01 Solidfuels(sources,winning,properties)
01
SOLID FUELS Sources, winning, properties
00/01653
Brown coal mining and use
Ewers, J. Brr~~n.~!. Wrrerntc-Krcrfi. 1999. 51, (4).40-46. (In German) Springer-VDI-Verlag GmbH & Co. KG. This review is available on the internet http://www.technikwissen.de/bwk heading ‘Literaturverzeichnisse’. The main areas for discussion include brown coal mining, upgrading, power generation and research on utilization.
00101654 Characterization of pulverized injection into blast furnaces
Chemical
fractionation
of trace elements
in coal and
Gentzis, T. and Goodarzi, F. E1rcrg.1. Solrrc.e.\. 1999. 2 I. (3). 233-256. The chemical fractionation (leaching) of elements from the Whitewood Mine subbituminous coals and coal ashes at 120, 750, and 1000°C are examined in this article. Water, ammonium acetate, and hydrochloric acid can be used to leach the elements Ba, Zn, and Mn from the coal. Potassium can be extracted in high quantities with NH40 acetate but only in small amounts with HCI. Hydrochloric acid leaches most of the iron, whereas very small quantities of the element are leached by water or NH40 acetate. Low extractability from coal was noted for Si, Ti. and Cu, an indication of their association with detrital minerals. Extractability of Na from coal was low, which indicates a relationship with minerals rather than being in the form of exchangeable ions. High leachability for Ca, Sr, and to a certain degree, Mn, Mg, and Na were noted for the 120°C ash samples. Zinc, Ba, S, and P showed a wide variation, reflecting a complex association with carbonate, sulfate, sulfide minerals, and organic matter. Silica, Al, B, Li, Cu. and Mo Al, Cu, Sr, and Mn were easily were completely insoluble. Calcium, extractable from the coal ash at 750°C. Copper in coal ash may be in the form of oxide, which is more leachable. Because Al is highly leachable it is possible that this element could be extracted from coal ash in countries that have no bauxite ore deposits. In the 1000°C ash, S, Zn, and Na were highly leached, whereas Ca, Ba, and Sr were moderately leached. The elements that demonstrated very low extractability include silica, Al, Fe, K, Mg, Ti, Mn and Cu.
Coal recovery from coal fines cleaning wastes by agglomeration with vegetable oils: effects of oil type and concentration
00/01656
Alonso, M. I. Ff‘r,c,/. 1999. 78. (7). 753-75’). The aim of this work was to obtain high calorific value products from the cleaning wastes from coal fines by agglomeration with vegetable oils. These wastes are normally disposed of in refuse dumps, causing important economic and environmental problems. Three Spanish coal fines wastes from different coal cleaning plants were agglomerated with crude and refined sunflower and soybean oils over a wide range of oil concentrations. The response of these fines wastes to agglomeration with the oils, was evaluated by the percentages of coal matter recovery, ash rejection and efficiency index. The best quality products were attained at the lowest oil concentrations, especially when the refined ones were used. In these cases, the agglomeration with vegetable oils allowed the recovery from coal fines wastes of a ready-to-burn fine coal fuel. 00/01657
condensed
Coal structure and the electronic aromatic compounds
spectra
law of
Chen. C. ML,~ILIII Z/mr,/?lr~rcr. 1999. 22. (I). I-S. (In Chinese) The relationship between the electronic spectra law of condensed compounds and coal macromolecular structure is reviewed.
aromatic
00/01656 Development of emittance of coal particles during devolatilization and burnoff Bhattacharya, S. P. and Wall, T. F. Fuel.1999, 78, (5). 51 I-519. During the measurement of particle temperature, devolatilization rate, rate of particle heat-up and power radiated by the particle during combustion and gasification, it is beneficial to have a knowledge of the spectral emittance of coal particles. Information on the development of emittance of coal particles which are devolatilized and burnt. as well as information on the emittance of char as a function of ash content are rare. Examined in this article is the evolution of spectral emittance of coal particles as they are devolatilized. In this study. two different coal samples were used. Spectral emission measurements were performed on opaque layers of coal particles
192
Fuel and Energy Abstracts
00101659 Effect of the rank and the petrographic structure of Polish steam coals on their sulfur content and the forms of its occurrence Karcz, H. CO.\/J&. ftr/i~~~~~~~r~ E,lc,rg. 1998. 46. (12). 2& 22. (In Polish) The distribution of sulfur in Polish coals, including its petrographic components and coal rank are presented.
cokes and coals for
1999. 55. (485). 127-128. (In De Avila Ribas, M. Mcrcrl. Morer., Portuguese) The desirable properties required by pulverized coal or coke that are to be used for iniecting into blast furnaces are described. Coal with low volatiles content and higiquality cokes can be used to increase the coke rate of the furnace. An analysis is also included on processing requirements and economics.
Wefts;
at wavelengths between 2 and I2 ,,m. and progressively at temperatures from 200 to 1000°C to illustrate the effects of particle size and coal type on emittance and more importantly the development of emittance with devolatilization. From one coal. char samples were generated in a drop tube furnace at three different burnout levels. Spectral emission measurements were performed on opaque layers of these char particles to demonstrate how the levels of emittance are affected by burnout and ash levels. Such measurements covering a wide range of temperature and wavelength are one of the very few reported in the literature. A brief discussion on the implications of these results on pyrometry is included to illustrate the magnitude of potential errors in temperature measurement.
July 2000
00/01660
subsequent
Hydraulic mining of coal sludge settling reflotation and dewatering
ponds and
Rapka, W. U/J/i-~udl,-Gcol. Pw:krtm. 1999. 6. (I ). 15-l 6. (In Czech) The areas of coal sludge settling ponds that are reviewed include hydraulic mining of the coal sludge and subsequent reflotation and dewatering.
00101661 heating
Irreversible
structural
changes
in coals during
Takanohashi, T. EJI(,~,cJ,~~II(,/.~.lYY9. 13.(2). 506.-512 A differential scanning calorimetry (DSC) study was conducted to the study the extraction residues of coals giving different extraction yields (which were prepared by changing the solvent composition of a carbon disulfide-Nmethyl-2-pyrrolidinone mixed solvent extraction). For the residues from Upper Freeport coal (APCS-I) which had extraction yields of less than 30 wt% (daf), an endothermic peak similar to that given by the raw coal was obsereved at approximately 350°C. This endothermic peak disappeared on the second and third scans, indicating that the peak is due to irreversible structural changes in coals. For the residues from the high extraction yield experiments, the peak was not observed up to 4Oo”C, even during the first scan. A discussion is also included on the reasoning behind these endothermic peaks from the relationship among the extraction, swelling, and structural changes of coals.
00/01662 Manufacture of expanded ammonium permissible explosive for coal mining
nitrate-based
Chen, T. Btro/~~~Qic,r,i. 199X. 27. (6). X- IO. (In Chlncse) The manufacturing of a non-TNT coal mining permissible AN explosive involved using expanded AN (a self-sensitizer used as oxidizing agent), an inhibitor and some combustible materials. The explosives are proved to be flame resistant. The explosives met the required standards of the same class permissible AN-TNT explosive.
00/01663 Method for determination parameters of hard and brown coal
of physicochemical
Corny, W. Pol. PL 369,840 (Cl. GOlN23/223), 30 Sep l9Y6, Appl. 297,919. I Mar 1993. 4. (In Polish) There are three stages involved in the detection of the physical and chemical parameters of coal and brown coal. The first step is the exposure of coal samples to low-energy -,- or X-ray radiation. the second involves the measurement of secondary radiation intensity and the third is the detection of the parameters in support of a calibration equation and results of secondary radiation intensity measurements. 00/01664 Mineralogy of barren rocks in Lower Miocene brown coal deposits of the Borsod Basin (N. Hungary) Viczian, I. Folk. /Co:/.. 1998. 127. (I-2). 127-144. (In Hungarian) Fourteen coal seam profiles of seven brown coal deposits were removed from the North Hungarian Borsod Basin so that detailed sampling could be performed on them. Mineralogical analysis was part of a complex study aiming to reconstruct the paleo-environmental relations of the deposition of the Ottnangian coal sequence. The samples and the <2 I’m fraction were assessed using X-ray diffraction. DTA-DTG methods were used to detect the organic carbon and total carbonate contents of the bulk samples and to characterize the water contents and absorbed cations in clay minerals. The lower stratigraphic horizons within the coal sequence formations underlying or inter-bedding the coal seams consist predominantly of redeposited volcanogenic material. Volcanogenic components are derived from local sources such as from the Ottnangian ‘Gyulakeszi’ rhyolite tuff and the products of its terrestrial weathering, which form the base of coal sequence. The clay layers within the coal seams contain plagioclase, partly of high temperature modification, little clinoptilolite. much smectite, little illite and various quantities of kaoliniteismectite mixed-layers or disordered kaolinite. The transformation of the acid volcanic glass and feldspars into smectite and the subsequent transformation of smectite into kaolinite is accompanied by silica production. This precipitants in amorphous form or in the form of opal-CT, cristobalite or quartz and results in diatomaceous and silicified coal and barren rock layers. The barren rock layers in the coal seams contain little detrital quartz and are practically carbonate-free, There are few bentonite layers in the coal seams derived of synchronous fallout of acid tuffs, which can be followed in the neighbouring occurrences. These