can be produced which is suitable for irrigation purposes. Most of the potentially toxic elements (Fe, Al, Mn, etc) and substantial amounts of sulphate ions are removed during treatment with coal fly ash. This research endeavours to establish the fate of the radioactive materials in mine water with coal fly ash containing radioactive materials. It was established that coal fly ash treatment method was capable of removing radioactive materials from mine water to within the target water quality range for drinking water standards. The alpha and beta radioactivity of the mine water was reduced by 88% and 75% respectively. The reduced radioactivity in the mine water was due to greater than 90% removal of U and Th radioactive materials from the mine water after treatment with coal fly ash as ThO2 and UO2. No radioisotopes were found to leach from the coal fly ash into the mine water. Copyright © 2013 Elsevier Ltd. All rights reserved.

Coal-Mining Tailings as a Pozzolanic Material in Cements Industry

Directory of Open Access Journals (Sweden)

Santiago Yagüe

2018-01-01

Full Text Available The generation of enormous volumes of mine-tailing waste is standard practice in the mining industry. Large quantities of these tailings are also sources of kaolinite-rich materials that accumulate in slag heaps, causing significant environmental degradation and visual impacts on the landscape. The consequences of coal refuse dumped in slagheaps calls for the study of eco-innovative solutions and the assessment of waste types. Moreover, the environmental benefits of reusing large amounts of contaminated waste are also evident. Hence, the objective of this investigation is to expand current knowledge of new siliceous-aluminium minerals and their pozzolanic activity. Four raw tailing samples are characterized to determine their chemical (by ICP/MS analysis, morphological (by SEM/EDX analysis, and mineralogical (by XRD analysis compositions prior to their thermal activation that transforms the inert wastes at various temperatures into materials with cementitious properties. The results of XRD analysis following activation confirmed that the kaolinite content is fully transformed into metakaolinite. The coal refuse samples presented sufficiently reliable levels of pozzolanic activity for use as additives in industrial cements.

Selected problems of mine ventilation under conditions of gas and fire hazards. [Poland

Energy Technology Data Exchange (ETDEWEB)

Rosiek, F; Sikora, M; Urbanski, J

1984-01-01

Activities of the the Department for Ventilation, Fires and Occupational Safety in Wroclaw are evaluated. Until 1981 the Department concentrated its research programs on ventilation in copper mines; since 1982 its programs have also covered ventilation and hazards of endogenous fire in black coal mines. The Department investigated hazards of coal spontaneous combustion in Lower Silesian coal mines and proved that the hazards are associated with occurrence of specific layers in coal seams. When coal left in the goaf area came from a layer prone to spontaneous combustion hazards of endogenous fires were high. The Department developed a method for fire prevention using periodic reversal of goaf ventilation. Schemes for reverse ventilation are discussed.

Starting procedure for internal combustion vessels

Science.gov (United States)

Harris, Harry A.

1978-09-26

A vertical vessel, having a low bed of broken material, having included combustible material, is initially ignited by a plurality of ignitors spaced over the surface of the bed, by adding fresh, broken material onto the bed to buildup the bed to its operating depth and then passing a combustible mixture of gas upwardly through the material, at a rate to prevent back-firing of the gas, while air and recycled gas is passed through the bed to thereby heat the material and commence the desired laterally uniform combustion in the bed. The procedure permits precise control of the air and gaseous fuel mixtures and material rates, and permits the use of the process equipment designed for continuous operation of the vessel.

Means of regulating combustible materials and products in external walls

Directory of Open Access Journals (Sweden)

Mikkola Esko

2016-01-01

Full Text Available This report presents proposals for defining means of regulating the use of combustible materials and products in external walls. Required protections are based on the quantities of fire loads and their contribution to fire development. The study is based on life safety and protection of property priorities taking into account reaction to fire classes related to different types of fire loads and fire compartmentation requirements of the adjacent spaces of concern. The proposals include the following main principles in relation to fire-separation requirements: In case of internal fire exposure the protective structure for combustible building parts needs to meet at least half of the fire-separating requirement for the compartment of concern. In case of external fire exposure the protection time requirement can be 15 minutes less than for the internal protection. The proposals are applicable for residential buildings and offices. In case of buildings with longer evacuation times more stringent requirement levels may be considered. For verification of protection performance of fire loads it is proposed to use existing standardized test methods (fire protection ability (K classes and fire-separating function (EI classes validated methods of calculation and/or large scale fire testing.

Method for storing radioactive combustible waste

Science.gov (United States)

Godbee, H.W.; Lovelace, R.C.

1973-10-01

A method is described for preventing pressure buildup in sealed containers which contain radioactively contaminated combustible waste material by adding an oxide getter material to the container so as to chemically bind sorbed water and combustion product gases. (Official Gazette)

The Heat of Combustion of Tobacco and Carbon Oxide Formation

Directory of Open Access Journals (Sweden)

Norman AB

2014-12-01

Full Text Available Recent studies demonstrated a relationship between mass burn rates of straight-grade cigarettes and heats of combustion of the tobacco materials. In the present work, relationships between measured heats of combustion and elemental composition of the tobacco materials were further analyzed. Heats of combustion measured in oxygen were directly correlated with the carbon and hydrogen content of the tobacco materials tested. Ash content of the materials was inversely related to the heats of combustion. The water insoluble residues from exhaustively extracted tobacco materials showed higher heats of combustion and higher carbon content than the non-extracted materials, confirming a direct relationship between carbon content and heat of combustion. A value for the heat of formation of tobacco was estimated (1175 cal/g from the heat of combustion data and elemental analysis results. The estimated value for heat of formation of tobacco appears to be constant regardless of the material type. Heat values measured in air were uniformly lower than the combustion heats in oxygen, suggesting formation of CO and other reaction products. Gases produced during bomb calorimetry experiments with five tobacco materials were analyzed for CO and CO2 content. When the materials were burned in oxygen, no CO was found in the gases produced. Measured heats of combustion matched estimates based on CO2 found in the gas and conversion of the sample hydrogen content to water. Materials burned in air produced CO2 (56% to 77% of the sample carbon content and appreciable amounts of CO (7% to 16% of the sample carbon content. Unburned residue containing carbon and hydrogen was found in the air combustion experiments. Estimated heat values based on amounts of CO and CO2 found in the gas and water formed from the hydrogen lost during combustion in air were higher than the measured values. These observations indicate formation of products containing hydrogen when the materials

Synchrotron-based X-Ray Spectroscopy Studies for Redox-based Remediation of Lead, Zinc, and Cadmium in Mine Waste Materials.

Science.gov (United States)

Karna, Ranju R; Hettiarachchi, Ganga M; Newville, Matthew; Sun, ChengJun; Ma, Qing

2016-11-01

Several studies have examined the effect of submergence on the mobility of metals present in mine waste materials. This study examines the effect of organic carbon (OC) and sulfur (S) additions and submergence time on redox-induced biogeochemical transformations of lead (Pb), zinc (Zn), and cadmium (Cd) present in mine waste materials collected from the Tri-State mining district located in southeastern Kansas, southwestern Missouri, and northeastern Oklahoma. A completely randomized design, with a two-way treatment structure, was used for conducting a series of column experiments. Two replicates were used for each treatment combination. Effluent samples were collected at several time points, and soil samples were collected at the end of each column experiment. Because these samples are highly heterogeneous, we used a variety of synchrotron-based techniques to identify Pb, Zn, and Cd speciation at both micro- and bulk-scale. Spectroscopic analysis results from the study revealed that the addition of OC, with and without S, promoted metal-sulfide formation, whereas metal carbonates dominated in the nonamended flooded materials and in mine waste materials only amended with S. Therefore, the synergistic effect of OC and S may be more promising for managing mine waste materials disposed of in flooded subsidence mine pits instead of individual S or OC treatments. The mechanistic understanding gained in this study is also relevant for remediation of waste materials using natural or constructed wetland systems. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Characterization of a mine fire using atmospheric monitoring system sensor data.

Science.gov (United States)

Yuan, L; Thomas, R A; Zhou, L

2017-06-01

Atmospheric monitoring systems (AMS) have been widely used in underground coal mines in the United States for the detection of fire in the belt entry and the monitoring of other ventilation-related parameters such as airflow velocity and methane concentration in specific mine locations. In addition to an AMS being able to detect a mine fire, the AMS data have the potential to provide fire characteristic information such as fire growth - in terms of heat release rate - and exact fire location. Such information is critical in making decisions regarding fire-fighting strategies, underground personnel evacuation and optimal escape routes. In this study, a methodology was developed to calculate the fire heat release rate using AMS sensor data for carbon monoxide concentration, carbon dioxide concentration and airflow velocity based on the theory of heat and species transfer in ventilation airflow. Full-scale mine fire experiments were then conducted in the Pittsburgh Mining Research Division's Safety Research Coal Mine using an AMS with different fire sources. Sensor data collected from the experiments were used to calculate the heat release rates of the fires using this methodology. The calculated heat release rate was compared with the value determined from the mass loss rate of the combustible material using a digital load cell. The experimental results show that the heat release rate of a mine fire can be calculated using AMS sensor data with reasonable accuracy.

Mine drainage treatment

OpenAIRE

Golomeova, Mirjana; Zendelska, Afrodita; Krstev, Boris; Golomeov, Blagoj; Krstev, Aleksandar

2012-01-01

Water flowing from underground and surface mines and contains high concentrations of dissolved metals is called mine drainage. Mine drainage can be categorized into several basic types by their alkalinity or acidity. Sulfide rich and carbonate poor materials are expected to produce acidic drainage, and alkaline rich materials, even with significant sulfide concentrations, often produce net alkaline water. Mine drainages are dangerous because pollutants may decompose in the environment. In...

Source identification of uranium-containing materials at mine legacy sites in Portugal.

Science.gov (United States)

Keatley, A C; Martin, P G; Hallam, K R; Payton, O D; Awbery, R; Carvalho, F P; Oliveira, J M; Silva, L; Malta, M; Scott, T B

2018-03-01

Whilst prior nuclear forensic studies have focused on identifying signatures to distinguish between different uranium deposit types, this paper focuses on providing a scientific basis for source identification of materials from different uranium mine sites within a single region, which can then be potentially used within nuclear forensics. A number of different tools, including gamma spectrometry, alpha spectrometry, mineralogy and major and minor elemental analysis, have been utilised to determine the provenance of uranium mineral samples collected at eight mine sites, located within three different uranium provinces, in Portugal. A radiation survey was initially conducted by foot and/or unmanned aerial vehicle at each site to assist sample collection. The results from each mine site were then compared to determine if individual mine sites could be distinguished based on characteristic elemental and isotopic signatures. Gamma and alpha spectrometry were used to differentiate between samples from different sites and also give an indication of past milling and mining activities. Ore samples from the different mine sites were found to be very similar in terms of gangue and uranium mineralogy. However, rarer minerals or specific impurity elements, such as calcium and copper, did permit some separation of the sites examined. In addition, classification rates using linear discriminant analysis were comparable to those in the literature. Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.

Potential conflicts connected with the recovery of secondary materials from post mining waste dump

Directory of Open Access Journals (Sweden)

Gawor Łukasz

2017-12-01

Full Text Available Coal mine spoil dumping grounds are present in the landscape of every mining region. Although the composition of waste material is in general safe for the environment (sedimentary rocks – sandstones, mudstones and siltstones, there may be up to 10% of coal particles in disposed wastes. The presence of organic material causes self-ignition processes and fire hazards. There is a need and the possibility of the recovery of coal, and which should be conducted according to legal regulations and environmental protection rules. The recovery should also be preceded by a feasibility study, a drilling campaign, laboratory tests and requires different environmental permissions. Recovery processes are connected with the work of a preparation plant, which is usually linked with protests from the local community and potential conflicts. This article presents the most significant hazards to the environment, health and human life connected with the functions associated with the installation of the recovery processes of coal from waste material deposited on the dumps. The methods of reducing these threats are described with regards to legal regulations, particularly law deeds concerning the safe recovery processes and further reclamation and restoration of degraded post-mining dumping grounds. The role and participation of interested community members at the preparation for investment stage as well as the period of realization of the preparation processes is described. The question of re-using and managing the post-mining dumping grounds after completion of the recovery processes is discussed.

Weathering processes in waste materials from a mining area in a semiarid zone

International Nuclear Information System (INIS)

Navarro-Hervás, Cortes; Pérez-Sirvent, Carmen; Martínez-Sánchez, María José; García-Lorenzo, Mari Luz; Molina, José

2012-01-01

Chemical and mineralogical characterization of waste materials present in an abandoned Pb, Zn–Ag mining site (SE, Spain) was carried out. In unaltered rocks, the mineralogy is characterized by plagioclase, pyroxene, magnetite, ilmenite, amphibole, biotite and quartz. Trace-element contents of these samples represent unaltered values. In mine-waste materials, pH ranged from acidic to slightly acidic and trace-element content was generally high, especially for Pb and Zn, although there were also substantial As concentrations. X-ray diffraction results suggested that these samples have a complex mineralogy, including alteration products. Surficial materials in the study area were affected by weathering processes, generating supergene assemblages, including Fe and Mn oxides and hydroxides, carbonates, hydrated sulfates and jarosite. Knowledge of the geochemical processes that took place in the past and which are still taking place provide an important tool for assessing associated environmental problems in this area.

Fly ashes from coal and petroleum coke combustion: current and innovative potential applications.

Science.gov (United States)

González, Aixa; Navia, Rodrigo; Moreno, Natalia

2009-12-01

Coal fly ashes (CFA) are generated in large amounts worldwide. Current combustion technologies allow the burning of fuels with high sulfur content such as petroleum coke, generating non-CFA, such as petroleum coke fly ash (PCFA), mainly from fluidized bed combustion processes. The disposal of CFA and PCFA fly ashes can have severe impacts in the environment such as a potential groundwater contamination by the leaching of heavy metals and/or particulate matter emissions; making it necessary to treat or reuse them. At present CFA are utilized in several applications fields such as cement and concrete production, agriculture and soil stabilization. However, their reuse is restricted by the quality parameters of the end-product or requirements defined by the production process. Therefore, secondary material markets can use a limited amount of CFA, which implies the necessity of new markets for the unused CFA. Some potential future utilization options reviewed herein are zeolite synthesis and valuable metals extraction. In comparison to CFA, PCFA are characterized by a high Ca content, suggesting a possible use as neutralizers of acid wastewaters from mining operations, opening a new potential application area for PCFA that could solve contamination problems in emergent and mining countries such as Chile. However, this potential application may be limited by PCFA heavy metals leaching, mainly V and Ni, which are present in PCFA in high concentrations.

Environmental impact of coal mining on the natural environment in Poland

International Nuclear Information System (INIS)

Wysocka, M.; Chalupnik, S.; Michalik, B.; Skowronek, J.; Skubacz, K.

2002-01-01

Saline waters occurring in underground coal mines in Poland often contain natural radioactive isotopes, mainly 226 Ra from uranium series and 228 Ra from thorium series. Approximately 40% of total amount of radium remains underground in a form of radioactive deposits, but 225 MBq of 226 Ra and 400 MBq of 228 Ra are released daily to the rivers with mine effluents. Technical measures as spontaneous precipitation of radium in gobs, decreasing of amounts of water inflows into underground working etc. have been undertaken in several coal mines and as the result total amount of radium released to the surface waters diminished of about 60% during last 5-6 years. Mine waters can cause a severe impact on the natural environment, mainly due to its salinity. But also the enhancement of radium concentration in river waters, bottom sediments and vegetation is observed. Sometimes radium concentration in rivers exceeds 0.7 kBq/m 3 , which is due to Polish law a permissible level for waste waters. The extended investigations were performed in all coal mines and on this basis the radium balance in effluents has been calculated. Measurements done in the vicinity of mine water's settling ponds and in rivers gave us an opportunity to survey radium behaviour in river waters and the range of contamination. Solid waste materials with enhanced natural radioactivity have been produced in huge amounts in power and coal industries in Poland. There are two main sources of these waste products. As a result of combustion of coal in power plants low radioactive waste materials are produced, with 226 Ra concentration seldom exceeding few hundreds of Bq/kg. Different situation is observed in coal mines, where as a result of precipitation of radium from radium-bearing waters radioactive deposits are formed. Sometimes natural radioactivity of such materials is very high, in case of scaling from coal mines radium concentration may reach 400 000 Bq/kg - similar activity as for 3% uranium ore

Design of a deposit of waste materials coming from mining exploitations

International Nuclear Information System (INIS)

Castro, Alvaro; Pinzon, Hernan; Vargas, William; Pinzon, Andres

2005-01-01

This paper presents the design process and stability assessment of a waste backfill in a limestone quarry method. The study shows the geotechnical and mining features of waste and underground materials affected by backfill. The mainly waste materials are: clay, gravel, and blocks of clay stone, sandstone and limestone, all to be disposed by a layered embankment. The constructive method is selected and the stability analysis of deposit and soil foundation was made by equilibrium method without considering deformations

Bursting Bubbles from Combustion of Thermoplastic Materials in Microgravity

Science.gov (United States)

Butler, K. B.

1999-01-01

Many thermoplastic materials in common use for a wide range of applications, including spacecraft, develop bubbles internally as they burn due to chemical reactions taking place within the bulk. These bubbles grow and migrate until they burst at the surface, forceably ejecting volatile gases and, occasionally, molten fuel. In experiments in normal gravity, Kashiwagi and Ohlemiller observed vapor jets extending a few centimeters from the surface of a radiatively heated polymethylmethacrylate (PMMA) sample, with some molten material ejected into the gas phase. These physical phenomena complicated the combustion process considerably. In addition to the non-steady release of volatiles, the depth of the surface layer affected by oxygen was increased, attributed to the roughening of the surface by bursting events. The ejection of burning droplets in random directions presents a potential fire hazard unique to microgravity. In microgravity combustion experiments on nylon Velcro fasteners and on polyethylene wire insulation, the presence of bursting fuel vapor bubbles was associated with the ejection of small particles of molten fuel as well as pulsations of the flame. For the nylon fasteners, particle velocities were higher than 30 cm/sec. The droplets burned robustly until all fuel was consumed, demonstrating the potential for the spread of fire in random directions over an extended distance. The sequence of events for a bursting bubble has been photographed by Newitt et al.. As the bubble reaches the fluid surface, the outer surface forms a dome while the internal bubble pressure maintains a depression at the inner interface. Liquid drains from the dome until it breaks into a cloud of droplets on the order of a few microns in size. The bubble gases are released rapidly, generating vortices in the quiescent surroundings and transporting the tiny droplets. The depression left by the escaping gases collapses into a central jet, which rises with a high velocity and may

Quantification of Optical and Physical Properties of Combustion-Generated Carbonaceous Aerosols (

Science.gov (United States)

Perera, Inoka Eranda; Litton, Charles D

2015-03-01

A series of experiments were conducted to quantify and characterize the optical and physical properties of combustion-generated aerosols during both flaming and smoldering combustion of three materials common to underground mines-Pittsburgh Seam coal, Styrene Butadiene Rubber (a common mine conveyor belt material), and Douglas-fir wood-using a combination of analytical and gravimetric measurements. Laser photometers were utilized in the experiments for continuous measurement of aerosol mass concentrations and for comparison to measurements made using gravimetric filter samples. The aerosols of interest lie in the size range of tens to a few hundred nanometers, out of range of the standard photometer calibration. To correct for these uncertainties, the photometer mass concentrations were compared to gravimetric samples to determine if consistent correlations existed. The response of a calibrated and modified combination ionization/photoelectric smoke detector was also used. In addition, the responses of this sensor and a similar, prototype ionization/photoelectric sensor, along with discrete angular scattering, total scattering, and total extinction measurements, were used to define in real time the size, morphology, and radiative transfer properties of these differing aerosols that are generally in the form of fractal aggregates. SEM/TEM images were also obtained in order to compare qualitatively the real-time, continuous experimental measurements with the visual microscopic measurements. These data clearly show that significant differences exist between aerosols from flaming and from smoldering combustion and that these differences produce very different scattering and absorption signatures. The data also indicate that ionization/photoelectric sensors can be utilized to measure continuously and in real time aerosol properties over a broad spectrum of applications related to adverse environmental and health effects.

Management of dry flue gas desulfurization by-products in underground mines. Annual report, October 1994--September 1995

Energy Technology Data Exchange (ETDEWEB)

Chugh, Y.P.; Dutta, D.; Esling, S. [and others

1995-10-01

On September 30, 1993, the U.S. Department of Energy-Morgantown Energy Technology Center (DOE-METC) and Southern Illinois University at Carbondale (SIUC) entered into a cooperative research agreement entitled {open_quotes}Management of Dry Flue Gas Desulfurization By-Products in Underground Mines{close_quotes} (DE-FC21-93MC30252). Under the agreement Southern Illinois University at Carbondale will develop and demonstrate several technologies for the placement of coal combustion residues (CCBs) in abandoned coal mines, and will assess the environmental impact of such underground CCB placement. This report describes progress in the following areas: environmental characterization, mix development and geotechnical characterization, material handling and system economics, underground placement, and field demonstration.

Biomass waste carbon materials as adsorbents for CO2 capture under post-combustion conditions

Directory of Open Access Journals (Sweden)

Elisa M Calvo-Muñoz

2016-05-01

Full Text Available A series of porous carbon materials obtained from biomass waste have been synthesized, with different morphologies and structural properties, and evaluated as potential adsorbents for CO2 capture in post-combustion conditions. These carbon materials present CO2 adsorption capacities, at 25 ºC and 101.3 kPa, comparable to those obtained by other complex carbon or inorganic materials. Furthermore, CO2 uptakes under these conditions can be well correlated to the narrow micropore volume, derived from the CO2 adsorption data at 0 ºC (VDRCO2. In contrast, CO2 adsorption capacities at 25 ºC and 15 kPa are more related to only pores of sizes lower than 0.7 nm. The capacity values obtained in column adsorption experiments were really promising. An activated carbon fiber obtained from Alcell lignin, FCL, presented a capacity value of 1.3 mmol/g (5.7 %wt. Moreover, the adsorption capacity of this carbon fiber was totally recovered in a very fast desorption cycle at the same operation temperature and total pressure and, therefore, without any additional energy requirement. Thus, these results suggest that the biomass waste used in this work could be successfully valorized as efficient CO2 adsorbent, under post-combustion conditions, showing excellent regeneration performance.

Twenty-fifth symposium (international) on combustion

International Nuclear Information System (INIS)

Anon.

1994-01-01

Approximately two-thirds of the papers presented at this conference are contained in this volume. The other one-third appear in special issues of ''Combustion and Flame'', Vol. 99, 1994 and Vol. 100, 1995. Papers are divided into the following sections: Supersonic combustion; Detonations and explosions; Internal combustion engines; Practical aspects of combustion; Incineration and wastes; Sprays and droplet combustion; Coal and organic solids combustion; Soot and polycyclic aromatic hydrocarbons; Reaction kinetics; NO x ; Turbulent flames; Turbulent combustion; Laminar flames; Flame spread, fire and halogenated fire suppressants; Global environmental effects; Ignition; Two-phase combustion; Solid propellant combustion; Materials synthesis; Microgravity; and Experimental diagnostics. Papers have been processed separately for inclusion on the data base

Investigation into slipping and falling accidents and materials handling in the South African mining industry.

CSIR Research Space (South Africa)

Schutte, PC

2003-03-01

Full Text Available The objective of this study was to analyze information on slipping and falling accidents and materials handling activities in the South African mining industry. Accident data pertaining to slipping, falling and materials handling accidents...

Screening of candidate corrosion resistant materials for coal combustion environments -- Volume 4. Final report, January 31, 1997

Energy Technology Data Exchange (ETDEWEB)

Boss, D.E.

1997-12-31

The development of a silicon carbide heat exchanger is a critical step in the development of the Externally-Fired Combined Cycle (EFCC) power system. SiC is the only material that provides the necessary combination of resistance to creep, thermal shock, and oxidation. While the SiC structural materials provide the thermomechanical and thermophysical properties needed for an efficient system, the mechanical properties of the SiC tubes are severely degraded through corrosion by the coal combustion products. To obtain the necessary service life of thousands of hours at temperature, a protective coating is needed that is stable with both the SiC tube and the coal combustion products, resists erosion from the particle laden gas stream, is thermal-shock resistant, adheres to SiC during repeated thermal shocks (start-up, process upsets, shut-down), and allows the EFCC system to be cost competitive. The candidate protective materials identified in a previous effort were screened for their stability to the EFCC combustion environment. Bulk samples of each of the eleven candidate materials were prepared, and exposed to coal slag for 100 hours at 1,370 C under flowing air. After exposure the samples were mounted, polished, and examined via x-ray diffraction, energy dispersive spectroscopy, and scanning electron microscopy. In general, the alumina-based materials behaved well, with comparable corrosion depths in all five samples. Magnesium chromite formed a series of reaction products with the slag, which included an alumina-rich region. These reaction products may act as a diffusion barrier to slow further reaction between the magnesium chromite and the slag and prove to be a protective coating. As for the other materials; calcium titanate failed catastrophically, the CS-50 exhibited extension microstructural and compositional changes, and zirconium titanate, barium zironate, and yttrium chromite all showed evidence of dissolution with the slag.

Study of dimensional changes during redox cycling of oxygen carrier materials for chemical looping combustion

NARCIS (Netherlands)

Fossdal, A.; Darell, O.; Lambert, A.; Schols, E.; Comte, E.; Leenman, R.N.; Blom, R.

2015-01-01

Dimensional and phase changes of four candidate oxygen carrier materials for chemical looping combustion are investigated by dilatometry and high-temperature X-ray diffraction during four redox cycles. NiO/Ni2AlO4 does not exhibit significant dimensional changes during cycling, and it is shown that

Environmental impacts associated with an abandoned mine in the Witbank Coalfield, South Africa

International Nuclear Information System (INIS)

Bell, F.G.; Bullock, S.E.T.; Haelbich, T.F.J.; Lindsay, P.

2001-01-01

Mining at Middelburg Colliery in the Witbank Coalfield commenced at the turn of the last century. Initially, there was little environmental degradation associated with mining activities; however, in the late 1930s, a pillar-robbing programme commenced. This has had a marked effect on the environment. Some of the most notable primary effects include subsidence, the appearance of tension cracks at the surface and crownhole development. Secondary effects include spontaneous combustion of the coal worked, as air has been provided with ready access to the mine, accelerated subsidence due to the strength of many pillars being reduced by burning, and a marked deterioration of groundwater quality in the area due to the seepage of acid mine drainage from the mine. Spoil heaps also form blemishes on the landscape. These contain significant amounts of coal and have undergone spontaneous combustion. The deterioration in the quality of water has led to the decimation of vegetation in some areas and the eradication of aquatic flora and fauna in a nearby stream

Uranium and thorium mining and milling: material security and risk assessment

International Nuclear Information System (INIS)

Steinhaeusler, F.; Zaitseva, L.

2005-01-01

Full text: At present physical protection for the front end of the nuclear fuel cycle is typically at a significantly lower level than at any other part of the nuclear fuel cycle. In view of past experiences (Israel, South Africa, Pakistan, India) it is feasible to take into consideration some generic threat scenarios, potentially resulting in loss of control over uranium or thorium, respectively their concentrates, such as: illegal mining of an officially closed uranium- or thorium mine; covert diversion of uranium- or thorium ore whilst officially mining another ore; covert transport of radioactive ore or product, using means of public rail, road, ship, or air transport; covert en route diversion of an authorized uranium- or thorium transport; covert removal of uranium-or thorium ore or concentrate from an abandoned facility. The Stanford-Salzburg database on nuclear smuggling, theft, and orphan radiation sources (DSTO) contains information on trafficking incidents involving mostly uranium, but also some thorium, from 30 countries in five continents with altogether 113 incidents in the period 1991 to 2004. These activities range from uranium transported in backpacks by couriers in Afghanistan, to a terrorist organization purchasing land in order to mine covertly for uranium in Australia, and the clandestine shipment of almost two tons of uranium hexafluoride from Asia to Africa, using the services of a national airline. Potential participants in such illegal operations range from entrepreneurs to members of organized crime, depending on the level of sophistication of the operation. End-users and 'customers' of such illegal operations are suspected to be non-state actors, organizations or governments involved in a covert operation with the ultimate aim to acquire a sufficient amount of nuclear material for a nuclear device. The actual risk for these activities to succeed in the acquisition of an adequate amount of suitable radioactive material depends on one or

Hydrologic data from wells at or in the vicinity of the San Juan coal mine, San Juan County, New Mexico

Science.gov (United States)

Stewart, Anne M.; Thomas, Nicole

2015-01-01

In 2010, in cooperation with the Mining and Minerals Division (MMD) of the State of New Mexico Energy, Minerals and Natural Resources Department, the U.S. Geological Survey (USGS) initiated a 4-year assessment of hydrologic conditions at the San Juan coal mine (SJCM), located about 14 miles west-northwest of the city of Farmington, San Juan County, New Mexico. The mine produces coal for power generation at the adjacent San Juan Generating Station (SJGS) and stores coal-combustion byproducts from the SJGS in mined-out surface-mining pits. The purpose of the hydrologic assessment is to identify groundwater flow paths away from SJCM coal-combustion-byproduct storage sites that might allow metals that may be leached from coal-combustion byproducts to eventually reach wells or streams after regional dewatering ceases and groundwater recovers to predevelopment levels. The hydrologic assessment, undertaken between 2010 and 2013, included compilation of existing data. The purpose of this report is to present data that were acquired and compiled by the USGS for the SJCM hydrologic assessment.

Frictional Performance and Temperature Rise of a Mining Nonasbestos Brake Material during Emergency Braking

Directory of Open Access Journals (Sweden)

Jiusheng Bao

2015-01-01

Full Text Available By simulating emergency braking conditions of mine hoisters, tribological experiments of a mining nonasbestos brake material sliding on E355CC steel friction disc investigated a pad-on-disc friction tester. It is shown that, under combined influence of braking velocity and pressure, the lubricating film and micro-convex-apices on wear surface would have complex physicochemical reactions which make the instant friction coefficient rise gradually while the instant surface temperature rises first and then falls. With the antifriction effect from lubricating film and the desquamating of composite materials, the mean friction coefficient decreases first, then rises, and decreases again with the increasing of initial braking velocity. And with the existence of micro-convex-apices and variation from increment ratio of load and actual contacting area, it rises first and then falls with the increasing of braking pressure. However, the mean surface temperature rises obviously with the increasing of both initial braking velocity and braking pressure for growth of transformed kinetic energy. It is considered that the friction coefficient cannot be considered as a constant when designing brake devices for mine hoisters. And special attention should be paid to the serious influence of surface temperature on tribological performance of brake material during emergency braking.

The use of coal mining wastes for manufacturing paving materials; Los esteriles del carbon como materia prima para la fabricacion de materiales para pavimentacion

Energy Technology Data Exchange (ETDEWEB)

1999-09-01

This project was aimed at proving the technical feasibility of the use of coal mining wastes in the manufacturing of paving materials; floor-tiles, flags, paving-stones, grit stones, etc.. With that aim, four types of coal mining wastes were selected out of an inventory and several tests were conducted and following the results, the most appropriate coal mining wastes, the acceptance limits and the quality control tests to be applied to the materials obtained from coal mining wastes as starting materials for the manufacturing of paving materials were established. Different laboratory test were conducted on the manufacturing of flags, floor-tiles and paving-stones. In addition, semi-industrial scale tests were carried out on the manufacturing of grit stones. Preliminary manufactory designs were elaborated for both material types. The study proved that coal mining wastes in a mixture with other raw materials can be used in the manufacturing of paving materials: floor-tiles, flags, paving-stones, grit stones. (Author)

Producer for vegetal combustibles for internal-combustion motors

Energy Technology Data Exchange (ETDEWEB)

1943-12-28

A producer is described for internal-combustion motors fed with wood or agricultural byproducts characterized by the fact that its full operation is independent of the degree of wetness of the material used.

Air pollution study in dust and suspended particulate materials in phosphate mines and Palmyra city

International Nuclear Information System (INIS)

Othman, I.; Sabra, Sh.; Al-Kharfan, K.

1994-01-01

A study was made during July 1991 in the phosphate mines (Khnifees and Sharqeh) and Palmyra city, total suspended particulate materials (SPM) were collected from these mines and Palmyra city. Also SPM of less than 10μ distribution were measured. The quantity of dust fall in phosphate mines and Palmyra city was estimated. The results show increase in the concentrations, especially the SPM of more than 10μ diameter. The highest value was in Khnifees administration and Sharqeh laboratory. Active traffic in Palmyra streets raised the SPM less than 10μ to a double value in Khnifees and Sharqeh villages. The quantity of dust-fall in mines area agrees with the concentration of total SPM. (author). 2 figs., 2 tabs

Ignition Delay of Combustible Materials in Normoxic Equivalent Environments

Science.gov (United States)

McAllister, Sara; Fernandez-Pello, Carlos; Ruff, Gary; Urban, David

2009-01-01

Material flammability is an important factor in determining the pressure and composition (fraction of oxygen and nitrogen) of the atmosphere in the habitable volume of exploration vehicles and habitats. The method chosen in this work to quantify the flammability of a material is by its ease of ignition. The ignition delay time was defined as the time it takes a combustible material to ignite after it has been exposed to an external heat flux. Previous work in the Forced Ignition and Spread Test (FIST) apparatus has shown that the ignition delay in the currently proposed space exploration atmosphere (approximately 58.6 kPa and32% oxygen concentration) is reduced by 27% compared to the standard atmosphere used in the Space Shuttle and Space Station. In order to determine whether there is a safer environment in terms of material flammability, a series of piloted ignition delay tests using polymethylmethacrylate (PMMA) was conducted in the FIST apparatus to extend the work over a range of possible exploration atmospheres. The exploration atmospheres considered were the normoxic equivalents, i.e. reduced pressure conditions with a constant partial pressure of oxygen. The ignition delay time was seen to decrease as the pressure was reduced along the normoxic curve. The minimum ignition delay observed in the normoxic equivalent environments was nearly 30% lower than in standard atmospheric conditions. The ignition delay in the proposed exploration atmosphere is only slightly larger than this minimum. Interms of material flammability, normoxic environments with a higher pressure relative to the proposed pressure would be desired.

Suppression of the Thermal Decomposition Reaction of Forest Combustible Materials in Large-Area Fires

Science.gov (United States)

Volkov, R. S.; Zhdanova, A. O.; Kuznetsov, G. V.; Strizhak, P. A.

2018-05-01

Experimental investigations on the characteristic time of suppression of the thermal decomposition reaction of typical forest combustible materials (aspen twigs, birch leaves, spruce needles, pine chips, and a mixture of these materials) and the volume of water required for this purpose have been performed for model fire hotbeds of different areas: SFCM = 0.0003-0.007 m2 and SFCM = 0.045-0.245 m2. In the experiments, aerosol water flows with droplets of size 0.01-0.25 mm were used for the spraying of model fire hotbeds, and the density of spraying was 0.02 L/(m2·s). It was established that the characteristics of suppression of a fire by an aerosol water flow are mainly determined by the sizes of the droplets in this flow. Prognostic estimates of changes in the dispersivity of a droplet cloud, formed from large (as large as 0.5 L) "drops" (water agglomerates) thrown down from a height, have been made. It is shown that these changes can influence the conditions and characteristics of suppression of a forest fire. Dependences, allowing one to forecast the characteristics of suppression of the thermal decomposition of forest combustible materials with the use of large water agglomerates thrown down from an aircraft and aerosol clouds formed from these agglomerates in the process of their movement to the earth, are presented.

Suppression of the Thermal Decomposition Reaction of Forest Combustible Materials in Large-Area Fires

Science.gov (United States)

Volkov, R. S.; Zhdanova, A. O.; Kuznetsov, G. V.; Strizhak, P. A.

2018-03-01

Experimental investigations on the characteristic time of suppression of the thermal decomposition reaction of typical forest combustible materials (aspen twigs, birch leaves, spruce needles, pine chips, and a mixture of these materials) and the volume of water required for this purpose have been performed for model fire hotbeds of different areas: SFCM = 0.0003-0.007 m2 and SFCM = 0.045-0.245 m2. In the experiments, aerosol water flows with droplets of size 0.01-0.25 mm were used for the spraying of model fire hotbeds, and the density of spraying was 0.02 L/(m2·s). It was established that the characteristics of suppression of a fire by an aerosol water flow are mainly determined by the sizes of the droplets in this flow. Prognostic estimates of changes in the dispersivity of a droplet cloud, formed from large (as large as 0.5 L) "drops" (water agglomerates) thrown down from a height, have been made. It is shown that these changes can influence the conditions and characteristics of suppression of a forest fire. Dependences, allowing one to forecast the characteristics of suppression of the thermal decomposition of forest combustible materials with the use of large water agglomerates thrown down from an aircraft and aerosol clouds formed from these agglomerates in the process of their movement to the earth, are presented.

Ghana Mining Journal

African Journals Online (AJOL)

... in the Ghana mining journal: Geology and Mineral Exploration, Mining, Quarrying, Geomechanics, Groundwater Studies, Hydrocarbon Development, Mineral Processing, Metallurgy, Material Science, Mineral Management Policies, Mineral Economics, Environmental Aspects, Computer Applications and Mining Education.

Combustion Gases And Heat Release Analysis During Flame And Flameless Combustion Of Wood Pellets

Directory of Open Access Journals (Sweden)

Horváth Jozef

2015-06-01

Full Text Available With the growing prices of fossil fuels, alternative fuels produced of biomass come to the fore. They are made of waste materials derived from the processing of wood and wood materials. The main objective of this study was to analyse the fire-technical characteristics of wood pellets. The study analysed three dust samples acquired from wood pellets made of various types of wood biomass. Wood pellet dust is produced when manipulating with pellets. During this process a potentially hazardous situations may occur. Biomass is chemically composed mostly of hemicellulose, cellulose and lignin. During straining of the biomass by heat flux, combustion initiation occurs. Also, there was a change in the composition of material throughout combustion gases production, and the amount of heat generated by a flame or flameless combustion. Measurement of fire characteristics was conducted according to ISO 5660-1 standard using a cone calorimeter. Two samples of wood pellet dust were tested under the heat flux of 35 kW.m−2 and 50 kW.m−2. The process of combustion, the time to ignition, the carbon monoxide concentration and the amount of released heat were observed.

Coal combustion products in Europe valuable raw materials for the construction industry

Energy Technology Data Exchange (ETDEWEB)

Berg, W. vom; Feuerborn, H.J. [European Coal Combustion Products Association e.V., Essen (Germany)

2005-07-01

Coal combustion products (CCPs) are formed with the production of electricity in coal-fired power plants. The production of these CCPs has been increased by the years due to legal requirements for flue gas cleaning. The utilisation of CCPS is well is established in some European countries, based on long term experience and technical as well as environmental benefits. As CCPs are defined as waste materials by existing legislation the power industry has to handle the stigma put on the products and hamper the beneficial use. (orig.)

Fire hazards in the use of polyurethane foam with special consideration given to its use in the mining industry

Energy Technology Data Exchange (ETDEWEB)

Florschuetz, P.; Hoffmann, R.; Pfeiffer, J.

1980-08-01

Discusses results from combustion tests conducted with polyurethane (PUR) foam and polyisocyanurate (PIC) foam, which are employed in mine construction, thermal insulation, and coating of coal preparation equipment. Fire point, inflammation point, flame propagation, carbon monoxide content in the fumes and other parameters were investigated. Coating the foam with a fire resistant chemical agent delayed the combustion process. Mixing foam with various quantities of foam components influenced the combustion process as well. The combustion results are presented in tables. It is concluded that the user's instructions for producing foam should be strictly adhered to and that larger sections of insulation by these foams in underground mines can only be permitted when additional protection measures are undertaken. (5 refs.) (In German)

Quantitative data on the fire behavior of combustible materials found in nuclear power plants: A literature review

International Nuclear Information System (INIS)

Nowlen, S.P.

1987-02-01

This report presents the findings of a task in which currently available fire research literature was reviewed for quantitative data on the burning characteristics of combustible materials that are found in nuclear power plants. The materials considered for which quantitative data were available include cable insulation materials, flammable liquids, furniture, trash and general refuse, and wood and wood products. A total of 90 figures and tables, taken primarily from the referenced works, which summarize the available quantitative fire characterization information for these materials is presented

Injection of FGD Grout to Abate Acid Mine Drainage in Underground Coal Mines

Energy Technology Data Exchange (ETDEWEB)

Mafi, S.; Damian, M.T.; Senita, R.E.; Jewitt, W.C.; Bair, S.; Chin, Y.C.; Whitlatch, E.; Traina, S.; Wolfe, W.

1997-07-01

Acid Mine Drainage (AMD) from abandoned underground coal mines in Ohio is a concern for both residents and regulatory agencies. Effluent from these mines is typically characterized by low pH and high iron and sulfate concentrations and may contaminate local drinking-water supplies and streams. The objective of this project is to demonstrate the technical feasibility of injecting cementitious alkaline materials, such as Flue Gas Desulfurization (FGD) material to mitigate current adverse environmental impacts associated with AMD in a small, abandoned deep mine in Coshocton County Ohio. The Flue Gas Desulfurization material will be provided from American Electric Power`s (AEP) Conesville Plant. It will be injected as a grout mix that will use Fixated Flue Gas Desulfurization material and water. The subject site for this study is located on the border of Coshocton and Muskingum Counties, Ohio, approximately 1.5 miles south-southwest of the town of Wills Creek. The study will be performed at an underground mine designated as Mm-127 in the Ohio Department of Natural Resources register, also known as the Roberts-Dawson Mine. The mine operated in the mid-1950s, during which approximately 2 million cubic feet of coal was removed. Effluent discharging from the abandoned mine entrances has low pH in the range of 2.8-3.0 that drains directly into Wills Creek Lake. The mine covers approximately 14.6 acres. It is estimated that 26,000 tons of FGD material will be provided from AEP`s Conesville Power Plant located approximately 3 miles northwest of the subject site.

Injection of FGD Grout to Abate Acid Mine Drainage in Underground Coal Mines

International Nuclear Information System (INIS)

Mafi, S.; Damian, M.T.; Senita, R.E.; Jewitt, W.C.; Bair, S.; Chin, Y.C.; Whitlatch, E.; Traina, S.; Wolfe, W.

1997-07-01

Acid Mine Drainage (AMD) from abandoned underground coal mines in Ohio is a concern for both residents and regulatory agencies. Effluent from these mines is typically characterized by low pH and high iron and sulfate concentrations and may contaminate local drinking-water supplies and streams. The objective of this project is to demonstrate the technical feasibility of injecting cementitious alkaline materials, such as Flue Gas Desulfurization (FGD) material to mitigate current adverse environmental impacts associated with AMD in a small, abandoned deep mine in Coshocton County Ohio. The Flue Gas Desulfurization material will be provided from American Electric Power's (AEP) Conesville Plant. It will be injected as a grout mix that will use Fixated Flue Gas Desulfurization material and water. The subject site for this study is located on the border of Coshocton and Muskingum Counties, Ohio, approximately 1.5 miles south-southwest of the town of Wills Creek. The study will be performed at an underground mine designated as Mm-127 in the Ohio Department of Natural Resources register, also known as the Roberts-Dawson Mine. The mine operated in the mid-1950s, during which approximately 2 million cubic feet of coal was removed. Effluent discharging from the abandoned mine entrances has low pH in the range of 2.8-3.0 that drains directly into Wills Creek Lake. The mine covers approximately 14.6 acres. It is estimated that 26,000 tons of FGD material will be provided from AEP's Conesville Power Plant located approximately 3 miles northwest of the subject site

THE DEVELOPMENT OF SYNTHETIC SOIL MATERIALS FOR THE SUCCESSFUL RECLAMATION OF ABANDONED MINED LAND SITES

Energy Technology Data Exchange (ETDEWEB)

Song Jin

2006-03-01

Abandoned mine sites associated with coal and metal mining across the western United States have been left as unproductive wastelands. The availability of soil materials or other materials to support the restoration of the vegetative cover and enhance the recovery of such areas is limited. The restoration of these areas often requires the use of available amendments such as organic waste products or to help stabilize the soil. Many of the organic waste products, including sewage sludge, clarifier sludge, fly ash sludge, and other by-products from the agricultural industries such as compost can be employed for beneficial uses. This study looked at the feasibility of applying organic waste products to a mine soil in Montana to increase soil fertility and enhance plant productivity. Waste rock samples were tested for acid forming potential via acid base accounting. Samples cores were constructed and leached with simulated rainwater to determine amendment affect on metal leaching. A greenhouse study was completed to determine the most suitable amendment(s) for the field mine land site. Results from the acid base accounting indicate that acid formed from the waste rock would be neutralized with the alkalinity in the system. Results also show that metals in solution are easily held by organics from the amendments and not allowed to leach in to the surrounding water system. Data from the greenhouse study indicated that the amendment of sewage sludge was most promising. Application of 2% sewage sludge along with 1% sewage sludge plus 1% clarifier sludge, 2% compost, and no treatment were used for mine land application. Initial results were encouraging and it appears that sewage sludge may be a good reclamation option for mine lands.

Performance of candidate gas turbine abradeable seal materials in high temperature combustion atmospheres

Energy Technology Data Exchange (ETDEWEB)

Simms, N.J. [Cranfield University, Power Generation Technology Centre, Cranfield, Beds, MK43 0AL (United Kingdom); Norton, J.F. [Cranfield University, Power Generation Technology Centre, Cranfield, Beds, MK43 0AL (United Kingdom); Consultant in Corrosion Science and Technology, Hemel Hempstead, Herts HP1 1SR (United Kingdom); McColvin, G. [Siemens Industrial Turbines Ltd., Lincoln, LN5 7FD (United Kingdom)

2005-11-01

The development of abradeable gas turbine seals for higher temperature duties has been the target of an EU-funded R and D project, ADSEALS, with the aim of moving towards seals that can withstand surface temperatures as high as {proportional_to} 1100 C for periods of at least 24,000 h. The ADSEALS project has investigated the manufacturing and performance of a number of alternative materials for the traditional honeycomb seal design and novel alternative designs. This paper reports results from two series of exposure tests carried out to evaluate the oxidation performance of the seal structures in combustion gases and under thermal cycling conditions. These investigations formed one part of the evaluation of seal materials that has been carried out within the ADSEALS project. The first series of three tests, carried out for screening purposes, exposed candidate abradeable seal materials to a simulated natural gas combustion environment at temperatures within the range 1050-1150 C in controlled atmosphere furnaces for periods of up to {proportional_to} 2,500 h with fifteen thermal cycles. The samples were thermally cycled to room temperature on a weekly basis to enable the progress of the degradation to be monitored by mass change and visual observation, as well as allowing samples to be exchanged at planned intervals. The honeycombs were manufactured from PM2000 and Haynes 214. The backing plates for the seal constructions were manufactured from Haynes 214. Some seals contained fillers or had been surface treated (e.g. aluminised). The second series of three tests were carried out in a natural gas fired ribbon furnace facility that allowed up to sixty samples of candidate seal structures (including honeycombs, hollow sphere structures and porous ceramics manufactured from an extended range of materials including Aluchrom YHf, PM2Hf, Haynes 230, IN738LC and MarM247) to be exposed simultaneously to a stream of hot combustion gas. In this case the samples were cooled

Integrated engineering and cost model for management of coal combustion byproducts

Energy Technology Data Exchange (ETDEWEB)

Sevim, H. [Department of Mining Engineering, Southern Illinois University at Carbondale, Carbondale, Illinois (United States); Renninger, S. [US Department of Energy, Morgantown Energy Technology Center, Morgantown, West Virginia (United States)

1998-07-01

An integrated engineering and cost model has been developed as a part of an overall research project for exploring the technical, environmental and economic feasibility of disposing coal combustion byproducts and flue gas desulfurisation products in underground coal mines in Illinois. The features of the model have been keyed in user-friendly software. In this paper, the purpose and the structure of the model are described. The capabilities of the software are illustrated through an example involving transportation of byproducts in containers from a power plant to a mine site, and subsequent placement of the byproducts in a abandoned underground coal mine using a hydraulic injection system. 3 refs.

Multifaceted processes controlling the distribution of hazardous compounds in the spontaneous combustion of coal and the effect of these compounds on human health.

Science.gov (United States)

Oliveira, Marcos L S; da Boit, Kátia; Pacheco, Fernanda; Teixeira, Elba C; Schneider, Ismael L; Crissien, Tito J; Pinto, Diana C; Oyaga, Rafael M; Silva, Luis F O

2018-01-01

Pollution generated by hazardous elements and persistent organic compounds that affect coal fire is a major environmental concern because of its toxic nature, persistence, and potential risk to human health. The coal mining activities are growing in the state of Santa Catarina in Brazil, thus the collateral impacts on the health and economy are yet to be analyzed. In addition, the environment is also enduring the collateral damage as the waste materials directly influence the coal by-products applied in civil constructions. This study was aimed to establish the relationships between the composition, morphology, and structural characteristics of ultrafine particles emitted by coal mine fires. In Brazil, the self-combustions produced by Al-Ca-Fe-Mg-Si coal spheres are rich in chalcophile elements (As, Cd, Cu, Hg, Pb, Sb, Se, Sn, and Zn), lithophile elements (Ce, Hf, In, La, Th, and U), and siderophile elements (Co, Cr, Mo, Fe, Ni, and V). The relationship between nanomineralogy and the production of hazardous elements as analyzed by advanced methods for the geochemical analysis of different materials were also delineated. The information obtained by the mineral substance analysis may provide a better idea for the understanding of coal-fire development and assessing the response of particular coal in different combustion processes. Copyright © 2017 Elsevier Inc. All rights reserved.

Process and unit for gasification of combustible material. Verfahren und Aggregat zur Vergasung brennbaren Gutes

Energy Technology Data Exchange (ETDEWEB)

Linneborn, J

1987-05-21

The invention refers to a process for the gasification of solid and combustible material in a moving bed and a unit in which this process can be carried out. By material to be gasified one means small material such as ground fossil coal and all organic substances such as wood, straw, husks and shells of fruit, to which sewage sludge can be added. The new process can be carried out, according to the invention, in a closed duct moved by vibration or shaking, in which the material or the ash produced moves from one end to the other by suitable vibration and comes into contact with round heat sources largely resistant to friction. This achieves rapid gasification of the material (at about 1000/sup 0/C) by convection and radiation.

Introduction to Physics and Chemistry of Combustion Explosion, Flame, Detonation

CERN Document Server

Liberman, Michael A

2008-01-01

Most of the material covered in this book deals with the fundamentals of chemistry and physics of key processes and fundamental mechanisms for various combustion and combustion related phenomena in gaseous combustible mixture. It provides the reader with basic knowledge of burning processes and mechanisms of reaction wave propagation. The combustion of a gas mixture (flame, explosion, detonation) is necessarily accompanied by motion of the gas. The process of combustion is therefore not only a chemical phenomenon but also one of gas dynamics. The material selection focuses on the gas phase and

Implementation of Paste Backfill Mining Technology in Chinese Coal Mines

Science.gov (United States)

Chang, Qingliang; Zhou, Huaqiang; Bai, Jianbiao

2014-01-01

Implementation of clean mining technology at coal mines is crucial to protect the environment and maintain balance among energy resources, consumption, and ecology. After reviewing present coal clean mining technology, we introduce the technology principles and technological process of paste backfill mining in coal mines and discuss the components and features of backfill materials, the constitution of the backfill system, and the backfill process. Specific implementation of this technology and its application are analyzed for paste backfill mining in Daizhuang Coal Mine; a practical implementation shows that paste backfill mining can improve the safety and excavation rate of coal mining, which can effectively resolve surface subsidence problems caused by underground mining activities, by utilizing solid waste such as coal gangues as a resource. Therefore, paste backfill mining is an effective clean coal mining technology, which has widespread application. PMID:25258737

Risk factors for the undermined coal bed mining method

Energy Technology Data Exchange (ETDEWEB)

Arad, V. [Petrosani Univ., Petrosani (Romania). Dept. of Mining Engineering; Arad, S. [Petrosani Univ., Petrosani (Romania). Dept of Electrical Engineering

2009-07-01

The Romanian mining industry has been in a serious decline and is undergoing ample restructuring. Analyses of reliability and risk are most important during the early stages of a project in guiding the decision as to whether or not to proceed and in helping to establish design criteria. A technical accident occurred in 2008 at the Petrila coal mine involving an explosion during the exploitation of a coal seam. Over time a series of technical accidents, such as explosions and ignitions of methane gas, roof blowing phenomena or self-ignition of coal and hazard combustions have occurred. This paper presented an analysis of factors that led to this accident as well an analysis of factors related to the mining method. Specifically, the paper discussed the geomechanical characteristics of rocks and coal; the geodynamic phenomenon from working face 431; the spontaneous combustion phenomenon; gas accumulation; and the pressure and the height of the undermined coal bed. It was concluded that for the specific conditions encountered in Petrila colliery, the undermined bed height should be between 5 and 7 metres, depending on the geomechanic characteristics of coal and surrounding rocks. 8 refs., 1 tab., 3 figs.

Oxygen isotopic signature of CO2 from combustion processes

Directory of Open Access Journals (Sweden)

W. A. Brand

2011-02-01

Full Text Available For a comprehensive understanding of the global carbon cycle precise knowledge of all processes is necessary. Stable isotope (13C and 18O abundances provide information for the qualification and the quantification of the diverse source and sink processes. This study focuses on the δ18O signature of CO2 from combustion processes, which are widely present both naturally (wild fires, and human induced (fossil fuel combustion, biomass burning in the carbon cycle. All these combustion processes use atmospheric oxygen, of which the isotopic signature is assumed to be constant with time throughout the whole atmosphere. The combustion is generally presumed to take place at high temperatures, thus minimizing isotopic fractionation. Therefore it is generally supposed that the 18O signature of the produced CO2 is equal to that of the atmospheric oxygen. This study, however, reveals that the situation is much more complicated and that important fractionation effects do occur. From laboratory studies fractionation effects on the order of up to 26%permil; became obvious in the derived CO2 from combustion of different kinds of material, a clear differentiation of about 7‰ was also found in car exhausts which were sampled directly under ambient atmospheric conditions. We investigated a wide range of materials (both different raw materials and similar materials with different inherent 18O signature, sample geometries (e.g. texture and surface-volume ratios and combustion circumstances. We found that the main factor influencing the specific isotopic signatures of the combustion-derived CO2 and of the concomitantly released oxygen-containing side products, is the case-specific rate of combustion. This points firmly into the direction of (diffusive transport of oxygen to the reaction zone as the cause of the isotope fractionation. The original total 18O signature of the material appeared to have little influence, however, a contribution of specific bio

Solid waste combustion for alpha waste incineration

International Nuclear Information System (INIS)

Orloff, D.I.

1981-02-01

Radioactive waste incinerator development at the Savannah River Laboratory has been augmented by fundamental combustion studies at the University of South Carolina. The objective was to measure and model pyrolysis and combustion rates of typical Savannah River Plant waste materials as a function of incinerator operating conditions. The analytical models developed in this work have been incorporated into a waste burning transient code. The code predicts maximum air requirement and heat energy release as a function of waste type, package size, combustion chamber size, and temperature. Historically, relationships have been determined by direct experiments that did not allow an engineering basis for predicting combustion rates in untested incinerators. The computed combustion rates and burning times agree with measured values in the Savannah River Laboratory pilot (1 lb/hr) and full-scale (12 lb/hr) alpha incinerators for a wide variety of typical waste materials

Heavy metal distribution in soils near Palapye, Botswana: An evaluation of the environmental impact of coal mining and combustion on soils in a semi-arid region

Science.gov (United States)

Zhai, M.; Totolo, O.; Modisi, M.P.; Finkelman, R.B.; Kelesitse, S.M.; Menyatso, M.

2009-01-01

Morupule Colliery near Palapye in eastern Botswana is the only coalmine in production in Botswana at present. Its coal is mainly used in the nearby coal-fired Morupule Power Station, which generates approximately 1,000 GWh of electricity per annum. After more than 30 years mining and more than 20 years of combustion, the sedimentation of outlet fly ash from the Morupule Power Station has increased concentrations of Cr, Ni, Zn and As by 13, 2.5, 16 and 5 ppm, respectively, in the fine portion (<53 ??m) of surface soils for approximately 9 km downwind. Elements that have higher concentrations in coal have stronger small-particle association during coal combustion and are less mobile in surface soils, thus showing stronger contaminations in surface soils around the coal-fired plant. Although the degree of contamination of Cr, Ni, Zn and As from coal combustion in the Palapye area at present is low, it is necessary to monitor concentrations of these elements in surface soils routinely in the future. This study also reveals moderate Pb and Zn contaminations in the Palapye area. The former is due to the use of leaded petroleum in motor vehicle traffic and the latter is mainly due to the use of galvanized iron sheets in construction. ?? 2009 Springer Science+Business Media B.V.

Determination of the hydrogen isotopic compositions of organic materials and hydrous minerals using thermal combustion laser spectroscopy.

Science.gov (United States)

Koehler, Geoff; Wassenaar, Leonard I

2012-04-17

Hydrogen isotopic compositions of hydrous minerals and organic materials were measured by combustion to water, followed by optical isotopic analysis of the water vapor by off-axis integrated cavity output spectroscopy. Hydrogen and oxygen isotopic compositions were calculated by numerical integration of the individual isotopologue concentrations measured by the optical spectrometer. Rapid oxygen isotope exchange occurs within the combustion reactor between water vapor and molecular oxygen so that only hydrogen isotope compositions may be determined. Over a wide range in sample sizes, precisions were ±3-4 per mil. This is comparable but worse than continuous flow-isotope ratio mass spectroscopy (CF-IRMS) methods owing to memory effects inherent in water vapor transfer. Nevertheless, the simplicity and reduced cost of this analysis compared to classical IRMS or CF-IRMS methods make this an attractive option to determine the hydrogen isotopic composition of organic materials where the utmost precision or small sample sizes are not needed.

Experimental research on combustion fluorine retention using calcium-based sorbents during coal combustion (II)

Energy Technology Data Exchange (ETDEWEB)

Qi, Q.; Ma, X.; Liu, J.; Wu, X.; Zhou, J.; Cen, K. [Liaoning Technical University, Fuxin (China). College of Resource and Environment Engineering

2008-12-15

Fluoride pollution produced by coal burning can be controlled with the calcium-based sorbent combustion fluorine technique in which calcium-based sorbents are mixed with the coal or sprayed into the combustion chamber. In a fixed bed tube furnace combustion experiment using one calcium-based natural mineral, limestone and one calcium-based building material, it was shown that the calcium-based sorbent particle grain size and pore structure have a big influence on the combustion fluorine retention effect. Reducing the calcium-based sorbent particle grain size and improving the calcium sorbent structure characteristics at very high temperature to enhance the fluorine retention effect is the important approach to the fluorine retention agent development. 8 refs., 1 fig., 5 tabs.

Operational Decision Support for Material Management in Continuous Mining Systems: From Simulation Concept to Practical Full-Scale Implementations

Directory of Open Access Journals (Sweden)

Masoud Soleymani Shishvan

2017-07-01

Full Text Available Material management in opencast mines is concerned with planning, organizing, and control of the flow of materials from their extraction points to destinations. It can be strongly affected by operational decisions that have to be made during the production process. To date, little research has focused on the application of simulation modeling as a powerful supportive tool for decision making in such systems. Practical experiences from implementing a simulation model of a mine for the operational support on an industrial scale are not known to the authors. This paper presents the extension of a developed stochastic simulation model by the authors from a conceptual stage (TRL4 to a new Technology Readiness Level (TRL 6 by implementing it in an industrially relevant environment. A framework for modeling, simulation, and validation of the simulation model applied to two large opencast lignite mines is presented in detail. Operational implementation issues, experiences, and challenges in practical applications are discussed. Furthermore, the strength of applying the simulation modeling as an operational decision support for material management in coal mining is demonstrated. Results of the case studies are used to describe the details of the framework, and to illustrate the strength and limitations of its application.

An injection technique for in-situ remediation of abandoned underground coal mines

International Nuclear Information System (INIS)

Canty, G.A.; Everett, J.W.

1998-01-01

Remediation of underground mines can prove to be a difficult task, given the physical constraints associated with introducing amendments to a subterranean environment. An acid mine abatement project involving in-situ chemical treatment method was conducted by the University of Oklahoma. The treatment method involved the injection of an alkaline coal combustion by-product (CCB) slurry into a flooded mine void (pH 4.4) to create a buffered zone. Injection of the CCB slurry was possible through the use of equipment developed by the petroleum industry for grouting recovery wells. This technology was selected because the CCB slurry could be injected under significant pressure and at a high rate. With higher pressure and rates of injection, a large quantity of slurry can be introduced into the mine within a limited amount of time. Theoretically, the high pressure and rate would improve dispersal of the slurry within the void. In addition, the high pressure is advantageous in fracturing or breaking-down obstructions to injection. During the injection process, a total of 418 tons of CCB was introduced within 15 hours. The mine did not refuse any of the material, and it is likely that a much larger mass could have been added. One injection well was drilled into a pillar of coal. Normally this would pose a problem when introducing a slurry; however, the coal pillar was easily fractured during the injection process. Currently, the pH of the mine discharge is above 6.5 and the alkalinity is approximately 100 mg/L as CACO 3

30 CFR 817.89 - Disposal of noncoal mine wastes.

Science.gov (United States)

2010-07-01

... INTERIOR PERMANENT PROGRAM PERFORMANCE STANDARDS PERMANENT PROGRAM PERFORMANCE STANDARDS-UNDERGROUND MINING... surface runoff do not degrade surface or ground water, that fires are prevented, and that the area remains... underground water. Wastes shall be routinely compacted and covered to prevent combustion and wind-borne waste...

Cementitious backfill in mining

Energy Technology Data Exchange (ETDEWEB)

Taute, A; Spice, J; Wingrove, A C [Van Niekerk, Kleyn Edwards (South Africa)

1993-03-01

This article describes the need for increased usage of backfill material in mining and presents some of the considerations for use of cemented materials. Laboratory test results obtained using a variety of cementitious binders and mine tailings are presented. 3 figs., 1 tab.

Materiais cerâmicos para células a combustível Ceramic materials for fuel cells

Directory of Open Access Journals (Sweden)

D. Z. de Florio

2004-12-01

Full Text Available A partir da definição de células a combustível, é feita uma introdução sucinta dos tipos de células e dos materiais cerâmicos que são empregados em projeto e fabricação destes dispositivos geradores de energia elétrica. Tomando por base a ampla literatura científica disponível em publicações periódicas internacionais indexadas e arbitradas, bem como patentes, são relatados com detalhes os materiais cerâmicos com comportamento elétrico adequado para uso como eletrólitos, anodos, catodos, interconectores e selantes, que são os componentes básicos de células a combustível de óxidos sólidos. Por fim, é feita uma avaliação do estado da arte na pesquisa e desenvolvimento de materiais cerâmicos para uso em células a combustível de óxidos sólidos.Basic definitions of fuel cells and a brief introduction of different types of fuel cells are given. A review of the most important ceramic materials being considered for the design and fabrication of devices for producing electrical energy is presented. Ceramic materials with suitable electrical behavior to be used as electrolytes, anodes, cathodes, interconnectors, and sealants of solid oxide fuel cells are reported with details, taking into account the large number of available indexed and refereed scientific publications and patents. Finally, an evaluation of the state of the art of the research and development of ceramic materials for solid oxide fuel cells is presented.

Study on friction behaviour of brake shoe materials for mining hoist

Science.gov (United States)

Ungureanu, M.; Ungureanu, N. S.; Crăciun, I.

2017-02-01

The friction coefficient in the brake linkages has an important influence on the braking efficiency and safety of machines. The paper presents a method for the study of the friction coefficient of the friction couple brake shoe-drum for mining hoist. In this context, it is interesting to define the friction coefficient, not just according to the materials in contact, but according to the entire ensemble of tribological factors of the friction couple.

Initiation, Combustion and Transition to Detonation in Homogeneous and Heterogeneous Reactive Mixtures: A Summary

Science.gov (United States)

1981-09-01

undoubtedly associ- uid expanding-vapor explosions, or’ course of an explosion. In buildings ated with the manufacture, handling, BLEVEs , and unconfined...with its need for fossil fuel away, owing to atmospheric inhomo- energy, introduced coal mine explo- geneities, it is heard as a "boom." The blast wave...1947, when the fuels in enclosures compressed-air lines ship Grand Camp caught fire Combustion explosions of dusts In enclosures Coal mines , grain

Effect of Metal Additives on the Combustion Characteristics of High-Energy Materials

Directory of Open Access Journals (Sweden)

Korotkikh Alexander

2016-01-01

Full Text Available Thermodynamic calculation of combustion parameters and equilibrium composition of HEMs combustion products showed, that at the increase of aluminum powder dispersity the specific impulse and combustion temperature of solid propellants are reduced due to the decrease of the mass fraction of active aluminum in particles. Partial or complete replacement of aluminum by metal powder (B, Mg, AlB2, Al\\Mg alloy, Fe, Ti and Zr in HEMs composition leads to the reduce of the specific impulse and combustion temperature. Replacement of aluminum powder by boron and magnesium in HEM reduces the mass fraction of condensed products in the combustion chamber of solid rocket motor. So, for compositions HEMs with boron and aluminum boride the mass fraction in chamber is reduced by 24 and 36 %, respectively, with respect to the composition HEMs with Al powder. But the mass fraction of CCPs in the nozzle exit increases by 13 % for HEMs with aluminum boride due to the formation of boron oxide in the condensed combustion products. Partial replacement of 2 wt. % aluminum powder by iron and copper additives in HEM leads to the reduce of CCPs mass fraction in chamber by 4–10 % depending on the aluminum powder dispersity duo to these metals are not formed condensed products at the HEMs combustion in chamber.

MnO/N–C anode materials for lithium-ion batteries prepared by cotton-templated combustion synthesis

Directory of Open Access Journals (Sweden)

Cheng-Gong Han

2017-10-01

Full Text Available We herein report a facile one-pot synthesis of MnO/N-doped carbon (N–C composites via a sustainable cotton-template glycine–nitrate combustion synthesis to yield superior anode materials for Li ion batteries. MnO nanoparticles with several nanometers were well-embedded in a porous N-doped carbon matrix. It displays the unique characteristics, including the shortened Li+-ion transport path, increased contact areas with the electrolyte solution, inhibited volume changes and agglomeration of nanoparticles, as well as good conductivity and structural stability during the cycling process, thereby benefiting the superior cycling performance and rate capability. This favorable electrochemical performance of obtained MnO/N–C composites via a one-pot biomass-templated glycine/nitrate combustion synthesis renders the suitability as anode materials for Li-ion batteries. Keywords: Biomass, Cotton, Manganese oxide, Lithium ion battery, Porous carbon

Molten salt combustion of radioactive wastes

International Nuclear Information System (INIS)

Grantham, L.F.; McKenzie, D.E.; Richards, W.L.; Oldenkamp, R.D.

1976-01-01

The Atomics International Molten Salt Combustion Process reduces the weight and volume of combustible β-γ contaminated transuranic waste by utilizing air in a molten salt medium to combust organic materials, to trap particulates, and to react chemically with any acidic gases produced during combustion. Typically, incomplete combustion products such as hydrocarbons and carbon monoxide are below detection limits (i.e., 3 ) is directly related to the sodium chloride vapor pressure of the melt; >80% of the particulate is sodium chloride. Essentially all metal oxides (combustion ash) are retained in the melt, e.g., >99.9% of the plutonium, >99.6% of the europium, and >99.9% of the ruthenium are retained in the melt. Both bench-scale radioactive and pilot scale (50 kg/hr) nonradioactive combustion tests have been completed with essentially the same results. Design of three combustors for industrial applications are underway

Coal Combustion Products Extension Program

Energy Technology Data Exchange (ETDEWEB)

Tarunjit S. Butalia; William E. Wolfe

2006-01-11

This final project report presents the activities and accomplishments of the ''Coal Combustion Products Extension Program'' conducted at The Ohio State University from August 1, 2000 to June 30, 2005 to advance the beneficial uses of coal combustion products (CCPs) in highway and construction, mine reclamation, agricultural, and manufacturing sectors. The objective of this technology transfer/research program at The Ohio State University was to promote the increased use of Ohio CCPs (fly ash, FGD material, bottom ash, and boiler slag) in applications that are technically sound, environmentally benign, and commercially competitive. The project objective was accomplished by housing the CCP Extension Program within The Ohio State University College of Engineering with support from the university Extension Service and The Ohio State University Research Foundation. Dr. Tarunjit S. Butalia, an internationally reputed CCP expert and registered professional engineer, was the program coordinator. The program coordinator acted as liaison among CCP stakeholders in the state, produced information sheets, provided expertise in the field to those who desired it, sponsored and co-sponsored seminars, meetings, and speaking at these events, and generally worked to promote knowledge about the productive and proper application of CCPs as useful raw materials. The major accomplishments of the program were: (1) Increase in FGD material utilization rate from 8% in 1997 to more than 20% in 2005, and an increase in overall CCP utilization rate of 21% in 1997 to just under 30% in 2005 for the State of Ohio. (2) Recognition as a ''voice of trust'' among Ohio and national CCP stakeholders (particularly regulatory agencies). (3) Establishment of a national and international reputation, especially for the use of FGD materials and fly ash in construction applications. It is recommended that to increase Ohio's CCP utilization rate from 30% in 2005 to

Multi-stage combustion using nitrogen-enriched air

Science.gov (United States)

Fischer, Larry E.; Anderson, Brian L.

2004-09-14

Multi-stage combustion technology combined with nitrogen-enriched air technology for controlling the combustion temperature and products to extend the maintenance and lifetime cycles of materials in contact with combustion products and to reduce pollutants while maintaining relatively high combustion and thermal cycle efficiencies. The first stage of combustion operates fuel rich where most of the heat of combustion is released by burning it with nitrogen-enriched air. Part of the energy in the combustion gases is used to perform work or to provide heat. The cooled combustion gases are reheated by additional stages of combustion until the last stage is at or near stoichiometric conditions. Additional energy is extracted from each stage to result in relatively high thermal cycle efficiency. The air is enriched with nitrogen using air separation technologies such as diffusion, permeable membrane, absorption, and cryogenics. The combustion method is applicable to many types of combustion equipment, including: boilers, burners, turbines, internal combustion engines, and many types of fuel including hydrogen and carbon-based fuels including methane and coal.

SELECTION OF SUSTAINABLE TECHNOLOGIES FOR COMBUSTION OF BOSNIAN COALS

Directory of Open Access Journals (Sweden)

Anes Kazagić

2010-01-01

Full Text Available This paper deals with optimization of coal combustion conditions to support selection a sustainable combustion technology and an optimal furnace and boiler design. A methodology for optimization of coal combustion conditions is proposed and demonstrated on the example of Bosnian coals. The properties of Bosnian coals vary widely from one coal basin to the next, even between coal mines within the same basin. Very high percentage of ash (particularly in Bosnian brown coal makes clear certain differences between Bosnian coal types and other world coal types, providing a strong argument for investigating specific problems related to the combustion of Bosnian coals, as well as ways to improve their combustion behaviour. In this work, options of the referent energy system (boiler with different process temperatures, corresponding to the different combustion technologies; pulverised fuel combustion (slag tap or dry bottom furnace and fluidized bed combustion, are under consideration for the coals tested. Sustainability assessment, based on calculation economic and environment indicators, in combination with common low cost planning method, is used for the optimization. The total costs in the lifetime are presented by General index of total costs, calculated on the base of agglomeration of basic economic indicators and the economic indicators derived from environmental indicators. So, proposed methodology is based on identification of those combustion technologies and combustion conditions for coals tested for which the total costs in lifetime of the system under consideration are lowest, provided that all environmental issues of the energy system is fulfilled during the lifetime. Inputs for calculation of the sustainability indicators are provided by the measurements on an experimental furnace with possibility of infinite variation of process temperature, supported by good praxis from the power plants which use the fuels tested and by thermal

Diagnostic analysis of electrodialysis in mine tailing materials

DEFF Research Database (Denmark)

Hansen, Henrik K.; Ribeiro, Alexandra B.; Mateus, Eduardo

2007-01-01

Removal of heavy metals from mine tailings and soil contaminated by copper mining activities was studied under batch electrodialytic conditions. Two types of mine tailings were treated: (i) freshly produced tailings coming directly from the flotation process, and (ii) tailings deposited...... in a tailings pond, for approximately 20 years. The main contaminant was copper-found in concentration around 800-1800 ppm. The fractionation of copper and other characteristics of the tailings differ for the two tailings, indicating natural oxidation reactions in the old deposited ones. Electrodialytical...

Physicochemical and mineralogical characterization of Musina mine copper and New Union gold mine tailings: Implications for fabrication of beneficial geopolymeric construction materials

Science.gov (United States)

Gitari, M. W.; Akinyemi, S. A.; Thobakgale, R.; Ngoejana, P. C.; Ramugondo, L.; Matidza, M.; Mhlongo, S. E.; Dacosta, F. A.; Nemapate, N.

2018-01-01

The mining industries in South Africa generates huge amounts of mine waste that includes tailings; waste rocks and spoils. The tailings materials are dumped in surface impoundments that turn to be sources of hazards to the environment and the surrounding communities. The main environmental hazards posed by these tailings facilities are associated with their chemical constituents. Exposure to chemical constituents can occur through windblown dust, erosion to surface water bodies, inhalation by human beings and animals and through bioaccumulation and bio magnification by plants. Numerous un-rehabilitated tailings dumps exist in Limpopo province of South Africa. The communities found around these mines are constantly exposed to the environmental hazards posed by these tailing facilities. Development of a cost-effective technology that can beneficially utilize these tailings can reduce the environmental hazards and benefit the communities. This paper presents the initial evaluation of the copper and gold mine tailings in Limpopo, South Africa with a view to assessing the suitability of conversion into beneficial geopolymeric materials. Copper tailings leachates had alkaline pH (7.34-8.49) while the gold tailings had acidic pH. XRD confirmed presence of aluminosilicate minerals. Geochemical fractionation indicates that majority of the major and trace species are present in residual fraction. A significant amount of Ca, Cu and K was available in the mobile fraction and is expected to be released on tailings contacting aqueous solutions. Results from XRF indicates the tailings are rich in SiO2, Al2O3 and CaO which are the main ingredients in geopolymerization process. The SiO2/Al2O3 ratios indicates the tailings would require blending with Al2O3 rich feedstock for them to develop maximum strength. Moreover, the tailings have particle size in the range of fine sand which indicates potential application as aggregates in conventional brick manufacture.

8th international congress on mining and metallurgy. 8. Congreso internacional de mineria y metalurgia

Energy Technology Data Exchange (ETDEWEB)

1988-01-01

The meeting covered many aspects of mining and metallurgy including: underground and surface mining of coal; coal preparation; desulfurization and conversion; coal and coal waste combustion, including FBC; coal quality and chemistry; coal gasification; research programs on coal, the economics of the Spanish coal industry; and the Spanish coal industry and the European Community.

Fast Reacting Nano Composite Energetic Materials: Synthesis and Combustion Characterization

Science.gov (United States)

2015-08-24

nanoenergetic composites finding extensive use in ordnance and industrial applications, because of its high heat of combustion (~32 kJ/g) (S. H. Fischer ...2011. Farley, Cory. "Reactions of Aluminum with Halogen Containing Oxides." Dissertation. Lubbock, TX, May 2013. Gesner, Jeff , Michelle Pantoya, and...characteristics of novel hybrid nanoenergetic formulations." Combustion and Flame 158 (2011): 964- 978. S. H. Fischer , M. C. Grubelich. "Theoretical

30 CFR 57.4104 - Combustible waste.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Combustible waste. 57.4104 Section 57.4104... Control Prohibitions/precautions/housekeeping § 57.4104 Combustible waste. (a) Waste materials, including liquids, shall not accumulate in quantities that could create a fire hazard. (b) Waste or rags containing...

Behaviour of radium isotopes released with brines and sediments from coal mines in Poland

International Nuclear Information System (INIS)

Wysocka, M.; Chalupnik, S.; Mielnikow, A.; Lebecka, J.; Skubacz, K.

1998-01-01

Saline waters occurring in underground coal mines in Poland often contain natural radioactive isotopes, mainly 226 Ra from uranium series and 228 Ra from thorium series. Approximately 40% of total amount of radium remains underground in a form of radioactive deposits, but 225 MBq of 226 Ra and 380 MBq of 228 Ra are released daily to the rivers with mine effluents. Technical measures as spontaneous precipitation of radium in gobs, decreasing of amounts of water inflowing into underground working etc. have been undertaken in several coal mines and in the result total amount of radium released to the surface waters diminished by about 60% during last 5-6 years. Mine waters can cause a severe impact on the natural environment. The enhancement of radium concentration in river waters, bottom sediments and vegetation is observed. Sometimes radium concentration in rivers exceeds 0.7 kBq/m 3 , which is due to Polish law a permissible level for liquid radioactive waste. It was necessary to undertake investigations for development the methods of the purification of mine waters from radium. The radium balance in effluents has been calculated and a map of radioactive contamination of river waters have been prepared. Solid wastes with enhanced natural radioactivity have been produced in huge amounts in energy and coal industries in Poland. There are two main sources of these waste products. As a result of combustion of coal in power plants low radioactive waste materials are produced, with 226 Ra concentration seldom exceeding few hundreds of Bq/kg. Different situation is be observed in coal mines, where as a result of precipitation of radium from radium-bearing waters radioactive deposits are formed. Sometimes natural radioactivity of such materials is very high, in case of scaling from coal mines radium concentration may reach 4x10 5 Bq/kg - similar activity as for 3% uranium ore. Therefore maintenance of solid waste with technologically enhanced natural radioactivity (TENR

Research Combustion Laboratory (RCL)

Data.gov (United States)

Federal Laboratory Consortium — The Research Combustion Laboratory (RCL) develops aerospace propulsion technology by performing tests on propulsion components and materials. Altitudes up to 137,000...

The use of coal mining wastes for manufacturing paving materials; Los Esteriles del Carbon como Materia Prima para la Fabricacion de Materiales para Pavimentacion

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-07-01

This project was aimed at proving the technical feasibility of the use of coal mining wastes in the manufacturing of paving materials: floor-tiles, flags, paving-stones, grit stones, etc. The study proved that coal mining wastes in a mixture with other raw materials can be used in the manufacturing of paving materials: floor-tiles, paving-stones, grit stones.

Case studies of sealing methods and materials used in the salt and potash mining industries

International Nuclear Information System (INIS)

Eyermann, T.J.; Sambeek, L.L. Van; Hansen, F.D.

1995-11-01

Sealing methods and materials currently used in salt and potash industries were surveyed to determine if systems analogous to the shaft seal design proposed for the Waste Isolation Pilot Plant (WIPP) exist. Emphasis was first given to concrete and then expanded to include other materials. Representative case studies could provide useful design, construction, and performance information for development of the WIPP shaft seal system design. This report contains a summary of engineering and construction details of various sealing methods used by mining industries for bulkheads and shaft liners. Industrial experience, as determined from site visits and literature reviews, provides few examples of bulkheads built in salt and potash mines for control of water. Sealing experiences representing site-specific conditions often have little engineering design to back up the methods employed and even less quantitative evaluation of seal performance. Cases examined include successes and failures, and both contribute to a database of experiences. Mass salt-saturated concrete placement under ground was accomplished under several varied conditions. Information derived from this database has been used to assess the performance of concrete as a seal material. Concrete appears to be a robust material with successes in several case studies. 42 refs

Case studies of sealing methods and materials used in the salt and potash mining industries

Energy Technology Data Exchange (ETDEWEB)

Eyermann, T.J.; Sambeek, L.L. Van [RE/SPEC Inc., Rapid City, SD (United States); Hansen, F.D. [Sandia National Labs., Albuquerque, NM (United States). Repository Isolation Systems Dept.

1995-11-01

Sealing methods and materials currently used in salt and potash industries were surveyed to determine if systems analogous to the shaft seal design proposed for the Waste Isolation Pilot Plant (WIPP) exist. Emphasis was first given to concrete and then expanded to include other materials. Representative case studies could provide useful design, construction, and performance information for development of the WIPP shaft seal system design. This report contains a summary of engineering and construction details of various sealing methods used by mining industries for bulkheads and shaft liners. Industrial experience, as determined from site visits and literature reviews, provides few examples of bulkheads built in salt and potash mines for control of water. Sealing experiences representing site-specific conditions often have little engineering design to back up the methods employed and even less quantitative evaluation of seal performance. Cases examined include successes and failures, and both contribute to a database of experiences. Mass salt-saturated concrete placement under ground was accomplished under several varied conditions. Information derived from this database has been used to assess the performance of concrete as a seal material. Concrete appears to be a robust material with successes in several case studies. 42 refs.

Using Combustion Synthesis to Reinforce Berms and Other Regolith Structures

Science.gov (United States)

Rodriquez, Gary

2013-01-01

The Moonraker Excavator and other tools under development for use on the Moon, Mars, and asteroids will be employed to construct a number of civil engineering projects and to mine the soil. Mounds of loose soil will be subject to the local transport mechanisms plus artificial mechanisms such as blast effects from landers and erosion from surface vehicles. Some of these structures will require some permanence, with a minimum of maintenance and upkeep. Combustion Synthesis (CS) is a family of processes and techniques whereby chemistry is used to transform materials, often creating flame in a hard vacuum. CS can be used to stabilize civil engineering works such as berms, habitat shielding, ramps, pads, roadways, and the like. The method is to unroll thin sheets of CS fabric between layers of regolith and then fire the fabric, creating a continuous sheet of crusty material to be interposed among layers of loose regolith. The combination of low-energy processes, ISRU (in situ resource utilization) excavator, and CS fabrics, seems compelling as a general method for establishing structures of some permanence and utility, especially in the role of robotic missions as precursors to manned exploration and settlement. In robotic precursory missions, excavator/ mobility ensembles mine the Lunar surface, erect constructions of soil, and dispense sheets of CS fabrics that are covered with layers of soil, fired, and then again covered with layers of soil, iterating until the desired dimensions and forms are achieved. At the base of each berm, for example, is a shallow trench lined with CS fabric, fired and filled, mounded, and then covered and fired, iteratively to provide a footing against lateral shear. A larger trench is host to a habitat module, backfilled, covered with fabric, covered with soil, and fired. Covering the applied CS fabric with layers of soil before firing allows the resulting matrix to incorporate soil both above and below the fabric ply into the fused layer

Replication of an ivg protocol to estimate bioaccessible arsenic in materials from a gold mining area in Brazil

Directory of Open Access Journals (Sweden)

Fábio Benedito Ono

2012-08-01

Full Text Available Tests for bioaccessibility are useful in human health risk assessment. No research data with the objective of determining bioaccessible arsenic (As in areas affected by gold mining and smelting activities have been published so far in Brazil. Samples were collected from four areas: a private natural land reserve of Cerrado; mine tailings; overburden; and refuse from gold smelting of a mining company in Paracatu, Minas Gerais. The total, bioaccessible and Mehlich-1-extractable As levels were determined. Based on the reproducibility and the accuracy/precision of the in vitro gastrointestinal (IVG determination method of bioaccessible As in the reference material NIST 2710, it was concluded that this procedure is adequate to determine bioaccessible As in soil and tailing samples from gold mining areas in Brazil. All samples from the studied mining area contained low percentages of bioaccessible As.

Standard operating procedure for combustion of 14C - samples with OX-500 biological material oxidizer

International Nuclear Information System (INIS)

Nashriyah Mat.

1995-01-01

This procedure is for the purpose of safe operation of OX-500 biological material oxidizer. For ease of operation, the operation flow chart (including testing the system and sample combustion) and end of day maintenance flow chart were simplified. The front view, diagrams and switches are duly copied from operating manual. Steps on sample preparation are also included for biotic and a biotic samples. This operating procedure is subjected to future reviews

Data mining for materials design: A computational study of single molecule magnet

Energy Technology Data Exchange (ETDEWEB)

Dam, Hieu Chi [Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292 (Japan); Faculty of Physics, Vietnam National University, 334 Nguyen Trai, Hanoi (Viet Nam); Pham, Tien Lam; Ho, Tu Bao [Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292 (Japan); Nguyen, Anh Tuan [Faculty of Physics, Vietnam National University, 334 Nguyen Trai, Hanoi (Viet Nam); Nguyen, Viet Cuong [HPC Systems, Inc., 3-9-15 Kaigan, Minato-ku, Tokyo 108-0022 (Japan)

2014-01-28

We develop a method that combines data mining and first principles calculation to guide the designing of distorted cubane Mn{sup 4+} Mn {sub 3}{sup 3+} single molecule magnets. The essential idea of the method is a process consisting of sparse regressions and cross-validation for analyzing calculated data of the materials. The method allows us to demonstrate that the exchange coupling between Mn{sup 4+} and Mn{sup 3+} ions can be predicted from the electronegativities of constituent ligands and the structural features of the molecule by a linear regression model with high accuracy. The relations between the structural features and magnetic properties of the materials are quantitatively and consistently evaluated and presented by a graph. We also discuss the properties of the materials and guide the material design basing on the obtained results.

Effect of Metal Additives on the Combustion Characteristics of High-Energy Materials

OpenAIRE

Korotkikh, Aleksandr Gennadievich; Glotov, Oleg; Sorokin, Ivan

2016-01-01

Thermodynamic calculation of combustion parameters and equilibrium composition of HEMs combustion products showed, that at the increase of aluminum powder dispersity the specific impulse and combustion temperature of solid propellants are reduced due to the decrease of the mass fraction of active aluminum in particles. Partial or complete replacement of aluminum by metal powder (B, Mg, AlB[2], Al\\Mg alloy, Fe, Ti and Zr) in HEMs composition leads to the reduce of the specific impulse and comb...

Synthesis and characterization of a ferrous compound material obtained by combustion of ferroboron and ferrotitanium mixtures

International Nuclear Information System (INIS)

Bejar, M.A; Fuenzalida, J.L

2008-01-01

A ferrous compound material was synthesized in this work, by the air auto-combustion of mixtures of powdered ferroboron and ferrotitanium, compacted under pressures of 79 and 93 MPa and preheated to a temperature of about 1000 o C. The synthesized compounds were characterized by XRD analysis, and macro and micro-hardness tests. The formation of titanium diboride was found in all the synthesized test pieces (au)

Question marks of the Czech coal mining industry

International Nuclear Information System (INIS)

Dopita, M.; Pesek, J.

1995-01-01

An overview of brown and black coal mining in the Czech Republic is presented, and problems of the extent of coal reserves and of the profitability of deep black coal mining are discussed. Costs of coal mining in foreign countries are given. Coal mining in the Czech Republic can be expected to be loss-making unless coal prices are increased. Since coal resources in the Czech Republic are limited, additional nuclear power plants will have to be constructed or else coal for power generation will have to be imported. The environmental aspects of coal mining and burning are discussed. Medium-term and long-term solutions to reduce the environmental burden include thermal power plant desulfurization, application of the fluidized-bed combustion regime to coals with large ash and/or sulfur contents, and introduction of gas in towns and power plants. In the short run, large-scale consumers in towns and coal basins should be obliged to accumulate reserves of low-sulfur coal for later use. (J.B.). 2 tabs., 3 figs., 8 refs

Characteristics of coal mine ventilation air flows.

Science.gov (United States)

Su, Shi; Chen, Hongwei; Teakle, Philip; Xue, Sheng

2008-01-01

Coal mine methane (CMM) is not only a greenhouse gas but also a wasted energy resource if not utilised. Underground coal mining is by far the most important source of fugitive methane emissions, and approximately 70% of all coal mining related methane is emitted to the atmosphere through mine ventilation air. Therefore, research and development on mine methane mitigation and utilisation now focuses on methane emitted from underground coal mines, in particular ventilation air methane (VAM) capture and utilisation. To date, most work has focused on the oxidation of very low concentration methane. These processes may be classified based on their combustion kinetic mechanisms into thermal oxidation and catalytic oxidation. VAM mitigation/utilisation technologies are generally divided into two basic categories: ancillary uses and principal uses. However, it is possible that the characteristics of ventilation air flows, for example the variations in methane concentration and the presence of certain compounds, which have not been reported so far, could make some potential VAM mitigation and utilisation technologies unfeasible if they cannot cope with the characteristics of mine site ventilation air flows. Therefore, it is important to understand the characteristics of mine ventilation air flows. Moreover, dust, hydrogen sulphide, sulphur dioxide, and other possible compounds emitted through mine ventilation air into the atmosphere are also pollutants. Therefore, this paper presents mine-site experimental results on the characteristics of mine ventilation air flows, including methane concentration and its variations, dust loadings, particle size, mineral matter of the dust, and other compounds in the ventilation air flows. The paper also discusses possible correlations between ventilation air characteristics and underground mining activities.

Disposal of coal combustion wastes in the hydraulic backfill process

Science.gov (United States)

Pierzyna, Piotr

2017-11-01

This article presents the results of studies regarding the physical properties of selected combustion by-products (CCPs) currently produced in the energy production industry. These properties have been compared with the requirements of the technologies applied in the Polish underground mines. The article gives special consideration to the application of the products in the hydraulic backfill technology. The possibility of using bottom-ashes and slags was considered. The amount of CCPs disposed in Polish hard coal mines is approximately 1.1 million Mg and the tendency is decreasing. In the past two years, approximately 100-150 thousand Mg of CCPs was used in the hydraulic backfill technology. The percentage of the fraction smaller than 0.1 mm is determining for the possibility of using a given type of CCPs in the backfill material. This practically excludes the possibility of using any fly ashes in that technology. In slags from conventional boilers and bottom ashes from fluidized bed boilers the fraction below 0.1 mm constitutes 25% of the total at maximum, which allows for their use in the materials used in hydraulic backfill as a component comprising from 30% to 60%, respectively. Slags (10 01 01) are characterized by the lack of bonding properties, which, in case of open backfill systems that are exposed to atmospheric conditions, constitutes an advantage in comparison to bottom ashes (10 01 24), which in turn definitely exhibit bonding properties. The solution of the problem of using bottom ashes is their supply and application on a current basis.

Assessment of source material (U and Th) in exploration, mining, processing of zircon sand in Central Kalimantan

International Nuclear Information System (INIS)

Dedi Hermawan; Pandu Dewanto; Sudarto

2011-01-01

From 2004 to 2008, according to data released by the Commerce Department, the volume of zircon sand and concentrates exports has increased highly. One of many locations in Indonesia that widely available zircon sand is Kalimantan island. For example, Central Kalimantan Province in 2007 to 2008 exports about 51,000 tones up to 79,000 tones of zircon sand annually. The concentration of source material in the zircon sand is important to be known because the presence of natural radioactive U and Th in zircon sand has the potential radiation hazard. Therefore it is necessary to conduct an assessment the potential reserves related to the source material contained in the zircon sand and radiation safety that are applied in the process of mining or processing of zircon sand. In this paper the location of mining and processing of zircon sand is restricted to the province of Central Kalimantan. From the assessment obtained that source material which is carried by zircon sand export form the province of Central Kalimantan have the potential to exceed the limits set by the BAPETEN Chairman Decree No.9 of 2006 About the Implementation of the Additional Protocol to the Accountability System and Control of Nuclear Materials. In terms of compliance with radiation safety, required increased surveillance of K3 during mining, process / processing by the worker, supervisor / supervisors and regional management company to be able the achievement of compliance with the provisions of the management of materials and the safety of radiation sources based on national regulations (BAPETEN) and international. (author)

Sandia Combustion Research Program

Energy Technology Data Exchange (ETDEWEB)

Johnston, S.C.; Palmer, R.E.; Montana, C.A. (eds.)

1988-01-01

During the late 1970s, in response to a national energy crisis, Sandia proposed to the US Department of Energy (DOE) a new, ambitious program in combustion research. Shortly thereafter, the Combustion Research Facility (CRF) was established at Sandia's Livermore location. Designated a ''user facility,'' the charter of the CRF was to develop and maintain special-purpose resources to support a nationwide initiative-involving US inventories, industry, and national laboratories--to improve our understanding and control of combustion. This report includes descriptions several research projects which have been simulated by working groups and involve the on-site participation of industry scientists. DOE's Industry Technology Fellowship program, supported through the Office of Energy Research, has been instrumental in the success of some of these joint efforts. The remainder of this report presents results of calendar year 1988, separated thematically into eleven categories. Referred journal articles appearing in print during 1988 and selected other publications are included at the end of Section 11. Our traditional'' research activities--combustion chemistry, reacting flows, diagnostics, engine and coal combustion--have been supplemented by a new effort aimed at understanding combustion-related issues in the management of toxic and hazardous materials.

Heavy metals behaviour during mono-combustion and co-combustion of sewage sludge

Energy Technology Data Exchange (ETDEWEB)

Lopes, M. Helena; Abelha, Pedro; Olieveira, J.F. Santos; Gulyurtlu, Ibrahim; Cabrita, Isabel [INETI-DEECA, Lisboa (Portugal)

2005-03-01

This paper presents the study of the combustion of granular dry sewage sludge performed on a pilot fluidized bed system. The results of mono-combustion of sludge and co-combustion with coal were compared with those of coal combustion for ash partitioning, the formation of gaseous pollutants and heavy metals behaviour. It was found that the mineral matter of sludge was essentially retained as bottom ashes. The production of fines ashes was small during the mono-combustion due to the tendency of coal to produce fine ashes which also contained unburned char. The degree of heavy metal volatilization was found to be slightly higher during co-combustion than in mono-combustion; however, most of them were retained in ashes and their emissions were found to be below the regulated levels. Hg was completely volatilized; however, during combustion trials involving coal it was captured by cyclone ashes at temperatures below 300 deg C. During sludge mono-combustion the retention of Hg in cyclone ashes containing low LOI was not enough to decrease emissions below the regulated levels; hence, it is necessary to install dedicated flue gas treatment for Hg removal. The leachability and ecotoxicity of sludge and ashes was compared with the new regulatory limits for landfill disposal in the EU. It was found that the release of organic matter and heavy metals found in the sludge was low from granular bed ashes; hence, except for sulphate release, bed ashes were converted into inert and non-ecotoxic materials. Ashes from test with limestone and cyclone ashes seemed to be more problematic because of pH effects and contamination with steel corrosion products. The recovery and reutilization of sludge bed ashes could, therefore, be possible, as long as the release of sulphate do not interfere with the process.

Optimized mine ventilation on demand (OMVOD)

International Nuclear Information System (INIS)

Anderson, M.

2009-01-01

This paper provided an overview of the Optimized Mine Ventilation on Demand (OMVOD) system that is being installed at Xstrata Nickel Rim South Project and at Vale Inco's Totten Mine in Sudbury. The OMVOD system is designed to dynamically monitor and control air quality and quantity in real time and dilute and remove hazardous substances including diesel particulate matter (DPM), carbon monoxide (CO) and nitrous oxide (NO 2 ). It is also designed to control the thermal environment and provide ventilation for humans as well as mobile equipment engine combustion according to regulatory standards. The paper highlighted the OMVOD system optimization of energy, air quality measurement and control and production management of the mines through real time dynamic automation. Topics of discussion included real-time tracking and monitoring of diesel equipment; real-time tracking of underground miners; real-time evaluation of mine ventilation networks; and real-time control and optimization of ventilation equipment. ABB and Simsmart Technologies have joined forces to provide underground mining customers with a ventilation optimization solution. Simsmart's OMVOD provides proven real time/dynamic automation technology to significantly reduce energy costs, provide health and safety benefits as well as major capital cost savings while realizing an increase in production.

Guaranteeing high output of a mine

Energy Technology Data Exchange (ETDEWEB)

Shetser, M G

1983-05-01

Operation of the Im. Kalinina coal mine in the Central Donbass is evluated. Seventeen coal seams, on the average 0.87 m thick, are prone to methane and coal dust explosions and to rock bursts. Some of the seams are also prone to spontaneous combustion. Rock layers in the roofs are prone to rock falls. Mining depth ranges from 740 to 850 m. Another working level is being constructed at a depth of 960 m. The steep coal seams are mined by means of the ANShch shield systems and the KGU system (with the 'Poisk' cutter loader). Strata control methods used in the mine are evaluated. Design of timber cribbings used for strata control in inclined workings is shown in a scheme. Construction of coal chutes and strata control in coal chutes are also described. Operation of KGU-1 powered supports which have been used in the mine for 10 years is evaluated. Improved strata control permitted daily coal output from a working face to be increased from 135 t in 1979 to 169 t in 1982. Yearly coal output increased from 605,000 t to 760,000 t. Labor productivity increased from 21.1 t/month to 25.9 t/month per miner. (In Russian)

Process for the manufacture of a filter material for cleaning industrial or internal combustion engine exhaust gases and filter material manufactured according to the process. Verfahren zur Herstellung eines Filterstoffes zur Reinigung von industriellen oder Brennkraftmaschinen-Abgasen und ein hiernach hergestellter Filterstoff

Energy Technology Data Exchange (ETDEWEB)

Bumbalek, A.

1986-01-02

This is a process for the manufacture of a filter material for cleaning industrial or internal combustion engine exhaust gases and filter material manufactured according to the process. The filter material is manufactured from the mineralized combustion product of peel of tropical fruits burnt at a temperature of 820/sup 0/C to 840/sup 0/C in an oxidising atmosphere excluding the production of carbon, particularly using banana skins and orange peels, which product is granulated with carrier materials or compressed.

Biodesulfurization of coals of different rank: Effect on combustion behavior

Energy Technology Data Exchange (ETDEWEB)

Rubiera, F.; Arenillas, A.; Fuente, E.; Pis, J.J. [CSIC, Oviedo (Spain). Inst. Nacional del Carbon; Marteinz, O.; Moran, A. [Univ. de Leon (Spain). Escuela de Ingenieria Tecnica Minera

1999-02-01

The emission of sulfur oxides during the combustion of coal is one of the causes, among other air pollution problems, of acid rain. The contribution of coal as the mainstay of power production will be determined by whether its environmental performance is equal or superior to other supply options. In this context, desulfurization of coal before combustion by biological methods was studied. Four Spanish high-sulfur content coals of different rank were inoculated with bacteria isolated from mine-drainage waters and with naturally occurring bacteria inherent in the coals to be treated. Higher levels of desulfurization were obtained in the case of the samples treated with their own accompanying bacteria and when aeration was increased. All the samples were amenable to the biodepyritization processes. However, it is of little value to achieve large sulfur reductions if a decrease in coal combustion performance is obtained in the process. For this reason, a comparison was made between the combustibility characteristics of the original coals and those of the biodesulfurized samples. Results indicated that combustibility was not substantially modified by the overall biological treatment. The benefits of reduced sulfur emissions into the atmosphere ought to be taken into account as part of the general evaluation of the processes.

Reclamation of waste rock material at the Summitville Mine Superfund site using organic matter and topsoil treatments

Energy Technology Data Exchange (ETDEWEB)

Winter, M.E.; Redente, E.F.

1999-07-01

The Summitville Mine was a high elevation (3,500 m) open-pit gold mine located in southwestern Colorado. The mine was abandoned in 1992 leaving approximately 200 ha of disturbed area comprised partially of two large waste rock piles. Reclamation of waste rock material is challenging due to extreme climatic conditions in conjunction with a high acid-production potential and low organic matter concentration of the material. In addition, stockpiled topsoil at the site is acidic and may be biologically inactive due to long-term storage, and therefore sufficient plant growth medium may be limited. The purpose of this study was to determine the effect of organic amendments (mushroom compost vs. biosolids) and topsoil (stockpiled vs. nonstockpiled) on aboveground biomass, herbaceous cover, and trace element uptake. An on-site field study was established in 1995 to identify the most effective combination of treatments for successful reclamation of waste rock material. Incorporation of organic matter increased total aboveground production and cover, with mushroom compost being more effective than biosolids, but did not show significant trends relative to trace element uptake. The use of topsoil did not show a significant response relative to aboveground production, cover, and trace element uptake. This study shows that waste rock materials can be directly revegetated if properly neutralized, fertilized, and amended with organic matter. Additionally, stockpiled topsoil was equivalent in plant growth to non-stockpiled topsoil when neutralized with lime.

Method of predicting air pollution of coal mines with use of new synthetic materials

Energy Technology Data Exchange (ETDEWEB)

Sukhanov, V V; Putilina, O.N.

1988-08-01

Presents a methodological approach that enables on the basis of laboratory experiment to give a hygienic evaluation of synthetic materials used in coal mines to harden coal and rock masses to prevent rock falls and caving and for hermetization of ventilation equipment. Polyurethane, carbamidoformaldehyde and phenolformaldehyde plastic foam are studied in an experiment tha examined quantitative emission ofsubstances from their original components in the process of forming contaminants. Synthetics in a beaker are placed in an exsiccator, mixed with air, samples of volatiles particles collected and dynamics of their emission are calculated using regression and linear equations. Amounts of 2,4- toluenediisocyanate and diethylamine produced by polyurethane, and formaldehyde and methanol from carbamidoformaldehyde did not exceed limits of maximum concentrations; phenolformaldehyde plastic foam produced amounts of phenols and formaldehydes that are significantly higher than maximal permissible concentrations. Laboratory procedure and use of formulae were confirmed by testing air in a Donetsugol' mine. Polyurethane and carbamidoformaldehyde didnot contaminate air above hygienically safe limits, while phenolformaldehyde plastic foam exceeded safety limits proving need for hygienic measures to protect miners from its contaminants. Adequacy of laboratory-mathematical method to evaluate emissions of harmful chemicals from resins under mining conditions shows value of laboratory testing of many resins for safety in mine use. 4 refs.

Chemical reactor for converting a first material into a second material

Science.gov (United States)

Kong, Peter C

2012-10-16

A chemical reactor and method for converting a first material into a second material is disclosed and wherein the chemical reactor is provided with a feed stream of a first material which is to be converted into a second material; and wherein the first material is combusted in the chemical reactor to produce a combustion flame, and a resulting gas; and an electrical arc is provided which is passed through or superimposed upon the combustion flame and the resulting gas to facilitate the production of the second material.

Thermogravimetric analysis of biowastes during combustion

International Nuclear Information System (INIS)

Otero, M.; Sanchez, M.E.; Gomez, X.; Moran, A.

2010-01-01

The combustion of sewage sludge (SS), animal manure (AM) and the organic fraction of municipal solid waste (OFMSW) was assessed and compared with that of a semianthracite coal (SC) and of a PET waste by thermogravimetric (TG) analysis. Differences were found in the TG curves obtained for the combustion of these materials accordingly to their respective proximate analysis. Non-isothermal thermogravimetric data were used to assess the kinetics of the combustion of these biowastes. The present paper reports on the application of the Vyazovkin model-free isoconversional method for the evaluation of the activation energy necessary for the combustion of these biowastes. The activation energy related to SS combustion (129.1 kJ/mol) was similar to that corresponding to AM (132.5 kJ/mol) while the OFMSW showed a higher value (159.3 kJ/mol). These values are quite higher than the one determined in the same way for the combustion of SC (49.2 kJ/mol) but lower than that for the combustion of a PET waste (165.6 kJ/mol).

Toxicological and chemical characterization of the process stream materials and gas combustion products of an experimental low-btu coal gasifier.

Science.gov (United States)

Benson, J M; Hanson, R L; Royer, R E; Clark, C R; Henderson, R F

1984-04-01

The process gas stream of an experimental pressurized McDowell-Wellman stirred-bed low-Btu coal gasifier, and combustion products of the clean gas were characterized as to their mutagenic properties and chemical composition. Samples of aerosol droplets condensed from the gas were obtained at selected positions along the process stream using a condenser train. Mutagenicity was assessed using the Ames Salmonella mammalian microsome mutagenicity assay (TA98, with and without rat liver S9). All materials required metabolic activation to be mutagenic. Droplets condensed from gas had a specific mutagenicity of 6.7 revertants/microgram (50,000 revertants/liter of raw gas). Methylnaphthalene, phenanthrene, chrysene, and nitrogen-containing compounds were positively identified in a highly mutagenic fraction of raw gas condensate. While gas cleanup by the humidifier-tar trap system and Venturi scrubber led to only a small reduction in specific mutagenicity of the cooled process stream material (4.1 revertants/microgram), a significant overall reduction in mutagenicity was achieved (to 2200 revertants/liter) due to a substantial reduction in the concentration of material in the gas. By the end of gas cleanup, gas condensates had no detectable mutagenic activity. Condensates of combustion product gas, which contained several polycyclic aromatic compounds, had a specific mutagenicity of 1.1 revertants/microgram (4.0 revertants/liter). Results indicate that the process stream material is potentially toxic and that care should be taken to limit exposure of workers to the condensed tars during gasifier maintenance and repair and to the aerosolized tars emitted in fugitive emissions. Health risks to the general population resulting from exposure to gas combustion products are expected to be minimal.

Comparison and Application of Two types of Filling Gel to Prevent Spontaneous Combustion at the Region where Top-Coal Caves above Entry

Directory of Open Access Journals (Sweden)

Wang Yuhuai

2016-01-01

Full Text Available Two types of gel were developed, by taking fly ash and foaming cement as aggregate, which is usually used as filling material at the region where top-coal caves above coal entry in the Jinggezhuang coal mine, and adding high molecular polymer and bio-gel as additive. Sweating rates of the two types of gel under various matching ratio and temperature were tested. And then sweating ratio and water retention ratio of the two gels were calculated, based on which, the optimized matching ratios, were determined. Viscosity indexes of the two-type gel under different ratios were tested. The optimized filling ratios of the two types of gel were determined according to the two indexes, water retention rate and the viscosity. The filling experiments were implemented and evaluated in site, the Jinggezhuang coal mine. The results show that the fly ash gel has a good achievement on preventing spontaneous combustion at the Region where Top-Coal Caves above entries. It is promising, economically and environmental friendly, and valuable in popularization in coal mines.

Natural radionuclides concentration in underground mine materials

Energy Technology Data Exchange (ETDEWEB)

Santos, T.O.; Rocha, Z.; Taveira, N.F.; Takahashi, L.C.; Pineiro, M.M., E-mail: talitaolsantos@yahoo.com.br, E-mail: rochaz@cdtn.br, E-mail: mayarapinheiroduarte@gmail.com, E-mail: lauratakahashi@hotmail.com, E-mail: natyfontaveira@hotmail.com [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Borges, P.F.; Cruz, P.; Gouvea, V.A.; Siqueira, J.B., E-mail: vgouvea@cnen.gov.br, E-mail: flavia.borges@cnen.gov.br, E-mail: pcruz@cnen.gov.br, E-mail: jbsiquei@cnen.gov.br [Comissão Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

2017-07-01

Natural Radionuclides are present in earth's environment since its origin. The main radionuclides present are {sup 40}K, as well as, {sup 238}U and {sup 232}Th with their decay products. These radionuclides occur in minerals in different activity concentration associated with geological and geochemical conditions, appearing at different levels from point to point in the world. Underground mines may present a high natural background radiation which is due to the presence of these radiogenic heavy minerals. To address this concern, this work outlines on the characterization of the natural radionuclides presence in underground mines in Brazil which are located in many cases on higher radiation levels bed rocks. The radon concentration was measured by using E-PERM Electrets Ion Chamber, AlphaGUARD and CR-39 track etch detectors. The radon progeny was determined by using DOSEman detector. Radon concentration measurement in groundwater was performed by using RAD7 detector. The {sup 238}U and {sup 232}Th activity concentration in ore and soil samples were determined by using Neutron Activation Analysis using TRIGA MARK I IPR-R1 Reactor. Gamma spectrometry was used to determine {sup 226}Ra, {sup 228}Ra and {sup 40}K activity concentrations. The results show that the natural radioactivity varies considerably from mine to mine and that there are not risks of radiological damage for exposed workers in these cases. Based on these data, recommendations for Brazilian regulatory standards are presented. (author)

Natural radionuclides concentration in underground mine materials

International Nuclear Information System (INIS)

Santos, T.O.; Rocha, Z.; Taveira, N.F.; Takahashi, L.C.; Pineiro, M.M.; Borges, P.F.; Cruz, P.; Gouvea, V.A.; Siqueira, J.B.

2017-01-01

Natural Radionuclides are present in earth's environment since its origin. The main radionuclides present are 40 K, as well as, 238 U and 232 Th with their decay products. These radionuclides occur in minerals in different activity concentration associated with geological and geochemical conditions, appearing at different levels from point to point in the world. Underground mines may present a high natural background radiation which is due to the presence of these radiogenic heavy minerals. To address this concern, this work outlines on the characterization of the natural radionuclides presence in underground mines in Brazil which are located in many cases on higher radiation levels bed rocks. The radon concentration was measured by using E-PERM Electrets Ion Chamber, AlphaGUARD and CR-39 track etch detectors. The radon progeny was determined by using DOSEman detector. Radon concentration measurement in groundwater was performed by using RAD7 detector. The 238 U and 232 Th activity concentration in ore and soil samples were determined by using Neutron Activation Analysis using TRIGA MARK I IPR-R1 Reactor. Gamma spectrometry was used to determine 226 Ra, 228 Ra and 40 K activity concentrations. The results show that the natural radioactivity varies considerably from mine to mine and that there are not risks of radiological damage for exposed workers in these cases. Based on these data, recommendations for Brazilian regulatory standards are presented. (author)

Dehydrogenase activity and quality of leachates in Technosols with gossan and sulfide materials from the São Domingos mine

Science.gov (United States)

Santos, Erika; Abreu, Manuela; Macías, Felipe; de Varennes, Amarílis

2014-05-01

Wastes produced by mining activity in São Domingos (Portuguese Iberian Pyrite Belt) were disposed over a large area. To speed up the ecological rehabilitation in this mine, an integrative strategy using different amendments+mine wastes was used to produce Technosols with enhanced soil functions. To evaluate the efficiency of these Technosols the dehydrogenase activity and chemical quality of leachates were monitored. Technosols were composed of different mine wastes (gossan and sulfide materials), collected at the São Domingos mine, and mixtures of amendments applied at 30 and 75 Mg/ha (rockwool+agriculture wastes+wastes from liquors distillation of strawberry tree fruits (Arbutus unedo L.) and/or carobs (Ceratonia siliqua L. fruits)). Three assays, under controlled conditions, were carried out: (1 and 2) Sulfide or gossan materials with/without amendments; (3) Sulfide wastes, with/without amendments, incubated during four months and then with application of an overlayer of gossan (~3 cm thick) with/without the same amendments. Dehydrogenase activity (DHA) and chemical characteristics of leachates (multielemental concentration, pH, and electric conductivity) were determined after four/seven/thirteen months of incubation. Sulfide wastes had more hazardous characteristics (pH~2 and total concentrations (g/kg) of Al (58.1), As (1.1), Cu (2.1), Fe (107.3), Pb (11.7), S (65.3) and Zn (1.1) than the gossan materials (pH=4.3; g/kg, Al: 24.8, As: 3.0, Cu: 0.2, Fe: 129, Pb: 9.2, S: 13.7, Zn: 0.04). Amendments application to gossan (assay 2) enhanced DHA in both sampling periods (µg TPF g dry weight 16 h-1, Control: 0,72-1,78; Amended treatments: 2.49-16.36 depending on mixture/application rate/sampling period). Greater application rates stimulated DHA (more than 1.5-fold with 75 Mg/ha). No differences were observed in DHA in the gossan layer with/without amendments (assay 3) suggesting a negative impact on gossan microrganisms from sulfide materials located below. In

Operational decision support for material management in continuous mining systems : From simulation concept to practical full-scale implementations

NARCIS (Netherlands)

Soleymani Shishvan, M.; Benndorf, J.

2017-01-01

Material management in opencast mines is concerned with planning, organizing, and control of the flow of materials from their extraction points to destinations. It can be strongly affected by operational decisions that have to be made during the production process. To date, little research has

Response of plant species to coal-mine soil materials

Energy Technology Data Exchange (ETDEWEB)

Day, A.D.; Tucker, T.C.; Thames, J.L.

1983-03-01

The two-year Black Mesa Coal Mine Research Study on the area near Kayenta, Arizona investigating the growth and establishment of seven plant species in unmined soil and coal-mined soils found that plant species grew better in unmined soil and that irrigation is essential during seedling establishment for the effective stabilization of coal-mined soils in a semi-arid environment. Differences among the species included variations in germination, response to irrigation, seedling establishment, and stem growth. 12 references, 2 figures, 2 tables.

Drying wood waste with a pulse combustion dryer

Energy Technology Data Exchange (ETDEWEB)

Buchkowski, A.G. [Spectrum Engineering Corp., Ltd., Peterborough, Ontario (Canada); Kitchen, J.A. [John A. Kitchen, Ltd., Hastings, Ontario (Canada)

1993-12-31

There is a vast amount of wood waste available to be used as an alternate fuel if its moisture could be reduced efficiently. Tests have been conducted to assess an industrial dryer using pulse combustion as a heating source for drying wood waste; specifically sawdust and pulverized wet hog fuel. Pulse combustion offers the advantage of high heat transfer, efficient combustion, and low NO{sub x} emissions. The material is injected into the exhaust gases in the tailpipe of the combustor which uses natural gas or propane as a fuel. The turbulence created by the pulsations enhance the drying process by reducing the boundary layer thicknesses. The materials is further dried in a rotary drum. The material has been dried without scorching or burning in tests where the inlet moisture content has been as high as 60% on a wet basis. The outlet moisture contents achieved have typically been 10%. Analysis of the test data and cost estimates of the equipment indicate that the pulse combustion drying system is at least comparable to existing systems in terms of operating costs, and offers very significant savings in capital costs. Testing with various other materials such as wood pulp, sludges and peat is continuing to further assess the equipment`s performance.

The nuclear fuel cycle, From the uranium mine to waste disposal

International Nuclear Information System (INIS)

2002-09-01

Fuel is a material that can be burnt to provide heat. The most familiar fuels are wood, coal, natural gas and oil. By analogy, the uranium used in nuclear power plants is called 'nuclear fuel', because it gives off heat too, although, in this case, the heat is obtained through fission and not combustion. After being used in the reactor, spent nuclear fuel can be reprocessed to extract recyclable energy material, which is why we speak of the nuclear fuel cycle. This cycle includes all the following industrial operations: - uranium mining, - fuel fabrication, - use in the reactor, - reprocessing the fuel unloaded from the reactor, - waste treatment and disposal. 'The nuclear fuel cycle includes an array of industrial operations, from uranium mining to the disposal of radioactive waste'. Per unit or mass (e.g. per kilo), nuclear fuel supplies far more energy than a fossil fuel (coal or oil). When used in a pressurised water reactor, a kilo of uranium generates 10,000 times more energy than a kilo of coal or oil in a conventional power station. Also, the fuel will remain in the reactor for a long time (several years), unlike conventional fuels, which are burnt up quickly. Nuclear fuel also differs from others in that uranium has to undergo many processes between the time it is mined and the time it goes into the reactor. For the sake of simplicity, the following pages will only look at nuclear fuel used in pressurised water reactors (or PWRs), because nuclear power plants consisting of one or more PWRs are the most widely used around the world. (authors)

Appalachian mine soil morphology and properties: Effects of weathering and mining method

Energy Technology Data Exchange (ETDEWEB)

Haering, K.C.; Daniels, W.L.; Galbraith, J.M. [Virginia Polytechnic Institute & State University, Blacksburg, VA (United States)

2004-08-01

Surface coal mining and reclamation methods in the Appalachians have changed dramatically since the passage of the Surface Mining Control and Reclamation Act (SMCRA) of 1977 and subsequent improvements in mining and reclamation technology. In this study, 30 pre-SMCRA mine soil profiles (4-20 yr old) were examined and sampled in 1980 and compared with 20 mine soil profiles (8-13 yr old) described in the same area in 2002 after it had been completely remined by modern deep cut methods. Mine soils in both sampling years had high rock fragment content (42-81%), relatively well-developed A horizons, and generally exhibited A-C or A-AC-C horizonation. Although six Bw horizons were described in 1980, only two met all requirements for cambic horizons. The 1980 mine soils developed in overburden dominated by oxidized, preweathered material due to relatively shallow mining cuts. The 1980 mine soils had lower rock fragment content, finer textures, lower pH, and tended to be more heterogeneous in horizonation, morphology, and texture than soils observed in 2002, which had formed primarily in unweathered overburden from deeper cuts. Half the pedons sampled in both years had densic materials within 70 cm of the surface. Four poorly to very poorly drained soil profiles were described in each sampling year containing distinct hydric soil indicators in surface horizons. While older pre-SMCRA mine soils do have many properties in common with newer mine soils, their properties are highly influenced by the fact that they generally have formed in more weathered overburden from higher in the geologic column. Overall, Appalachian mine soils are much more complex in subsoil morphology than commonly assumed, and differential compaction greatly complicates their internal drainage and limits their overall productivity potential.

Annual Report: Advanced Combustion (30 September 2012)

Energy Technology Data Exchange (ETDEWEB)

Hawk, Jeffrey [NETL; Richards, George

2012-09-30

The Advanced Combustion Project addresses fundamental issues of fire-side and steam-side corrosion and materials performance in oxy-fuel combustion environments and provides an integrated approach into understanding the environmental and mechanical behavior such that environmental degradation can be ameliorated and long-term microstructural stability, and thus, mechanical performance can lead to longer lasting components and extended power plant life. The technical tasks of this effort are Oxy-combustion Environment Characterization, Alloy Modeling and Life Prediction, and Alloy Manufacturing and Process Development.

Physical and combustion characterization of pyrolytic oils derived from biomass material upgraded by catalytic hydrogenation

Energy Technology Data Exchange (ETDEWEB)

Vitolo, S.; Ghetti, P. (Universita di Pisa, Pisa (Italy). Dipartimento di Ingegneria Chimica)

1994-11-01

Physical and combustion properties of a pyrolytic bio-oil are determined both as-obtained and after catalytic hydrodeoxygenation. The tests demonstrate that the hydrogenation treatment improves the oil as regards combustibility, viscosity and acidity. Combustion properties of the oil have been characterized by evaporation and temperature programmed combustion profiles. Short communication. 21 refs., 4 figs., 2 tabs.

Practical application of solid phase spectrophotometry in analysis of materials and goods of mining and metallurgy

International Nuclear Information System (INIS)

Duan Qunzhang

1999-01-01

The author reviewed recent development and practical application of solid phase spectrophotometry in analysis of materials and goods of mining-metallurgy. Separation and preconcentration and conditions of coloring determination, sensitivity and range of detection, as well as interference of corresponding method are discussed

Imouraren mining exploitation : Complementary studies Synthetic report Volum B - Mines

International Nuclear Information System (INIS)

1980-01-01

The object of the current study is to determine the main technical characteristics of the reference project of a mine that can supply the necessary ore quantity at a production of 3000 tonnes uranium per year, along 10 years. The project is one of the possible solutions for exploiting the mine. The current study permits to establish : investment and functioning cost estimation, overall project of the mining exploitation program, necessary strength estimation, average ore grades evaluation and variations of these grades, utilities needs, production vizing program, main exploitation methods and necessary materials. Reference project study of the mine serves as base to the economics studies and studies optimization [fr

Methane combustion over lanthanum-based perovskite mixed oxides

Energy Technology Data Exchange (ETDEWEB)

Arandiyan, Hamidreza [New South Wales Univ., Sydney (Australia). School of Chemical Engineering

2015-11-01

This book presents current research into the catalytic combustion of methane using perovskite-type oxides (ABO{sub 3}). Catalytic combustion has been developed as a method of promoting efficient combustion with minimum pollutant formation as compared to conventional catalytic combustion. Recent theoretical and experimental studies have recommended that noble metals supported on (ABO{sub 3}) with well-ordered porous networks show promising redox properties. Three-dimensionally ordered macroporous (3DOM) materials with interpenetrated and regular mesoporous systems have recently triggered enormous research activity due to their high surface areas, large pore volumes, uniform pore sizes, low cost, environmental benignity, and good chemical stability. These are all highly relevant in terms of the utilization of natural gas in light of recent catalytic innovations and technological advances. The book is of interest to all researchers active in utilization of natural gas with novel catalysts. The research covered comes from the most important industries and research centers in the field. The book serves not only as a text for researcher into catalytic combustion of methane, 3DOM perovskite mixed oxide, but also explores the field of green technologies by experts in academia and industry. This book will appeal to those interested in research on the environmental impact of combustion, materials and catalysis.

Effect of plasma spraying modes on material properties of internal combustion engine cylinder liners

Science.gov (United States)

Timokhova, O. M.; Burmistrova, O. N.; Sirina, E. A.; Timokhov, R. S.

2018-03-01

The paper analyses different methods of remanufacturing worn-out machine parts in order to get the best performance characteristics. One of the most promising of them is a plasma spraying method. The mathematical models presented in the paper are intended to anticipate the results of plasma spraying, its effect on the properties of the material of internal combustion engine cylinder liners under repair. The experimental data and research results have been computer processed with Statistica 10.0 software package. The pare correlation coefficient values (R) and F-statistic criterion are given to confirm the statistical properties and adequacy of obtained regression equations.

Carbon Shale Combustion in the Fluidized Bed Reactor

Directory of Open Access Journals (Sweden)

Olek Małgorzata

2014-06-01

Full Text Available The purpose of this article is to present the possibilities of coal shale combustion in furnaces with bubbling fluidized bed. Coal shale can be autothermally combusted in the fluidized bed, despite the low calorie value and high ash content of fuel. Established concentrations of CO (500 ppm and VOC (30 mg/m3 have indicated a high conversion degree of combustible material during combustion process. Average concentrations of SO2 and NOx in the flue gas were higher than this received from the combustion of high quality hard coal, 600 ppm and 500 ppm, respectively. Optional reduction of SO2 and NOx emission may require the installation of flue gas desulphurization and de-NOx systems.

Reconstruction of industrial boiler type DKVR-13 aiming for combustion of waste materials from oil-yielding production

International Nuclear Information System (INIS)

Gadzhanov, P.

1997-01-01

One of the methods for improving of the energy efficiency is the use of a secondary energy resources such as waste products from industrial processes. In case of the oil extraction a great amount of waste product (sunflower shells) with a good thermal potential is available. During the industrial process from 100 kg raw material 15 kg shells are obtained. The combustion heat is about 1700 kJ/kg. The volatile compounds yield is 66.1%. An installation has been constructed intended to use the waste product from the extraction, consisting of: a water tube boiler with a steam capacity of 20 t/h and two PKM-12 type flue boilers and two DKVR 10-13 type water tube boilers. The DKVR 10-13 type boilers are designed for the production of 22.77 kg/s saturated steam with pressure 1.28 MPa and temperature 194 o C. They have an unified constructional schemes with a two-drum evaporating system and a natural circulation. The furnace has a horizontally evaporation beam washed by the gas flux. The reconstruction is aimed to create condition for the use of the sunflower shells as a main fuel and the natural gas or other fuel as additional. The scheme is one using the sloping bed combustion. 70% of the steam production is due to the shells combustion. Calculations for the grid parameters have been done. An additional heater improves the efficiency with 4.5% and the expected annual fuel saving is 300 t. The introduction of hot air (165 o C) provides both combustion and ecological benefits

Effects of combustible stacking in large compartments

DEFF Research Database (Denmark)

Gentili, Filippo; Giuliani, Luisa; Bontempi, Franco

2013-01-01

This paper focuses on the modelling of fire in case of various distributions of combustible materials in a large compartment. Large compartments often represent a challenge for structural fire safety, because of lack of prescriptive rules to follow and difficulties of taking into account the effect...... of non uniform distribution of the combustible materials and fire propagation. These aspects are discussed in this paper with reference to an industrial steel building, taken as case study. Fires triggered by the burning of wooden pallets stored in the premises have been investigated with respect...

Ash quality and environmental quality assurance system in co-combustion - Co-combustion of forest industry waste

International Nuclear Information System (INIS)

Laine-Ylijoki, J.; Wahlstroem, M.

2000-01-01

The environmental acceptability and possible utilization of co-combustion ashes will have a significant influence on the wider use of co-combustion in the future. At present the correlation between currently used fuels, their mixture ratios, and quality variations in ashes are not known, which complicates the assessment of possible utilization and environmental acceptability of co-combustion ashes. The composition of ashes has also been found to vary significantly. Effective utilization requires that process variations to alter ash composition and quality variations are known in advance. The aim of the research was to characterize the fly ash from co- combustion of peat, wood and biological paper mill sludge produced under different fuel loadings, especially with and without sludge addition, ant to identify critical parameters influencing on the ash composition. The variations in the leaching properties of ashes collected daily were followed up. The environmental acceptability of the ashes produced under different fuel loadings, especially their suitability for use in road constructions, were evaluated. The project included also the preparation of laboratory reference material from ash material. Guidelines were developed for sampling, sample preparation and analysis, and leaching tests. Furthermore, a quality control system, including sampling strategies, sample analysis and leaching testing, was established

in remediating acid mine drainage

African Journals Online (AJOL)

The management and treatment of contaminated mine water is one of the most urgent problems facing the South African mining industry. The cost advantage of permeable reactive barriers (PRBs) has seen their increased application as means of passively treating mine drainage. A PRB is built by placing a reactive material ...

Final environmental impact statement. Marquez uranium mine

International Nuclear Information System (INIS)

1984-01-01

As one of many activities TVA has undertaken to ensure an adequate supply of uranium for these plants, TVA has proposed to underground mine, through its operator, the uranium deposits located in the Canon de Marquez in McKinley County, New Mexico. Construction and operation of the underground mine would be expected to have the following environmental effects: (a) a temporary change in land use for 48.5 hectares from wildlife habitat and recreation to mineral extraction; (b) a minor alteration in topography near the proposed pond sites due to reclamation of waste rock piles; (c) minimal impacts on land due to limited vehicular traffic and road construction; (d) temporary depression of ground water levels in the Westwater Canyon Member of the Morrison Formation in the mine vicinity during mine life; (e) short-term project-induced impacts to surface water and shallow ground water quality; (f) a temporary decrease in air quality in the vicinity of the mining operations due to fugitive dust and exhaust emissions from combustion-driven mining and support vehicles and releases of radon and short-lived radon progeny from ventilation shafts and ore piles; (g) a temporary decrease of plant and animal species at the mine site; (h) a minor and temporary effect on aquatic systems downstream from the mine and settling ponds due to sedimentation; and (i) a minor increase of noise levels in the immediate vicinity of mine shafts and vents. The no action alternative and alternatives for securing uranium ore by other methods were considered but were found insufficient to meet TVA objectives. None of the alternatives explored were environmentally preferable. TVA also evaluated site specific alternatives including the following: different shaft and support building siting, mining techniques, and reclamation options. 25 figures, 20 tables

Fractionated-combustion analysis of carbonate-containing phases in composite materials of the hydroxyapatite-calcium carbonate system

Science.gov (United States)

Goldberg, M. A.; Shibaeva, T. V.; Smirnov, V. V.; Kutsev, S. V.; Barinov, S. M.; Grigorovich, K. V.

2012-12-01

Materials in the hydroxyapatite (HA)-calcium carbonate (CC) system were synthesized by a precipitation method from aqueous solutions. According to the data of X-ray phase analysis and IR spectroscopy, the powders consisted of CC and AB-type carbonate-substituted HA (CHA). In order to determine the content of carbonate-containing phases in materials, the temperature-temporal mode of fractionated-combustion analysis of carbon was developed. The quantitative phase ratios and the degree of substitution of carbonate groups in CHA were determined. It was shown that the degree of substitution of carbonate groups in CHA increased from 2.47 to 5.31 wt % as the CC content increased from 13.50 to 88.33 wt %.

Combustion characterization of rape seed meal and suggestions for optimal use in combustion appliances; Foerbraenningskarakterisering av rapsmjoel och foerslag till optimalt nyttjande i olika foerbraenningsanlaeggningar

Energy Technology Data Exchange (ETDEWEB)

Eriksson, Gunnar; Hedman, Henry; Oehman, Marcus; Bostroem, Dan; Pettersson, Esbjoern; Pommer, Linda; Lindstroem, Erica; Backman, Rainer; Oehman, Rikard

2007-12-15

When rape oil is chemically extracted, rape seed meal, a solid residue remains. Currently, it is used as animal feed. Several plants for the production of rape methyl ester (RME, biodiesel) are in operation or under construction. Combustion properties have been studied for rape seed meal produced as a by product to rape-methyl esther (RME, biodiesel). Composition of the material has been measured, using proximate and ultimate analysis. The lower heating value was 18.2 +- 0.3 MJ/kg d.w. and the ash content was 7-8 percent d.w. The material is rich in nitrogen and sulphur. Concentrations of K, P, Ca and Mg are high in the fuel. Rape seed meal was mixed with bark and pelletised. Bark pellets were also used as a reference fuel. Pellets with 10 and 30 percent rape seed meal were produced. Material with 80 percent rape seed meal and 20 percent planer shavings was also pelletised. Wood had to be added to provide enough friction in the pelletising process, with adapted equipment rape seed meal could probably be easily pelletised). The material was studied using Thermo-Gravimetric Analysis (TGA), and compared with data from tests with wood powder. The pyrolysis of the rape seed meal has a characteristic temperature of 320 deg C. Devolatilisation starts at 150 deg C (at a lower temperature than for wood powder), and proceeds within a rather wide temperature range. The probable cause is the difference in organic content, in particular protein content. The result does not suggest that the material will be difficult to ignite. Experiments in a bench-scale fluidised bed (5 kW) showed that pellets containing only bark, and the mixture rape seed meal/wood had a bed agglomeration temperature well over the normal operational bed temperature. For the fuel mixtures rape seed meal and bark, the agglomeration temperature was slightly over the operational temperature. Particle emissions from fluidised bed combustion and grate combustion were, the latter simulated using a commercial

Sodium nitrate combustion limit tests

International Nuclear Information System (INIS)

Beitel, G.A.

1976-04-01

Sodium nitrate is a powerful solid oxidant. Energetically, it is capable of exothermically oxidizing almost any organic material. Rate-controlling variables such as temperature, concentration of oxidant, concentration of fuel, thermal conductivity, moisture content, size, and pressure severely limit the possibility of a self-supported exothermic reaction (combustion). The tests reported in this document were conducted on one-gram samples at atmospheric pressure. Below 380 0 C, NaNO 3 was stable and did not support combustion. At moisture concentrations above 22 wt percent, exothermic reactions did not propagate in even the most energetic and reactive compositions. Fresh resin and paraffin were too volatile to enable a NaNO 2 -supported combustion process to propagate. Concentrations of NaNO 3 above 95 wt percent or below 35 wt percent did not react with enough energy release to support combustion. The influence of sample size and confining pressure, both important factors, was not investigated in this study

Data Mining and Complex Problems: Case Study in Composite Materials

Science.gov (United States)

Rabelo, Luis; Marin, Mario

2009-01-01

Data mining is defined as the discovery of useful, possibly unexpected, patterns and relationships in data using statistical and non-statistical techniques in order to develop schemes for decision and policy making. Data mining can be used to discover the sources and causes of problems in complex systems. In addition, data mining can support simulation strategies by finding the different constants and parameters to be used in the development of simulation models. This paper introduces a framework for data mining and its application to complex problems. To further explain some of the concepts outlined in this paper, the potential application to the NASA Shuttle Reinforced Carbon-Carbon structures and genetic programming is used as an illustration.

Data mining for better material synthesis: The case of pulsed laser deposition of complex oxides

Science.gov (United States)

Young, Steven R.; Maksov, Artem; Ziatdinov, Maxim; Cao, Ye; Burch, Matthew; Balachandran, Janakiraman; Li, Linglong; Somnath, Suhas; Patton, Robert M.; Kalinin, Sergei V.; Vasudevan, Rama K.

2018-03-01

The pursuit of more advanced electronics, and finding solutions to energy needs often hinges upon the discovery and optimization of new functional materials. However, the discovery rate of these materials is alarmingly low. Much of the information that could drive this rate higher is scattered across tens of thousands of papers in the extant literature published over several decades but is not in an indexed form, and cannot be used in entirety without substantial effort. Many of these limitations can be circumvented if the experimentalist has access to systematized collections of prior experimental procedures and results. Here, we investigate the property-processing relationship during growth of oxide films by pulsed laser deposition. To do so, we develop an enabling software tool to (1) mine the literature of relevant papers for synthesis parameters and functional properties of previously studied materials, (2) enhance the accuracy of this mining through crowd sourcing approaches, (3) create a searchable repository that will be a community-wide resource enabling material scientists to leverage this information, and (4) provide through the Jupyter notebook platform, simple machine-learning-based analysis to learn the complex interactions between growth parameters and functional properties (all data/codes available on https://github.com/ORNL-DataMatls). The results allow visualization of growth windows, trends and outliers, which can serve as a template for analyzing the distribution of growth conditions, provide starting points for related compounds and act as a feedback for first-principles calculations. Such tools will comprise an integral part of the materials design schema in the coming decade.

Combustion synthesis: A new approach for preparation of thermoelectric zinc antimonide compounds

Energy Technology Data Exchange (ETDEWEB)

Rouessac, F., E-mail: Florence.Rouessac@univ-montp2.fr [Institut Charles Gerhardt Montpellier, UMR 5253 CNRS-UM2-ENSCM-UM1, C2M Universite Montpellier 2, CC 1504 Place Eugene Bataillon, 34095 Montpellier Cedex 5 (France); Ayral, R.-M. [Institut Charles Gerhardt Montpellier, UMR 5253 CNRS-UM2-ENSCM-UM1, C2M Universite Montpellier 2, CC 1504 Place Eugene Bataillon, 34095 Montpellier Cedex 5 (France)

2012-07-25

Highlights: Black-Right-Pointing-Pointer Reliable preparation method of thermoelectric materials. Black-Right-Pointing-Pointer Formation of zinc antimonide by the combustion synthesis method is investigated. Black-Right-Pointing-Pointer XRD and Raman spectroscopy as a function of temperature. Black-Right-Pointing-Pointer SHS: a new way for synthesizing thermoelectric materials. - Abstract: Due to the interesting properties of Zn{sub 4}Sb{sub 3} thermoelectric material, a reliable preparation method of this material is required. In this study, the formation of zinc antimonides by the combustion synthesis method is investigated and subjected to characterization using X-ray diffraction and Raman spectroscopy as a function of temperature. The results show that combustion synthesis can be a new way for synthesizing these thermoelectric materials.

Contamination of settling ponds and rivers as a result of discharge of radium-bearing waters from Polish coal mines.

Science.gov (United States)

Chalupnik, S; Michalik, B; Wysocka, M; Skubacz, K; Mielnikow, A

2001-01-01

Saline waters from underground coal mines in Poland often contain natural radioactive isotopes, mainly 226Ra from the uranium decay series and 228Ra from the thorium series. Approximately 40% of the total amount of radium remains underground as radioactive deposits, but 225 MBq of 226Ra and 400 MBq of 228Ra are released daily into the rivers along with the other mine effluents from all Polish coal mines. Technical measures such as inducing the precipitation of radium in gobs, decreasing the amount of meteoric inflow water into underground workings, etc. have been undertaken in several coal mines, and as a result of these measures, the total amount of radium released to the surface waters has diminished by about 60% during the last 5-6 years. Mine water can have a severe impact on the natural environment, mainly due to its salinity. However, associated high levels of radium concentration in river waters, bottom sediments and vegetation have also been observed. Sometimes radium concentrations in rivers exceed 0.7 kBq/m3, which is the permitted level for waste waters under Polish law. The extensive investigations described here were carried out for all coal mines and on this basis the total radium balance in the effluents has been calculated. Measurements in the vicinity of mine settling ponds and in rivers have given us an opportunity to study radium behaviour in river waters and to assess the degree of contamination. Solid waste materials with enhanced natural radioactivity have been produced in huge amounts in the power and coal industries in Poland. As a result of the combustion of coal in power plants, low-radioactive waste materials are produced, with 226Ra concentration seldom exceeding a few hundreds of Bq/kg. A different situation is observed in coal mines, where, as a result of precipitation of radium from radium-bearing waters, highly radioactive deposits are formed. Sometimes the radioactivity of such materials is extremely high; precipitates from coal

Effect of raw material particle-size distribution on combustion characteristics of stem wood pellets; Paaverkan av partikelfraktionsfoerdelningen paa utbraenningshastigheten hos traepellets vid nyttjande av olika soenderdelningsmetoder

Energy Technology Data Exchange (ETDEWEB)

Israelsson, Samuel; Henriksson, Gunnar; Boman, Christoffer; Oehman, Marcus

2007-01-15

The objective of the project was to determine the effect of raw material particle-size distribution on combustion characteristics of stem wood pellets. Several well defined pellet qualities were produced from raw materials (stem wood of pine and spruce) which had both different particle-size distributions and were produced with different milling equipments (hammer mill/refiner). The pellets were produced in a traditional (bench-scale) pellet mill and in a laboratory pellet mill/press. The combustion characteristics of the individual pellets were determined in a laboratory scale oven. Char yield, -shrinkage, -density and the micro pore volume of the produced char were also determined. Differences in total conversion times of approximately 5 % at experimental condition relevant for typical pellets equipment were determined for the different pellet qualities. The underlying reasons for the obtained differences in the combustion characteristics between the different pellet qualities are discussed in the report

Theoretical Energy Release of Thermites, Intermetallics, and Combustible Metals

Energy Technology Data Exchange (ETDEWEB)

Fischer, S.H.; Grubelich, M.C.

1999-05-14

Thermite mixtures, intermetallic reactants, and metal fuels have long been used in pyrotechnic applications. Advantages of these systems typically include high energy density, high combustion temperature, and a wide range of gas production. They generally exhibit high temperature stability and possess insensitive ignition properties. For the specific applications of humanitarian demining and disposal of unexploded ordnance, these pyrotechnic formulations offer additional benefits. The combination of high thermal input with low brisance can be used to neutralize the energetic materials in mines and other ordnance without the "explosive" high-blast-pressure events that can cause extensive collateral damage to personnel, facilities, and the environment. In this paper, we review the applications, benefits, and characteristics of thermite mixtures, intermetallic reactants, and metal fuels. Calculated values for reactant density, heat of reaction (per unit mass and per unit volume), and reaction temperature (without and with consideration of phase changes and the variation of specific heat values) are tabulated. These data are ranked in several ways, according to density, heat of reaction, reaction temperature, and gas production.

ASSESSMENTS OF FUTURE ENVIRONMENTAL TRENDS AND PROBLEMS OF INCREASED USE, RECYCLING, AND COMBUSTION OF FIBER-REINFORCED, PLASTIC AND METAL COMPOSITE MATERIALS

Science.gov (United States)

The purpose of the study is to identify and define future environmental concerns related to the projected utilization, recycling, and combustion of composite materials. The study is being conducted for the Office of Strategic Assessment and Special Studies (OSASS) of the U.S. Env...

Development of Novel Fe-Based Coating Systems for Internal Combustion Engines

Science.gov (United States)

Bobzin, K.; Öte, M.; Königstein, T.; Dröder, K.; Hoffmeister, H.-W.; Mahlfeld, G.; Schläfer, T.

2018-04-01

Nowadays, combustion engines are the most common way to power vehicles. Thereby, losses occur due to cooling, exhaust gas and friction. With regard to frictional losses, highest potentials for optimization can be found in the tribological system of the inner surface of combustion chamber and piston ring. Besides friction, corrosive stress increases, e.g., due to utilization of exhaust gas recovery. In order to save energy, reduce emissions and enhance the life span of combustion engines, the demand for innovative coating material systems, especially for the inner surface of combustion chamber, increases. This study focuses on the development of innovative iron-based coating materials for the combustion chamber. As a first step, the plasma transferred wire arc and rotating single wire arc (RSW) technologies were compared using 0.8% C-steel as a reference. Subsequently, RSW was used for coating deposition using an innovative iron-based feedstock material. In order to improve wear and corrosion resistance, boron and chromium were added to the feedstock material. After deposition, different honing topographies were manufactured and compared under tribological load. Furthermore, electrochemical corrosion tests were conducted using an electrolyte simulating the exhaust gas concentrate. Especially with regard to corrosion, the novel coating system FeCrBMn showed promising results.

Development of Novel Fe-Based Coating Systems for Internal Combustion Engines

Science.gov (United States)

Bobzin, K.; Öte, M.; Königstein, T.; Dröder, K.; Hoffmeister, H.-W.; Mahlfeld, G.; Schläfer, T.

2018-02-01

Nowadays, combustion engines are the most common way to power vehicles. Thereby, losses occur due to cooling, exhaust gas and friction. With regard to frictional losses, highest potentials for optimization can be found in the tribological system of the inner surface of combustion chamber and piston ring. Besides friction, corrosive stress increases, e.g., due to utilization of exhaust gas recovery. In order to save energy, reduce emissions and enhance the life span of combustion engines, the demand for innovative coating material systems, especially for the inner surface of combustion chamber, increases. This study focuses on the development of innovative iron-based coating materials for the combustion chamber. As a first step, the plasma transferred wire arc and rotating single wire arc (RSW) technologies were compared using 0.8% C-steel as a reference. Subsequently, RSW was used for coating deposition using an innovative iron-based feedstock material. In order to improve wear and corrosion resistance, boron and chromium were added to the feedstock material. After deposition, different honing topographies were manufactured and compared under tribological load. Furthermore, electrochemical corrosion tests were conducted using an electrolyte simulating the exhaust gas concentrate. Especially with regard to corrosion, the novel coating system FeCrBMn showed promising results.

Geotechnical investigations on backfill materials in the Asse salt mine

International Nuclear Information System (INIS)

Kappei, G.

1986-01-01

The compression behaviour of rock salt grit is being investigated by compression tests at the Asse salt mine. The various test parameters are introduced and their results are discussed. The permeability of rock salt grit with saturated NaCl-brine in dependency upon the grain size and compactness, resp. the porosity, is being determined at the Asse salt mine. The test equipment and the results determined here are shown. In addition to laboratory tests, geotechnical investigations are taking place in a carnallitic chamber of the Asse salt mine which had been backfilled in earlier years. They chiefly concern measurements of the deformation rates in drifts - which were mined between the chambers in remaining pillars - as well as horizontal deformation measurements in the backfilling. (orig./DG)

Management of dry flue gas desulfurization by-products in underground mines

Energy Technology Data Exchange (ETDEWEB)

Sevim, H.

1997-06-01

Disposal of coal combustion by-products (CCBs) in an environmentally sound manner is a major issue facing the coal and utility industries in the US today. Disposal into abandoned sections of underground coal mines may overcome many of the surface disposal problems along with added benefits such as mitigation of subsidence and acid mine drainage. However, many of the abandoned underground coal mines are located far from power plants, requiring long distance hauling of by-products which will significantly contribute to the cost of disposal. For underground disposal to be economically competitive, the transportation and handling cost must be minimized. This requires careful selection of the system and optimal design for efficient operation. The materials handling and system economics research addresses these issues. Transportation and handling technologies for CCBs were investigated from technical, environmental and economic points of view. Five technologies were found promising: (1) Pneumatic Trucks, (2) Pressure Differential Rail Cars, (3) Collapsible Intermodal Containers, (4) Cylindrical Intermodal Tanks, and (5) Coal Hopper Cars with Automatic Retractable Tarping. The first two technologies are currently being utilized in transporting by-products from power plants to disposal sites, whereas the next three are either in development or in conceptualization phases. In this research project, engineering design and cost models were developed for the first four technologies. The engineering design models are in the form of spreadsheets and serve the purpose of determining efficient operating schedules and sizing of system components.

Oil sands mine planning and waste management using goal programming

Energy Technology Data Exchange (ETDEWEB)

Ben-Awuah, E.; Askari-Nasab, H. [Alberta Univ., Edmonton, AB (Canada). Dept. of Civil and Environmental Engineering; Alberta Univ., Edmonton, AB (Canada). Mining Optimization Laboratory

2010-07-01

A goal programming method was used to plan waste management processes at an oil sands mine. This method requires the decision maker (DM) to set goals. Mine planning is used to determine a block extraction schedule that maximizes net present value (NPV). Due to land restrictions, tailings facilities are sited within the pit area and dykes are used to contain the tailings. Many of the materials used to construct the dykes come from the mining operation. The mine plan scheduled both ore and dyke material concurrently. Dykes were constructed simultaneously as the mine phase advanced. A model was used to classify an oil sands block model into different material types. A mixed integer goal programming (MIGP) method was used to generate a strategic schedule. Block clustering techniques were used to large-scale mine planning projects. The method was used to verify and validate synthetic and real case data related to the cost of mining all material as waste, and the extra cost of mining dyke material. A case study of an oil sands project was used to demonstrate the method. The study showed that the developed model generates a smooth and uniform strategic schedule for large-scale mine planning projects. tabs., figs.

Oil sands mine planning and waste management using goal programming

International Nuclear Information System (INIS)

Ben-Awuah, E.; Askari-Nasab, H.; Alberta Univ., Edmonton, AB

2010-01-01

A goal programming method was used to plan waste management processes at an oil sands mine. This method requires the decision maker (DM) to set goals. Mine planning is used to determine a block extraction schedule that maximizes net present value (NPV). Due to land restrictions, tailings facilities are sited within the pit area and dykes are used to contain the tailings. Many of the materials used to construct the dykes come from the mining operation. The mine plan scheduled both ore and dyke material concurrently. Dykes were constructed simultaneously as the mine phase advanced. A model was used to classify an oil sands block model into different material types. A mixed integer goal programming (MIGP) method was used to generate a strategic schedule. Block clustering techniques were used to large-scale mine planning projects. The method was used to verify and validate synthetic and real case data related to the cost of mining all material as waste, and the extra cost of mining dyke material. A case study of an oil sands project was used to demonstrate the method. The study showed that the developed model generates a smooth and uniform strategic schedule for large-scale mine planning projects. tabs., figs.

A jewel in the desert: BHP Billiton's San Juan underground mine

Energy Technology Data Exchange (ETDEWEB)

Buchsbaum, L.

2007-12-15

The Navajo Nation is America's largest native American tribe by population and acreage, and is blessed with large tracks of good coal deposits. BHP Billiton's New Mexico Coal Co. is the largest in the Navajo regeneration area. The holdings comprise the San Juan underground mine, the La Plata surface mine, now in reclamation, and the expanding Navajo surface mine. The article recounts the recent history of the mines. It stresses the emphasis on sensitivity to and helping to sustain tribal culture, and also on safety. San Juan's longwall system is unique to the nation. It started up as an automated system from the outset. Problems caused by hydrogen sulfide are being tackled. San Juan has a bleederless ventilation system to minimise the risk of spontaneous combustion of methane and the atmospheric conditions in the mine are heavily monitored, especially within the gob areas. 3 photos.

Role of complex utilization of mineral raw materials In geological research

Energy Technology Data Exchange (ETDEWEB)

Takacs, P.; Varju, G.

1979-01-01

Presents Hungarian research efforts on ways of utilizing the secondary raw materials alunite, pumice and slate coal from various mines. The slate coal is separated from brown coal and disposed of at spoil banks of brown coal mines, due to its high ash content (up to 56.8% under dry conditions), silicate content up to 58.2% and low calorific value between 1500 and 2780 kcal/kg. The research proposal for utilizing slate coal is directed at partial separation of the mineral and coal content by comminution, peptization and hydrocentrifugal separation. The larger part of the silicate content is held in the colloid suspension, which could be used for conditioning drilling mud or foundry sand. The produced coal concentrate has a reduced ash content and higher calorific value (between 500 and 800 kcal/kg) and could be employed in soil amelioration or combustion. (10 refs.) (In German)

Dust Combustion Safety Issues for Fusion Applications

Energy Technology Data Exchange (ETDEWEB)

L. C. Cadwallader

2003-05-01

This report summarizes the results of a safety research task to identify the safety issues and phenomenology of metallic dust fires and explosions that are postulated for fusion experiments. There are a variety of metal dusts that are created by plasma erosion and disruptions within the plasma chamber, as well as normal industrial dusts generated in the more conventional equipment in the balance of plant. For fusion, in-vessel dusts are generally mixtures of several elements; that is, the constituent elements in alloys and the variety of elements used for in-vessel materials. For example, in-vessel dust could be composed of beryllium from a first wall coating, tungsten from a divertor plate, copper from a plasma heating antenna or diagnostic, and perhaps some iron and chromium from the steel vessel wall or titanium and vanadium from the vessel wall. Each of these elements has its own unique combustion characteristics, and mixtures of elements must be evaluated for the mixture’s combustion properties. Issues of particle size, dust temperature, and presence of other combustible materials (i.e., deuterium and tritium) also affect combustion in air. Combustion in other gases has also been investigated to determine if there are safety concerns with “inert” atmospheres, such as nitrogen. Several coolants have also been reviewed to determine if coolant breach into the plasma chamber would enhance the combustion threat; for example, in-vessel steam from a water coolant breach will react with metal dust. The results of this review are presented here.

Mine planning and scheduling at Ranger Uranium Mine - environmental requirements and economics

International Nuclear Information System (INIS)

Bath, L.J.

1984-01-01

Ranger Uranium Mines operates an open cut located in the Northern Territory. Strict environmental controls govern all operations and the water management requirements have the greatest impact on mine planning. The two main goals of planning are to provide mill feed and to mine sufficient suitable quality waste rock for ongoing construction of the tailings dam. Early planning concentrated on staged development of the pit to provide access to as much ore as possible for a given amount of development. All waste was considered to be suitable construction material. Grade control of crusher feed was the main problem in planning, as wide variations occur in ore grade over relatively short distances. Water management for the site operates a 'no release' system for contaminated waters. Design storage has proven inadequate, and the open cut has been used as the extra storage. As construction of future stages of the tailings dam requires non-mineralised rock materials which meet specific quality criteria, the mine has had to re-examine long term planning and pit development strategies. This has entailed the collection of much data not required under normal mining conditions, such as the assaying of waste drill core. The overall impact on mine planning of the environmental regulations has been to alter the philosophy of earlier planning, making it necessary to create a new strategy for pit development with the accent on exposing waste

Solution of environmental protection problems and complex utilization of raw materials during mining and processing of uranium ores

International Nuclear Information System (INIS)

Litvinenko, V.G.; Savva, P.P.

1993-01-01

Consideration is given to the complex of measures taken in Priargunsky industrial mine-chemical association and directed to environment protection, complex utilization of raw materials during mining and processing of uranium ores. These measures include: 1) reduction of toxic chemical agent effluents into atmosphere due to introduction of new methods and gas cleaning systems; 2) rational use of water resources owing to application of circulating water supply systems, waste waters treatment and effective control of the state of water consumption by industrial enterprises; 3) utilization of gangue and industrial solid wastes

Mine water treatment

Energy Technology Data Exchange (ETDEWEB)

Komissarov, S V

1980-10-01

This article discusses composition of chemical compounds dissolved or suspended in mine waters in various coal basins of the USSR: Moscow basin, Kuzbass, Pechora, Kizelovsk, Karaganda, Donetsk and Chelyabinsk basins. Percentage of suspended materials in water depending on water source (water from water drainage system of dust suppression system) is evaluated. Pollution of mine waters with oils and coli bacteria is also described. Recommendations on construction, capacity of water settling tanks, and methods of mine water treatment are presented. In mines where coal seams 2 m or thicker are mined a system of two settling tanks should be used: in the upper one large grains are settled, in the lower one finer grains. The upper tank should be large enough to store mine water discharged during one month, and the lower one to store water discharged over two months. Salty waters from coal mines mining thin coal seams should be treated in a system of water reservoirs from which water evaporates (if climatic conditions permit). Mine waters from mines with thin coal seams but without high salt content can be treated in a system of long channels with water plants, which increase amount of oxygen in treated water. System of biological treatment of waste waters from mine wash-houses and baths is also described. Influence of temperature, sunshine and season of the year on efficiency of mine water treatment is also assessed. (In Russian)

Coal mine site reclamation

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-02-15

Coal mine sites can have significant effects on local environments. In addition to the physical disruption of land forms and ecosystems, mining can also leave behind a legacy of secondary detrimental effects due to leaching of acid and trace elements from discarded materials. This report looks at the remediation of both deep mine and opencast mine sites, covering reclamation methods, back-filling issues, drainage and restoration. Examples of national variations in the applicable legislation and in the definition of rehabilitation are compared. Ultimately, mine site rehabilitation should return sites to conditions where land forms, soils, hydrology, and flora and fauna are self-sustaining and compatible with surrounding land uses. Case studies are given to show what can be achieved and how some landscapes can actually be improved as a result of mining activity.

Review of South American mines

International Nuclear Information System (INIS)

Anon.

1984-01-01

A general overview is presented of the mining activity and plans for South America. The countries which are presented are Columbia, Argentina, Brazil, Venezuela, Chile, Peru, and Bolivia. The products of the mines include coal, bauxite, gold, iron, uranium, copper and numerous other minor materials. A discussion of current production, support and processing facilities, and mining strategies is also given

Combustion

CERN Document Server

Glassman, Irvin

2008-01-01

Combustion Engineering, a topic generally taught at the upper undergraduate and graduate level in most mechanical engineering programs, and many chemical engineering programs, is the study of rapid energy and mass transfer usually through the common physical phenomena of flame oxidation. It covers the physics and chemistry of this process and the engineering applications-from the generation of power such as the internal combustion automobile engine to the gas turbine engine. Renewed concerns about energy efficiency and fuel costs, along with continued concerns over toxic and particulate emissions have kept the interest in this vital area of engineering high and brought about new developments in both fundamental knowledge of flame and combustion physics as well as new technologies for flame and fuel control. *New chapter on new combustion concepts and technologies, including discussion on nanotechnology as related to combustion, as well as microgravity combustion, microcombustion, and catalytic combustion-all ...

30 CFR 57.4500 - Heat sources.

Science.gov (United States)

2010-07-01

... Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Fire Prevention and Control... shall be separated from combustible materials if a fire hazard could be created. ...

30 CFR 56.4500 - Heat sources.

Science.gov (United States)

2010-07-01

... Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Fire Prevention and Control... shall be separated from combustible materials if a fire hazard could be created. ...

Exploring the techno-economic feasibility of mine rock waste utilisation in road works: The case of a mining deposit in Ghana.

Science.gov (United States)

Agyeman, Stephen; Ampadu, Samuel I K

2016-02-01

Mine rock waste, which is the rock material removed in order to access and mine ore, is free from gold processing chemical contaminants but presents a significant environmental challenge owing to the large volumes involved. One way of mitigating the environmental and safety challenges posed by the large volume of mine rock waste stockpiled in mining communities is to find uses of this material as a substitute for rock aggregates in construction. This article reports on a study conducted to evaluate the engineering properties of such a mine deposit to determine its suitability for use as road pavement material. Samples of mine rock waste, derived from the granitic and granodioritic intrusive units overlying the gold-bearing metavolcanic rock and volcano-clastic sediments of a gold mining area in Ghana, were obtained from three mine rock waste disposal facilities and subjected to a battery of laboratory tests to determine their physical, mechanical, geotechnical, geometrical and durability properties. The overall conclusion was that the mine rock waste met all the requirements of the Ghana Ministry of Transportation specification for use as aggregates for crushed rock subbase, base and surface dressing chippings for road pavements. The recommendation is to process it into the required sizes for the various applications. © The Author(s) 2015.

Issues in waste combustion

Energy Technology Data Exchange (ETDEWEB)

Gustavsson, Lennart; Robertson, Kerstin; Tullin, Claes [Swedish National Testing and Research Inst., Boraas (Sweden); Sundquist, Lena; Wrangensten, Lars [AaF-Energikonsult AB, Stockholm (Sweden); Blom, Elisabet [AaF-Processdesign AB, Stockholm (Sweden)

2003-05-01

The main purpose of this review is to provide an overview of the state-of-the-art on research and development issues related to waste combustion with relevance for Swedish conditions. The review focuses on co-combustion in grate and fluidised bed furnaces. It is primarily literature searches in relevant databases of scientific publications with to material published after 1995. As a complement, findings published in different report series, have also been included. Since the area covered by this report is very wide, we do not claim to cover the issues included completely and it has not been possitile to evaluate the referred studies in depth. Basic knowledge about combustion issues is not included since such information can be found elsewhere in the literature. Rather, this review should be viewed as an overview of research and development in the waste-to-energy area and as such we hope that it will inspire scientists and others to further work in relevant areas.

Setting up experimental incineration system for low-level radioactive samples and combustion experiments

International Nuclear Information System (INIS)

Yumoto, Yasuhiro; Hanafusa, Tadashi; Nagamatsu, Tomohiro; Okada, Shigeru

1997-01-01

An incineration system was constructed which were composed of a combustion furnace (AP-150R), a cyclone dust collector, radioisotope trapping and measurement apparatus and a radioisotope storage room built in the first basement of the Radioisotope Center. Low level radioactive samples (LLRS) used for the combustion experiment were composed of combustible material or semi-combustible material containing 500 kBq of 99m TcO 4 or 23.25 kBq of 131 INa. The distribution of radioisotopes both in the inside and outside of combustion furnace were estimated. We measured radioactivity of a smoke duct gas in terminal exit of the exhaust port. In case of combustion of LLRS containing 99m TcO 4 or 131 INa, concentration of radioisotopes at the exhaust port showed less than legal concentration limit of these radioisotopes. In cases of combustion of LLRS containing 99m TcO 4 or 131 INa, decontamination factors of the incineration system were 120 and 1.1, respectively. (author)

Interactive wood combustion for botanical tree models

KAUST Repository

Pirk, Sören

2017-11-22

We present a novel method for the combustion of botanical tree models. Tree models are represented as connected particles for the branching structure and a polygonal surface mesh for the combustion. Each particle stores biological and physical attributes that drive the kinetic behavior of a plant and the exothermic reaction of the combustion. Coupled with realistic physics for rods, the particles enable dynamic branch motions. We model material properties, such as moisture and charring behavior, and associate them with individual particles. The combustion is efficiently processed in the surface domain of the tree model on a polygonal mesh. A user can dynamically interact with the model by initiating fires and by inducing stress on branches. The flames realistically propagate through the tree model by consuming the available resources. Our method runs at interactive rates and supports multiple tree instances in parallel. We demonstrate the effectiveness of our approach through numerous examples and evaluate its plausibility against the combustion of real wood samples.

Solution-combustion synthesized aluminium-doped spinel (LiAl(subx)Mn(sub2-x)O(sub4) as a high-performance lithium-ion battery cathode material

CSIR Research Space (South Africa)

Kebede, MA

2015-06-01

Full Text Available High-performing (LiAl(subx)Mn(sub2-x)O(sub4) (x = 0, 0.125, 0.25, 0.375, and 0.5) spinel cathode materials for lithium-ion battery were developed using a solution combustion method. The as-synthesized cathode materials have spinel cubic structure...

MONITORING OF MINING

Directory of Open Access Journals (Sweden)

Berislav Šebečić

1996-12-01

Full Text Available The way mining was monitored in the past depended on knowledge, interest and the existing legal regulations. Documentary evidence about this work can be found in archives, libraries and museums. In particular, there is the rich archival material (papers and books concerning the work of the one-time Imperial and Royal Mining Captaincies in Zagreb, Zadar, Klagenfurt and Split, A minor part of the documentation has not yet been transferred to Croatia. From mining handbooks and books we can also find out about mining in Croatia. In the context of Austro-Hungary. For example, we can find out that the first governorships in Zagreb and Zadar headed the Ban, Count Jelacic and Baron Mamula were also the top mining authorities, though this, probably from political motives, was suppressed in the guides and inventories or the Mining Captaincies. At the end of the 1850s, Croatia produced 92-94% of sea salt, up to 8.5% of sulphur, 19.5% of asphalt and 100% of oil for the Austro-Hungarian empire. From data about mining in the Split Mining Captaincy, prepared for the Philadephia Exhibition, it can be seen that in the exploratory mining operations in which there were 33,372 independent mines declared in 1925 they were looking mainly for bauxite (60,0%, then dark coal (19,0%, asphalts (10.3% and lignites (62%. In 1931, within the area covered by the same captaincy, of 74 declared mines, only 9 were working. There were five coal mines, three bauxite mines and one for asphalt. I suggest that within state institution, the Mining Captaincy or Authority be renewed, or that a Mining and Geological Authority be set ap, which would lead to the more complete affirmation of Croatian mining (the paper is published in Croatian.

The Characteristics of Methane Combustion Suppression by Water Mist and Its Engineering Applications

Directory of Open Access Journals (Sweden)

Rongkun Pan

2017-10-01

Full Text Available To safely mine coal, engineers must prevent gas combustion and explosions, as well as seek feasible and reasonable techniques to control for these types of incidents. This paper analyzes the causes and characteristics of methane combustion and explosions. Water mist is proposed to prevent and control methane combustion in an underground confined space. We constructed an experiment platform to investigate the suppression of methane combustion using water mist for different conditions. The experimental results showed that water mist is highly effective for methane flame inhibition. The flame was extinguished with water mist endothermic cooling. However, the annular regions of water vapor around the fire played a vital role in flame extinction. Water from the evaporating mist replaces the oxygen available to the fuel. Additionally, the time required for fuel ignition is prolonged. For these reasons, the water particle action to flame surface is reinforced and the fuel’s reaction with air is delayed. As a result, flame stretching and disturbances occur, which serve to extinguish the flame. Engineering application tests were carried out in the goaf, drill hole and upper-corner to investigate the prevention and control of methane gas combustion, with the results showing a good application effect.

Bioenergy originating from biomass combustion in a fluidized bed

Energy Technology Data Exchange (ETDEWEB)

Crujeira, T.; Gulyurtlu, I.; Lopes, H.; Abelha, P.; Cabrita, I. [INETI/DEECA, Lisboa (Portugal)

2008-07-01

Bioenergy could significantly contribute to reducing and controlling greenhouse emissions (GHG) and to replace fossil fuels in large power plants. Although the use of biomass, originating from forests, could be beneficial, particularly in preventing fires, there are obstacles to achieve a sustainable supply chain of biomass in most European countries. In addition, there are also technical barriers as requirements of biomass combustion may differ from those of coal, which could mean significant retrofitting of existing installations. The combustion behaviour of different biomass materials were studied on a pilot fluidised bed combustor, equipped with two cyclones for particulate matter removal. The gaseous pollutants leaving the stack were sampled under isokinetic conditions for particulate matter, chlorine compounds, heavy metals and dioxins and furans (PCDD/F). The results obtained indicated that the combustion of these materials did not present any operational problem, although for temperatures above 800{sup o}C, bed agglomeration could be observed for all biomass materials studied. Most of the combustion of biomass, contrary to what is observed for coal, takes place in the riser where the temperature was as much as 150{sup o}C above that of the bed. Stable combustion conditions were achieved as well as high combustion efficiency. When compared with the emissions of bituminous coal, the most used fossil fuel, the emissions of CO and SO2 were found to be lower and NOx emissions were similar to those of coal. HCl and PCDD/F could be considerable with biomasses containing high chlorine levels, as in the case of straw. It was observed that the nature of ash could give rise serious operating problems.

Planning in deep coal mines prone to spontaneous combustion. Planificacion de explotaciones subterraneas de carbon con propension a fuegos

Energy Technology Data Exchange (ETDEWEB)

Leon Marco, P

1991-03-01

During the planning process, analysis and assessment of criteria which contribute to spontaneous combustion are used to forecast the level of risk. This information is then used to determine what action should be taken to eliminate or reduce spontaneous combustion. The measures taken involve varying the factors which affect spontaneous combustion in order to make conditions unfavourable to the occurrence of the phenomenon. 1 fig.

Expansion of Neyveli lignite mines

Energy Technology Data Exchange (ETDEWEB)

Kasturi, T S

1982-06-01

This paper describes activities at Neyveli lignite mines in the Tamil Nadu region of India. The equipment used, in mining and materials handling is described. Problems encountered in the conveyor transport system are described, and the solutions finally adopted are presented.

Tube bundle system studies at Signal Peak Energy Bull Mountains #1 Mine.

Science.gov (United States)

Zipf, R K; Ochsner, R; Krog, R; Marchewka, W; Valente, M; Jensen, R

2014-03-01

A tube bundle system (TBS) is a mechanical system for continuously drawing gas samples through tubes from multiple monitoring points located in an underground coal mine for analysis and display on the surface. The U.S. National Institute for Occupational Safety and Health (NIOSH), in collaboration with Signal Peak Energy (SPE), LLC, Bull Mountains No. 1 Mine, operated a TBS during mining of two bleederless, longwall panels. This paper describes the gas analysis data and its interpretation. As verified by the TBS, coal at the SPE mine tends to oxidize slowly. It was known that a reservoir of low-oxygen concentration atmosphere developed about 610 m (2,000 ft) behind the longwall face. A bleederless ventilation system facilitates formation of an inert atmosphere in this longwall gob and decreases the likelihood of spontaneous combustion. Connections of the mine atmosphere to the surface through subsidence cracks could allow airflow into the longwall gob, revive coal oxidation and increase spontaneous combustion risk. The atmospheric composition of the sealed areas was homogeneous, except in the immediate vicinity of suspected ingassing points. The TBS verified that gases within the partially sealed, bleederless longwall gob expanded into the longwall tailgate area when barometric pressure decreased. The concentration of carbon dioxide in the back return airflow at the longwall tailgate was observed to increase by a factor of three and possibly up to 10 times the typical background concentration of 0.5 to 1.0%, depending on the size of the longwall gob and the magnitude of barometric pressure decrease. TBS have the inherent disadvantage of slow response time due to travel time of the gas samples and sequential gas analyses. A TBS or similar continuous monitoring system could be beneficial in detecting and providing warning of potentially hazardous gas concentrations, if the slow response time of the system is always understood.

Method of making metal oxide ceramic powders by using a combustible amino acid compound

Science.gov (United States)

Pederson, Larry R.; Chick, Lawrence A.; Exarhos, Gregory J.

1992-01-01

This invention is directed to the formation of homogeneous, aqueous precursor mixtures of at least one substantially soluble metal salt and a substantially soluble, combustible co-reactant compound, typically an amino acid. This produces, upon evaporation, a substantially homogeneous intermediate material having a total solids level which would support combustion. The homogeneous intermediate material essentially comprises highly dispersed or solvated metal constituents and the co-reactant compound. The intermediate material is quite flammable. A metal oxide powder results on ignition of the intermediate product which combusts same to produce the product powder.

Low-reactive circulating fluidized bed combustion (CFBC) fly ashes as source material for geopolymer synthesis

International Nuclear Information System (INIS)

Xu Hui; Li Qin; Shen Lifeng; Zhang Mengqun; Zhai Jianping

2010-01-01

In this contribution, low-reactive circulating fluidized bed combustion (CFBC) fly ashes (CFAs) have firstly been utilized as a source material for geopolymer synthesis. An alkali fusion process was employed to promote the dissolution of Si and Al species from the CFAs, and thus to enhance the reactivity of the ashes. A high-reactive metakaolin (MK) was also used to consume the excess alkali needed for the fusion. Reactivities of the CFAs and MK were examined by a series of dissolution tests in sodium hydroxide solutions. Geopolymer samples were prepared by alkali activation of the source materials using a sodium silicate solution as the activator. The synthesized products were characterized by mechanical testing, scanning electron microscopy (SEM), X-ray diffractography (XRD), as well as Fourier transform infrared spectroscopy (FTIR). The results of this study indicate that, via enhancing the reactivity by alkali fusion and balancing the Na/Al ratio by additional aluminosilicate source, low-reactive CFAs could also be recycled as an alternative source material for geopolymer production.

Combustion engineering

CERN Document Server

Ragland, Kenneth W

2011-01-01

Introduction to Combustion Engineering The Nature of Combustion Combustion Emissions Global Climate Change Sustainability World Energy Production Structure of the Book   Section I: Basic Concepts Fuels Gaseous Fuels Liquid Fuels Solid Fuels Problems Thermodynamics of Combustion Review of First Law Concepts Properties of Mixtures Combustion StoichiometryChemical EnergyChemical EquilibriumAdiabatic Flame TemperatureChemical Kinetics of CombustionElementary ReactionsChain ReactionsGlobal ReactionsNitric Oxide KineticsReactions at a Solid SurfaceProblemsReferences  Section II: Combustion of Gaseous and Vaporized FuelsFlamesLaminar Premixed FlamesLaminar Flame TheoryTurbulent Premixed FlamesExplosion LimitsDiffusion FlamesGas-Fired Furnaces and BoilersEnergy Balance and EfficiencyFuel SubstitutionResidential Gas BurnersIndustrial Gas BurnersUtility Gas BurnersLow Swirl Gas BurnersPremixed-Charge Engine CombustionIntroduction to the Spark Ignition EngineEngine EfficiencyOne-Zone Model of Combustion in a Piston-...

Journal of Mining and Geology: Editorial Policies

African Journals Online (AJOL)

Focus and Scope. Journal of Mining and Geology is the scientific publication of the Nigerian Mining and Geosciences Society. Its scope covers the fields of the geosciences, mining, metallurgy, materials science and geoenvironmental studies. Section Policies. Articles. Checked Open Submissions, Checked Indexed ...

Study and application of measures for prevention of spontaneous combustion of coal in goaf induced by air leakage

Energy Technology Data Exchange (ETDEWEB)

Liu, Y.; Tang, H.; Zou, S.; Shi, S. [Xiangtan Mining Institute (China)

1996-12-01

To prevent spontaneous ignition of coal due to air leakage in the goaf, air stoppings were built periodically in a U-shaped air leakage area based on computer simulation and site experience. The measure had reduced remarkably the quantity and extent of air leakage in the mined-out area and expanded the extent of non-spontaneous combustion area, thus prevented effectively the risk of spontaneous ignition and gas explosion. Application of this method in Mugang Mine of Liuzhi Bureau for more than two years had reduced the economic loss by over 3 million Yuan RMB. This method is characterized by simple operation, low cost, etc. It is suitable for mines in under developed area and mines with complicated conditions which are prone to spontaneous ignition. 5 refs., 3 figs., 1 tab.

Mining industry in Republic of Macedonia

International Nuclear Information System (INIS)

Vrentsovski, Angele

1996-01-01

Mining production has a special significance in the economy of the Republic of Macedonia. The mining comprises 6% of national earnings in the Republic of Macedonia and accounts for 16% of all people employed in industry. Mining products include coal which assures over 80% of all electrical energy as well as raw materials for metallurgy, the refractory and clay industry, decorative stones, etc. Given the conditions of the fixed economy in the former Yugoslavia, the State controlled the prices associated with mining. Following the break up of Yugoslavia and the independence of the Republic of Macedonia, a new period was entered, one dictated by a market economy and massive privatization - a period of transition. This new period was hindered by the blockades on both north and south borders and resulted in negative repercussions for mining production, especially raw materials which were intended for export. This paper intends to describe the current situation of mining production and to evaluate the realistic economic opportunities regarding the new market conditions. (author). 5 refs., 2 tabs

Technologies for Decreasing Mining Losses

Science.gov (United States)

Valgma, Ingo; Väizene, Vivika; Kolats, Margit; Saarnak, Martin

2013-12-01

In case of stratified deposits like oil shale deposit in Estonia, mining losses depend on mining technologies. Current research focuses on extraction and separation possibilities of mineral resources. Selective mining, selective crushing and separation tests have been performed, showing possibilities of decreasing mining losses. Rock crushing and screening process simulations were used for optimizing rock fractions. In addition mine backfilling, fine separation, and optimized drilling and blasting have been analyzed. All tested methods show potential and depend on mineral usage. Usage in addition depends on the utilization technology. The questions like stability of the material flow and influences of the quality fluctuations to the final yield are raised.

Fluidized bed combustion: mixing and pollutant limitation

Energy Technology Data Exchange (ETDEWEB)

Leckner, B. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Energy Conversion

1997-10-01

Fluidized bed combustion (FBC) has been applied commercially during a few decades, and sufficient knowledge is gained to design boilers with sizes of up to several hundreds of megawatt thermal power (MW{sub th}). The knowledge of what goes on inside a large combustion chamber is still limited, however, and this impedes further optimization and efficient solution of problems that might occur. Despite this lack of knowledge the present survey deals with combustion chamber processes and discusses mixing and distribution of fuel and air in the combustion chamber and its importance for sulphur capture and reduction of emissions of nitrogen oxides. It is desirable to present the material in a general way and to cover the entire field of FBC. However, the scarce openly published information deals mostly with coal combustion in atmospheric circulating fluidized bed (CFB) combustors, and therefore this application will receive most attention, but reference is also made to pressurized combustion and to other fuels than coal. In this context the important work made in the LIEKKI project on the analysis of different fuels and on the influence of pressure should be especially pointed out. (orig.)

Strategies for the implementation of an environmental mining plan of the construction materials in Bogota. Phase 1 Diagnostic

International Nuclear Information System (INIS)

Gonzalez Oviedo, Leopoldo; Parrado L, Guillermo; Cardenas, John Fernan

1995-01-01

The study contains the geologic aspects, miners and environmental of 10 areas selected in Bogota where construction materials exist, like they are sands, clays, and gravels, in each area a definition is made, the productive units are described, reserves, mining production and environmental impacts are given generated by the material exploitation; a prioritizing of potential areas is included to implement a miner-environmental plan of this industry in Bogota

Proceedings of the 2006 Combustion Institute Canadian Section spring technical meeting

International Nuclear Information System (INIS)

Devaud, C.; Weckman, E.; Lam, C.; Spike, E.

2006-01-01

This conference provided a networking opportunity for academic, government and industrial combustion researchers from across Canada. All aspects of combustion were discussed, particularly those related to new engine technologies that reduce exhaust gas emissions while maintaining performance. Major engine operating and fuelling control parameters that improve combustion efficiency were identified. The conference was divided into several sessions dealing with combustion emissions and pollutants such as soot and particulates; alternative fuels including biofuels and fuel cells; chemical kinetics; droplet and spray combustion; combustion synthesis of materials; detonations, explosions, fires, flammability, flares and incineration; environmental issues and hazard analysis; and, numerical modeling and simulation. The conference featured 61 presentations, of which 39 have been catalogued separately for inclusion in this database

Comparing the greenhouse gas emissions from three alternative waste combustion concepts

International Nuclear Information System (INIS)

Vainikka, Pasi; Tsupari, Eemeli; Sipilä, Kai; Hupa, Mikko

2012-01-01

Highlights: ► Significant GHG reductions are possible by efficient WtE technologies. ► CHP and high power-to-heat ratio provide significant GHG savings. ► N 2 O and coal mine type are important in LCA GHG emissions of FBC co-combustion. ► Substituting coal and fuel oil by waste is beneficial in electricity and heat production. ► Substituting natural gas by waste may not be reasonable in CHP generation. - Abstract: Three alternative condensing mode power and combined heat and power (CHP) waste-to-energy concepts were compared in terms of their impacts on the greenhouse gas (GHG) emissions from a heat and power generation system. The concepts included (i) grate, (ii) bubbling fluidised bed (BFB) and (iii) circulating fluidised bed (CFB) combustion of waste. The BFB and CFB take advantage of advanced combustion technology which enabled them to reach electric efficiency up to 35% and 41% in condensing mode, respectively, whereas 28% (based on the lower heating value) was applied for the grate fired unit. A simple energy system model was applied in calculating the GHG emissions in different scenarios where coal or natural gas was substituted in power generation and mix of fuel oil and natural gas in heat generation by waste combustion. Landfilling and waste transportation were not considered in the model. GHG emissions were reduced significantly in all of the considered scenarios where the waste combustion concepts substituted coal based power generation. With the exception of condensing mode grate incinerator the different waste combustion scenarios resulted approximately in 1 Mton of fossil CO 2 -eq. emission reduction per 1 Mton of municipal solid waste (MSW) incinerated. When natural gas based power generation was substituted by electricity from the waste combustion significant GHG emission reductions were not achieved.

Mining in the Federal Republic of Germany 2012. Mining industries and statistics. 64th year 2013. Documentation

International Nuclear Information System (INIS)

2013-11-01

The annual report of the series ''The mining industry in the Federal Republic of Germany - Mountain Economics and Statistics'' is published by the Federal Ministry of Economics and Technology in cooperation with the mining authorities of the federal states. It contains comprehensive data of all production facilities of mining industry in Germany and describes the position of the German industry in the context of the overall economic development. The report shows an interest in local raw materials as well as on the international raw materials economy. Moreover, the present publication provides a detailed statistics section. [de

Microbial ecology of coal mine refuse

Energy Technology Data Exchange (ETDEWEB)

Cameron, R. E.; Miller, R. M.

1977-01-01

Baseline microbial and ecological studies of samples obtained from two abandoned coal mine refuse sites in the State of Illinois indicate that the unfavorable nature of refuse materials can be a very limiting factor for survival and growth of organisms. Despite the ''foothold'' obtained by some microorganisms, especially acidophilic fungi and some acidotolerant algae, the refuse materials should be amended or ameliorated to raise the pH, provide needed nutrients, especially nitrogen, and provide biodegradable organic matter, both for physical and biological purposes. Finally, the role of microbial populations, responses, and interactions in acid mine wastes must be put into larger perspective. Acid mine drainage amounts to over 4 million tons per year of acidity from active and abandoned mines. Microorganisms appear to be significantly responsible for this problem, but they also can play a beneficial and significant role in the amelioration or alleviation of this detrimental effect as abandoned mines are reclaimed and returned to useful productivity.

Mining wastes

International Nuclear Information System (INIS)

Pradel, J.

1981-01-01

In this article mining wastes means wastes obtained during extraction and processing of uranium ores including production of uraniferous concentrates. The hazards for the population are irradiation, ingestion, dust or radon inhalation. The different wastes produced are reviewed. Management of liquid effluents, water treatment, contamined materials, gaseous wastes and tailings are examined. Environmental impact of wastes during and after exploitation is discussed. Monitoring and measurements are made to verify that ICRP recommendations are met. Studies in progress to improve mining waste management are given [fr

Small-scale, self-propagating combustion realized with on-chip porous silicon.

Science.gov (United States)

Piekiel, Nicholas W; Morris, Christopher J

2015-05-13

For small-scale energy applications, energetic materials represent a high energy density source that, in certain cases, can be accessed with a very small amount of energy input. Recent advances in microprocessing techniques allow for the implementation of a porous silicon energetic material onto a crystalline silicon wafer at the microscale; however, combustion at a small length scale remains to be fully investigated, particularly with regards to the limitations of increased relative heat loss during combustion. The present study explores the critical dimensions of an on-chip porous silicon energetic material (porous silicon + sodium perchlorate (NaClO4)) required to propagate combustion. We etched ∼97 μm wide and ∼45 μm deep porous silicon channels that burned at a steady rate of 4.6 m/s, remaining steady across 90° changes in direction. In an effort to minimize the potential on-chip footprint for energetic porous silicon, we also explored the minimum spacing between porous silicon channels. We demonstrated independent burning of porous silicon channels at a spacing of 0.5 m on a chip surface area of 1.65 cm(2). Smaller porous silicon channels of ∼28 μm wide and ∼14 μm deep were also utilized. These samples propagated combustion, but at times, did so unsteadily. This result may suggest that we are approaching a critical length scale for self-propagating combustion in a porous silicon energetic material.

The Impact of Coal Combustion Fly Ash Used as a Supplemental Cementitious Material on the Leaching of Constituents from Cements and Concretes

Science.gov (United States)

The objective of this report is to compare the leaching of portland cement-based materials that have been prepared with and without coal combustion fly ash to illustrate whether there is evidence that the use of fly ash in cement and concrete products may result in increased leac...

Combustion

CERN Document Server

Glassman, Irvin

1987-01-01

Combustion, Second Edition focuses on the underlying principles of combustion and covers topics ranging from chemical thermodynamics and flame temperatures to chemical kinetics, detonation, ignition, and oxidation characteristics of fuels. Diffusion flames, flame phenomena in premixed combustible gases, and combustion of nonvolatile fuels are also discussed. This book consists of nine chapters and begins by introducing the reader to heats of reaction and formation, free energy and the equilibrium constants, and flame temperature calculations. The next chapter explores the rates of reactio

Renew, reduce or become more efficient? The climate contribution of biomass co-combustion in a coal-fired power plant

International Nuclear Information System (INIS)

Miedema, Jan H.; Benders, René M.J.; Moll, Henri C.; Pierie, Frank

2017-01-01

Highlights: • Coal mining is more energy and CO_2 efficient than biomass production. • Co-combustion of 60% biomass with coal doubles mass transport compared to 100% coal. • Low co-combustion levels reduce GHG emissions, but the margins are small. • Total supply chain efficiency is the highest for the coal reference at 41.2%. - Abstract: Within this paper, biomass supply chains, with different shares of biomass co-combustion in coal fired power plants, are analysed on energy efficiency, energy consumption, renewable energy production, and greenhouse gas (GHG) emissions and compared with the performance of a 100% coal supply chain scenario, for a Dutch situation. The 60% biomass co-combustion supply chain scenarios show possibilities to reduce emissions up to 48%. The low co-combustion levels are effective to reduce GHG emissions, but the margins are small. Currently co-combustion of pellets is the norm. Co-combustion of combined torrefaction and pelleting (TOP) shows the best results, but is also the most speculative. The indicators from the renewable energy directive cannot be aligned. When biomass is regarded as scarce, co-combustion of small shares or no co-combustion is the best option from an energy perspective. When biomass is regarded as abundant, co-combustion of large shares is the best option from a GHG reduction perspective.

A novel solution combustion synthesis of cobalt oxide nanoparticles as negative-electrode materials for lithium ion batteries

International Nuclear Information System (INIS)

Wen Wei; Wu Jinming; Tu Jiangping

2012-01-01

Highlights: ► We examine the electrochemical performance of cobalt oxides fabricated by solution combustion synthesis for rechargeable lithium-ion battery applications. ► The additive of NaF in precursor results in an eruption combustion mode. ► The eruption combustion leads to fluffy networks with smaller grains and more macroporous voids. ► The network contributes to higher discharge capacity, higher initial coulombic efficiency, and better cycling performance for rechargeable lithium-ion batteries. - Abstract: Low cost mass production of cobalt oxide nanoparticles with high electrochemical performance is of practical interest for rechargeable lithium-ion batteries. In this report, cobalt oxide nanoparticles were fabricated by solution combustion synthesis, with the introduction of NaF into the precursor to alter the combustion mode. The novel eruption combustion resulted in fluffy networks with smaller particles and more macroporous voids, which contributed to the higher discharge capacity, higher initial coulombic efficiency, and better cycling performance when compared with that achieved by the conventional combustion mode.

Environmental mining plan of the construction materials industry in Cartagena, Phase 1 Diagnostic. Vol.1 and Vol.2(Annex)

International Nuclear Information System (INIS)

Castiblanco, Carmen Rosa; Franco Serna, Jose Vicente; Nino, Jaime

1996-01-01

INGEOMINAS carried out this project in the cities of Cartagena, Bucaramanga, Cali and Bogota, in two phases: Phase 1 (Diagnostic) and Phase II (Formulation of Handling Plan). The phase 1 that here is described, it upgrades the knowledge of the extractive industry of the construction materials for the city of Cartagena, through bibliographical revision and field work, carried out in 50 quarries that supply from these materials to the city. This study, besides the economic and legal handling, identifies technical aspects related with the geology, the mining and the environmental situation. In accordance with their likeness, geologic, morphological and of exploitation (extraction methods and mining development), the quarries met in five groups: Exploitations on calcareous deposits of the La Popa Formation, exploitations on clay deposits of the La Popa Formation, exploitations on detritus deposits of half grain to thick (La Popa-Arenosa Formation; Pendales Conglomerate and Rotinet Formation) and exploitation of calcareous of the Arroyo de Piedra Formation. The extraction of these materials is characterized by its low degree of development technician, lack of planning mining, lack of appropriate infrastructure that allows a better development of the sector, is also evident the control lack on the part of the entities in charge of the handling of this industry. These factors added to a demand every time in increase of these materials, they have taken to a progressive deterioration in the landscape, increase of the noise and particles in the air and in the waters. The low control in this activity has generated the proliferation of informal exploitations that they find in this activity a way of subsistence

Construction and maintenance of underground mine roads

Energy Technology Data Exchange (ETDEWEB)

Logan, A.S.; Seedsman, R.W. [Coffey Partners International Pty. Ltd. (Australia)

1995-12-31

Good roads are essential in moving men and materials to and from the underground workplace. An underground coal industry funded project was recently completed on underground mine road construction and maintenance. This paper discusses practical approaches to construction and maintenance of underground mine roads using transferable civil technologies and innovative techniques. Mine pavements are generally low-cost (relative to civil roads), constructed to varying standards using locally available materials to best meet the mobility needs of the mine. Performance of pavements is thus largely dependent on the environmental conditions, quality of the available road making materials, maintenance policies and available resources. This paper explains the causes of bad roads in various underground environments. It details available management strategies, construction and water control techniques, road maintenance and vehicle considerations. It concludes that the trend to larger rubber tires mining equipment needs to be matched with construction and maintenance of high quality road surfaces. For large operations, the total cost due to poor roads may equate to in excess of $A1 million per annum. The strategies outlined in this paper provide the basis for construction and maintenance of underground mine roads to help achieve desired production targets. (author). 2 tabs., 4 figs., 7 refs.

Pulsating combustion - Combustion characteristics and reduction of emissions

Energy Technology Data Exchange (ETDEWEB)

Lindholm, Annika

1999-11-01

In the search for high efficiency combustion systems pulsating combustion has been identified as one of the technologies that potentially can meet the objectives of clean combustion and good fuel economy. Pulsating combustion offers low emissions of pollutants, high heat transfer and efficient combustion. Although it is an old technology, the interest in pulsating combustion has been renewed in recent years, due to its unique features. Various applications of pulsating combustion can be found, mainly as drying and heating devices, of which the latter also have had commercial success. It is, however, in the design process of a pulse combustor, difficult to predict the operating frequency, the heat release etc., due to the lack of a well founded theory of the phenomenon. Research concerning control over the combustion process is essential for developing high efficiency pulse combustors with low emissions. Natural gas fired Helmholtz type pulse combustors have been the experimental objects of this study. In order to investigate the interaction between the fluid dynamics and the chemistry in pulse combustors, laser based measuring techniques as well as other conventional measuring techniques have been used. The experimental results shows the possibilities to control the combustion characteristics of pulsating combustion. It is shown that the time scales in the large vortices created at the inlet to the combustion chamber are very important for the operation of the pulse combustor. By increasing/decreasing the time scale for the large scale mixing the timing of the heat release is changed and the operating characteristics of the pulse combustor changes. Three different means for NO{sub x} reduction in Helmholtz type pulse combustors have been investigated. These include exhaust gas recirculation, alteration of air/fuel ratio and changed inlet geometry in the combustion chamber. All used methods achieved less than 10 ppm NO{sub x} emitted (referred to stoichiometric

Mine waste acidic potential and distribution of antimony and arsenic in waters of the Xikuangshan mine, China

International Nuclear Information System (INIS)

Zhou, Jianwei; Nyirenda, Mathews T.; Xie, Lina; Li, Yi; Zhou, Baolong; Zhu, Yue; Liu, Huilin

2017-01-01

The Xikuangshan (XKS) mine in China has vast quantities of waste material and reported antimony (Sb) and arsenic (As) contamination of water in the mine area. This study estimated the potential of acid mine drainage (AMD) generation by waste material at XKS mine by using paste pH, acid base accounting and net acid generation geochemical static tests. Distribution of Sb and As in surface and groundwater in relation to mine waste AMD producing potential was also investigated. Thirty four (34) water samples and representative samples of three mine wastes from different periods (fresh, 10 and 50 years) were collected for this study: waste rock, smelting slag and tailings. The AMD prediction shows that waste rock (from 10 year period) is acid producing while the fresh mine waste had alkaline paste pH indicating the presence of reactive carbonates. Hence AMD generation may have occurred after a long time due to dissolution of carbonates. Water analysis found Sb with higher concentration than As with means of 3.74 mg/L and 0.19 mg/L respectively. Highest Sb and As concentrations were observed in the North mine along the water flow path from waste heaps and tailing pond; Mine water in the South mine also had elevated Sb and As concentrations. Mining activities at the XKS mine have accelerated Sb and As releases because of the disturbed natural equilibrium. Proper mine waste management and collection and treatment of outflow from the waste rock heaps and tailing ponds seem to be a promising mitigation options. - Highlights: • High levels of Sb and As were detected in alkaline water at Xikuangshan mine. • Static test showed that mine waste aged over 10 years was acid generating. • Mine waste influenced the high concentration of Sb and As in water. • The Sb/As ratios in water favored Sb because of high Sb content in the ore body.

Validation of new ceramic materials from tungsten mining wastes. Mechanical properties; Validacion de nuevos materiales ceramicos a partir de rocas de desecho de mineria. Propiedades mecanicas

Energy Technology Data Exchange (ETDEWEB)

Duran Suarez, J. A.; Montoya Herrera, J.; Silva, A. P.; Peralbo Cano, R.; Castro-Gomes, J. P.

2014-07-01

New ceramic materials obtained from tungsten mining wastes, from region of Beira Interior in Portugal, with no commercial use, responsible for landscape and environmental problems are presented. These preshaped new ceramic products, prepared in a wide thermal range (800 degree centigrade to 1300 degree centigrade) was evaluated by mechanical test, but also was characterized the starting raw materials: tungsten wastes mining and industrial kaolin. Results, which also include a mineralogical characterization of ceramic products and morphologic evaluation of neoformed by scanning electron microscopy, show firstly, the feasibility of converting a large number of these wastes in marketable ceramics. Thanks to the experimentation carried out, the ability to generate ceramic materials is emphasized, without the presence of mineral clay, due to the particular composition of these waste of mining with content of acid, neutral and basic oxides. (Author)

Fluidized bed and pulverized coal combustion residues for secondary pavements

International Nuclear Information System (INIS)

Ghafoori, N.; Diawara, H.; Wang, L.

2009-01-01

The United States produced nearly 125 million tons of coal combustion products in 2006. These by-products include fly ash, flue gas desulphurization materials, bottom ash, boiler slag, and other power plant by-products. The expense associated with waste disposal, lack of disposal sites, and significant environmental damage linked with the disposal of coal combustion residues have encouraged innovative utilization strategies such as the fluidized bed combustion (FBC) unit. This paper presented the results of a laboratory investigation that examined the properties of composites developed with different proportions of pre-conditioned FBC spent bed, pulverized coal combustion fly ash, natural fine aggregate, and Portland cement. The purpose of the study was to examine the extent to which the by-product composites could replace currently used materials in secondary roads. The paper presented the research objectives and experimental programs, including matrix constituent and proportions; mixture proportions; and mixing, curing, sampling, and testing. The discussion of results centered around compressive strength and expansion by internal sulfate attack. It was concluded that with proper proportioning, by-products of pulverized and fluidized bed combustion promote binding of sand particles and provide adequate strength under various curing and moisture conditions 4 refs., 6 tabs.

Mineralogic and element association of coals from the Gevra mine, Korba coal field, Madhya Pradesh, India

International Nuclear Information System (INIS)

Hart, B.R.; Powell, M.A.; Fyfe, W.S.; Sahu, K.C.; Tripathy, S.

1991-01-01

As a part of a project to study the content and distribution of trace elements in coals and coal by-products from coal mining areas of India, the mineral and elemental composition of the whole coal and concentration of the selective elements in the whole coal mined from the Gevra mine of the Korba coal field in Madhya Pradesh are studied. The vertical trend of the selected elements are defined and possible relationships of these elements to the minerals present in or associated with the above coal are examined. The Gevra Coals have ash contact ( 3 times world average) and low sulphur content (1/4 of world average). Most elements are found to be positively correlated with ash indicating an inorganic association. Elements which show organic affinity include S, Cl, I and In. Fe, Cu, Zn and Pb occur in sulfide phases, the dominant Fe phase identified is siderite which also contain Mn and Mg. Th and U along with varying proportions of rare earths, Ce, Dy, La and Y have been identified with discrete phosphate minerals. Most trace elements have been found to be concentrated in the upper and lower portions of the coal seam exposed in Gevra mine and in partings. It is, therefore, suggested that selective mining and removal of high ash/inorganic material, particularly the upper and lower portion of the seam, will greatly reduce the mobilization of Al, As, Co, Fe, Hf, Sc, Si, Ti and to a lesser degree Cr, La, Mn, Th U and V during combustion of coal in power plants and consequently will reduce the influx of trace elements to the environment. (M.G.B.). 23 refs., 5 figs

Mine-built ponds economically clear acid mine waters

Energy Technology Data Exchange (ETDEWEB)

Chironis, N P

1987-01-01

One of the by-products of surface mining is acid mine drainage. Traditional treatment of acid drainage is the addition of a base chemical such as sodium hydroxide, soda ash or lime to neutralize the water and allow metals, such as iron and manganese, to settle out. However researchers were intrigued by the idea of using home-made wetlands containing bogs of sphagnum moss to do the job naturally and more cheaply without the heavy application of chemicals. Such plants as cattails were found to be very effective. Aspects considered are: the wetlands affinity for acid water; the aid of algae and bacteria; building a wetland; and recommendations by the Bureau of Mines for constructing wetlands including flow capacity, pH goal, minerals removal, design criteria, plant materials, growing media, plant settling, nutrients, water level and flow control.

UTILIZATION OF LOW NOx COAL COMBUSTION BY-PRODUCTS

Energy Technology Data Exchange (ETDEWEB)

J.Y. Hwang; X. Huang; M.G. McKimpson; R.E. Tieder; A.M. Hein; J.M. Gillis; D.C. Popko; K.L. Paxton; Z. Li; X. Liu; X. Song; R.I. Kramer

1998-12-01

Low NO{sub x} combustion practices are critical for reducing NO{sub x} emissions from power plants. These low NO{sub x} combustion practices, however, generate high residual carbon contents in the fly ash produced. These high carbon contents threaten utilization of this combustion by-product. This research has successfully developed a separation technology to render fly ash into useful, quality-controlled materials. This technology offers great flexibility and has been shown to be applicable to all of the fly ashes tested (more than 10). The separated materials can be utilized in traditional fly ash applications, such as cement and concrete, as well as in nontraditional applications such as plastic fillers, metal matrix composites, refractories, and carbon adsorbents. Technologies to use beneficiated fly ash in these applications are being successfully developed. In the future, we will continue to refine the separation and utilization technologies to expand the utilization of fly ash. The disposal of more than 31 million tons of fly ash per year is an important environmental issue. With continued development, it will be possible to increase economic, energy and environmental benefits by re-directing more of this fly ash into useful materials.

Arsenic partitioning among particle-size fractions of mine wastes and stream sediments from cinnabar mining districts.

Science.gov (United States)

Silva, Veronica; Loredo, Jorge; Fernández-Martínez, Rodolfo; Larios, Raquel; Ordóñez, Almudena; Gómez, Belén; Rucandio, Isabel

2014-10-01

Tailings from abandoned mercury mines represent an important pollution source by metals and metalloids. Mercury mining in Asturias (north-western Spain) has been carried out since Roman times until the 1970s. Specific and non-specific arsenic minerals are present in the paragenesis of the Hg ore deposit. As a result of intensive mining operations, waste materials contain high concentrations of As, which can be geochemically dispersed throughout surrounding areas. Arsenic accumulation, mobility and availability in soils and sediments are strongly affected by the association of As with solid phases and granular size composition. The objective of this study was to examine phase associations of As in the fine grain size subsamples of mine wastes (La Soterraña mine site) and stream sediments heavily affected by acid mine drainage (Los Rueldos mine site). An arsenic-selective sequential procedure, which categorizes As content into seven phase associations, was applied. In spite of a higher As accumulation in the finest particle-size subsamples, As fractionation did not seem to depend on grain size since similar distribution profiles were obtained for the studied granulometric fractions. The presence of As was relatively low in the most mobile forms in both sites. As was predominantly linked to short-range ordered Fe oxyhydroxides, coprecipitated with Fe and partially with Al oxyhydroxides and associated with structural material in mine waste samples. As incorporated into short-range ordered Fe oxyhydroxides was the predominant fraction at sediment samples, representing more than 80% of total As.

Mine Planning for Asteroid Orebodies

Science.gov (United States)

Gertsch, L. S.; Gertsch, R. E.

2000-01-01

Given that an asteroid (or comet) has been determined to contain sufficient material of value to be potentially economic to exploit, a mining method must be selected and implemented. This paper discusses the engineering necessary to bring a mine online, and the opportunities and challenges inherent in asteroid mineral prospects. The very important step of orebody characterization is discussed elsewhere. The mining methods discussed here are based on enclosing the asteroid within a bag in some fashion, whether completely or partially. In general, asteroid mining methods based on bags will consist of the following steps. Not all will be required in every case, nor necessarily in this particular sequence. Some steps will be performed simultaneously. Their purpose is to extract the valuable material from the body of the asteroid in the most efficient, cost-effective manner possible. In approximate order of initiation, if not of conclusion, the steps are: 1. Tether anchoring to the asteroid. 2. Asteroid motion control. 3. Body/fragment restraint system placement. 4. Operations platform construction. 5. Bag construction. 6. Auxiliary and support equipment placement. 7. Mining operations. 8. Processing operations. 9. Product transport to markets.

Using tracers to understand the hydrology of an abandoned underground coal mine

International Nuclear Information System (INIS)

Canty, G.A.; Everett, J.W.

1998-01-01

Flooded underground mines pose a difficult problem for remediation efforts requiring hydrologic information. Mine environments are hydraulically complicated due to sinuous travel paths and variable hydraulic gradients. For an acidic mine remediation project, conducted by the University of Oklahoma in conjunction with the Oklahoma Conservation Commission, a tracer study was undertaken to identify basic hydrologic properties of a flooded coal mine. The study was conducted to investigate the possibility of in-situ remediation of acidic mine water with the use of alkaline coal combustion by-products. Information on the rate of flow and ''connectiveness'' of injection wells with the discharge point was needed to develop a treatment strategy. Fluorescent dyes are not typically used in mine tracer studies because of the low pH values associated with certain mines and a tendency to adsorb ferric iron precipitates. However, Rhodamine WT was used in one tracer test because it can be detected at low concentrations. Due to poor recovery, a second tracer test was undertaken using a more conservative tracer-chloride. Each tracer produced similar travel time results. Findings from this study suggest that Rhodamine WT can be used under slightly acidic conditions, with mixed results. The more conservative tracer provided somewhat better results, but recovery was still poor. Use of these tracers has provided some valuable information with regard to mine hydrology, but additional questions have been raised

Skylab experiments. Volume 3: Materials science. [Skylab experiments on metallurgy, crystal growth, semiconductors, and combustion physics in weightless environment for high school level education

Science.gov (United States)

1973-01-01

The materials science and technology investigation conducted on the Skylab vehicle are discussed. The thirteen experiments that support these investigations have been planned to evaluate the effect of a weightless environment on melting and resolidification of a variety of metals and semiconductor crystals, and on combustion of solid flammable materials. A glossary of terms which define the space activities and a bibliography of related data are presented.

Inertisation and mine fire simulation using computer software

Energy Technology Data Exchange (ETDEWEB)

Stewart Gillies; Hsin Wei Wu [Gillies Wu Mining Technology (Australia)

2007-05-15

Inertisation is a technique used to enhance the safety of underground coal mine areas either to avoid the potential for a combustion event or to stabilise a situation after an ignition, fire or heating. The primary objective of the study was to review coal mine inertisation in Australia, in particular, to focus on the use of the Polish mine fire simulation software 'VENTGRAPH' to gain better understanding of how inertisation (GAG, Mineshield, Nitrogen Pressure Swing Adsorption (Floxal) and Tomlinson Boiler) units interact with the complex ventilation behaviour underground during a substantial fire. Most emphasis has been given to understanding the behaviour of the GAG unit because of its high capacity output. Critical aspects targeted for examination include location of the unit for high priority fire positions, size of borehole or pipe range required, time required for inertisation output to interact with and extinguish a fire, effects of seam gases on fire behaviour with inertisation present and main fan management. The project aims to increase understanding of behaviour of mine fires in modern mine ventilation networks with the addition of inert gas streams. A second aim of the project has been to take findings from the simulation exercises and develop inertisation related modifications to the program in conjunction with the Polish program authors. Exercises based on Oaky North and Oaky No 1 mines have involved 'evaluation or auditing' of ability to deliver inert gases generated from GAG units to high priority underground fire locations. These exercises have been built around modelling of fire scenarios across the mine layouts. The fire simulation exercises at Oaky North and Oaky No 1 mines demonstrated that it is possible to efficiently evaluate possible inertisation strategies appropriate to a complex mine layout extracting a gassy seam and determine which approach strategy (if any) can be used to stabilise a mine in a timely fashion.

Fluidised bed combustion system

International Nuclear Information System (INIS)

McKenzie, E.C.

1976-01-01

Fluidized bed combustion systems that facilitates the maintenance of the depth of the bed are described. A discharge pipe projects upwardly into the bed so that bed material can flow into its upper end and escape downwardly. The end of the pipe is surrounded by an enclosure and air is discharged into the enclosure so that material will enter the pipe from within the enclosure and have been cooled in the enclosure by the air discharged into it. The walls of the enclosure may themselves be cooled

Mechanisms and kinetics of granulated sewage sludge combustion.

Science.gov (United States)

Kijo-Kleczkowska, Agnieszka; Środa, Katarzyna; Kosowska-Golachowska, Monika; Musiał, Tomasz; Wolski, Krzysztof

2015-12-01

This paper investigates sewage sludge disposal methods with particular emphasis on combustion as the priority disposal method. Sewage sludge incineration is an attractive option because it minimizes odour, significantly reduces the volume of the starting material and thermally destroys organic and toxic components of the off pads. Additionally, it is possible that ashes could be used. Currently, as many as 11 plants use sewage sludge as fuel in Poland; thus, this technology must be further developed in Poland while considering the benefits of co-combustion with other fuels. This paper presents the results of experimental studies aimed at determining the mechanisms (defining the fuel combustion region by studying the effects of process parameters, including the size of the fuel sample, temperature in the combustion chamber and air velocity, on combustion) and kinetics (measurement of fuel temperature and mass changes) of fuel combustion in an air stream under different thermal conditions and flow rates. The combustion of the sludge samples during air flow between temperatures of 800 and 900°C is a kinetic-diffusion process. This process determines the sample size, temperature of its environment, and air velocity. The adopted process parameters, the time and ignition temperature of the fuel by volatiles, combustion time of the volatiles, time to reach the maximum temperature of the fuel surface, maximum temperature of the fuel surface, char combustion time, and the total process time, had significant impacts. Copyright © 2015 Elsevier Ltd. All rights reserved.

Gaseous products and smoke generation on combustion of the insulation materials of nuclear cables

International Nuclear Information System (INIS)

Noguchi, Isamu; Takami, Hiroshi; Ueyama, Michio; Fujimura, Shun-ichi.

1976-01-01

Serious requirements have been introduced to the cables used for nuclear power plants on their flame retardation in the IEEE Standard 383-1974. The movements that the users prescribe the quantity of corrosive gas generated from cables are also observed. This report describes on the measured results of the gaseous products generated by burning polyethylene, polyvinyl-chloride (PVC) and their flame-resistant products, and a part of the covering materials of the cables for nuclear power plants (flame-resistant, crosslinking polyethylene, flame-resistant, low hydrochloric acid PVC, flame-resistant jute) in the infra-red rapid heating combustion test facility designed by the Furukawa Electric Co. Ltd. In addition, the report introduces the test method for the smoke generation evaluation of polymers and a part of the measured results. The gaseous products of combustion were collected and determined quantitatively by gas chromatographic method. Since smoke generation is affected greatly by the kinds, shape, atmosphere, temperature, ignition procedure and others of burnt matters, the establishment of the evaluation test method is difficult, and a number of methods have been proposed. As the measured results showed, it is clear that smoke generation increases with the increase of flame resistant reagent addition. The smoke generation of PVC was of course great in quantity because it contains considerable amount of chlorine for its molecular structure. Flame-resistant polyethylene generates smoke much more than polyethylene without flame-resisting treatment because of its flame resistivity, but less than that of PVC. (Wakatsuki, Y.)

FIBROUS MONOLITH WEAR RESISTANT COMPONENTS FOR THE MINING INDUSTRY

Energy Technology Data Exchange (ETDEWEB)

Kenneth L. Knittel

2005-05-09

The work performed on this program was to develop wear resistant, tough FM composite materials with efforts focused on WC-Co based FM systems. The materials were developed for use in mining industry wear applications. Components of interest were drill bit inserts for drilling blast holes. Other component applications investigated included wear plates for a variety of equipment such as pit shovels, wear surfaces for conveyors, milling media for ball milling operations, hydrocyclone cones, grader blades and dozer teeth. Cross-cutting technologies investigated included hot metal extrusion dies, drill bits for circuit board fabrication, cutting tools for cast iron and aluminum machining. An important part of the work was identification of the standard materials used in drilling applications. A materials trade study to determine those metals and ceramics used for mining applications provided guidance for the most important materials to be investigated. WC-Co and diamond combinations were shown to have the most desirable properties. Other considerations such as fabrication technique and the ability to consolidate shifted the focus away from diamond materials and toward WC-Co. Cooperating partners such as Kennametal and Kyocera assisted with supplies, evaluations of material systems, fabricated parts and suggestions for cross-cutting technology applications for FM architectures. Kennametal provided the raw materials (WC-Co and Al-TiCN powders) for the extent of the material evaluations. Kyocera shared their research into various FM systems and provided laboratory testing of fabricated materials. Kyocera also continued research of the FM systems with the intention of developing commercial markets for a variety of applications. The continued development of FM technology by Kyocera is seen as a direct result of the cooperation established under this funding. Kyocera has a specific interest in the commercial development of the FM technology and have licensed it and have paid

Numerical modelling approach for mine backfill

Indian Academy of Sciences (India)

Muhammad Zaka Emad

2017-07-24

Jul 24, 2017 ... conditions. This paper discusses a numerical modelling strategy for modelling mine backfill material. The .... placed in an ore pass that leads the ore to the ore bin and crusher, from ... 1 year, depending on the mine plan.

Wood products in the waste stream: Characterization and combustion emissions. Volume 1. Final report

International Nuclear Information System (INIS)

1992-11-01

Waste wood is wood separated from the solid-waste stream and processed into a uniform-sized product that is reused for other purposes such as fuel. As an alternative to the combustion of fossil fuels, it has raised concerns that if it is 'contaminated' with paints, resins, preservatives, etc., unacceptable environmental impacts may be generated during combustion. Given the difficulty of separating contaminated materials from waste wood and the large energy potential existing in the resource, it is important to identify possible problems associated with contaminated waste wood combustion. The study describes research about technical, public policy, and regulatory issues that affect the processing and combustion of waste wood for fuel. The project's purpose was to provide environmental regulators, project developers, and others with data to make informed decisions on the use of waste wood materials as a combustion resource. Potential environmental problems and solutions were identified. A specific project result was the identification of combustion system operation parameters and air pollution control technologies that can minimize emissions of identified air and solid waste contaminants from combustion of wood waste

Mining in Australia

Energy Technology Data Exchange (ETDEWEB)

Shimada, S

1986-01-01

Statistics are given on: 1) Australian dependence on imported raw materials in 1980; 2) production levels in the different mining fields in 1981; 3) trends in the production of minerals over the years 1961-1981. The role of the mining industry in the Australian economy is outlined, and brief details given of its structure. Further statistics are given regarding trends in the production of coal, iron, salt, lead and zinc during the period 1961-1981, together with details of the number of people employed in these industries. Operations at some of the principal mines (coal, iron ore and salt) are outlined and 1983 production figures for all mineral resources are given. 18 refs., 21 figs., 5 tabs.

Data mining in agriculture

CERN Document Server

Mucherino, Antonio; Pardalos, Panos M

2009-01-01

Data Mining in Agriculture represents a comprehensive effort to provide graduate students and researchers with an analytical text on data mining techniques applied to agriculture and environmental related fields. This book presents both theoretical and practical insights with a focus on presenting the context of each data mining technique rather intuitively with ample concrete examples represented graphically and with algorithms written in MATLAB®. Examples and exercises with solutions are provided at the end of each chapter to facilitate the comprehension of the material. For each data mining technique described in the book variants and improvements of the basic algorithm are also given. Also by P.J. Papajorgji and P.M. Pardalos: Advances in Modeling Agricultural Systems, 'Springer Optimization and its Applications' vol. 25, ©2009.

Addition of schelita residue from the mine in Cerro Cora Bodo / RN in the composition of ceramic materials

International Nuclear Information System (INIS)

Almeida, A.B.D. de; Souza, M. M. de; Farias, D.S.U. de; Lima, T.C. de; Nobrega, L.F.P. de M.; Mendes, L.B.

2016-01-01

Mining activities produce mineral waste that can degrade the environment. The waste generated by companies is not reused due to the fact they fail to present an application for it that proves to be economically viable. Seeking the reuse of mineral waste and reduce the environmental impacts, this work addresses the chemical characterization by x-ray fluorescence (FRX), of the processing of scheelite reject at Bodo mine in Cerro Cora-RN. For the procedure, the sample was collected, grounded and sieved to #200, and then characterized to evaluate its chemical composition and its potential to be incorporated into materials. Besides the characterization, a water absorption test and also a bending test were performed to analyze the power and tension of the material. The result of the analysis indicated that the sample researched presents a greater concentration of SiO_2 to be used as a structuring element in ceramic mass, but in the traditional formulation, it will only be added 10% of the reject in its formulation, because besides the SiO_2 in the sample analyzed other elements that act with fluxes were found. It was also observed the material has low water absorption, but the reject reached low strength and breakdown voltage. We concluded that the reject of scheelite presents great potential, and therefore, further tests can be conducted to analyze the possibility of being added as raw material for the formulation of other materials like cement. (author)

Possibility of Coal Combustion Product Conditioning

Science.gov (United States)

Błaszczyński, Tomasz Z.; Król, Maciej R.

2018-03-01

This paper is focused on properties of materials known as green binders. They can be used to produce aluminium-siliceous concrete and binders known also as geopolymers. Comparing new ecological binders to ordinary cements we can see huge possibility of reducing amount of main greenhouse gas which is emitted to atmosphere by 3 to even 10 times depending of substrate type used to new green material production. Main ecological source of new materials obtaining possibility is to use already available products which are created in coal combustion and steel smelting process. Most of them are already used in many branches of industry. They are mostly civil engineering, chemistry or agriculture. Conducted research was based on less popular in civil engineering fly ash based on lignite combustion. Materials were examine in order to verify possibility of obtaining hardened mortars based of different factors connected with process of geopolymerization, which are temperature, amount of reaction reagent and time of heat treatment. After systematizing the matrices for the basic parameters affecting the strength of the hardened mortars, the influence of the fly ash treatment for increasing the strength was tested.

1998 mines and quarries guidebook

International Nuclear Information System (INIS)

1998-01-01

The 1998 edition of the mines and quarries guidebook provides: a comprehensive overview of mining activities in France and French-speaking countries relative to coal, uranium, non-ferrous ores and metals, industrial minerals, lime, limestone, silica, cermet and saline minerals; a list of recycling companies; a list of quarries and building material exploitations (organisational structure of main companies, granulates, cement industry, gypsum, plaster, tiles, bricks, stones..); a list and coordinates by department of more than 1400 quarries with the material exploited; an inventory of mining exploitations of Belgium, Switzerland and French speaking countries of Africa, a listing and organisational structure of research and engineering centres and administrations; an alphabetical and analytical repertory of more than 700 supplying companies of the mineral industry; and the status, organization and members of the mineral industry society. (J.S.)

Development of a fire detector for underground coal mines

Energy Technology Data Exchange (ETDEWEB)

Hemingway, M.A.; Walsh, P.T.; Hunneyball, S.R.; Williams, M.; Jobling, S.; Pell, B.; West, N.G. [Health and Safety Laboratory, Buxton (United Kingdom)

2005-07-01

Current fire detectors in use in UK coal mines, based on semiconductor sensors which detect gaseous products of combustion, are under-utilised, are not user-friendly, have performance limitations due to interferences and are obsolete. A joint research project was therefore instigated to develop an improved fire detector. This paper describes tests performed in an experimental mine roadway on various types of sensor. The sensors were exposed to smouldering conveyor belt, coal, wood, oil and grease, and diesel exhaust fume. A potential advanced detector is based on the combination of blue and infrared optical smoke sensors which distinguish fires and diesel exhaust from coal dust, nitric oxide or nitrogen dioxide sensors to distinguish smoulderi8ng fires form diesel exhaust, and carbon monoxide sensors for general body monitoring. 6 refs., 5 figs.

Co-combustion of coal and non-recyclable paper & plastic waste in a fluidised bed reactor

Energy Technology Data Exchange (ETDEWEB)

Boavida, D.; Abelha, P.; Gulyurtlu, I.; Cabrita, I. [DEECA-INETI, Lisbon (Portugal)

2002-07-01

Co-combustion of waste with coal was carried out using a fluidised bed combustor with the aim of achieving a fuel mixture with little variations in its heating value and simultaneously reducing the accumulation of non-toxic waste material by upgrading them for energy purposes. Results obtained indicate that the feeding of waste materials could present serious problems which could render conditions for a stable combustion difficult to achieve. The waste was fed mixed with coal and there was some difference observed in results regarding the combustion efficiency and emissions. Part of the combustion of waste material, contrary to that of coal, was observed to take place in the freeboard where the temperature was as much as 150{degree}C above that of the bed. 6 refs., 8 figs., 8 tabs.

Hematite mining in the ancient Americas: Mina Primavera, A 2,000 year old Peruvian mine

Science.gov (United States)

Vaughn, Kevin J.; Grados, Moises Linares; Eerkens, Jelmer W.; Edwards, Matthew J.

2007-12-01

Mina Primavera, a hematite (Fe2O3) mine located in southern Peru, was exploited beginning approximately 2,000 years ago by two Andean civilizations, the Nasca and Wari. Despite the importance of hematite in the material culture of the ancient Americas, few hematite mines have been reported in the New World literature and none have been reported for the Central Andes. An estimated 3,710 tonnes of hematite were extracted from the mine for over 1,400 years at an average rate of 2.65 tonnes per year, suggesting regular and extensive mining prior to Spanish conquest. The hematite was likely used as a pigment for painting pottery, and the mine demonstrates that iron ores were extracted extensively at an early date in the Americas.

Oxygen Carrier Aided Combustion (OCAC of Wood Chips in a Semi-Commercial Circulating Fluidized Bed Boiler Using Manganese Ore as Bed Material

Directory of Open Access Journals (Sweden)

Magnus Rydén

2016-11-01

Full Text Available Oxygen Carrier Aided Combustion (OCAC is realized by using an active oxygen-carrying bed material in fluidized bed boilers. The active material is reduced in fuel rich parts of the boiler and oxidized in air rich parts. Advantages could be achieved such as new mechanisms for oxygen transport in space and time. Here calcined manganese ore has been used as active bed material in a 12 MWth circulating fluidized bed boiler. The fuel was wood chips and the campaign lasted more than two weeks. From an operational point of view, manganese ore worked excellently. From the temperature profile of the boiler it can be concluded that fuel conversion was facilitated, especially in the dense bottom bed. The effect did not always translate to reduced emissions, which suggests that final combustion in the cyclone outlet was also influenced. Substituting 10% of the sand bed with manganese ore made it possible to reduce the air to fuel ratio without generating large amounts of CO. The use of 100% manganese ore resulted in higher emissions of CO than the sand reference, but, when combined sulphur feeding, dramatic reductions in CO emissions, up to 90% compared to sand reference, was achieved.

Legal Policy Of Peoples Rights In Around Mining Corporate Post-Mining Activities

Directory of Open Access Journals (Sweden)

Teng Berlianty

2015-08-01

Full Text Available This study aims to gain an understanding of the essence of the rights of communities around post-mining corporate responsibility towards the fulfillment of the rights of communities around post-mining as well as government policies to protect the sustainability of the post-mining communities around the mining business. This type of research is a normative legal research methods using primary legal materials secondary and tertiary. With the approach of sociolegal through down the field in Gebe to get data concrete. Data were analyzed with qualitative analysis. The results showed that the essence of the rights of communities around mining operations after the mine in the form of the right to a decent life welfare the right to social security in the form of employment the guarantee of free education and healthcare for the local population as well as the right to a good environment and healthy as a guarantee of the continuity of human existence and future generations. These rights have not been fully realized post-mining. Corporate responsibility in accordance with Article 74 of Law No. 40 of 2007 on the fulfillment of the rights of communities around mining operations after the mine in the form of welfare responsibilities clothing food and shelter especially electricity and water have not been met then the social responsibility to empower communities around the mine as stakeholders as well as environmental responsibility. Legal policy such as the empowerment of communities around the mine in order to be self-sufficient after the post-mining public service policies in education and health as a form of existence of government using existing programs nationally and subordinate to the PT. Antam. as well as environmental protection policies in the form of post-mining reclamation formulated in the companys liabilities.

Lignite mining in India - technology highlights

Energy Technology Data Exchange (ETDEWEB)

Tandon, G L

1984-01-01

Figures for lignite production and its role in the Indian energy scene are presented. Lignite mining at Neyveli is described in detail, including: advance preparation of the overburden strata; modifications to bucket wheel excavators; tackling the sticky surface clays; ground water management; storm water control; tackling higher overburden-to-lignite ratios; materials handling; communications within the mine; the development of indigenous mining equipment; and ecology and environmental control.

Combustion of environmentally altered molybdenum trioxide nanocomposites

Energy Technology Data Exchange (ETDEWEB)

Moore, Kevin; Pantoya, Michelle L. [Mechanical Engineering Department, Texas Tech University, 2500 Broadway, Lubbock, TX 79409 (United States)

2006-06-15

Nanocomposite thermite mixtures are currently under development for many primer applications due to their high energy densities, high ignition sensitivity, and low release of toxins into the environment. However, variability and inconsistencies in combustion performance have not been sufficiently investigated. Environmental interactions with the reactants are thought to be a contributing factor to these variabilities. Combustion velocity experiments were conducted on aluminum (Al) and molybdenum trioxide (MoO{sub 3}) mixtures to investigate the role of environmental interactions such as light exposure and humidity. While the Al particles were maintained in an ambient, constant environment, the MoO{sub 3} particles were exposed to UV or fluorescent light, and highly humid environments. Results show that UV and fluorescent lighting over a period of days does not significantly contribute to performance deterioration. However, a humid environment severely decreases combustion performance if the oxidizer particles are not heat-treated. Heat treatment of the MoO{sub 3} greatly increases the material's ability to resist water absorption, yielding more repeatable combustion performance. This work further quantifies the role of the environment in the decrease of combustion performance of nanocomposites over time. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

Characterisation of ashes produced by co-combustion of recovered fuels and peat

Energy Technology Data Exchange (ETDEWEB)

Frankenhaeuser, M.; Zevenhoven, R. [Borealis Polymers Oy, Porvoo (Finland); Skrifvars, B.J. [Aabo Akademi, Turku (Finland); Orjala, M. [VTT Energy, Espoo (Finland); Peltola, K. [Foster Wheeler Energy (Finland)

1996-12-01

Source separation of combustible materials from household or municipal solid waste yields a raw material for the production of Packaging Derived Fuel (PDF). This fuel can substitute the traditional fuels in heat and power generation and is also called recycled fuel. Co-combustion of these types of fuels with coal has been studied in several LIEKKI-projects and the results have been both technically and environmentally favourable. (author)

NOx Emission Reduction by Oscillating Combustion

Energy Technology Data Exchange (ETDEWEB)

John C. Wagner

2004-03-31

High-temperature, natural gas-fired furnaces, especially those fired with preheated air, produce large quantities of NO{sub x} per ton of material processed. Regulations on emissions from industrial furnaces are becoming increasingly more stringent. In addition, competition is forcing operators to make their furnaces more productive and/or efficient. Switching from preheated air to industrial oxygen can increase efficiency and reduce NO{sub x}, but oxygen is significantly more costly than air and may not be compatible with the material being heated. What was needed, and what was developed during this project, is a technology that reduces NO{sub x} emissions while increasing furnace efficiency for both air- and oxy-fired furnaces. Oscillating combustion is a retrofit technology that involves the forced oscillation of the fuel flow rate to a furnace. These oscillations create successive, fuel-rich and fuel-lean zones within the furnace. Heat transfer from the flame to the load increases due to the more luminous fuel-rich zones, a longer overall flame length, and the breakup of the thermal boundary layer. The increased heat transfer shortens heat up times, thereby increasing furnace productivity, and reduces the heat going up the stack, thereby increasing efficiency. The fuel-rich and fuel-lean zones also produce substantially less NO{sub x} than firing at a constant excess air level. The longer flames and higher heat transfer rate reduces overall peak flame temperature and thus reduces additional NO{sub x} formation from the eventual mixing of the zones and burnout of combustibles from the rich zones. This project involved the development of hardware to implement oscillating combustion on an industrial scale, the laboratory testing of oscillating combustion on various types of industrial burners, and the field testing of oscillating combustion on several types of industrial furnace. Before laboratory testing began, a market study was conducted, based on the

NOx Emission Reduction by Oscillating combustion

Energy Technology Data Exchange (ETDEWEB)

Institute of Gas Technology

2004-01-30

High-temperature, natural gas-fired furnaces, especially those fired with preheated air, produce large quantities of NO{sub x} per ton of material processed. Regulations on emissions from industrial furnaces are becoming increasingly more stringent. In addition, competition is forcing operators to make their furnaces more productive and/or efficient. Switching from preheated air to industrial oxygen can increase efficiency and reduce NO{sub x}, but oxygen is significantly more costly than air and may not be compatible with the material being heated. What was needed, and what was developed during this project, is a technology that reduces NO{sub x} emissions while increasing furnace efficiency for both air- and oxy-fired furnaces. Oscillating combustion is a retrofit technology that involves the forced oscillation of the fuel flow rate to a furnace. These oscillations create successive, fuel-rich and fuel-lean zones within the furnace. Heat transfer from the flame to the load increases due to the more luminous fuel-rich zones, a longer overall flame length, and the breakup of the thermal boundary layer. The increased heat transfer shortens heat up times, thereby increasing furnace productivity, and reduces the heat going up the stack, thereby increasing efficiency. The fuel-rich and fuel-lean zones also produce substantially less NO{sub x} than firing at a constant excess air level. The longer flames and higher heat transfer rate reduces overall peak flame temperature and thus reduces additional NO{sub x} formation from the eventual mixing of the zones and burnout of combustibles from the rich zones. This project involved the development of hardware to implement oscillating combustion on an industrial scale, the laboratory testing of oscillating combustion on various types of industrial burners, and the field testing of oscillating combustion on several types of industrial furnace. Before laboratory testing began, a market study was conducted, based on the

Data Mining and Machine Learning Tools for Combinatorial Material Science of All-Oxide Photovoltaic Cells.

Science.gov (United States)

Yosipof, Abraham; Nahum, Oren E; Anderson, Assaf Y; Barad, Hannah-Noa; Zaban, Arie; Senderowitz, Hanoch

2015-06-01

Growth in energy demands, coupled with the need for clean energy, are likely to make solar cells an important part of future energy resources. In particular, cells entirely made of metal oxides (MOs) have the potential to provide clean and affordable energy if their power conversion efficiencies are improved. Such improvements require the development of new MOs which could benefit from combining combinatorial material sciences for producing solar cells libraries with data mining tools to direct synthesis efforts. In this work we developed a data mining workflow and applied it to the analysis of two recently reported solar cell libraries based on Titanium and Copper oxides. Our results demonstrate that QSAR models with good prediction statistics for multiple solar cells properties could be developed and that these models highlight important factors affecting these properties in accord with experimental findings. The resulting models are therefore suitable for designing better solar cells. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Combustion Stratification for Naphtha from CI Combustion to PPC

KAUST Repository

Vallinayagam, R.

2017-03-28

This study demonstrates the combustion stratification from conventional compression ignition (CI) combustion to partially premixed combustion (PPC). Experiments are performed in an optical CI engine at a speed of 1200 rpm for diesel and naphtha (RON = 46). The motored pressure at TDC is maintained at 35 bar and fuelMEP is kept constant at 5.1 bar to account for the difference in fuel properties between naphtha and diesel. Single injection strategy is employed and the fuel is injected at a pressure of 800 bar. Photron FASTCAM SA4 that captures in-cylinder combustion at the rate of 10000 frames per second is employed. The captured high speed video is processed to study the combustion homogeneity based on an algorithm reported in previous studies. Starting from late fuel injection timings, combustion stratification is investigated by advancing the fuel injection timings. For late start of injection (SOI), a direct link between SOI and combustion phasing is noticed. At early SOI, combustion phasing depends on both intake air temperature and SOI. In order to match the combustion phasing (CA50) of diesel, the intake air temperature is increased to 90°C for naphtha. The combustion stratification from CI to PPC is also investigated for various level of dilution by displacing oxygen with nitrogen in the intake. The start of combustion (SOC) was delayed with the increase in dilution and to compensate for this, the intake air temperature is increased. The mixture homogeneity is enhanced for higher dilution due to longer ignition delay. The results show that high speed image is initially blue and then turned yellow, indicating soot formation and oxidation. The luminosity of combustion images decreases with early SOI and increased dilution. The images are processed to generate the level of stratification based on the image intensity. The level of stratification is same for diesel and naphtha at various SOI. When O concentration in the intake is decreased to 17.7% and 14

Challenges of safety in Indian mines during twenty-first century

Energy Technology Data Exchange (ETDEWEB)

Batra, S.C. [Directorate General of Mines Safety, Dhanbad (India)

1997-12-31

Mining industry in India has been progressing steadily during the last five decades. Production of coal, limestone, iron ore, bauxite, copper, lead and zinc ores has gone up several times during this period. Ambitious production targets have been set for the years to come. With depletion of easily mineable deposits, mining activities would have to be extended to difficult geo-mining locales like greater depth and geologically disturbed areas. Extension of workings to deeper horizons would give rise to problems and mechanisation would introduce hazards like accidental fires, electrocution, environmental pollution by internal combustion engines, generation of dust, noise and vibration. The mining industry will have to prepare itself right from now to meet the challenges of safety and health problems. Thus strategies will have to be evolved to solve problems of strata control including slope stability, ventilation, hazards of explosions etc. Timber supports would have to be phased out and be replaced by steel supports. Disasters and their prevention would need a fresh look. Communication, human resource development and management information system are the other areas needing attention. 10 refs., 1 tab., 2 app.

Mine waters: Acidic to circumneutral

Science.gov (United States)

Nordstrom, D. Kirk

2011-01-01

Acid mine waters, often containing toxic concentrations of Fe, Al, Cu, Zn, Cd, Pb, Ni, Co, and Cr, can be produced from the mining of coal and metallic deposits. Values of pH for acid mine waters can range from –3.5 to 5, but even circumneutral (pH ≈ 7) mine waters can have high concentrations of As, Sb, Mo, U, and F. When mine waters are discharged into streams, lakes, and the oceans, serious degradation of water quality and injury to aquatic life can ensue, especially when tailings impoundments break suddenly. The main acid-producing process is the exposure of pyrite to air and water, which promotes oxidative dissolution, a reaction catalyzed by microbes. Current and future mining should plan for the prevention and remediation of these contaminant discharges by the application of hydrogeochemical principles and available technologies, which might include remining and recycling of waste materials.

Uranium mines and French mining companies: a magnificent adventure

International Nuclear Information System (INIS)

Blanc, J.

2008-01-01

The French mining adventure still arouses enthusiasm. The search for uranium began in 1945 with the creation of the Cea (Atomic Energy Board) whose one mission was to supply the nascent French nuclear programme with the necessary materials. Prospecting works were then led throughout France, Madagascar, the Ivory Coast and the French equatorial Africa. More than 60 years later the only surviving actor of this quest for uranium has become the mining department of Areva Nuclear Cycle which is itself a sub-company of Areva. The author, who was an ancient high executive of Cogema draws a detailed history of the French uranium mining industry with with its ups and downs, by analysing the impact of the 2 oil crisis and of the decline of nuclear energy in the decade following the Chernobyl accident. (A.C.)

Controlling ventilation for safe escape from coal mine fires

Energy Technology Data Exchange (ETDEWEB)

Wala, A M [University of Kentucky, Lexington, KY (United States). Mining Engineering Dept.

1966-04-01

If a fire occurs outby an underground coal mine section, the immediate safe evacuation of miners from the working section should always take precedence. Unfortunately, in many cases, the dedicated escapeway (escape routes) for the evacuation of the miners become contaminated by the byproducts of fire from the adjacent entries. The purpose of this paper is to present the ventilation-control process that would keep the escapeway free from contaminants and, thus, available for travel. A few scenarios of mine fires in longwall development panels are analysed and discussed. To perform these studies, a mine-fire simulator (MFS) was used. This (MFS) provides a dynamic representation of the fire`s progress (in real time) and gives a color-graphic visualization of the spready of oxygen, combustion products and temperature of the gases throughout the ventilation system. Also presented and discussed are ways in which the MFS can be used as a training and teaching tool for miners and particularly, for ventilation and safety specialists. 7 refs., 10 figs.

Mine haul road fugitive dust emission and exposure characterisation

Energy Technology Data Exchange (ETDEWEB)

Thompson, R.J.; Visser, A.T. [University of Pretoria, Pretoria (South Africa). Dept. of Mining Engineering

2001-03-01

Excessive dust generation from mine haul roads is a problem common to most surface coal mining operations. Optimal wearing course material selection parameters reduce, but do not toally eliminate the potential to produce dust. For existing operations, which may not have optimally designed and maintained roads, the problem of identifying the haul road dust defect, quantifying its impact on both safety and health and assigning priorities within the constraints of limited capital and manpower is problematic. This is reflected in the fact that most surface mine operators agree dust-free roads are desirable, but find it difficult to translate this into cost-effective betterment activities. The aim of this paper is to describe fugitive dust emission and exposure characteristics associated with ultra-heavy mine haul trucks running on unpaved mine haul roads. Models are described which enable mines to assess the likely dustiness of their chosen haul road material as a function of surface loading of fines, traffic types and volume, together with various material parameters. By combining these models with the results of quantitative exposure profiling, a mine can, in conjunction with the assessment, determine the most cost- and safety-effective haul road dust management strategy. 18 refs., 10 figs., 2 tabs.

Ignition delays, heats of combustion, and reaction rates of aluminum alkyl derivatives used as ignition and combustion enhancers for supersonic combustors

Science.gov (United States)

Ryan, T. W., III; Harlowe, W. W.; Schwab, S.

1992-01-01

The work was based on adapting an apparatus and procedure developed at Southwest Research Institute for rating the ignition quality of fuels for diesel engines. Aluminum alkyls and various Lewis-base adducts of these materials, both neat and mixed 50/50 with pure JP-10 hydrocarbon, were injected into the combustion bomb using a high-pressure injection system. The bomb was pre-charged with air that was set at various initial temperatures and pressures for constant oxygen density. The ignition delay times were determined for the test materials at these different initial conditions. The data are presented in absolute terms as well as comparisons with the parent alkyls. The relative heats of reaction of the various test materials were estimated based on a computation of the heat release, using the pressure data recorded during combustion in the bomb. In addition, the global reaction rates for each material were compared at a selected tmperature and pressure.

IEA combustion agreement : a collaborative task on alternative fuels in combustion

International Nuclear Information System (INIS)

Larmi, M.

2009-01-01

The focus of the alternative fuels in combustion task of the International Energy Agency is on high efficiency engine combustion, furnace combustion, and combustion chemistry. The objectives of the task are to develop optimum combustion for dedicated fuels by fully utilizing the physical and chemical properties of synthetic and renewable fuels; a significant reduction in carbon dioxide, NOx and particulate matter emissions; determine the minimum emission levels for dedicated fuels; and meet future emission standards of engines without or with minimum after-treatment. This presentation discussed the alternative fuels task and addressed issues such as synthetic fuel properties and benefits. The anticipated future roadmap was presented along with a list of the synthetic and renewable engine fuels to be studied, such as neat oxygenates like alcohols and ethers, biogas/methane and gas combustion, fuel blends, dual fuel combustion, high cetane number diesel fuels like synthetic Fischer-Tropsch diesel fuel and hydrogenated vegetable oil, and low CN number fuels. Implementation examples were also discussed, such as fuel spray studies in optical spray bombs; combustion research in optical engines and combustion chambers; studies on reaction kinetics of combustion and emission formation; studies on fuel properties and ignition behaviour; combustion studies on research engines; combustion optimization; implementing the optimum combustion in research engines; and emission measurements. Overall milestone examples and the overall schedule of participating countries were also presented. figs.

Co-combustion of coal and non-recyclable paper and plastic waste in a fluidised bed reactor

Energy Technology Data Exchange (ETDEWEB)

D. Boavida; P. Abelha; I. Gulyurtlu; I. Cabrita [DEECA-INETI, Lisbon (Portugal)

2003-10-01

Co-combustion of waste with coal was carried out using a fluidised bed combustor with the aim of achieving a fuel mixture with little variations in its heating value and simultaneously reducing the accumulation of non-toxic waste material by upgrading them for energy purposes. Results obtained indicate that the feeding of waste materials plays an important role to achieve conditions for a stable combustion. The form in which the fuel is fed to the combustor makes a significant contribution to achieve desirable combustion performance and differences were observed in results regarding the combustion efficiency and emissions when waste was fed densified or in a fluffy state when it was burned mixed with coal. Part of the combustion of waste material, contrary to that of coal, was observed to take place in the freeboard where the temperature was as much as 150{sup o}C above that of the bed. 15 refs., 8 figs., 8 tabs.

Nitrogen Chemistry in Fluidized Bed Combustion of Coal

DEFF Research Database (Denmark)

Jensen, Anker Degn

and reduction by homogeneous and heterogeneous reactions. The data for the estimation of kinetics of the heterogeneous reactions were measured by one of the partners in the project for char and bed material sampled from a pressurized FBC pilot plant burning Kiveton Park coal. Experimental data from the pilot...... plant were used for model verification. The simulations of the NO emission during staged combustion and NH3 injection for NO reduction were in qualitative agreement with the experimental data. A parametric study of the influence of operating conditions on the conversion of fuel-N to NO showed......, the gas interchange coefficient, the bubble size and the bubble rise velocity. The most important combustion parameters were the rate of CO and CH4 combustion and the fraction of CO produced from char combustion. By using a rate of production analysis, the important reactions in the NO model were...

Current situation regarding the co-combustion of waste materials in power plants; Aktuelle Situation der Mitverbrennung von Abfallstoffen in Kraftwerken

Energy Technology Data Exchange (ETDEWEB)

Schirmer, U.; Krueger, H.; Puch, K.H. [VGB Technische Vereinigung der Grosskraftwerksbetreiber e.V., Essen (Germany)

1998-09-01

In view of the wholly insufficient capacity, relative to current arisings, of waste incineration plants, residue processing plants and plants for the utilisation of other combustible materials we are inevitably faced with the question whether power plant furnaces might not be suited for the thermal treatment and utilisation of wastes and residues. This possibility has been studied by many VGB member companies and seriously investigated for its practicability in several cases. The investigations were premised on the following fundamental positions. The VGB members are prepared to contribute to the solution of the above problems as long as this is possible without detriment to their duties as energy suppliers. They can only assume this responsibility if the requirements of the licensing laws are observed. This concerns the quality and arising quantities of wastes to be taken in, emissions, and the disposal of combustion residues. Power plants typically make more or less complete use of their own process residues, a feature which as far as possible should not be impaired by the co-combustion process. The technical problems posed by the co-combustion of suitable residues and wastes are usually solvable. Co-combustion offers an alternative and a supplement to dedicated waste utilisation plants or plants for the utilisation of suitable residues. Beyond this some companies are interested in profiting from the fees that will be due to them for utilising wastes. From 1990 to 1992 a VGB working group studied the option of co-combustion on the basis of the above premises. The material elaborated by the group now in turn serves as a basis for the following deliberations. [Deutsch] Da die Kapazitaet der Abfallverbrennungsanlagen, der Anlagen zur Reststoffverwertung und der Anlagen zur Nutzung sonstiger brennbaren Stoffe fuer das vorhandene Angebot bei weitem nicht ausreicht, ergibt sich die Frage der Eignung von Kraftwerksfeuerungen zur thermischen Behandlung und Verwertung von

Internal combustion engine using premixed combustion of stratified charges

Science.gov (United States)

Marriott, Craig D [Rochester Hills, MI; Reitz, Rolf D [Madison, WI

2003-12-30

During a combustion cycle, a first stoichiometrically lean fuel charge is injected well prior to top dead center, preferably during the intake stroke. This first fuel charge is substantially mixed with the combustion chamber air during subsequent motion of the piston towards top dead center. A subsequent fuel charge is then injected prior to top dead center to create a stratified, locally richer mixture (but still leaner than stoichiometric) within the combustion chamber. The locally rich region within the combustion chamber has sufficient fuel density to autoignite, and its self-ignition serves to activate ignition for the lean mixture existing within the remainder of the combustion chamber. Because the mixture within the combustion chamber is overall premixed and relatively lean, NO.sub.x and soot production are significantly diminished.

Modification of combustion aerosols in the atmosphere

Energy Technology Data Exchange (ETDEWEB)

Weingartner, E [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1996-07-01

Combustion aerosols particles are released on large scale into the atmosphere in the industrialized regions as well as in the tropics (by wood fires). The particles are subjected to various aging processes which depend on the size, morphology, and chemical composition of the particles. The interaction of combustion particles with sunlight and humidity as well as adsorption and desorption of volatile material to or from the particles considerably changes their physical and chemical properties and thus their residence time in the atmosphere. This is of importance because combustion particles are known to have a variety of health effects on people. Moreover, atmospheric aerosol particles have an influence on climate, directly through the reflection and absorption of solar radiation and indirectly through modifying the optical properties and lifetime of clouds. In a first step, a field experiment was carried out to study the sources and characteristics of combustion aerosols that are emitted from vehicles in a road tunnel. It was found that most of the fine particles were tail pipe emissions of diesel powered vehicles. The calculation shows that on an average these vehicles emit about 300 mg fine particulate matter per driven kilometer. This emission factor is at least 100 times higher than the mean emission factor estimated for gasoline powered vehicles. Furthermore, it is found that during their residence time in the tunnel, the particles undergo significant changes: The particles change towards a more compact structure. The conclusion is reached that this is mainly due to adsorption of volatile material from the gas phase to the particle surface. In the atmosphere, the life cycle as well as the radiative and chemical properties of an aerosol particle is strongly dependent on its response to humidity. Therefore the hygroscopic behavior of combustion particles emitted from single sources (i.e. from a gasoline and a diesel engine) were studied in laboratory experiments.

Solution of problems, emerging with the transition to thin seams mining on underground mines

International Nuclear Information System (INIS)

Malkin, A.S.; Podshivalov, V.E.; Zhdamirov, V.M.; Kostarev, A.P.; Kulakov, A.N.; Savchenkov, V.E.

1997-01-01

The greatest volume of useful carbon-energetical and carbon-technological resources in the countries of the world consists of coal. Most likely, problems of the development of coal wining technology and coal consumption will interest scientists and mining engineers for a long time. Moreover, competing with the petroleum and gas industries becomes increasingly difficult. Considerable increases in coal production in countries with warm climates, and favourable mining and geological conditions also damages the international market for the coal industries of Russia (and Australia, India, and Vietnam). In a situation of critical deficits in both financial and material means in Russia, it is necessary to change the structure of the means of production and investment policies for the development of coal mining at every individual mine. 1 fig

Combustion Stratification for Naphtha from CI Combustion to PPC

KAUST Repository

Vallinayagam, R.; Vedharaj, S.; An, Yanzhao; Dawood, Alaaeldin; Izadi Najafabadi, Mohammad; Somers, Bart; Johansson, Bengt

2017-01-01

This study demonstrates the combustion stratification from conventional compression ignition (CI) combustion to partially premixed combustion (PPC). Experiments are performed in an optical CI engine at a speed of 1200 rpm for diesel and naphtha (RON

Fuel and combustion stratification study of Partially Premixed Combustion

OpenAIRE

Izadi Najafabadi, M.; Dam, N.; Somers, B.; Johansson, B.

2016-01-01

Relatively high levels of stratification is one of the main advantages of Partially Premixed Combustion (PPC) over the Homogeneous Charge Compression Ignition (HCCI) concept. Fuel stratification smoothens heat release and improves controllability of this kind of combustion. However, the lack of a clear definition of “fuel and combustion stratifications” is obvious in literature. Hence, it is difficult to compare stratification levels of different PPC strategies or other combustion concepts. T...

Development of flameless combustion; Desarrollo de la combustion sin flama

Energy Technology Data Exchange (ETDEWEB)

Flores Sauceda, M. Leonardo; Cervantes de Gortari, Jaime Gonzalo [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)]. E-mail: 8344afc@prodigy.net.mx; jgonzalo@servidor.unam.mx

2010-11-15

The paper intends contribute to global warming mitigation joint effort that develops technologies to capture the CO{sub 2} produced by fossil fuels combustion and to reduce emission of other greenhouse gases like the NO{sub x}. After reviewing existing combustion bibliography is pointed out that (a) touches only partial aspects of the collective system composed by Combustion-Heat transfer process-Environment, whose interactions are our primary interest and (b) most specialists think there is not yet a clearly winning technology for CO{sub 2} capture and storage. In this paper the study of combustion is focused as integrated in the aforementioned collective system where application of flameless combustion, using oxidant preheated in heat regenerators and fluent gas recirculation into combustion chamber plus appropriated heat and mass balances, simultaneously results in energy saving and environmental impact reduction. [Spanish] El trabajo pretende contribuir al esfuerzo conjunto de mitigacion del calentamiento global que aporta tecnologias para capturar el CO{sub 2} producido por la combustion de combustibles fosiles y para disminuir la emision de otros gases invernadero como NOx. De revision bibliografica sobre combustion se concluye que (a) trata aspectos parciales del sistema compuesto por combustion-proceso de trasferencia de calor-ambiente, cuyas interacciones son nuestro principal interes (b) la mayoria de especialistas considera no hay todavia una tecnologia claramente superior a las demas para captura y almacenaje de CO{sub 2}. Se estudia la combustion como parte integrante del mencionado sistema conjunto, donde la aplicacion de combustion sin flama, empleando oxidante precalentado mediante regeneradores de calor y recirculacion de gases efluentes ademas de los balances de masa y energia adecuados, permite tener simultaneamente ahorros energeticos e impacto ambiental reducido.

COMBUSTION OF BIOMASS AND CHARCOAL MADE FROM BABASSU NUTSHELL

Directory of Open Access Journals (Sweden)

Thiago de Paula Protásio

2017-03-01

Full Text Available In recent years, studies have examined the use of lignocellulosic wastes for energy generation. However, there is a lack of information on the combustibility of the residual biomass, especially the bark and charcoal of babassu nut. In this study, thermogravimetric analysis (TGA, differential thermal analysis (DTA and differential scanning calorimetry (DSC were used to achieve the following objectives: to evaluate the combustion of the residual biomass from the babassu nut; to evaluate the combustion of charcoal produced from this biomass, considering different final carbonization temperatures; and to determine the effect of the final carbonization temperature on the thermal stability of charcoal and on its performance in combustion. Thermal analyses were performed in synthetic air. In order to evaluate the characteristics of charcoal combustion and fresh biomass, the ignition temperature (Ti, the burnout temperature (Tf, characteristic combustion index (S, ignition index (Di, time corresponding to the maximum combustion rate (tp, and ignition time (tig were considered. The combustion of the babassu nutshell occurred in three phases and it was observed that this lignocellulosic material is suitable for the direct generation of heat. The increase in the final carbonization temperature caused an increase in the ignition temperature, as well as in the burnout temperature, the ignition time and the time corresponding to the maximum combustion rate. The results indicate that the increase in the carbonization temperature causes a decrease in combustion reactivity and, consequently, the charcoals produced at lower temperatures are easier to ignite and exhibit better performance in ignition.

Mining Waste Classification and Quantity of Non-Metal Minesin Slovenia

Directory of Open Access Journals (Sweden)

Ana Burger

2007-06-01

Full Text Available Mining is an important human activity that creates wealth and supplies materials for maintaining standard of living and further human development. However, mining has also negative impacts on the environment and society. One of them is the production of mining waste throughout the entire mining cycle, in particular in the mine development and operation /production stage.Due to the EU Directive 2006/21/EC on the management of waste from the extractive industries and its implementation in Member state, estimation on quality and quantity of mining waste from active non-metal mines in Slovenia was carried out. In the selected mines mining and processing was closely examined. With material flow analysis quantity and characteristics of mining waste were defined for several mines of different commodities.Data on mining waste were afterwards generalized in order to get an overall country evaluation on mining waste “production” of non-metal mines.Mining waste as a result of mining and beneficiation processes in non-metal mines of Slovenia is either inert or non-hazardous. Most of the mining waste is used for mine reclamation running simultaneously with the production phase. The largest amounts of mining waste per unit produced are created in dimension stone industry. Since the dimensionstone production is small, the waste amount is negligible. Large quantities of mining waste are produced in crushed stone and, sand and gravel operations, because aggregate production is pretty large with regard to other non-metals production in Slovenia. We can therefore conclude that large quantities of mining waste from non-metal mines, which are mostly used in reclamation and for side products, do not represent danger to the environment.

Ammonium nitrate: combustion mechanism and the role of additives

Energy Technology Data Exchange (ETDEWEB)

Sinditskii, Valery P.; Egorshev, Viacheslav Yu.; Levshenkov, Anton I.; Serushkin, Valery V. [Department of Chemical Engineering, Mendeleev University of Chemical Technology, 9 Miusskaya Sq., 125047, Moscow (Russian Federation)

2005-09-01

This paper presents an analysis of the observed combustion behavior of AN mixtures with different additives, fuels, and energetic materials. It has been determined on the basis of flame structure investigation by fine tungsten-rhenium thermocouples that the surface temperature of AN is controlled by the dissociation reaction of the salt occurring at the surface. Results obtained have indicated that the leading reaction of combustion of AN doped with additives proceeds in the condensed phase up to pressures of 20-30 MPa. A reason for the inability of pure AN to burn is suggested and the role of additives in the combustion mechanism is discussed. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

Study of Nuclear Environment and Material Strategy

International Nuclear Information System (INIS)

Kamei, Takashi

2011-01-01

Progress of global warming requires us to establish a low-carbon society. Carbon-dioxide (CO 2 ) is emitted from two major sectors in the world. The largest CO 2 emitting sector is power sector having 46 % of the world share. Nuclear power has an important role because it does not emit CO 2 while it produces electricity. The second largest sector is transportation and has about 23 % of the world share. 73 % of transportation is land-transportation, that is to say automobile. Therefore, lots of motor-car companies are expressing their vision to supply electric vehicle (EV) or hybrid vehicle (HV) in these few years. In order to manufacture EV and HV, rare-earth materials such as neodymium (Nd) and dysprosium (Dy) are necessary. EV and HV are driven by an electric motor using permanent magnet. Nd is used to improve torque of permanent magnet. Dy is used as supplement for the case of HV in order to enhance thermal resistance because electric motor is exposed to high temperature circumference with combustion engine. 97 % of world supply of rare-earth production is shared by China. The reduction of exportation amount of rare-earth from China to Japan have brought a significant impact on Japan's industries especially for motor-car companies, which are going to supply EV and HV. Japan is going to develop new rare-earth mines outside of China such as in Vietnam. The most important problem relating to rare-earth mining is 'thorium'. The popular minerals containing rare-earth are monazite, bastnasite and so on. Thorium is mostly included in the same minerals. Therefore, thorium is separated whenever rare-earth is refined. Thorium separated in China can be stored for future usage as nuclear fuel. Though thorium began to be considered also in a working group of Atomic Energy Society of Japan since 2010, it is not clear when thorium starts to be used and how much amount of thorium will be consumed. It is estimated that consumption of thorium will be smaller than the production

Measures for a quality combustion (combustion chamber exit and downstream); Mesures pour une combustion de qualite (sortie de chambre de combustion et en aval)

Energy Technology Data Exchange (ETDEWEB)

Epinat, G. [APAVE Lyonnaise, 69 (France)

1996-12-31

After a review of the different pollutants related to the various types of stationary and mobile combustion processes (stoichiometric, reducing and oxidizing combustion), measures and analyses than may be used to ensure the quality and efficiency of combustion processes are reviewed: opacimeters, UV analyzers, etc. The regulation and control equipment for combustion systems are then listed, according to the generator capacity level

76 FR 81761 - Mine Safety Disclosure

Science.gov (United States)

2011-12-28

... or other mine to file a current report on Form 8-K with the Commission reporting receipt of certain....\\24\\ Issuers have been providing disclosure in their periodic and current reports filed with the... Release, that to the extent mine safety issues are material, under our current rules disclosure could be...

Recultivation of mining waste dumps in the Ruhr area, Germany

International Nuclear Information System (INIS)

Schulz, D.

1996-01-01

In 1993 Ruhrkohle AG produced 41.9 million tons of coal and 19.1 million m 3 of mining waste. Of this, 0.7 million m 3 were used underground as stowing material, 4.7 million m 3 was used commercially, while the remaining 13.7 million m 3 required dumping. Efforts related to the use and disposal of the material up to now dumped are concentrating on applying technical methods to reduce the production of waste underground, on opening up new markets of this material, on utilization of mining waste as a building material, and on low-environmental-impact dumping. Since the late 1970s, the mining waste heaps in the Ruhr mining region have been conceived and designed as landscape structures, i.e. they are integrated into the landscape by means of careful planning and design, and are immediately planted with vegetation. 9 refs., 5 figs

MEDPREPARATY, PRIMENIMYYe PRI OSTROM OTRAVLENII UGARNYM GAZOM V SHAKHTAKH. ZAMENITELI PLAZMY KROVI. GOLUBAYA KROV' [MEDICATIONS WHICH CAN BE USED IN CASE OF CARBON MONOXIDE ACUTE POISONING IN THE MINES. BLOOD PLASMA SUBSTITUTES. BLUE BLOOD

Directory of Open Access Journals (Sweden)

Khromov A.V.

2017-09-01

Full Text Available Fires in the operational underground mine openings, as a rule, are catastrophic and lead to numerous victims. Due to the transfer of combustion products by the ventilation stream of the mine ventilation, they can be spread over long distances from the fire site and mortally injure miners along the course of the air stream. Essential assistance to miners in such emergency situations is provided by means of individual protection of miners, which are breathing apparatus of various types - so-called self-rescuers. There are cases anyway when they cannot protect from poisonous combustion products action. Then in the arsenal of mine rescuers there must be medical preparations capable of restoring the respiratory functions of the miners the fire victims. The purpose of this article is to familiarize mining specialists and VGSCh workers with the current state of medical preparations for carbon monoxide effect neutralization.

Thermodynamic characteristics of a low concentration methane catalytic combustion gas turbine

International Nuclear Information System (INIS)

Yin, Juan; Su, Shi; Yu, Xin Xiang; Weng, Yiwu

2010-01-01

Low concentration methane, emitted from coal mines, landfill, animal waste, etc. into the atmosphere, is not only a greenhouse gas, but also a waste energy source if not utilised. Methane is 23 times more potent than CO 2 in terms of trapping heat in the atmosphere over a timeframe of 100 years. This paper studies a novel lean burn catalytic combustion gas turbine, which can be powered with about 1% methane (volume) in air. When this technology is successfully developed, it can be used not only to mitigate the methane for greenhouse gas reduction, but also to utilise such methane as a clean energy source. This paper presents our study results on the thermodynamic characteristics of this new lean burn catalytic combustion gas turbine system by conducting thermal performance analysis of the turbine cycle. The thermodynamic data including thermal efficiencies and exergy loss of main components of the turbine system are presented under different pressure ratios, turbine inlet temperatures and methane concentrations.

Uranium pollution in an estuary affected by pyrite acid mine drainage and releases of naturally occurring radioactive materials

International Nuclear Information System (INIS)

Villa, M.; Manjon, G.; Hurtado, S.; Garcia-Tenorio, R.

2011-01-01

Highlights: → Huelva estuary is affected by former phosphogypsum releases and pyrite acid mine drainage. → Time evolution of uranium concentration is analyzed after halting of NORM releases. → Two new contamination sources are preventing the complete uranium cleaning: (1) The leaching of phosphogypsum stacks located close to Tinto River. (2) Pyrite acid mine drainage. → High uranium concentrations are dissolved in water and precipitate subsequently. - Abstract: After the termination of phosphogypsum discharges to the Huelva estuary (SW Spain), a unique opportunity was presented to study the response of a contaminated environmental compartment after the cessation of its main source of pollution. The evolution over time of uranium concentrations in the estuary is presented to supply new insights into the decontamination of a scenario affected by Naturally Occurring Radioactive Material (NORM) discharges. The cleaning of uranium isotopes from the area has not taken place as rapidly as expected due to leaching from phosphogypsum stacks. An in-depth study using various techniques of analysis, including 234 U/ 238 U and 230 Th/ 232 Th ratios and the decreasing rates of the uranium concentration, enabled a second source of uranium contamination to be discovered. Increased uranium levels due to acid mine drainage from pyrite mines located in the Iberian Pyrite Belt (SW Spain) prevent complete uranium decontamination and, therefore, result in levels nearly twice those of natural background levels.

Gaseous emissions during concurrent combustion of biomass and non-recyclable municipal solid waste.

Science.gov (United States)

Laryea-Goldsmith, René; Oakey, John; Simms, Nigel J

2011-02-01

Biomass and municipal solid waste offer sustainable sources of energy; for example to meet heat and electricity demand in the form of combined cooling, heat and power. Combustion of biomass has a lesser impact than solid fossil fuels (e.g. coal) upon gas pollutant emissions, whilst energy recovery from municipal solid waste is a beneficial component of an integrated, sustainable waste management programme. Concurrent combustion of these fuels using a fluidised bed combustor may be a successful method of overcoming some of the disadvantages of biomass (high fuel supply and distribution costs, combustion characteristics) and characteristics of municipal solid waste (heterogeneous content, conflict with materials recycling). It should be considered that combustion of municipal solid waste may be a financially attractive disposal route if a 'gate fee' value exists for accepting waste for combustion, which will reduce the net cost of utilising relatively more expensive biomass fuels. Emissions of nitrogen monoxide and sulphur dioxide for combustion of biomass are suppressed after substitution of biomass for municipal solid waste materials as the input fuel mixture. Interactions between these and other pollutants such as hydrogen chloride, nitrous oxide and carbon monoxide indicate complex, competing reactions occur between intermediates of these compounds to determine final resultant emissions. Fluidised bed concurrent combustion is an appropriate technique to exploit biomass and municipal solid waste resources, without the use of fossil fuels. The addition of municipal solid waste to biomass combustion has the effect of reducing emissions of some gaseous pollutants.

Green mines green energy : establishing productive land on mine tailings

Energy Technology Data Exchange (ETDEWEB)

Tisch, B.; Zinck, J.; Vigneault, B. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Mining and Mineral Sciences Laboratories

2008-07-01

Municipal governments and provincial regulators are under increasing pressure to divert clean organic waste materials from landfill sites and establish productive uses for them. This article described the Natural Resources Canada (NRCan) CANMET Green Mines Green Energy consortium. Composed of mining, forestry, government, and academic representatives, the consortium's aim is to expand the use of organic waste residuals in the rehabilitation of mine sites for use as a feedstock in biofuel production. The program's themes include: (1) determining the conditions required to maximize growth; (2) investigating the interaction of various organic covers on tailings pore water, effluent and mineralogy; (3) investigating the potential economic and environmental impacts on all relevant sectors; and (4) disseminating findings to all relevant stakeholders. Tests are currently being conducted to determine the potential impact of municipal waste materials on tailings oxidation and effluent chemistry. The effect of biosolids and compost-derived dissolved organic carbon on effluent treatability and toxicity is also being investigated. Results from the investigations to date suggest that sulfate reduction at the tailings-biosolids interface is taking place. It was concluded that steady state has not yet been reached after a 1 year period. 10 refs., 1 tab., 7 figs.

Combustion stratification for naphtha from CI combustion to PPC

NARCIS (Netherlands)

Vallinayagam, R.; Vedharaj, S.; An, Y.; Dawood, A.; Izadi Najafabadi, M.; Somers, L.M.T.; Johansson, B.H.

2017-01-01

This study demonstrated the change in combustion homogeneity from conventional diesel combustion via partially premixed combustion towards HCCI. Experiments are performed in an optical diesel engine at a speed of 1200 rpm with diesel fuel. Single injection strategy is employed and the fuel is

Low NOx combustion technologies for high-temperature natural gas combustion

International Nuclear Information System (INIS)

Flamme, Michael

1999-01-01

Because of the high process temperature which is required for some processes like glass melting and the high temperature to which the combustion air is preheated, NOx emission are extremely high. Even at these high temperatures, NOx emissions could be reduced drastically by using advanced combustion techniques such as staged combustion or flame-less oxidation, as experimental work has shown. In the case of oxy-fuel combustion, the NOx emission are also very high if conventional burners are used. The new combustion techniques achieve similar NOx reductions. (author)

Underground coal mining technology - the future

Energy Technology Data Exchange (ETDEWEB)

Lama, R P [Kembla Coal and Coke Pty Limited, Wollongong, NSW (Australia)

1989-01-01

Discusses development of underground coal mining in Australia in the last four decades. The following aspects are reviewed: technology for underground mining (longwall mining, unidirectional cutting, bidirectional cutting, operation of more than one shearer on a working face, optimum dimensions of longwall blocks), longwall productivity (productivity increase will depend on increasing the availability factor of equipment, reducing failures due to human errors, organizational models, improving on-site decision making, improving monitoring, maintenance, planning and scheduling, concept of 'Transparent Mine'), roadway development systems (types of heading machines, standard systems for mine drivage and roof bolting and their productivity), size of coal mines, man and material transport systems (20,000-30,000 t/d from a single longwall face, mine shafts with a diameter 9-10 m), mine layout design (layout of longwall blocks, main intakes and returns situated in rock layers), mine environmental systems (ventilation systems, gas control), management, training and interpersonal relationships. Future coal mines will be developed with an integral capacity of 8-10 Mt/a from a single longwall operation with main development arteries placed in rocks. Development of gate roadways will require novel solutions with continuous cutting, loading and bolting. Information technology, with the concept of 'transparent mine', will form the backbone of decision making.

Natural self-reclamation of soils and landscapes affected by agriculture and mining

Science.gov (United States)

Alekseenko, Vladimir; Bech, Jaume; Alekseenko, Alexey; Shvydkaya, Natalya; Puzanov, Alexander; Roca, Núria

2017-04-01

Processes of possible self-restoration of technogenically disturbed soils are studied in Central and Southern European Russia. Reclamation procedures are mainly not implemented in this vast region, and the natural soil restoration is supposed. Heaps overlaying the former steppe and cropland landscapes are created in the course of rock waste stacking after preparative and cleaning mining works during the underground coal extraction. Approximately 1 500 heaps occupying over 8 000 ha were formed in the area of the Donets Coal Basin. Soils are destroyed under heaps, land subsidence occurs in coal mining areas and acid lakes are usually formed in these ground depressions. Spontaneous combustions happen often and can continue for decades. In order to prevent them, heap surfaces are in some cases levelled and filled with water, forming peculiar ponds. After 70 years of heaps existence and ca. 50 years after their ignition, soil formation is just in the early stages. Heap surface differs a lot in geochemical and mineralogical characteristics from those of surrounding steppe soils that suffered substantial changes at distances up to 1 km. Development of plant communities in areas near coal dumps and heaps is one of the indicators of landscape-geochemical changes. Formation of ruderal phytocenoses with 10-15 % of local flora, as well as invasive and introduced plants occurred under the complex impact of ecological conditions. Communities formed by them are distinguished by the structure simplicity, low species diversity, and plant growth anomalies. Quarries and dumps are formed during underground and open-cast mining of ore deposits. During the last 50 years after abandoning mines in forest areas, the 30 m deep quarries have filled with the creep material less for 0.5 m, and sediments from water streams have added 1-3 cm. Thickness of argillaceous layers does not exceed 1-2 cm at small rock chips of the dumps that measures up to 70 km in length. The dumps are partially

Combustion instability control in the model of combustion chamber

International Nuclear Information System (INIS)

Akhmadullin, A N; Ahmethanov, E N; Iovleva, O V; Mitrofanov, G A

2013-01-01

An experimental study of the influence of external periodic perturbations on the instability of the combustion chamber in a pulsating combustion. As an external periodic disturbances were used sound waves emitted by the electrodynamics. The purpose of the study was to determine the possibility of using the method of external periodic perturbation to control the combustion instability. The study was conducted on a specially created model of the combustion chamber with a swirl burner in the frequency range from 100 to 1400 Hz. The study found that the method of external periodic perturbations may be used to control combustion instability. Depending on the frequency of the external periodic perturbation is observed as an increase and decrease in the amplitude of the oscillations in the combustion chamber. These effects are due to the mechanisms of synchronous and asynchronous action. External periodic disturbance generated in the path feeding the gaseous fuel, showing the high efficiency of the method of management in terms of energy costs. Power required to initiate periodic disturbances (50 W) is significantly smaller than the thermal capacity of the combustion chamber (100 kW)

The geomicrobiology of used and disused mines in Britain

International Nuclear Information System (INIS)

Christofi, N.; Philp, J.C.; West, J.M.; Robbins, J.E.

1984-03-01

Several used and disused mines in Britain have been analysed for microbial presence, content and activity. The sites sampled are located in Cornwall, Derbyshire and Cumbria. The mines in Cornwall can be called 'working' and were being operated at the time of sampling. The mine in Derbyshire was disused until recently re-opened by cavers while the mines in Cumbria had remained closed up to the time of sampling. Waters and solid materials have been sampled where detailed microbiology has been undertaken. In Cumbria a detailed description of structures of biological interest was carried out. Both heterotrophic and autotrophic microorganisms have been found in some waters and on mine walls. The actual content of each mine is different according to local conditions and chemistries. The results of the microbiological analyses are given. The origin of these microorganisms cannot be determined although it is likely that they have been introduced by water running down mine shafts from surface strata and/or from excavation processes. Activity measurements have shown that waters in some mines are organic carbon limited. There are indications from the working mines that such carbon would be available from autotrophic populations present within the ecosystem or from backfill material. (author)

Pilas de combustible de membrana polimérica

OpenAIRE

Asensio, Juan Antonio

2011-01-01

En aquest treball revisem breument les piles de combustible polimèriques (PEM) basades en membranes d’intercanvi protònic i que constitueixen la tecnologia idònia de piles de combustible de baixa temperatura, i per tant les més adequades per a aplicació en transport. Revisarem els materials que les componen però també els desenvolupaments necessaris per a la seva implantació definitiva en un mercat inclement amb les tecnologies cares, per netes que siguin. En este trabajo revisamos breveme...

TSC mobile mining and extraction technology

Energy Technology Data Exchange (ETDEWEB)

Lavender, W.J. [TSC Company Ltd., Calgary, AB (Canada)

2001-11-01

This Power-Point presentation described an innovative mining and extraction technology developed by Calgary-based TSC Company Ltd. that has provided a major breakthrough in bitumen production from mineable oil sands. The presentation described the process and key mechanical components as demonstrated on oil sands leases. It also described the step change in cost structure and profitability. Oil sands mining provide a hugh resource base with no exploration costs and no decline in production. Despite these advantages, oil sands mining faces the challenge of high capital and operating costs and materials handling. Other challenges include the variability of the ore and environmental impacts. This paper described the fundamentals of the new technology called the Tar Sand Combine (TSC), a continuous mining machine, crusher, cyclone, tailings filter and stacker all in one mobile module. Several viewgraphs were included with the presentation to depict the recovery process as successfully demonstrated at a pilot project. Patent is pending on the process and components. The advantages of the TSC are reduced materials handling, and no tailings ponds are generated since tailings remain where they are mined. The final product is clean bitumen. The specifications of a commercial TSC are: 2000 ton/stream hour mining produce 25,000 bpsd bitumen at 12 per cent ore grade; mined ore bitumen recovery is greater than 95 per cent and the availability factor is 85 per cent. It was concluded that the TSC can maximize oil sands reserves, while providing significant cost savings and environmental benefits. 2 tabs., 24 figs.

Analysis of Index Gases of Coal Spontaneous Combustion Using Fourier Transform Infrared Spectrometer

Directory of Open Access Journals (Sweden)

Xiaojun Tang

2014-01-01

Full Text Available Analysis of the index gases of coal for the prevention of spontaneous combustion is of great importance for the enhancement of coal mine safety. In this work, Fourier Transform Infrared Spectrometer (FTIRS is presented to be used to analyze the index gases of coal in real time to monitor spontaneous combustion conditions. Both the instrument parameters and the analysis method are introduced at first by combining characteristics of the absorption spectra of the target analyte with the analysis requirements. Next, more than ten sets of the gas mixture containing ten components (CH4, C2H6, C3H8, iso-C4H10, n-C4H10, C2H4, C3H6, C2H2, CO, and CO2 are included and analyzed with a Spectrum Two FTIRS made by Perkin Elmer. The testing results show that the detection limit of most analytes is less than 2×10-6. All the detection limits meet the monitoring requirements of coal spontaneous combustion in China, which means that FTIRS may be an ideal instrument and the analysis method used in this paper is sufficient for spontaneous combustion gas monitoring on-line and even in situ, since FTIRS has many advantages such as fast analysis, being maintenance-free, and good safety.

Measures to restore metallurgical mine wasteland using ecological restoration technologies: A case study at Longnan Rare Earth Mine

Science.gov (United States)

Rao, Yunzhang; Gu, Ruizhi; Guo, Ruikai; Zhang, Xueyan

2017-01-01

Whereas mining activities produce the raw materials that are crucial to economic growth, such activities leave extensive scarring on the land, contributing to the waste of valuable land resources and upsetting the ecological environment. The aim of this study is therefore to investigate various ecological technologies to restore metallurgical mine wastelands. These technologies include measures such as soil amelioration, vegetation restoration, different vegetation planting patterns, and engineering technologies. The Longnan Rare Earth Mine in the Jiangxi Province of China is used as the case study. The ecological restoration process provides a favourable reference for the restoration of a metallurgical mine wasteland.

North American Bats and Mines Project: A cooperative approach for integrating bat conservation and mine-land reclamation

Energy Technology Data Exchange (ETDEWEB)

Ducummon, S.L. [Bat Conservation International, Austin, TX (United States)

1997-12-31

Inactive underground mines now provide essential habitat for more than half of North America`s 44 bat species, including some of the largest remaining populations. Thousands of abandoned mines have already been closed or are slated for safety closures, and many are destroyed during renewed mining in historic districts. The available evidence suggests that millions of bats have already been lost due to these closures. Bats are primary predators of night-flying insects that cost American farmers and foresters billions of dollars annually, therefore, threats to bat survival are cause for serious concern. Fortunately, mine closure methods exist that protect both bats and humans. Bat Conservation International (BCI) and the USDI-Bureau of Land Management founded the North American Bats and Mines Project to provide national leadership and coordination to minimize the loss of mine-roosting bats. This partnership has involved federal and state mine-land and wildlife managers and the mining industry. BCI has trained hundreds of mine-land and wildlife managers nationwide in mine assessment techniques for bats and bat-compatible closure methods, published technical information on bats and mine-land management, presented papers on bats and mines at national mining and wildlife conferences, and collaborated with numerous federal, state, and private partners to protect some of the most important mine-roosting bat populations. Our new mining industry initiative, Mining for Habitat, is designed to develop bat habitat conservation and enhancement plans for active mining operations. It includes the creation of cost-effective artificial underground bat roosts using surplus mining materials such as old mine-truck tires and culverts buried beneath waste rock.

Rotary combustion device

NARCIS (Netherlands)

2008-01-01

Rotary combustion device (1) with rotary combustion chamber (4). Specific measures are taken to provide ignition of a combustible mixture. It is proposed that a hollow tube be provided coaxially with the axis of rotation (6), so that a small part of the mixture is guided into the combustion chamber.

Radiation exposures due to fossil fuel combustion

Science.gov (United States)

Beck, Harold L.

The current consensus regarding the potential radiation exposures resulting from the combustion of fossil fuels is examined. Sources, releases and potential doses to humans are discussed, both for power plants and waste materials. It is concluded that the radiation exposure to most individuals from any pathway is probably insignificant, i.e. only a tiny fraction of the dose received from natural sources in soil and building materials. Any small dose that may result from power-plant emissions will most likely be from inhalation of the small insoluble ash particles from the more poorly controlled plants burning higher than average activity fuel, rather than from direct or indirect ingestion of food grown on contaminated soil. One potentially significant pathway for exposure to humans that requires further evaluation is the effect on indoor external γ-radiation levels resulting from the use of flyash in building materials. The combustion of natural gas in private dwellings is also discussed, and the radiological consequences are concluded to be generally insignificant, except under certain extraordinary circumstances.

Study of the degradation of power generation combustion components at elevated temperature

International Nuclear Information System (INIS)

Castrejon, J.; Serna, S.; Wong-Moreno, A.; Fragiel, A.; Lopez-Lopez, D.

2006-01-01

Elevated temperature combustion of fuel oil that contains large amounts of vanadium, asphaltenes and mostly sulfur, presents a major challenge for materials selection and design of combustion components for the electric power generation. The combustion system, which consists of air nozzles and air swirlers, plays a key role in the performance of electric power plants. Air nozzles and air swirlers, which were operated for one year in a 350 MW boiler, were analyzed, presenting accelerated degradation. The particular features of corrosion behavior of these components made by stainless steels: 304, 446 and HH, are presented. The results obtained after optical, metallographic, and microprobe analysis revealed that the components flame contact at very high operating temperature promoted all materials degradation mechanisms. Under this scenario, it is very difficult to find a material resistant to such accelerated wastage conditions. So, the solution of the problem must be oriented to re-design and improve the efficiency of the flame contact with these components

Study of the degradation of power generation combustion components at elevated temperature

Energy Technology Data Exchange (ETDEWEB)

Castrejon, J. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas-UAEM, Av. Universidad 1001, C.P. 62209, Cuernavaca, Mor., Mexico (Mexico); Serna, S. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas-UAEM, Av. Universidad 1001, C.P. 62209, Cuernavaca, Mor., Mexico (Mexico)]. E-mail: aserna@uaem.mx; Wong-Moreno, A. [Instituto Mexicano del Petroleo, Eje Central No. 152, Col. San. Bartolo Atepehuacan, C.P. 07730, Mexico, DF (Mexico); Fragiel, A. [Centro de Ciencias de la Materia Condensada-UNAM, Km 7 Carretera Tijuana-Ensenada, C.P. 22800, Ensenada, Baja California (Mexico); Lopez-Lopez, D. [Instituto Mexicano del Petroleo, Eje Central No. 152, Col. San. Bartolo Atepehuacan, C.P. 07730, Mexico, DF (Mexico)

2006-01-15

Elevated temperature combustion of fuel oil that contains large amounts of vanadium, asphaltenes and mostly sulfur, presents a major challenge for materials selection and design of combustion components for the electric power generation. The combustion system, which consists of air nozzles and air swirlers, plays a key role in the performance of electric power plants. Air nozzles and air swirlers, which were operated for one year in a 350 MW boiler, were analyzed, presenting accelerated degradation. The particular features of corrosion behavior of these components made by stainless steels: 304, 446 and HH, are presented. The results obtained after optical, metallographic, and microprobe analysis revealed that the components flame contact at very high operating temperature promoted all materials degradation mechanisms. Under this scenario, it is very difficult to find a material resistant to such accelerated wastage conditions. So, the solution of the problem must be oriented to re-design and improve the efficiency of the flame contact with these components.

Predicting the combustion kinetics of Chinese coals

Energy Technology Data Exchange (ETDEWEB)

Niksa, Stephen [Niksa Energy Associates LLC, Belmont, CA (United States); Fujiwara, Naoki [Idemitsu Kosan Co., Ltd, Chiba (Japan). Coal and Environment Research Lab.

2013-07-01

The database on the devolatilization of Chinese coals in the English literature represents coals from all ranks and the major Chinese mines. It was mostly acquired with TGAs. There are sufficient datasets from devices that imposed rapid heating rates to bracket combustor behavior. The domains of heating rate, temperature, pressure, and particle size are either directly relevant to combustion conditions, or close enough to manage with modest extrapolations. Whereas the data on ultimate total yields is sufficient to validate a model for any coal type, more detailed product distributions and char compositions would be desirable. Based on the accurate interpretation of this database, there are few unresolved issues surrounding the applicability of FLASHCHAIN {sup registered} for combustion applications in China. The sub-database on devolatilization under rapid heating conditions represents 34 samples. The predicted yields were within the measurement uncertainties of 4 daf wt. % for 29 of these coals. Among the five ultimate yields that were not accurately predicted, three had measured values less than the proximate volatile matter (PVM), despite the rapid heating rates in the tests. Similarly, the sub-database on devolatilization under slow heating conditions characterizes ultimate devolatilization yields of 30 samples. The predicted yields were within the measurement uncertainties for 22 of these coals. Among the eight that were not accurately predicted, three had measured values that were much lower than the PVM (which is a problem even after accounting for the slow heating rates in the tests) and three were in studies that did not report ultimate analyses for the coals tested. Unfortunately, the database on the combustion behavior of the chars from Chinese coals is insufficient to specify char oxidation kinetics.

Characteristics of combustion products: a review of the literature

Energy Technology Data Exchange (ETDEWEB)

Chan, M.K.W.; Mishima, J.

1983-07-01

To determine the effects of fires in nuclear-fuel-cycle facilities, Pacific Northwest Laboratory (PNL) has surveyed the literature to gather data on the characteristics of combustion products. This report discusses the theories of the origin of combustion with an emphasis on the behavior of the combustible materials commonly found in nuclear-fuel-cycle facilities. Data that can be used to calculate particulate generation rate, size, distribution, and concentration are included. Examples are given to illustrate the application of this data to quantitatively predict both the mass and heat generated from fires. As the final result of this review, information gaps are identified that should be filled for fire-accident analyses in fuel-cycle facilities. 29 figures, 32 tables.

Characteristics of combustion products: a review of the literature

International Nuclear Information System (INIS)

Chan, M.K.W.; Mishima, J.

1983-07-01

To determine the effects of fires in nuclear-fuel-cycle facilities, Pacific Northwest Laboratory (PNL) has surveyed the literature to gather data on the characteristics of combustion products. This report discusses the theories of the origin of combustion with an emphasis on the behavior of the combustible materials commonly found in nuclear-fuel-cycle facilities. Data that can be used to calculate particulate generation rate, size, distribution, and concentration are included. Examples are given to illustrate the application of this data to quantitatively predict both the mass and heat generated from fires. As the final result of this review, information gaps are identified that should be filled for fire-accident analyses in fuel-cycle facilities. 29 figures, 32 tables

Mine drivage in hydraulic mines

Energy Technology Data Exchange (ETDEWEB)

Ehkber, B Ya

1983-09-01

From 20 to 25% of labor cost in hydraulic coal mines falls on mine drivage. Range of mine drivage is high due to the large number of shortwalls mined by hydraulic monitors. Reducing mining cost in hydraulic mines depends on lowering drivage cost by use of new drivage systems or by increasing efficiency of drivage systems used at present. The following drivage methods used in hydraulic mines are compared: heading machines with hydraulic haulage of cut rocks and coal, hydraulic monitors with hydraulic haulage, drilling and blasting with hydraulic haulage of blasted rocks. Mining and geologic conditions which influence selection of the optimum mine drivage system are analyzed. Standardized cross sections of mine roadways driven by the 3 methods are shown in schemes. Support systems used in mine roadways are compared: timber supports, roof bolts, roof bolts with steel elements, and roadways driven in rocks without a support system. Heading machines (K-56MG, GPKG, 4PU, PK-3M) and hydraulic monitors (GMDTs-3M, 12GD-2) used for mine drivage are described. Data on mine drivage in hydraulic coal mines in the Kuzbass are discussed. From 40 to 46% of roadways are driven by heading machines with hydraulic haulage and from 12 to 15% by hydraulic monitors with hydraulic haulage.

COMBUSTION PROPERTIES OF EUCALYPTUS WOOD

Directory of Open Access Journals (Sweden)

Yalçın ÖRS

1999-03-01

Full Text Available In this study, the combustion properties of some impregnation materials (abiotic and biotic factors used for eucalyptus wood in interior or exterior environments were investigated. The experimental samples were prepared from Eucalyptus wood based on ASTM-D-1413-76 Tanalith-CBC, boric acid, borax, vacsol-WR, immersol-WR, polyethylen glycole-400 and ammonium sulphate were used as an impregnation material. The results indicated that, vacuum treatment on Eucalyptus gave the lowest retention value of salts. Compounds containing boron+salt increased fire resistance however water repellents decreased the wood flammability.

Using X-ray methods to evaluate the combustion sulfur minerals and graphitic carbon in coals and ashes

International Nuclear Information System (INIS)

Wertz, D.L.; Collins, L.W.

1988-01-01

Coals are complex mixtures of vastly different materials whose combustion kinetics may well exhibit symbiotic effects. Although the sulfur oxide gases produced during the combustion of coals may have a variety of sources, they are frequently caused by the thermal degradation of inorganic minerals to produce ''acid rain''. Since many of the minerals involved either as reactants or products in coal combustion produce well defined x-ray power diffraction (XRPD) patterns, the fate of these minerals may be followed by measuring the XRPD patterns of combustion products. Coal 1368P, a coal with an unusually high pyrite (FeS/sub 2/) fraction, has been the subject materials in our investigations of the fate of the inorganic minerals during combustion. These studies include measuring the fate of pyrite and of graphitic carbon in coal 1368P under varying combustion conditions. The results discussed in this paper were obtained by standard XRPD methods

Comprehensive characterization of humic-like substances in smoke PM2.5 emitted from the combustion of biomass materials and fossil fuels

Science.gov (United States)

Fan, Xingjun; Wei, Siye; Zhu, Mengbo; Song, Jianzhong; Peng, Ping'an

2016-10-01

Humic-like substances (HULIS) in smoke fine particulate matter (PM2.5) emitted from the combustion of biomass materials (rice straw, corn straw, and pine branch) and fossil fuels (lignite coal and diesel fuel) were comprehensively studied in this work. The HULIS fractions were first isolated with a one-step solid-phase extraction method, and were then investigated with a series of analytical techniques: elemental analysis, total organic carbon analysis, UV-vis (ultraviolet-visible) spectroscopy, excitation-emission matrix (EEM) fluorescence spectroscopy, Fourier transform infrared spectroscopy, and 1H-nuclear magnetic resonance spectroscopy. The results show that HULIS account for 11.2-23.4 and 5.3 % of PM2.5 emitted from biomass burning (BB) and coal combustion, respectively. In addition, contributions of HULIS-C to total carbon and water-soluble carbon in smoke PM2.5 emitted from BB are 8.0-21.7 and 56.9-66.1 %, respectively. The corresponding contributions in smoke PM2.5 from coal combustion are 5.2 and 45.5 %, respectively. These results suggest that BB and coal combustion are both important sources of HULIS in atmospheric aerosols. However, HULIS in diesel soot only accounted for ˜ 0.8 % of the soot particles, suggesting that vehicular exhaust may not be a significant primary source of HULIS. Primary HULIS and atmospheric HULIS display many similar chemical characteristics, as indicated by the instrumental analytical characterization, while some distinct features were also apparent. A high spectral absorbance in the UV-vis spectra, a distinct band at λex/λem ≈ 280/350 nm in EEM spectra, lower H / C and O / C molar ratios, and a high content of [Ar-H] were observed for primary HULIS. These results suggest that primary HULIS contain more aromatic structures, and have a lower content of aliphatic and oxygen-containing groups than atmospheric HULIS. Among the four primary sources of HULIS, HULIS from BB had the highest O / C molar ratios (0.43-0.54) and [H

Combustion physics

Science.gov (United States)

Jones, A. R.

1985-11-01

Over 90% of our energy comes from combustion. By the year 2000 the figure will still be 80%, even allowing for nuclear and alternative energy sources. There are many familiar examples of combustion use, both domestic and industrial. These range from the Bunsen burner to large flares, from small combustion chambers, such as those in car engines, to industrial furnaces for steel manufacture or the generation of megawatts of electricity. There are also fires and explosions. The bountiful energy release from combustion, however, brings its problems, prominent among which are diminishing fuel resources and pollution. Combustion science is directed towards finding ways of improving efficiency and reducing pollution. One may ask, since combustion is a chemical reaction, why physics is involved: the answer is in three parts. First, chemicals cannot react unless they come together. In most flames the fuel and air are initially separate. The chemical reaction in the gas phase is very fast compared with the rate of mixing. Thus, once the fuel and air are mixed the reaction can be considered to occur instantaneously and fluid mechanics limits the rate of burning. Secondly, thermodynamics and heat transfer determine the thermal properties of the combustion products. Heat transfer also plays a role by preheating the reactants and is essential to extracting useful work. Fluid mechanics is relevant if work is to be performed directly, as in a turbine. Finally, physical methods, including electric probes, acoustics, optics, spectroscopy and pyrometry, are used to examine flames. The article is concerned mainly with how physics is used to improve the efficiency of combustion.

Advanced Fuels and Combustion Processes for Propulsion

Science.gov (United States)

2010-09-01

production from biomass steam reforming – Conduct a feasibility analysis of the proposed integrated process Energia Technologies - D. Nguyen & K. Parimi...strength foam material development by Ultramet – Combustion experiments performed U. Of Alabama – End-user input provided by Solar Turbines Major

Organic matter in constructed soils from a coal mining area in southern Brazil

Energy Technology Data Exchange (ETDEWEB)

Dick, Deborah P.; Avila, Leticia G. [Universidade Federal do Rio Grande do Sul, Inst. de Quimica, Porto Alegre, RS (Brazil); Knicker, Heike [Technische Universitaet Muenchen, Lehrstuhl fuer Bodenkunde, Freising-Weihenstephan (Germany); Inda, Alberto V. Jr.; Giasson, Elvio; Bissani, Carlos A. [Universidade Federal do Rio Grande do Sul, Dept. de Ciencia do Solo, Porto Alegre, RS (Brazil)

2006-11-15

In southern Brazil, the landscape restoration after the exhaustion of open cast coal mines involves the filling of mine cavities with both pedogenic and geological material. The objective of this work was to determine the content and chemical composition of the organic matter of two constructed soils (24 years and 2 years) in a coal mining area in southern Brazil. An undisturbed Acrisol and geological material from three sites were also sampled. Samples were analyzed for carbon and nitrogen contents by dry combustion and for chemical composition of the organic matter by {sup 13} C NMR CPMAS and FTIR spectroscopies. Prior to the spectroscopic analyses, the samples were treated with 10% (m/m) hydrofluoric acid solution, which lead to a carbon enrichment in the sample of 2-46 times. The three coal samples were mainly composed of aromatic C (46-63%) and alkyl C (10-28%), and differed largely in the carbon content (18-312 g kg{sup -1}). The C/N ratio of 27 and the proportions of O-alkyl C (26%) and aromatic C (29%) found in the native soil (18 g C kg{sup -1} soil) suggest a coal contamination of the native site. The proportions of O/N-alkyl C (15-17%), alkyl C (22-23%) and aromatic C (39-41%) observed in the organic matter of the A1 horizon of the two constructed soils were intermediate to those of the coal samples and the native soil. In the younger constructed soil the proportion of O/N-alkyl diminished and that of aromatic C increased with depth, whereas in the older constructed soil this trend was less evident. Our results show that, during the 24 years after site reconstruction, the input of vegetation residues diluted the proportion of recalcitrant organic matter. The aromaticity index calculated from the FTIR data (I{sub 1620} /I{sub 2920}) correlated positively with the aryl C/alkyl C ratio, obtained from the NMR data, evidencing the applicability of the FTIR index for geological and coal contaminated samples. (Author)

Mining and its effects on the environment

International Nuclear Information System (INIS)

Kadlec, J.

1996-01-01

The article advocates mineral resource mining against fierce environmentalists who can see only the adverse aspects of this branch of industry. The following concepts are argued against: endangerment and permanent disturbance of the environment due to the mining and processing of mineral raw materials; excessive exploitation and selling-out of Czech national mineral resources; and inefficiency of administrative tools to protect Czech mineral resources and environment. It is concluded that mineral raw materials mining does not endanger the environment more than other anthropogenic activities do. Mining on its own is not responsible for the current poor condition of the environment in the Czech Republic, nor is it a source of permanent disturbance of the environment, as often unjustly claimed. The permanently sustainable development programme, referred to in the Environmental Protection Act, should only mitigate some adverse aspects of anthropogenic activities but is not expected to eliminate them altogether because this would imply elimination of their inflicter as such. (P.A.)

Mine dirt production. Produccion de esteriles del carbon

Energy Technology Data Exchange (ETDEWEB)

Gonzalez Canibano, J [HUNOSA, Madrid (Spain)

1990-02-01

The article deals with the production of dirt from coal mines in various countries giving an idea of the huge quantities of waste material generated by the mining industry. Discusses the difficulty of finding industrial applications for such large amounts of material with the aim of solving and/or minimising the problems created by this waste matter, namely, pollution, degradation of the countryside, storage, etc. 25 refs., 11 tabs., 14 figs.

Hydrogeologic and environmental impact of amjhore pyrite mines, India

Science.gov (United States)

Choubey, Vishnu D.; Rawat, Rajendra K.

1991-01-01

Drainage from active and inactive pyrite mines has produced chemical and physical pollution of both ground- and surface water in Amjhore region. In the present case, chemical pollution is caused by exposing pyrite minerals to oxidation or leaching, resulting in undesirable concentrations of dissolved materials. Pyrite mining suddenly exposed large quantities of sulfides to direct contact with oxygen, and oxidation proceeds rapidly, resulting in acidity and release of metal (Fe) and sulfates to the water system, eventually resulting in water pollution in the region. The magnitude and impact of the problem is just being recognized and, as the present and the future projected demand for clean water is of top priority, the present studies were undertaken. Mine drainage includes water flowing from the surface and underground mines and runoff or seepage from the pyrite mines. This article describes the various hydrologic factors that control acid water formation and its transport. The mine drainage is obviously a continuing source of pollution and, therefore, remedial measures mainly consisting of a double-stage limestone-lime treatment technique have been suggested. The present results will be used to develop an alternative and more effective abatement technology to mitigate acid production at the source, namely, the technique of revegetation of the soil cover applied to the waste mine dump material. Water quality change is discussed in detail, with emphasis on acidity formed from exposed pyrite material and on increase in dissolved solids. Preventive and treatment measures are recommended.

An appraisal of the potential use of fly ash for reclaiming coal mine spoil.

Science.gov (United States)

Ram, Lal C; Masto, Reginald E

2010-01-01

Growing dependence on coal-fired power plants for electrical generation in many countries presents ongoing environmental challenges. Burning pulverized coal in thermal power plants (TPPs) generates large amounts of fly ash (FA) that must be disposed of or otherwise handled, in an environmentally-sound manner. A possible option for dealing with fly ash is to use it as an amendment for mine spoil or other damaged soil. It has been demonstrated through studies in India and other countries that FA alone or in combination with organic or inorganic materials can be used in a productive manner for reclamation of mine spoil. The characteristics of FA, including silt-sized particles, lighter materials with low bulk density (BD), higher water holding capacity, favorable pH and significant concentrations of many essential plant nutrients, make it a potentially favorable amendment for mine spoil reclamation. Studies have indicated that the application of FA has improved the physical, chemical and biological qualities of soil to which it is applied. The release of trace metals and soluble salts from FA could be a major limitation to its application. This is particularly true of fresh, un-weathered FA or acidic FA, although perhaps not a concern for weathered/pond ash or alkaline FA. Some potential contaminants, especially metals and other salt ions, could be immobilized and rendered biologically inert by the addition of certain inorganic and organic amendments. However, in view of the variability in the characteristics of FAs that are associated with location, feed coal, combustion conditions and other factors, the suitability of a particular FA for a specific soil/mine spoil needs to be critically evaluated before it is applied in order to maximize favorable results and eliminate unexpected consequences. FA generated in India tends to be mostly alkaline, with lower levels of trace elements than are often found in FAs from other countries. The concentrations of potential

Preliminary assessment of the health and environmental impacts of fluidized-bed combustion of coal as applied to electrical utility systems

Energy Technology Data Exchange (ETDEWEB)

None

1977-02-01

The objective of this study was to assess the health and environmental impacts of fluidized-bed combustion of coal (FBC), specifically as applied to base-load generation of electrical energy by utilities. The public health impacts of Fluidized-Bed Combustion (FBC) plants are expected to be quite similar to those for Low Sulfur Coal (LSC) and Flue Gas Desulfurization (FGD) plants because all appear to be able to meet Federal emission standards; however, there are emissions not covered by standards. Hydrocarbon emissions are higher and trace element emissions are lower for FBC than for conventional technologies. For FBC, based on an analytical model and a single emission data point, the polycyclic organic material decreases the anticipated lifespan of the highly exposed public very slightly. Added health protection due to lower trace element emissions is not known. Although there is a large quantity of solid wastes from the generating plant, the environmental impact of the FBC technology due to solid residue appears lower than for FGD, where sludge management requires larger land areas and presents problems due to the environmentally noxious calcium sulfite in the waste. Fixing the sludge may become a requirement that increases the cost of wet-limestone FGD but makes that system more acceptable. The potential for aquatic or terrestrial impacts from hydrocarbon emissions is low. If application of AFBC technology increases the use of local high-sulfur coals to the detriment of western low-sulfur coal, a sociological benefit could accrue to the FBC (or FGD) technology, because impacts caused by western boom towns would decrease. The infrastructure of areas that mine high-sulfur coal in the Midwest are better equipped to handle increased mining than the West.

SO2 Release as a Consequence of Alternative Fuel Combustion in Cement Rotary Kiln Inlets

DEFF Research Database (Denmark)

Cortada Mut, Maria del Mar; Nørskov, Linda Kaare; Glarborg, Peter

2015-01-01

The combustion of alternative fuels in direct contact with the bed material of the rotary kiln may cause local reducing conditions and, subsequently, decomposition of sulfates from cement raw materials, increasing the SO2 concentration in the gas phase. The decomposition of sulfates increases...... the sulfur circulation and may be problematic because high sulfur circulation can cause sticky material buildup, affecting the process operation of the cement kiln system. The SO2 release from cement raw materials during combustion of pine wood and tire rubber has been studied experimentally in a high...

Gaseous emissions during concurrent combustion of biomass and non-recyclable municipal solid waste

Directory of Open Access Journals (Sweden)

Oakey John

2011-02-01

Full Text Available Abstract Background Biomass and municipal solid waste offer sustainable sources of energy; for example to meet heat and electricity demand in the form of combined cooling, heat and power. Combustion of biomass has a lesser impact than solid fossil fuels (e.g. coal upon gas pollutant emissions, whilst energy recovery from municipal solid waste is a beneficial component of an integrated, sustainable waste management programme. Concurrent combustion of these fuels using a fluidised bed combustor may be a successful method of overcoming some of the disadvantages of biomass (high fuel supply and distribution costs, combustion characteristics and characteristics of municipal solid waste (heterogeneous content, conflict with materials recycling. It should be considered that combustion of municipal solid waste may be a financially attractive disposal route if a 'gate fee' value exists for accepting waste for combustion, which will reduce the net cost of utilising relatively more expensive biomass fuels. Results Emissions of nitrogen monoxide and sulphur dioxide for combustion of biomass are suppressed after substitution of biomass for municipal solid waste materials as the input fuel mixture. Interactions between these and other pollutants such as hydrogen chloride, nitrous oxide and carbon monoxide indicate complex, competing reactions occur between intermediates of these compounds to determine final resultant emissions. Conclusions Fluidised bed concurrent combustion is an appropriate technique to exploit biomass and municipal solid waste resources, without the use of fossil fuels. The addition of municipal solid waste to biomass combustion has the effect of reducing emissions of some gaseous pollutants.

Dioxins and polyvinylchloride in combustion and fires.

Science.gov (United States)

Zhang, Mengmei; Buekens, Alfons; Jiang, Xuguang; Li, Xiaodong

2015-07-01

This review on polyvinylchloride (PVC) and dioxins collects, collates, and compares data from selected sources on the formation of polychlorinated dibenzofurans (PCDFs) and dibenzo-p-dioxins (PCDDs), or in brief dioxins, in combustion and fires. In professional spheres, the incineration of PVC as part of municipal solid waste is seldom seen as a problem, since deep flue gas cleaning is required anyhow. Conversely, with its high content of chlorine, PVC is frequently branded as a major chlorine donor and spitefully leads to substantial formation of dioxins during poorly controlled or uncontrolled combustion and open fires. Numerous still ill-documented and diverse factors of influence may affect the formation of dioxins during combustion: on the one hand PVC-compounds represent an array of materials with widely different formulations; on the other hand these may all be exposed to fires of different nature and consequences. Hence, attention should be paid to PVC with respect to the ignition and development of fires, as well as attenuating the emission of objectionable compounds, such as carbon monoxide, hydrogen chloride, polycyclic aromatic hydrocarbons, and dioxins. This review summarises available dioxin emissions data, gathers experimental and simulation studies of fires and combustion tests involving PVC, and identifies and analyses the effects of several local factors of influence, affecting the formation of dioxins during PVC combustion. © The Author(s) 2015.

Raw-materials mixtures from waste of the coal industry for production of ceramic materials

Energy Technology Data Exchange (ETDEWEB)

Galpern, E I [Scientific-Manufacturing Enterprise ` ` Ceramics` ` , Donetsk (Ukraine); Pashchenko, L V [Inst. of Physical, Organic and Coal Chemistry of NASU, Donetsk (Ukraine)

1998-09-01

The liquidation of waste dumps on the surface of mining enterprises and realization of measures by environment protection of air and aquatic basins are connected to the complex processing of mining mass. The main directions of utilization of mining rocks and coal wastes realized in Ukraine industry are: - filling of mines worked-out area by grouting solutions; - ceramic brick, porous filling materials and binding materials production; - road-making, construction of hydrostructures and industrial objects; - output of concrete items predominantly for using in mining conditions. The peculiarity of wastes using in above-mentioned fields is the possibility of their mass application in quantities commensurable with valumes of their yields. The experience of enterprises work which process mining rocks into building materials by burning method (ceramic brick, porous aggregates of concretes as aggloporite, expanded clay aggregate) has shown that unconstant and, as the rule, exceeding norms content of carbon and sulphur in the rock results to deterioration of products quality and technological factors of production. Unstability of carbon content in raw material makes the burning process hardly operated. Obtained products having residual carbon in the view of coke residue are often characterized by lower physical-mechanical characteristics. (orig./SR)

Gas pollutants from detonation and combustion of industrial explosives

Energy Technology Data Exchange (ETDEWEB)

Campos, J.; Pines, A.; Gois, J.C.; Portugal, A. (University of Coimbra, Coimbra (Portugal). Mechanical Engineering Dept.)

1993-01-01

The potential hazards of fumes, from blasting operations in underground mines, have long been recognised. Beyond this normal use of explosives, there are also large amounts of energy substances which cannot be used because their life time is outdated or they are not within the minimal quality requirements. There is a lack of information concerning tests, procedures and theoretical predictions of pollutant concentrations in fumes from detonation and combustion operations with industrial explosives. The most common industrial explosives in Portugal are ammonium nitrate-fuel oil compositions (anfo), and dynamite. Recently, ammonium nitrate based emulsion explosives are more and more used in industrial applications. This paper presents the structure and fundamental thermodynamic equations of THOR computer code to calculate the combustion and detonation products (CO[sub 2], CO, H[sub 2]O, N[sub 2], O[sub 2], H[sub 2], OH, NO, H, N, O, HCN, NH[sub 3], NO[sub 2], N[sub 2]O, CH[sub 4] gases and two kinds of solid carbon - graphite and diamond) for the minimum value of Gibbs free energy, using three well known equations of state - BKW, H9 and H12. Detonation experiments are described and gas analysis discussed. Measured pollutants concentrations (CO, CO[sub 2], NO and NO[sub 2]), as a function of volume of explosion chamber, prove the dependence of expansion mechanisms on CO and NO formation and recombination and validate theoretical predictions. Incineration of explosives in a fluidised bed is described. Products composition from isobare adiabatic combustion of selected explosives has been calculated and correlated with previous calculations for a detonation regime. The obtained results demonstrate the possibility of predicting gas composition of detonation and combustion products of industrial explosives. 22 refs., 14 figs., 1 tab.

Oxygen Transport Membrane Reactors for Oxy-Fuel Combustion and Carbon Capture Purposes

Science.gov (United States)

Falkenstein-Smith, Ryan L.

This thesis investigates oxygen transport membrane reactors (OTMs) for the application of oxy-fuel combustion. This is done by evaluating the material properties and oxygen permeability of different OTM compositions subjected to a variety of operating conditions. The scope of this work consists of three components: (1) evaluate the oxygen permeation capabilities of perovskite-type materials for the application of oxy-fuel combustion; (2) determine the effects of dual-phase membrane compositions on the oxygen permeation performance and membrane characteristics; and (3) develop a new method for estimating the oxygen permeation performance of OTMs utilized for the application of oxy-fuel combustion. SrSc0.1Co0.9O3-delta (SSC) is selected as the primary perovskite-type material used in this research due to its reported high ionic and electronic conductive properties and chemical stability. SSC's oxygen ion diffusivity is investigated using a conductivity relaxation technique and thermogravimetric analysis. Material properties such as chemical structure, morphology, and ionic and electronic conductivity are examined by X-ray diffraction (XRD), Scanning Electron Microscope (SEM), and conductivity testing using a four-probe method, respectively. Oxygen permeation tests study the oxygen permeability OTMs under modified membrane temperatures, sweeping gas flow rates, sweeping gas compositions, membrane configurations, and membrane compositions. When utilizing a pure CO2 sweeping gas, the membrane composition was modified with the addition of Sm0.2Ce0.8O1.9-delta (SDC) at varying wt.% to improve the membranes mechanical stability. A newly developed method to evaluate the oxygen permeation performance of OTMs is also presented by fitting OTM's oxygen permeability to the methane fraction in the sweeping gas composition. The fitted data is used to estimate the overall performance and size of OTMs utilized for the application of oxy-fuel combustion. The findings from this

Lewis pressurized, fluidized-bed combustion program. Data and calculated results

Science.gov (United States)

Rollbuhler, R. J.

1982-03-01

A 200 kilowatt (thermal), pressurized, fluidized bed (PFB) reactor and research test facility were designed, constructed, and operated. The facility was established to assess and evaluate the effect of PFB hot gas effluent on aircraft turbine engine materials that may have applications in stationary powerplant turbogenerators. The facility was intended for research and development work and was designed to operate over a wide range of conditions. These conditions included the type and rate of consumption of fuel (e.g., coal) and sulfur reacting sorbent material: the ratio of feed fuel to sorbent material; the ratio of feed fuel to combustion airflow; the depth of the fluidized reaction bed; the temperature and pressure in the reaction bed; and the type of test unit that was exposed to the combustion exhaust gases.

The combustion behavior of large scale lithium titanate battery

Science.gov (United States)

Huang, Peifeng; Wang, Qingsong; Li, Ke; Ping, Ping; Sun, Jinhua

2015-01-01

Safety problem is always a big obstacle for lithium battery marching to large scale application. However, the knowledge on the battery combustion behavior is limited. To investigate the combustion behavior of large scale lithium battery, three 50 Ah Li(NixCoyMnz)O2/Li4Ti5O12 batteries under different state of charge (SOC) were heated to fire. The flame size variation is depicted to analyze the combustion behavior directly. The mass loss rate, temperature and heat release rate are used to analyze the combustion behavior in reaction way deeply. Based on the phenomenon, the combustion process is divided into three basic stages, even more complicated at higher SOC with sudden smoke flow ejected. The reason is that a phase change occurs in Li(NixCoyMnz)O2 material from layer structure to spinel structure. The critical temperatures of ignition are at 112–121°C on anode tab and 139 to 147°C on upper surface for all cells. But the heating time and combustion time become shorter with the ascending of SOC. The results indicate that the battery fire hazard increases with the SOC. It is analyzed that the internal short and the Li+ distribution are the main causes that lead to the difference. PMID:25586064

Energy implications of recycling packaging materials

Energy Technology Data Exchange (ETDEWEB)

Gaines, L.L. [Argonne National Lab., IL (United States); Stodolsky, F. [Argonne National Lab., Washington, DC (United States)

1994-03-01

In 1992, Congress sought to rewrite the United States comprehensive solid waste legislation -- the Resource Conservation and Recovery Act (RCRA). Commodity-specific recycling rates were proposed for consumer-goods packaging materials and newsprint We compare the impacts on energy, materials use, and landfill volume of recycling at those rates to the impacts for alternative methods of material disposition to determine the optimum for each material. After products have served their intended uses, there are several alternative paths for material disposition. These include reuse, recycling to the same product, recycling to a lower-valued product, combustion for energy recovery, incineration without energy recovery, and landfill. Only options considered to be environmentally sound are Included. Both houses of Congress specifically excluded combustion for energy recovery from counting towards the recovery goats, probably because combustion is viewed as a form of disposal and is therefore assumed to waste resources and have n environmental effects. However, co-combustion in coal-fired plants or combustion in appropriately pollution-controlled waste-to-energy plants Is safe, avoids landfill costs, and can displace fossil fuels. In some cases, more fossil fuels can be displaced by combustion than by recycling. We compare the alternative life-cycle energies to the energies for producing the products from virgin materials. Results depend on the material and on the objective to be achieved. There are trade-offs among possible goals. For instance, paper packaging recycling conserves trees but may require greater fossil-fuel input than virgin production. Therefore, the objectives for proposed legislation must be examined to see whether they can most effectively be achieved by mandated recycling rates or by other methods of disposition. The optimal choices for the United States may not necessarily be the same as those for Europe and other parts of the world.

Prediction of the acid generating potential of coal mining spoils

International Nuclear Information System (INIS)

Monterroso, C.; Macias, F.

1998-01-01

The sulfide oxidation impact on mined land reclamation makes it necessary for mine spoils to be classified according to their acidifying potential. In this paper predictions were made of the acid generating potential of sulfide-containing spoils from the Puentes lignite mine (Galicia, NW Spain), and the limits of sulfur contents allowable for their storage in aerobic conditions, were established. Using samples of fresh spoils, analyses were made of the content and speciation of sulfur, pH was measured after oxidation of the sample with H 2 O 2 (pH of oxidation = pH OX ), and titration of the oxidation extract with 0.1N NaOH to pH = 7 was carried out (Net Acid Production = NAP). The total sulfur content (S T ) varied between 3%, with pyritic-S being the most common form (> 80%). pH OX varied between 1.6 and 6.4 and NAP between 1.2 and 85.0 Kg-CaCO 3 t -1 . A high correlation was found between the NAP and the S T (r-0.98, p T > 0.15% cause high risks of mine-soil acidification, and create the need for large doses of CaCO 3 to be used on final surface of the mine dump. Use of fly ash, produced from the combustion of lignite, as an alternative to commercial lime is more effective in the control of acidity generated by spoils with high S T . 20 refs., 5 figs., 1 tab

Some Factors Affecting Combustion in an Internal-Combustion Engine

Science.gov (United States)

Rothrock, A M; Cohn, Mildred

1936-01-01

An investigation of the combustion of gasoline, safety, and diesel fuels was made in the NACA combustion apparatus under conditions of temperature that permitted ignition by spark with direct fuel injection, in spite of the compression ratio of 12.7 employed. The influence of such variables as injection advance angle, jacket temperature, engine speed, and spark position was studied. The most pronounced effect was that an increase in the injection advance angle (beyond a certain minimum value) caused a decrease in the extent and rate of combustion. In almost all cases combustion improved with increased temperature. The results show that at low air temperatures the rates of combustion vary with the volatility of the fuel, but that at high temperatures this relationship does not exist and the rates depend to a greater extent on the chemical nature of the fuel.

Reduced NOX combustion method

International Nuclear Information System (INIS)

Delano, M.A.

1991-01-01

This patent describes a method for combusting fuel and oxidant to achieve reduced formation of nitrogen oxides. It comprises: It comprises: heating a combustion zone to a temperature at least equal to 1500 degrees F.; injecting into the heated combustion zone a stream of oxidant at a velocity within the range of from 200 to 1070 feet per second; injecting into the combustion zone, spaced from the oxidant stream, a fuel stream at a velocity such that the ratio of oxidant stream velocity to fuel stream velocity does not exceed 20; aspirating combustion gases into the oxidant stream and thereafter intermixing the aspirated oxidant stream and fuel stream to form a combustible mixture; combusting the combustible mixture to produce combustion gases for the aspiration; and maintaining the fuel stream substantially free from contact with oxidant prior to the intermixture with aspirated oxidant

International cooperative research project between NEDO and NASA on advanced combustion science utilizing microgravity

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

This paper describes an international cooperative research project between NEDO and NASA on advanced combustion science utilizing microgravity. In June, 1994, NEDO and NASA reached a basic agreement with each other about this cooperative R and D on combustion under microgravity conditions. In fiscal 2000, Japan proposed an experiment using the drop tower facilities and parabolic aircraft at NASA Glen Research Center and at JAMIC (Japan Microgravity Center). In other words, the proposals from Japan included experiments on combustion of droplets composed of diversified fuels under different burning conditions (vaporization), flame propagation in smoldering porous materials and dispersed particles under microgravity conditions, and control of interactive combustion of two droplets by acoustical and electrical perturbations. Additionally proposed were experiments on effect of low external air flow on solid material combustion under microgravity, and sooting and radiation effects on the burning of large droplets under microgravity conditions. This report gives an outline of the results of these five cooperative R and D projects. The experiments were conducted under ordinary normal gravity and microgravity conditions, with the results compared and examined mutually. (NEDO)

Combustion synthesis of TiB2-based cermets: modeling and experimental results

International Nuclear Information System (INIS)

Martinez Pacheco, M.; Bouma, R.H.B.; Katgerman, L.

2008-01-01

TiB 2 -based cermets are prepared by combustion synthesis followed by a pressing stage in a granulate medium. Products obtained by combustion synthesis are characterized by a large remaining porosity (typically 50%). To produce dense cermets, a subsequent densification step is performed after the combustion process and when the reacted material is still hot. To design the process, numerical simulations are carried out and compared to experimental results. In addition, physical and electrical properties of the products related to electrical contact applications are evaluated. (orig.)

The combustion of biomass - the impact of its types and combustion technologies on the emission of nitrogen oxide

Directory of Open Access Journals (Sweden)

Mladenović Milica R.

2016-01-01

Full Text Available Harmonization of environmental protection and the growing energy needs of modern society promote the biomass application as a replacement for fossil fuels and a viable option to mitigate the green house gas emissions. For domestic conditions this is particularly important as more than 60% of renewables belongs to biomass. Beside numerous benefits of using biomass for energy purposes, there are certain drawbacks, one of which is a possible high emission of NOx during the combustion of these fuels. The paper presents the results of the experiments with multiple biomass types (soybean straw, cornstalk, grain biomass, sunflower oil, glycerin and paper sludge, using different combustion technologies (fluidized bed and cigarette combustion, with emphasis on the emission of NOx in the exhaust gas. A presentation of the experimental installations is given, as well as an evaluation of the effects of the fuel composition, combustion regimes and technology on the NOx emissions. As the biomass combustion took place at temperatures low enough that thermal and prompt NOx can be neglected, the conclusion is the emissions of nitrogen oxides primarily depend on the biomass composition- it is increasing with the increase of the nitrogen content, and decreases with the increase of the char content which provides catalytic surface for NOx reduction by CO. [Projekat Ministarstva nauke Republike Srbije, br. TR33042: Improvement of the industrial fluidized bed facility, in scope of technology for energy efficient and environmentally feasible combustion of various waste materials in fluidized bed i br. III42011: Development and improvement of technologies for efficient use of energy of several forms of agricultural and forest biomass in an environmentally friendly manner, with the possibility of cogeneration

Method and device for diagnosing and controlling combustion instabilities in internal combustion engines operating in or transitioning to homogeneous charge combustion ignition mode

Science.gov (United States)

Wagner, Robert M [Knoxville, TN; Daw, Charles S [Knoxville, TN; Green, Johney B [Knoxville, TN; Edwards, Kevin D [Knoxville, TN

2008-10-07

This invention is a method of achieving stable, optimal mixtures of HCCI and SI in practical gasoline internal combustion engines comprising the steps of: characterizing the combustion process based on combustion process measurements, determining the ratio of conventional and HCCI combustion, determining the trajectory (sequence) of states for consecutive combustion processes, and determining subsequent combustion process modifications using said information to steer the engine combustion toward desired behavior.

Interesting spontaneous combustion fire at Haus Aden colliery

Energy Technology Data Exchange (ETDEWEB)

Both, W; Weinheimer, O

1976-02-05

Spontaneous combustion ahead of the face occurred in an over-worked and under-worked seam. When the first cavity containing hot ash was found, an attempt to extinguish the fire with water was abandoned because of the quantity of steam produced, but the fire was extinguished by covering it with paste containing magnesium chloride and hydroxide and calcium chloride. Mining operations continued while the coal surrounding the hot region was cooled with water. The steps taken to detect and deal with other fires in advance of the face are described. These included pre-infusion with calcium chloride solution via boreholes and treatment of the hot cavities encountered with magnesium chloride paste. This method of fire-fighting was more successful than the use of water alone.

Decommissioning Combustible Waste Treatment using Oxygen-Enriched Incinerator

Energy Technology Data Exchange (ETDEWEB)

Min, Byungyoun; Lee, Yoonji; Yun, Gyoungsu; Lee, Kiwon; Moon, Jeikwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-05-15

The aim of the paper is current status of treatment for the decommissioning combustible waste in KAERI and for the purpose of the volume reduction and clearance for decommissioning combustible wastes generated by the decommissioning projects. The incineration technology has been selected for the treatment of combustible wastes. About 34 tons of decommissioning combustible waste has been treated using Oxygen Enriched incineration. Temperature, pressure of major components, stack gas concentration, i. e., SOx, NOx, CO, CO{sub 2} and HCl, and the residual oxygen were measured. Measured major parameters during normal operation were sustained on a stable status within a criteria operation condition. Oxygen enriched air, 22vol. % (dry basis) was used for stable incineration. The volume reduction ratio has achieved about 1/117. The incineration with decommissioning radioactive combustible waste is possible with moderate oxygen enrichment of 22 vol.% (dry basis) into the supply air. The incineration facility operated quite smoothly through the analysis major critical parameters of off-gas. The pressure, off-gas flow and temperature of major components remained constant within the range specified. The measures gases and particulate materials in stack were considerably below the regulatory limits. The achieved volume reduction ratio through incineration is about 1/117.

The Diesel Combustion Collaboratory: Combustion Researchers Collaborating over the Internet

Energy Technology Data Exchange (ETDEWEB)

C. M. Pancerella; L. A. Rahn; C. Yang

2000-02-01

The Diesel Combustion Collaborator (DCC) is a pilot project to develop and deploy collaborative technologies to combustion researchers distributed throughout the DOE national laboratories, academia, and industry. The result is a problem-solving environment for combustion research. Researchers collaborate over the Internet using DCC tools, which include: a distributed execution management system for running combustion models on widely distributed computers, including supercomputers; web-accessible data archiving capabilities for sharing graphical experimental or modeling data; electronic notebooks and shared workspaces for facilitating collaboration; visualization of combustion data; and video-conferencing and data-conferencing among researchers at remote sites. Security is a key aspect of the collaborative tools. In many cases, the authors have integrated these tools to allow data, including large combustion data sets, to flow seamlessly, for example, from modeling tools to data archives. In this paper the authors describe the work of a larger collaborative effort to design, implement and deploy the DCC.

Study of new technique of solid combustible materials to determination of volatile elements by flame atomic absorption spectrophotometry

International Nuclear Information System (INIS)

Campos, R.C. de.

1988-01-01

A new technique for direct trace element analysis of solid combustible materials is described. The samples (up to 10 mg) are weighed on a graphite platform wich is then placed in a quartz tube, at the focal point of three infrared lamps. When the lamps are turned on, the sample burns in a stream of air, and the resulting dry aerosol containing volatile elements such as Hg, Cd, Bi, Tl, Zn, Pb and Cu is carried into the mixing chamber and thence into the flame, where the atomic absorption measurement is carried out. This technique overcomes chemical sample preparation steps, avoiding contaminations of losses associated with these steps. A ''furnace in flame'' system where the aerosol is transported to a flame heated T-tube is also described. The influence of flame stoichiometry, observation height, platform material and air flux intensity was studied inorder to determine optimal analytical conditions. (author) [pt

FY1995 annual report on the advanced combustion science in microgravity field

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-03-01

Research was implemented continuously from the previous year on combustion equipment enabling advanced combustion technologies, by studying combustion in a microgravity field, for the purpose of preventing environmental pollution caused by diversification of energy sources and exhaust gasses. In joint studies with NASA, the 1995 themes were continued, for which tests were conducted 34 times using Japanese drop test equipment. Further, studies were added for flammability limits and flame dynamics of spherical flames in homogeneous and heterogeneous mixed fuels. The evaluation and analysis of the experiments and test data by the microgravity test equipment were such that laser ignitions of floating or fuel-oozing droplets, spherical/cylindrical combustion of liquid fuels, for example, were studied in regards to the combustion and vaporization process of fuel droplets, that high calorie fuel combustion in microgravitation field for example was investigated in relation to the combustion characteristics of high density fuels, that flame stability of lean premixed gasses for example was researched concerning flammability limit, and that NOx generation mechanism in liquid fuel combustion was looked into in connection with emission mechanisms of pollutant gaseous materials. (NEDO)

A practical approach in porous medium combustion for domestic application: A review

Science.gov (United States)

Ismail, A. K.; Ibrahim, N. H.; Shamsuddin, K. A.; Abdullah, M. Z.; Zubair, M.

2018-05-01

Combustion in porous media has been widely studied. Many application involving the combustion of porous media has been reported in various way with most consider on numerical works and industrial application. Besides, recent application of porous medium combustion for domestic is the topic of interest among researchers. In this paper, a review was conducted on the combustion of porous media in term of practical application for domestic consumers. Details on the type of fuel used including bio fuel and their system have been search thoroughly. Most of the system have utilized compressed air system to provide lean combustion in domestic application. Some self-aspirating system of porous medium burner was also reported. The application of new technology such as cogeneration by using thermoelectric cells in tandem with porous medium combustion is also revised according to recent work which have already been published. Besides, the recent advances which include coating of porous material is also considered at the end of this paper.

Acid mine drainage as an important mechanism of natural radiation enhancement in mining areas

International Nuclear Information System (INIS)

Fernandes, H.M.; Franklin, M.R.

2002-01-01

Acid mine drainage (AMD) is a world wide problem that occurs whenever sulfidic material is present in association to the mined ore. The acidic waters generated by the process of sulfide minerals oxidation can mobilize important amounts of pollutants and cause significant environmental impacts. The composition of the drainage will depend, on a very large extent, on the mineralogy of the rocks. The purpose of this paper is to demonstrate that acid mine drainage has the potential to enhance the natural levels of environmental radioactivity. The paper revises some strategies to be used in the diagnostic of the problem. General mathematical formulations that can assist on the prediction of the duration of the problem, and the definition of the size of the oxidizing zones in a waste dump are given. A study case on a waste dump of the Pocos de Caldas Uranium Mining Site, Brazil is also presented. (author)

Plant growth response in experimental soilless mixes prepared from coal combustion products and organic waste materials

Energy Technology Data Exchange (ETDEWEB)

Bardhan, S.; Watson, M.; Dick, W.A. [Ohio State University, Wooster, OH (United States)

2008-07-15

Large quantities of organic materials such as animal manures, yard trimmings, and biosolids are produced each year. Beneficial use options for them are often limited, and composting has been proposed as a way to better manage these organic materials. Similarly, burning of coal created 125 million tons of coal combustion products (CCP) in the United States in 2006. An estimated 53 million tons of CCP were reused, whereas the remainder was deposited in landfills. By combining CCP and composted organic materials (COM), we were able to create soilless plant growth mixes with physicochemical conditions that can support excellent plant growth. An additional benefit is the conservation of natural raw materials, such as peat, which is generally used for making soilless mixes. Experimental mixes were formulated by combining CCP and COM at ratios ranging from 2:8 to 8:2 (vol/vol), respectively. Water content at saturation for the created mixes was 63% to 72%, whereas for the commercial control, it was 77%. pH values for the best performing mixes ranged between 5.9 and 6.8. Electrical conductivity and concentrations of required plant nutrient were also within plant growth recommendations for container media. Significantly (P < 0.0001) higher plant biomass growth (7%-130%) was observed in the experimental mixes compared with a commercial mix. No additional fertilizers were provided during the experiment, and reduced fertilization costs can thus accrue as an added benefit to the grower. In summary, combining CCP and COM, derived from source materials often viewed as wastes, can create highly productive plant growth mixes.

New class of combustion processes

International Nuclear Information System (INIS)

Merzhanov, A.G.; Borovinskaya, I.P.

1975-01-01

A short review is given of the results of work carried out since 1967 on studying the combustion processes caused by the interaction of chemical elements in the condensed phase and leading to the formation of refractory compounds. New phenomena and processes are described which are revealed when investigating the combustion of the systems of this class, viz solid-phase combustion, fast combustion in the condensed phase, filtering combustion, combustion in liquid nitrogen, spinning combustion, self-oscillating combustion, and repeated combustion. A new direction in employment of combustion processes is discussed, viz. a self-propagating high-temperature synthesis of refractory nitrides, carbides, borides, silicides and other compounds

Charakterizace produktů spalování paliv a jejich potenciální aplikace v procesu odstraňování polutantů z vodného prostředí

Czech Academy of Sciences Publication Activity Database

Ruppenthalová, Lucie; Pavlovský, J.

2017-01-01

Roč. 59, č. 1 (2017), s. 9-13 ISSN 1210-7697 R&D Projects: GA MŠk(CZ) LO1406; GA MŠk ED2.1.00/03.0082 Institutional support: RVO:68145535 Keywords : fuel combustion * pollutants * unburned carbon Subject RIV: DH - Mining, incl. Coal Mining OBOR OECD: Materials engineering

Accuracy of forecast of mine tremors location

Energy Technology Data Exchange (ETDEWEB)

Jan Drzewieck [Central Mining Institute, Katowice (Poland)

2009-09-15

The Upper Silesian Coal Basin is one of the most active mining areas in the world in respect of seismicity. Underground mining in this area takes place in a special environment with a high degree of risk of unpredictable event occurrence. Especially dangerous are phenomena that occur during the extraction of deposits at great depths in the environment of compact rocks. Deep underground mining violates the balance of these rocks and induces dynamic phenomena at the longwall life (in terms of distance) referred to as mine tremors. The sources of these tremors are located in layers characterised by high strength, especially in thick sandstone strata occurring in the roof of the mined seam. In the paper a discussion is presented about the influence of mining intensity (longwall face speed) on the location of mine tremor sources, both in the direction of longwall life (in terms of distance) and towards the surface. The presented material has been prepared based on the results of tests and measurements carried out at the Central Mining Institute. 8 refs., 5 figs.

Experimental validation for combustion analysis of GOTHIC code in 2-dimensional combustion chamber

International Nuclear Information System (INIS)

Lee, J. W.; Yang, S. Y.; Park, K. C.; Jung, S. H.

2002-01-01

In this study, the prediction capability of GOTHIC code for hydrogen combustion phenomena was validated with the results of two-dimensional premixed hydrogen combustion experiment executed by Seoul National University. The experimental chamber has about 24 liter free volume (1x0.024x1 m 3 ) and 2-dimensional rectangular shape. The test were preformed with 10% hydrogen/air gas mixture and conducted with combination of two igniter positions (top center, top corner) and two boundary conditions (bottom full open, bottom right half open). Using the lumped parameter and mechanistic combustion model in GOTHIC code, the SNU experiments were simulated under the same conditions. The GOTHIC code prediction of the hydrogen combustion phenomena did not compare well with the experimental results. In case of lumped parameter simulation, the combustion time was predicted appropriately. But any other local information related combustion phenomena could not be obtained. In case of mechanistic combustion analysis, the physical combustion phenomena of gas mixture were not matched experimental ones. In boundary open cases, the GOTHIC predicted very long combustion time and the flame front propagation could not simulate appropriately. Though GOTHIC showed flame propagation phenomenon in adiabatic calculation, the induction time of combustion was still very long compare with experimental results. Also, it was found that the combustion model of GOTHIC code had some weak points in low concentration of hydrogen combustion simulation

Mining and mining authorities in Saarland 2016. Mining economy, mining technology, occupational safety, environmental protection, statistics, mining authority activities. Annual report

International Nuclear Information System (INIS)

2016-01-01

The annual report of the Saarland Upper Mining Authority provides an insight into the activities of mining authorities. Especially, the development of the black coal mining, safety and technology of mining as well as the correlation between mining and environment are stressed.

Passive control of thermoacoustic instabilities in swirl-stabilized combustion at elevated pressures

Directory of Open Access Journals (Sweden)

L Justin Williams

2016-09-01

Full Text Available In this study, a porous insert is placed at the dump plane of a swirl-stabilized lean premixed combustor to passively suppress thermoacoustic instabilities. The diffuser-shaped annular ring of porous inert material influences the turbulent flow field directly, including recirculation zones and vortical and/or shear layer structures to passively control the acoustic performance of the combustor. The porous inert material is made of silicon carbide–hafnium carbide coated, high-strength, high-temperature-resistant open-cell foam materials. In this study, the porous insert concept is investigated at above-ambient operating pressures to demonstrate its suitability for practical combustion applications. Experiments are conducted in quartz and metal combustors, without and with the porous insert while varying operating pressure, equivalence ratio, and reactant flow rate. Measurements show that the porous insert, and consequent changes in the combustor flow field, decrease the sound pressure levels at the frequency of combustion instability at all operating conditions investigated in this study. The porous insert also decreases the broadband combustion noise, i.e. the measured sound pressure levels over a wide frequency range.

MANAGEMENT AND TREATMENT OF WATER FROM HARD-ROCK MINES {ENGINEERING ISSUE}

Science.gov (United States)

This Engineering Issue document on treatment of mining waters is a practical guide to understanding and selecting technologies for the environmental management of waste materials and effluents at hard-rock mines. For the purposes of this discussion, hard-rock mining primarily ref...

Fabrication and processing of next-generation oxygen carrier materials for chemical looping combustion

Energy Technology Data Exchange (ETDEWEB)

Nadarajah, Arunan [Univ. of Toledo, OH (United States)

2017-04-26

Among numerous methods of controlling the global warming effect, Chemical Looping Combustion is known to be the most viable option currently. A key factor to a successful chemical looping process is the presence of highly effective oxygen carriers that enable fuel combustion by going through oxidation and reduction in the presence of air and fuel respectively. In this study, CaMnO_3-δ was used as the base material and doped on the A-site (Sr or La) and B-site (Fe, Ti, Zn and Al) by 10 mol % of dopants. Solid state reaction followed by mechanical extrusion (optimized paste formula) was used as the preparation method A series of novel doped perovskite-type oxygen carrier particles (Ca_xLa (Or Sa)_1-x Mn_1-yByO_3-δ (B-site = Fe, Ti, Al, or Zr)) were synthesized by the proposed extrusion formula. The produced samples were characterized with XRD, SEM, BET and TGA techniques. According to the results obtained from TGA analysis, the oxygen capacity of the samples ranged between 1.2 for CLMZ and 1.75 for CSMF. Reactivity and oxygen uncoupling behaviors of the prepared samples were also evaluated using a fluidized bed chemical looping reactor using methane as the fuel at four different temperatures (800, 850, 900, 950 °C). All of the oxygen carriers showed oxygen uncoupling behavior and they were able to capture and release oxygen. Mass-based conversion of the perovskites was calculated and temperature increase proved to increase the mass-based conversion rate in all of the samples under study. Gas yield was calculated at 950 °C as well, and results showed that CLMZ, CM and CSMF showed 100% gas yields and CLMF and CSMZ showed approximately 85% yield in fluidized bed reactor, which is a high and acceptable quantity. Based on extended reactor tests the modified calcium manganese perovskite structures (CSMF) can be a good candidate for future pilot tests.

Volatiles and char combustion rates of demineralised lignite and wood blends

International Nuclear Information System (INIS)

Yilgin, Melek; Pehlivan, Dursun

2009-01-01

Today, much interest is given to the utilisation of materials of plant origin as substitutions of fossil fuels in meeting energy needs to reduce the level of atmospheric pollutant emissions and global warming threat, and emphasis has been placed on the co-combustion of coal and biomass. In this study, volatiles and char combustion behaviour of the fuel pellets composed from demineralised lignite and poplar wood sawdust, were investigated in a cylindrical wire mesh basket placed in a preheated tube furnace. The results have shown that ignition times of the pellets decreased with the burning temperature and shortened further due to demineralisation of lignite. Volatiles combustion rates of the samples did not correlate well with combustion times. However, they can be correlated with their respective proximate volatile matter contents. Char burnout times decreased with increasing combustion rates and correlated well with the respective proximate fixed carbon contents of the samples. Deviations were more considerable in the case of rate data. (author)

How the environmental community views the mining industry

International Nuclear Information System (INIS)

Maest, A.

1990-01-01

Working with the Environmental Mining Network, a coalition of ∼75 environmental groups nationwide formed to encourage environmentally-sound hard-rock mining. Emphasis is on changing the industrial process so that wastes are not created in the first place, instead of creating the wastes and dealing with them as an afterthought. The tradition of pollution control is slowly being replaced with prevention. Objectives of pollution prevention for mining include: Reduction of the volume of material extracted, beneficiated, processed, and removed for exploration by improving techniques for these processes, mining less, and encouraging remining and use of scrap materials; Reduction of the toxicity and environmental impact of wastes that are nonetheless generated by employing techniques that minimize the release of contaminants to the environment; Identifying current and developing technologies for pollution prevention in the mining industry and distribute this among the regulated community. Pollution prevention should be incorporated in design and performance standards. Assessment and demonstration of pollution prevention should be part of the permit application. Implementation of serious non-rhetorical pollution prevention by the mining industry has the potential to give miners and environmentalists a common ground and common goals where we could truely be in a win-win situation in terms of encouraging both environmental and economic robustness

Evaluating possible industrial applications of combustible shales and shale ash wastes

Directory of Open Access Journals (Sweden)

Н. К. Кондрашева

2016-08-01

Full Text Available Today energy consumption is constantly growing while explored reserves of easily accessible oil are depleting, which is a reason why most countries tend to diversify their energy mix, develop non-hydrocarbon energy sources and use domestic types of fuel, including the low grade ones. Thereby interest is raised to such a source of hydrocarbons as combustible shales. Combustible shales appear to be one of the highest-potential types of organic raw materials, which may offset and in future even substitute oil products and gas. The paper is investigating behavior and structure of combustible shales during heat treatment in order to identify their possible industrial applications. A synchronous thermal analysis has been held, chemical composition of combustible shales’ mineral fraction and optimal conditions for shale fines briquetting have been determined.

The effects of changing municipal solid waste characteristics on combustion fuel quality

International Nuclear Information System (INIS)

Artz, N.S.; Franklin, M.A.

1991-01-01

This paper discusses the quality of municipal solid waste (MSW) as a combustion fuel based on two aspects: heat of combustion and heavy metal content. Characterization of MSW by the material flows methodology now provides a historical data series on the composition of MSW for nearly 30 years (1960-1988). Over this period, there have been marked changes in MSW composition, with paper and plastics increasing in percentage while glass and metals have declined. This paper will illustrate the effects of this changing composition on heat of combustion. Using a computer model and standard heat of combustion values for the components of MSW, heating values of MSW (in Btu per pound) are calculated for the 30-year time period. Changes in heating values are highlighted and projections are made to year 2010. Recognizing the increasing importance of the recovery of materials from MSW for recycling, the paper illustrates the effects of removing varying quantities of recyclable materials (e.g., newspapers, corrugated boxes, plastic bottles, glass bottles, metals, yard wastes) on the heating value of the remaining MSW. The paper's final section summarizes recent studies performed for EPA and others on the presence of heavy metals (lead, cadmium, and mercury) in the products discarded in MSW. Again, time trends are used to demonstrate the changing presence of these metals

New Zealand mining legislation and recommendations for change following the Pike River disaster