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卷 59, 编号 1 (2016)
- 年: 2016
- 文章: 6
- URL: https://journals.rcsi.science/1068-364X/issue/view/13902
Coal
Properties of Ulug Khem Coal. 1. Types of vitrinite and its associations with microcomponents and minerals
摘要
A review of research on Ulug Khem coal between 1951 and 2013 shows that its properties are largely determined by the plant material from which it is formed. This results in different types of vitrinite in Ulug Khem coal, with differences in clinkering properties, vitrinite reflectance, and yield of volatiles. Detailed petrographic analysis of coal from the Ulug bed in the Mezhegei deposit shows numerous associations of collinite with telinite and of telinite with bitumenite and also numerous associations of vitrinite with minerals. Thanks to the different properties of different types of vitrinite in Ulug Khem coal, the different associations of vitrinite with minerals, and the high ash basicity, coke produced from batch containing Ulug Khem coal will be characterized by low CSR and high CRI. That finding will be discussed in part 2.
1-7
Monitoring the sulfur content of coal
摘要
Information regarding the sulfur content of the coal is required not only in metallurgy but also when burning coal as a fuel. The traditional method of determining the sulfur content of coal is unsuitable for large-scale monitoring of processes because it is laborious and not sufficiently reliable. Nuclear-physics methods are free of those problems. However, satisfactory precision of the results is only possible with relatively constant composition of the coal or when the matrix effect due to fluctuations in the composition is taken into account. In the present work, the composition of coal is studied by correlation and regression analysis of the ash composition in coal from different deposits. The correlation coefficients between the main ash components (Al2O3, SiO2, SO3, CaO, and Fe2O3) are calculated. For the example, of coal from Kazakhstan and the Minusinsk Basin, statistically significant correlations are established between the contents of sulfur and calcium in the coal; the correlation coefficient is 0.75–0.93. No significant and consistent correlations are found between other ash components. These findings permit optimal development of nuclear-physics methods of monitoring the sulfur content of coal—specifically, in improving the precision of the analysis by taking account of the matrix effect due to redistribution of the mineral components.
8-13
Coke
Coke sorting at PAO Zaporozhkoks
摘要
Coke sorting at battery 2A of PAO Zaporozhkoks is analyzed. The transportation and sorting of coke play an important role in determining its granulometric composition and mechanical strength, which, in turn, affect its blast-furnace performance. Recommendations regarding the transportation, sorting, and delivery of commercial coke produced at battery 2A are developed on the basis of research into the properties of coke in different size classes. A system for the simultaneous production of two types of commercial coke—blast-furnace coke and foundry coke—is developed and shown to be effective in practice.
14-22
Chemistry
Modification of polymer–bitumen binder by lignite humic acids
摘要
The positive influence of lignite, charcoal, peat, lignin, and their products on the properties of bitumen and asphalt has been studied extensively. However, nothing is known about the possibility of regulating the performance of bitumen binders and asphalt by means of humic acids extracted from the coal. The present work addresses the use of lignite humic acids to modify polymer–bitumen binder so as to improve its adhesion to acidic mineral filler. The industrial utilization of this applied research calls for additional experiments and the collection of statistical data with an expanded range of lignite humic acids.
23-26
Carbonization of coal pitch with graphite additives
摘要
The influence of added pyrolytic graphite and graphite foam on the crystalline structure of the product formed in the carbonization of moderate-temperature coal pitch at 900°C is investigated by X-ray diffraction analysis. All the additives catalyze the formation of graphite structures in pitch carbonization. However, no direct dependence of the catalytic efficiency on the structure of the carbon additive or its specific surface is observed. In the presence of graphite additives with a specific surface of 4–12 m2/g, more than 20% of a crystalline fraction is formed in the carbonization of pitch. This fraction is highly ordered, with large crystallites. On adding graphite foam, with a high specific surface (110 m2/g) and low packing density (4 g/L), the formation of graphite structures on pitch carbonization is less effective.
27-34
Industrial Safety
Explosion of gas–air mixtures in coke production
摘要
The combustion temperatures of mixtures of 43 highly inflammable and combustible liquids with air are determined at constant volume, at concentrations corresponding to the upper and lower limits on flame propagation in conditions of constant pressure. The results show that these temperatures are approximately the same for different materials. The combustion temperatures of air–vapor mixtures containing a safe (according to handbook data) concentration of retardant may exceed that of the limiting compositions. This raises doubts regarding the validity of handbook data obtained in tests in small chambers. The limiting combustion temperatures of mixtures containing air and the gases and vapor formed in coke production are calculated; these results are required for reliable determination of the retardant concentrations of inert gases.
35-39