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12. Relationships among coking coals and related cokes characteristics: a statistical evaluation

Creator:
Serenčíšová, Jana, Zdeněk Klika, Ivan Kolomazník, Lucie Bartoňová, and Baran, Pavel
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
uhlí, koks, coal, coke, CRI, CSR, multivariate statistics, 7, and 551
Language:
English
Description:
From 61 coking coals, 36 coal blends were prepared. Using a pilot coke oven, cokes were prepared from both 61 coking coals (Type I cokes) and 36 coal blends (Type II cokes). Coals were characterized by 14 coal characteristics and cokes by Coke Reactivity Index CRI and Coke Strength after Reaction with CO2 CSR. For the study of mutual statistic relationships among experimentally determined characteristics of coals and cokes, the Factor (FA) and Regression Analyses (RA) were used. FA distributed characteristics of coals and Type I cokes into 4 factors while characteristics of coal blends and Type II cokes were distributed into 7 factors. In case of pure coals and Type I cokes, strong relationships with high correlation coefficients (R > 0.60 ) were more abundant than in case of coal blends and Type II cokes. FA was used for the selection of coal characteristics that influence the coke quality the most significantly. These characteristics were then recalculated by RA for the predictions of CRI/CSR of Type I cokes. Predictions of CRI/CSR of Type II cokes were calculated from coal blends by the same procedure. The comparison of the predicted and experimentally determined CRI and CSR indexes showed much more reliable prediction of CRI/CSR indexes calculated from coals than calculated from coal blends. This study also explains the dominant reasons of this observation., Jana Serenčíšová, Zdeněk Klika, Ivan Kolomazník, Lucie Bartoňová and Pavel Baran., and Obsahuje bibliografii
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

14. Temperature conditions of coal formation

Creator:
Pavel Straka and Náhunková, Jana
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, uhlí, coal, aluminum complexes, NMR, thermal analysis, 7, and 551
Language:
English
Description:
In the frame of advanced studies of coal structure the temperature conditions of coal origin were investigated through thermal stability of aluminum complexes in coal substance. These compounds were discovered by solid-state nuclear magnetic resonance measurements of 27Al as a part of coal substance closely bonded to organic mass of coal. In obtained spectra, Al-hexaphenoxide and Al-tetrahydroxy-diphenoxide complexes were identified. These complexes were further prepared and their thermal stability tested by thermal analysis method. It was found that a) they can originate under room temperature and atmospheric pressure and b) they are thermally stable only up to approximately 85 or 95 °C. As both Al-hexaphenoxide and Al-tetrahydroxy-diphenoxide complexes are the integrated constituents of coal substance it can be deduced that, in the beginning, coal was formed under very mild thermal conditions. As investigated materials, coals and clays from the Czech basins and gagatite from Poland were measured., Pavel Straka and Jana Náhunková., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

15. The evaluation of chars reactivity using thermogravimetry and multivariate statistical method

Creator:
Minkina, Mariusz, Zajusz-Zubek, Elwira, and Mianowski, Andrzej
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, uhlí, termická analýza, coal, thermal analysis, chars, canonical correlation analysis, reactivity, 7, and 551
Language:
English
Description:
The reactivity of a char depends very on the parent coal. Much information about correlation between properties of coal and reactivity of chars is lost by using only standard methods for a large dataset evaluation. In this research a set of 8 coals has been investigated by thermal analysis and reactivity of obtained chars was analyzed as a function of properties of parent coal properties using Canonical correlation analysis. The reactivity of chars was determined by thermogravimetric analysis of nonisothermal combustion in oxygen. It can be stated that methods of multivariate data analysis are useful tools for the interpretation of coal chars reactivity data., Mariusz Minkina, Elwira Zajusz-Zubek and Andrzej Mianowski., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

18. Utilization of coal in the czech Republic review overlook

Creator:
Václav Roubíček, Pavel Kolat, and Jaroslav Buchtele
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, výroba elektrické energie, uhlí, hornictví, power generation, coal, mining, GHG emissions, 7, and 551
Language:
English
Description:
Review article presents utilisation of coal in industry, coal in power generation, gas production, Czech energy policy and outlook and application of clean coal technology in the Czech power stations. The further exploitation and utilisation of Czech coal resources requires the implementation of development programme aimed at the application of the new, economically effective technologies, of coal mining, utilisation, gasification. Emissions of GHG in CR., Václav Roubíček, Pavel Kolat and Jaroslav Buchtele., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

19. VLF mapping and resistivity imaging of contaminated quaternary formations near to "Panewniki" coal waste disposal (Southern Poland)

Creator:
Kowalska, Arlena, Kondracka, Marta, and Mendecki, Maciej Jan
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, uhlí, doly, coal, mines, electrical resistivity imaging, electrical conductivity, VLF method, groundwater contamination, coal waste dump, 7, and 551
Language:
English
Description:
The purpose of this work was to detect groundwater pollution and to identify the conditions of soil and groundwater near the coal waste disposal "Panewniki" Halemba-Wirek Coal Mine using geoelectrical measurements. The firs t applied method was the VLF (Very Low Frequency) technique. This method, using military signals, allowed to perform the in-phase and the quadrature maps. Data were collected from four study areas located near the coal waste dump. Observed anomalies on both maps for each area showed places with different conductivity al lowed to detect the contaminated and uncontaminated zones. The VLF survey indicated that the contamination occurs in the eastern part of study area and is characterized by positive values of both measured electrical fields (the in-phase and the quadrature components). After preliminary contaminated zones were recognized using VLF met hod, an electrical imaging meth od was applied. Two electrical imaging profiles were carried out near the waste dump. The measurements a llowed to create the geoele ctrical model of surrounding area and to investigate the leachate plume. The electrical imaging showed that the greatest pollution occur in the area immediately adjacent to the coal waste what is confirmed by VL F survey. Based on the geological and ge ophysical knowledge from archives and on present researches, the contaminated aquifer with electrical resistivity of 5 to 15 Ω m deposited at depths of 3 to 7 m was found., Arlena Kowalska, Marta Kondracka and Maciej Jan Mendecki., and Obsahuje bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public