Distribution of chalcophilic elements in coal from the sixth seam of the Kachulka Mine, Balkan Basin

Distribution of chalcophilic elements in coal from the sixth seam of the Kachulka Mine, Balkan Basin

01 Solid fuels (sources, winning, properties) 02/01252 Coal for charging in coke ovens Fukada, K. et al. Jpn. Kokai Tokkyo Koho JP 2001 181,644 (CI...

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01 Solid fuels (sources, winning, properties) 02/01252

Coal for charging in coke ovens

Fukada, K. et al. Jpn. Kokai Tokkyo Koho JP 2001 181,644 (CI. CIOB47/00), 3 Jul 2001, Appl. 1999/367,554, 24 Dec 1999. 5. (In Japanese) The coal contains 20-80% fine non-baking coal particles having specified particle diameter range. Preferably, the particles have maximum diameter <6 mm and contain <40% particles with diameter <0.5 mm.

02/01253 Comprehensive processing of brown coals as an urgent problem in the Ukrainian coal industry Zborshchik, M.P. and Ostapenko, M.A. Koks Khim., 2001, 5, 7-10. (In Russian) Due to shortage of petroleum products and gas in Ukraine, search for alternative fuel and energy sources is under way. Use of brown coals, shales, low-grade hard coals, and hydrocarbon-containing wastes is at the centre of attention. The discussion in this paper is focused on brown coal processing.

02/01254 Corrosivities derived from two Illinois coals with a low and a high CI content under low NOx conditions Chou, M.-I.M. et al. Proc. Int. Tech. Conf. Coal Util. Fuel Syst., 2001, 26th, 899-907. Since the late 1960s, the British literature has correlated corrosion of utility boilers with the total amount of CI in coals, and has indicated accelerated corrosion when using coals with CI content of 0.3% or more. On the other hand, laboratory corrosion data available in the USA indicated that CI in high CI coals were not a major cause of corrosion. However, these laboratory data were insufficient to evaluate the potential beneficial effects from the CI in coal on low-NOx burner applications. The purpose of this study was to conduct pilot-scale tests to determine corrosion rates under reducing/sulfiding conditions that would be experienced by a water-wall in a low-NOx boiler. Two pilotscale tests using high-(0.41%) and low- (0.10%) CI Illinois coals were performed. The corrosion rates were measured, using conventional probes, made of T22 metal-alloy, for a duration that would give reliable comparisons. Combustion of the high- and low-Cl coal resulted in no correlation between the CI content and the corrosivity of a coal. The max;mum reduction of the tube wall thickness due to corrosion was the same for both the high and low CI coal examined. In addition, no chloride deposition was observed in the corrosion sample obtained from the high CI coal test. These findings are of potential importance to the coal industry, especially, in the state of Illinois where there are a large reserves of high CI coal.

02/01255 Determination of Ptolemais lignite quality variations-supportive fuels and homogenization method to improve lignite quality for power generation purposes Kavourides, K. and Pavloudakis, F.F. Oryktos Ploutos, 2001, 118, 7-20. Lignite produced from multi-seam deposits of the Ptolemais (Greece) area is characterized by intensive fluctuations in its heating value and ash content, which cause temporary deviations from specification fuels to power plants. The use of homogenization methods, to maintain quality specifications and to limit variations of the lignite, including the addition of dried lignite. For this purpose, lignite quality data were obtained by laboratory analyses of the average daily samples collected from Main Field, Kardia Field, and South Field mines. As a result, the homogenization method contributed significantly to the reduction of both the frequency and degree of lignite quality deviation from fuel specifications, in which the lignite quality deviation from specifications was eliminated for the vast majority of instances, over test times of 510 days. Thus, the supply of homogenized lignite as feed for thermal power plants was recommented as a method for standardizing feed quality, contributing to reduced operational expenses, and reduction of the specific cost of electricity.

02/01256 Determination of stages of thermal degradation of solid fuels according to thermogravimetric analysis data Goryushkin, V.F. et al. Koks Khim., 2001, 5, 4-6. (In Russian) A method for processing thermogravimetric analysis, data was proposed. Stages of thermal transformation of coal substances and their temperature ranges were established. The temperature intervals of the thermal degradation stages agreed with the stages of release of individual gases according to data by other researchers.

02/01257 Distribution of chalcophilic elements in coal from the sixth seam of the Kschulka Mine, Balkan Basin Kortenski, I. et al. Spis. Bulg. Geol. Druzh., 1999, 60, (1-3), 83-91. (In Bulgarian) Bituminous coals from the sixth bed of the Kachulka Mine have been investigated. The occurrence of the following minerals have been established: kaolinite, illite, montmorillonite, pyrite, marcasite, chalcopyrite, galena, calcite, dolomite, siderite, quartz, anortite, gypsum, anhydrite and jarosite. It has been observed that a part of pyrite, dolomite and calcite are epigenetic infiltrational minerals. The low

contents of the investigated chalcophile elements (except As) are due to the sea transgression from the East to the West. More of them show a higher organic affinity. Co and Cd have the highest possible correlation coefficients with carbonyl, lower with hydroxyl, and the lowest with carboxyl groups. Co-Cd, Pb-Zn-Cu-Ni and As-Mo associations were separated. They showed a pos. correlation with the functional groups. The lowest correlation coefficient was established for Pb and Zn, with an intermediate (mixed) affinity. The distribution of these elements and coal ash from the area of the sixth coal bed proved that the mining was conducted in the north part of the sea transgression. At the same time the freshwater streams have penetrated the peat bog from the north-northwest. After their mixing with the seawater, the geochemical barrier was formed, and bigger amounts of chalcophile elements were deposited around it. The elements with a lower organic affinity (Pb, Zn, partly Cu) were concentrated mainly on the east side of this barrier, but those with a higher organic affinity - on the west side. This is due to the pH value decrease, under the influence of the fresh and peat waters, which neutralized to a great extent the sea transgression influence. As and Mo are related mainly with the plant tissues and pyrite. A higher concentration of more elements (except Pb and Zn) was observed near the earth surface of the bed, which is resulting from their participation in the epigenetic pyrite mineralization.

02/01258 Estimation of size and shape of pores in moist coal utilizing sorbed water as a molecular probe Hayashi, J. et al. Energy Fuels, 2001, 15, (4), 903-909. This work was undertaken aiming to estimate the size of pores in moist coals on the basis of the NMR relaxation characteristics of water sorbed in the pores as the molecular probe. Raw Yallourn brown coal (water content; 1.46 kg-water/kg-daf coal) and Beulah Zap lignite (0.53) were employed as the raw materials and were partially or completely dried at 303 K. Samples with known water contents were subjected to 1H NMR analysis taking a Carr-Purcel/Meiboom-Gill (CPMG) pulse sequence. The results of the analysis revealed that the initial amplitude of the CPMG signal corresponds quantitatively to the total amount of 'mobile' proton. It was found that there are three components with different transverse relaxation times (T2), that are attributed to free water, pore water (freezable bound water and nonfreezable water), and mobile coal hydroxyls. The relaxation characteristics of the water components were further analysed on the basis of a theory that relates the dimension of pore to the relaxation time of pore liquid, and finally the following conclusions were reached: (i) pores filled with the pore water are slitlike rather than cylindrical in shape; (ii) the dimensions of pores are ~3 and 2 nm for the raw Yallourn and Beulah Zap, respectively; (iii) the pore dimension decreases with the content of pore water roughly in a linear manner.

02/01259 Evaluation of the industrial suitability of coal fields in the Jastrzebska Coal Company Nawrat, S. and Smuda, A. Zesz. Nauk. Politech. S/ask., Gorn., 2000, 246, (4), 251-263. (In Polish) General characteristics of coal resources within the range of coal mines gathered in JSW SA Poland are presented. Present and future resources and the assessment of their quality are discussed. Analysis of available resources of JSW SA coal mines makes possible to assess the lifetime of each coal mines and gives a base for other detailed economical analyses.

02/01260 Extraction of coal below 350°C in flowing nonpolar solvent Miura, K. et al. Fuel, 2001, 80, (11), 1573-1582. Eight Argonne premium coals and an Australian brown coal (Morwell) were extracted in a flowing stream of either tetralin or 1-methylnaphthalene under 10 MPa at 200--400°C to examine the dissolution/ depolymerization behaviour of coal in liquid phase. The flowing solvent was used to minimize the secondary interaction between the extract and the macromolecular network of coal. Four bituminous coals were extracted with negligible decomposition below 350°C. The extract yield reached 65-80% for the bituminous coals at 350°C, and the extract was separated into about 25-40% of soluble fraction at room temperature (soluble) and about 40% of solid precipitated at room temperature (deposit). The detailed analyses of the soluble, the deposit and the residue through ultimate analysis, ]3C solid NMR, GPC, and matrixassisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) enabled to examine the structure of Pittsburgh #8 (PITT) in detail. The raw PITT coal was found to contain small molecules (Mw = 130-600) and large molecules Mw = 1300--3500) in its network. The soluble consisted of only small molecules, but both small and large molecules were involved in the deposit and the residue. The extraction method employed in this work was found to be effective to separate coal into different molecule size fractions without decomposition for bituminous coals. The soluble, being obtained in 2ff~0% yield and consisting of molecules smaller than 600 of Mw, and

Fuel and Energy Abstracts

May 2002

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