Ukrainian Coal Chemistry Institute

Kharkiv, Ukraine

Ukrainian Coal Chemistry Institute

Kharkiv, Ukraine
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Ulanovskiy M.L.,Ukrainian Coal Chemistry Institute
Coke and Chemistry | Year: 2014

Literature analysis shows that the physical significance of the equation from which the index Bb is calculated does not support its description as the ash basicity index. For quantitative assessment of the coal’s mineral component, which has an important influence on the coke quality—specifically, on CSR and CRI—the potential reactivity of coke (CRP) is recommended as a better characterization of the index Bb. Three- and two-parameter versions of the formula for CRP are presented. Models of the relation CRP = f(Ib) are developed for different parameter ranges. It is found that CRP and Ib are not analogs. Therefore, in the development of resources for the production of high-quality coke (in terms of CRP and CRI), these parameters should both be used. © 2014, Allerton Press, Inc.


Miroshnichenko D.V.,Ukrainian Coal Chemistry Institute | Golovko M.B.,Ukrainian Coal Chemistry Institute
Coke and Chemistry | Year: 2014

It is established that the yield of coke and its primary byproducts may be predicted on the basis of elementary and petrographic analysis of the coal (batch) employed. The contribution of individual groups of petrographic components in the coal to the yield of coke and its primary byproducts is determined; coal from the Ukraine, Russia, and the United States is considered. The method developed for predicting the yield of coke and its primary byproducts on the basis of petrographic data is tested at PAO Alchevskkoks and ChAO Makeevkoks. © 2014, Allerton Press, Inc.


Miroshnichenko D.V.,Ukrainian Coal Chemistry Institute | Desna N.A.,Ukrainian Coal Chemistry Institute | Ulanovskiy M.L.,Ukrainian Coal Chemistry Institute
Coke and Chemistry | Year: 2014

In the light of research on the artificial oxidation of coal in the laboratory, earlier results on the natural oxidation of coal in open storage at different coke Ukrainian plants are analyzed. On the basis of the kinetics of coal oxidation in natural conditions, the need to correct existing standards for open storage is evaluated. Since the dependence of the degree of oxidation do on the storage time is sigmoid, the results are analyzed on the basis of the Avrami-Erofeev equation for the kinetics of heterogeneous reactions. The constants of that equation and the rate constants of oxidation are calculated for enriched coal of different ranks (G, Zh, K, and OS) in summer and winter. The influence of the degree of metamorphism on the rate constant of natural oxidation in summer and winter is mathematically described. On the basis of the Avrami-Erofeev equation, limiting open-storage times for the coal are established. The earlier limiting storage times must be corrected. © 2014, Allerton Press, Inc.


Ulanovskiy M.L.,Ukrainian Coal Chemistry Institute
Coke and Chemistry | Year: 2014

In a recent issue of this journal, Malyi described experiments on the modification of DG coal for its subsequent use in coking batch in place of G coal. Analysis of that paper shows that, contrary to Malyi’s statements, there is no shortage of G coal, because the Donets Basin comfortably meets the demand. The model mixture that Malyi uses for modification is complex in composition and contains considerable sulfur. He does not state its properties or the available reserves. Malyi’s ideas regarding the pyrolysis of coal are shown to be very contradictory, while his experimental data prompt skepticism, since the measured ash content, total sulfur content, and clinkering properties of the batch differ from those calculated on the basis of the properties and proportions of the batch components. When using batch that contains modified DG coal in place of G coal, the coke yield is reduced, and its quality is impaired. These findings support the conclusion that Malyi’s research is unnecessary, unpromising, and unworthy of further consideration. © 2014, Allerton Press, Inc.


Ulanovskiy M.L.,Ukrainian Coal Chemistry Institute
Coke and Chemistry | Year: 2014

To standardize the terminology used in technical journals and reference books on coal and coke chemistry, the evolution of certain terms is traced over several decades. Despite standards regarding terms and definitions, nonstandard expressions such as the content of volatiles, calorific value, reflectivity, hot strength, cold strength, and screen composition may be found in published materials. Definitions for quality and property are discussed, as well as two new terms: the potential reactivity of coke and the coking potential. © 2014, Allerton Press, Inc.


Miroshnichenko D.V.,Ukrainian Coal Chemistry Institute
Coke and Chemistry | Year: 2014

The influence of oxidation on the packing density of coal is considered. The packing density of coal concentrates is found to considerably exceed the standardized values. (It may be more than 1.0 t/m3.) That leads to overfilling and possible destruction of the silos in the closed coal store, the bunkers in the dosing section, and the coal towers of the coke batteries. Mathematical analysis of experimental data shows that the elevated packing density is due to significant oxidation of the coal, expressed by the oxidation index, the analytical moisture content, and their ratio to the mean grain diameter of the coal. © 2014 Allerton Press, Inc.


Miroshnichenko D.V.,Ukrainian Coal Chemistry Institute
Coke and Chemistry | Year: 2013

Methods of assessing coal strength are compared on the basis of a literature review. The Hardgrove grindability index (HGI) is the most expedient. There is a close relation between HGI and the coal quality, as well as the power consumed in grinding. Accordingly, the HGI values of coal samples may be used to optimize the crushing of coal as a preliminary to coke production. © 2013 Allerton Press, Inc.


Miroshnichenko D.V.,Ukrainian Coal Chemistry Institute | Drozdnik I.D.,Ukrainian Coal Chemistry Institute | Kaftan Y.S.,Ukrainian Coal Chemistry Institute | Desna N.A.,Ukrainian Coal Chemistry Institute
Coke and Chemistry | Year: 2015

The oxidation of coal from the Pokrovskoe mine consists of stages of initial and intense oxidation in both laboratory and natural conditions. The oxidation temperature has a significant influence on the prop- erties of the coal. In laboratory oxidation, the surface layer of the coal grains is significantly modified, with loss of plastic–viscous properties and reduction in ignition temperature. In addition, at different tempera- tures, different chemical processes will predominate. The oxidation of Pokrovskoe coal is assumed to result predominantly in peroxide formation in natural conditions (from –1 to 22°C), whereas oxidation in a drying chamber (at 140°C) is accompanied by decomposition of the peroxides and the formation of coal–oxygen complexes. Hence, the oxidation of coal is different in laboratory and natural conditions, and correspond- ingly the change in technological properties of the coal will be different. The rate constants, the preexponen- tial factors, and the activation energy for the oxidation of Pokrovskoe coal are calculated by methods devel- oped in physical chemistry. The rate constants of oxidation are k0–1 = 0.0041 × 10–4 and 2.7933 × 10–4 min–1 in natural and laboratory conditions, respectively; the corresponding values of the preexponential factors are k0= 266.0 and 267.8 min–1. In the range 7.3–140°C, the activation energy is Ea = 11.3 kcal/mol. © Allerton Press, Inc., 2015.


Fidchunov A.L.,Ukrainian Coal Chemistry Institute
Coke and Chemistry | Year: 2015

The production of coke with improved reactivity CRI and postreactive strength CSR calls for higher coke-discharge temperatures; that will inevitable be associated with increased emissions of nitrogen oxides (NOx). The influence of the air excess and temperature in the heating channels on the quantity of nitrogen oxides in the system is studied experimentally. The influence of the gas leakage from the coke ovens to the heating system and the purity of the coke-oven gas used for heating on the NOx formation is demonstrated. © 2015, Allerton Press, Inc.


Golovko M.B.,Ukrainian Coal Chemistry Institute
Coke and Chemistry | Year: 2015

To study the relation between the chemical composition and melting point of coal ash, 33 samples of coal from the Western Donets Basin are studied. The melting coefficients proposed previously for ash are analyzed in relation to the chemical composition of Western Donets Basin coal, and the correlations between these coefficients and the melting point of the ash are analyzed. A new ash-melting index Iam is proposed for predicting the flow temperature of ash from Western Donets Basin coal. The corresponding equations may be used to calculate the expected flow temperature of the ash, with sufficient accuracy. The results are also of interest in predicting the reactivity CRI and postreactive strength CSR of coke, since the chemical composition and melting point of the ash largely determine those parameters. © 2015, Allerton Press, Inc.

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