Volume 61, Nº 10 (2018)
- Ano: 2018
- Artigos: 8
- URL: https://journals.rcsi.science/1068-364X/issue/view/13975
Coal
Petrographic Analysis of >1.40-g/cm3 Coal Fractions
Resumo
The petrographic composition of fractions of density 1.40–1.45 g/cm3 from coal of different metamorphic development is studied. In terms of their petrographic composition, these fractions are mainly of two-component type, and the inertinite group is dominant. Visual analysis of polished samples reveals their maceral composition: the vitrinite group is represented mainly by telocollinite, desmocollinite, and telinite. The macerals of the inertinite group are fusinite, semifusinite, and sclerotinite. In some samples, fusinite with a somewhat intact cell structure is observed.
Coke
Economic Benefits from Optimal Drum Treatment of Blast-Furnace Coke
Resumo
Practically all steel plants rely on a narrow range of options in improving the quality of blast-furnace coke: adjusting the properties of the coal batch and improving the technology for coke production. At the same time, the preliminary crushing of coke not only stabilizes its properties but also significantly enhances them, so that the specified composition and strength may be obtained. As an example, the efficiency of coke crushing is optimized in specific conditions. The calculations laid out in the example should facilitate the adoption of this approach.
Chemistry
Study on Reaction Behavior of Tar from Lignite Pyrolysis
Resumo
Coal tar from lignite pyrolysis is prone to react during the transportation, heating and upgrading processing, which significantly affects the yield and quality of coal tar. From the view of industry, it is of significance to study the coal tar reactivity during heating. In this paper, the effects of reaction temperature and retention time on reaction of tar were studied. It is found that the influence of the heating temperature on the tar reaction is more significant than the heating time. With the increase of reaction temperature, the yield of coke and gas significantly increased. The content of light and heavy components in the reacted tar is decreased with the increase of reaction temperature. The composition of light tar obtained from tar reaction was also affected by the reaction temperature and retention time. The content of aliphatics, aromatics and phenolics decreased with the increase of temperature. However, when the retention time was 10 s, the content of phenolic compounds increased first and then decreased with the increase of temperature, the highest content at 550°C is 3.4%, and reaches the lowest at 750°C is 0%.
Tar-Based Modification of Carbon Mass for Self-Igniting Anodes
Resumo
The modification of carbon mass for self-igniting anodes is considered. The mass consists of a binder–filler system. The modifier employed is the phenolic fraction of coal tar. The filler is anthracite treated at 1800°C. The binder is moderate-temperature electrode pitch (grade B). Research shows that cocarbonization of the modifier in the binder–filler system on heating may consist of two processes: 1) before transition of the pitch to a viscofluid state, the additive facilitates mutual approach of its macromolecules and expands the temperature range of nucleation of graphite-like structures; 2) on account of adhesive forces, the phenolic fraction is attached to the filler (thermoanthracite) surface. That, in turn, should intensify the wetting, adsorption, adhesion, and sintering capacity of the electrode pitch (binder).
Influence of Chemical Modification on the Structure, Composition, and Properties of Lignite Humic Acids
Resumo
The influence of chemical modification on the functional–group composition of humic acids derived from Tisul’sk lignite (Kansko-Achinsk Basin) is studied. The structural changes of the humic acids as a result of destructive alkylation of n-butanol and oxidation of hydrogen peroxide are compared, by means of IR, Raman, ESR, and NMR spectroscopy. Alkylation of the humic acids changes the composition and content of the aliphatic fragments in their structure. Oxidation by hydrogen peroxide increases the content of acid-bearing groups.
Comparison of the Composition of Gasoline Fractions Obtained by Semicoking of Kukersite Oil Shale in Kiviter and Petroter Systems
Resumo
Industrial gasoline fractions of tar obtained by semicoking of kukersite shale in the Kiviter gas generator and in a Petroter system with solid-state heating are analyzed in detail by chromatography and mass spectrometry. On that basis, the content of groups and types of compounds in the samples may be compared. The gasoline fraction from the Petroter system contains about twice as many aromatic hydrocarbons (28), four times as many dienes (9), and a third of the paraffins (9.5) as in the fraction from the Kiviter gas generator.
Industrial Safety
Mechanical and Thermal Sensitivity of Mixtures of Ammonium Nitrate with Combustible Hydrocarbons
Resumo
Two explosive compositions ISU-4K and ISU-5R based on ammonium nitrate with added coke, diesel fuel, and rubber crumbs are tested so as to establish their sensitivity to mechanical and thermal perturbations. The flash point corresponding to 60-s delay is established. The kinetic parameters of thermal disintegration of the explosives are determined. The information obtained may be used in compiling standard documents (of GOST, OST, TU, VTU, and other types) and writing industrial regulations.