ISSN 1068364X, Coke and Chemistry, 2011, Vol. 54, No. 11, pp. 391–397. © Allerton Press, Inc., 2011. Original Russian Text © V.P. Ivanov, I.S. Bondarenko, S.A. Pantykin, 2011, published in Koks i Khimiya, 2011, No. 11, pp. 8–15.
COAL
Assessing the Value of Coking Coal in Terms of Coking Properties and Genetic Compatibility V. P. Ivanova, I. S. Bondarenkoa, and S. A. Pantykinb a
Kuznetsk Center, Eastern CoalChemistry Institute, Novokuznetsk, Russia email:
[email protected] bOOO Vostochnyi NauchnoInzhenernyi Tsentr Ugol’, Novokuznetsk, Russia email:
[email protected] Received September 19, 2011
Abstract—On the basis of new research by the Sapozhnikov method (State Standard GOST 1186), as well as data on the yield of volatiles (State Standard GOST 6382) and the petrological characteristics, new defini tions are proposed in assessing the clinkering and coking of coal for bed coking. Under that proposal, clin kering properties and coking properties would refer exclusively to samples of individual coals; clinkering abil ity and coking ability would apply to coal blends and coal batch. As is shown, data for the petrographic com position and vitrinite reflection coefficient permit assessment of the genetic compatibility of coal, which may be used as a behavioral characteristic of coal in batch for blastfurnace coke production. DOI: 10.3103/S1068364X11110056
The technological value of coal for the production of blastfurnace coke may be assessed in part on the basis of its coking properties, determined by compar ing the coal components within the batch [1, 2]. How ever, this approach does not fully reveal the coking ability of the coal, since standardization of coal suit able for bed coking is required, and the rank assign ment of coal (State Standard GOST 25543–88) is independent of its coking properties. We know that the characteristics employed in rank assignment (Ro, ΣLC, Vdaf, y) vary within a single rank of coal, and the coal within the rank may differ signif icantly in coking properties. In practice, the rank composition of coal batch is unchanged, but its coking properties will differ, since coal supplies with the same rank assignment will not be fully interchangeable within the batch. The possibility of subjective adjustment of the ranks was noted in [3]. Therefore, the technology value of coal—and especially its coking properties—cannot be established on the basis of its rank. We know that coal consists of a mixture of natural organic components (vitrinite, inertinite, semivitrin ite, liptinite) and inorganic components (quartz, sul fides, clay, carbonates) with different physicochemi cal, technological, and mechanical properties. In other words, coal is a complex material with an inho mogeneous composition. It may be characterized as a natural composite and as a firstorder mixture. Accordingly, coal batch may be regarded as an arti ficial composite and as a secondorder mixture, since it consists of a set of firstorder mixtures, as illustrated in the diagram.
If we consider coal as a complex material of first order and coal blends (coal batches) as secondorder materials, we may readily determine the main factors responsible for their inhomogeneity. In natural com posites, the inhomogeneity will be mainly due to the petrographic composition of the coal, which may be characterized by a particular metamorphic stage and level of reduction. In artificial composites, the inho mogeneity will be due to a set of genetic factors: the metamorphic stage, the petrographic composition, and the level of reduction. Hence, it is important to determine the properties of simple coal; for coal batch, by contrast, it is impor tant to understand its behavior—that is, the interac tion of the properties of the coal components in spec ified conditions. Correspondingly, distinct terms are required to establish the properties and behavior of the coal. In the first case, we may speak of the clinkering properties and coking properties of the coal; in the second case, we may speak of the clinkering ability and coking ability of a coal blend (coal batch), which depend on the interaction of the properties of the indi vidual components. We now consider this distinction in more detail. Clinkering is the process by which powders and finely disperse materials combine to form larger pieces at high temperatures, according to [4]. Clinkering coal, when in the form of small grains, is able to combine into larger pieces at high temperatures, through the plastic phase, again according to the definition in [4]. The clinkering ability of coal is its ability to pass to the plastic state on heating in the absence of air, with the
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IVANOV et al. Coal
Coal batch (coal blend)
A natural composite and a firstorder mixture
An artificial composite and a secondorder mixture
Properties of coal
Behavior of coal system
Clinkering properties and coking properties of coal
Clinkering ability and coking ability of coal batch
Characterizing coal and coal batch.
formation of a more or less bound nonvolatile residue, according to [5]. The following refinement was offered in [6]: “The clinkering ability of coal or a coal blend that softens on pyrolysis is the ability of the residual granular material to form a carbon mass of some strength.” In other words, this conception of the clinkering ability incor porates both the clinkering properties of the coal com ponents and their behavior. However, this statement is also offered in [6]: “The clinkering ability reflects the clinkering properties of the coal, since more lean impurity may be added to coal with greater clinkering ability.” In this approach, in other words, the clinker ing properties are more important as an index of the coal’s behavior than as a measure of the coal’s ability to manifest such properties. It is important to note that, when we speak of coal grains and of petrographic components, we are employing two very different concepts. The indiscrim inate use of these terms is a methodological error, in our view. We know that coal characterized by different petrographic composition but the same grain size will have different clinkering properties—for example, different plasticlayer thickness and different free swelling. In the clinkering of petrographic components, the vitrinite in an individual coal will first bind the inert components present in the closest concretions and then other inert components within the coal grain. In the presence of excess plastic mass, it will begin to make contact with other coal grains. Therefore, the coal grain must be regarded as an aggregate petrological coal particle. At the same time, if we consider the clinkering abil ity as the coal’s ability to remain in a plastic state for a certain time, this will be identical to the clinkering properties in the case of an individual coal compo nent, which consists of isometamorphic petrographi
cally uniform coal particles (for any uniform crushed coal mass). For a coal blend, the coal’s ability to remain in a plastic state for a certain time will be determined by the contact zone between clinkering grains of different petrographic composition and metamorphic stage, which will depend on their set of rheological proper ties [7]. In turn, the clinkering ability of coal corresponds to the intermediate stage in the transformation of coal to coke on heating. Consequently, the ability of the coal to pass to the plastic state, with the subsequent forma tion of large pieces, will determine its capacity for coke formation. The coking ability was characterized in two ways in [4]: as the coal’s ability to be transformed to coke on heating to 950–1050°C and in the absence of air; and as the coal’s ability to form highquality coke with other coal components. Coking coal was defined as coal from which coke may be obtained by special treatment. Coking coal was defined differently in [6]: as the ability of a mixture of coke grains to produce a solid res idue that consists of pieces of specified size and strength in specified conditions. This definition should also mention that mineral impurities partici pate in the process. “The coking process consists of a complex system of physicomechanical transformations of the coal on account of thermal destruction and condensation,” according to [7]. In addition, the coking of coal is associated with “the clinkering strength of the coal components in the plastic state and the development of internal stress in the solidified coke mass.” The current interpretation of coking ability includes phenomena such as progressive polyconden sation, ordering of the carbon structure, and change in mass of the disperse coal mass under the action of pro longed forced clinkering in continuous bed heating. In our view, any discussion of coke formation must focus on the ability of the coal to form a coke body and not simply a solid residue. For a coal batch (coal blend), coke formation will be due to the presence of coal capable of forming a coke body with specified parameters (in other words, coke of satisfactory qual ity). In that case, we may distinguish between coal with cokeforming properties and coal that is only capable of forming a solid residue. Hence, for individual coal components, we need to determine the coking properties—that is, its ability to form coke. For coal batch, we need to determine the coking ability of the coal components—that is, their combined ability to form a coke body. This entails optimizing the coal batch within the limits of the spec ified coal parameters. Experience shows that coal batch consisting of concentrates that are coal blends may be optimized COKE AND CHEMISTRY
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when their coking properties resemble those of uni form coal. Is there a relationship between the clinkering prop erties and coking properties of coal? Is there such a relationship for coal blends? There is no clear and direct relation between the clinkering properties of the coal and the properties of metallurgical coke, accord ing to [6]. In other words, there is no direct relation between the clinkering properties of the coal and the strength of the porous coke body. The strength of the coke body consists of the clinkering strength of the coal grains or petrographic components, the cohesive strength of the coke, and the coke determined by the coke porosity [6]. In other words, we need information regarding the clinkering of the coal, in order to determine its capac ity for coke formation. In practice, this information is embodied in the distinction between coking coal and additives. This terminology allows us to distinguish between coal capable of forming coke in individual coking and only in blends, since it indicates the tech nological characteristics of the coal and its place in the blend. Thus, we suggest that the customary imprecision in terminology interferes with correct assessment of coal’s properties and especially of the likely product quality. Therefore, we propose a clear distinction between the clinkering properties of individual coal components and the clinkering ability of coal blends. Likewise, we distinguish between the coking properties of individual coal components and the coking ability of coal blends. Various methods may be used to assess the behavior of coal and coal blends on heating, clinkering, and coking. “Special direct methods are required for direct judgments regarding the clinkering properties of coal,” according to [5]; the same is true regarding the coking properties of coal. The most widespread international methods assess the clinkering properties (Roga method, freeswelling index, Gieseler method), Audibert–Arnu dilatation, and coking properties (Gray–King method) of coal. In Russia and the Commonwealth of Independent States, a plastometric method (the Sapozhnikov method) is widely employed. This method character izes the coal’s ability to form a plastic layer, its swell ing, and its shrinkage. As already noted, determination of the coking properties of coal on the basis of blending permits assessment of its behavior on coking with other coals. The Nikolaev method permits determination of its clinkering ability. Another option is regression analysis of the chemicopetrographic and plastometric charac teristics of individual coal components [2, 8]. This method provides a good complement to the Nikolaev method (State Standard GOST 9521) when semiin dustrial coking is impossible. COKE AND CHEMISTRY
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Researchers also use the Simonis method, the Institute of Mining method, and tests of coal batch to identify the properties of individual coal components that affect the thermodynamic, physicomechanical, and mechanicochemical properties of coke, as well as its crack susceptibility. These findings indirectly char acterize the coking properties of the coal. In assessing coal from individual geological regions, it is found that the given methods do not pro vide reliable information regarding the technological potential of coal. This is especially true for coal whose rank assignment is unclear (coals of borderline rank) and for which assessment of the coking properties is difficult. Note that this problem always appears in establishing the available reserves of such coal and in determining their applicability in bed coking. Conse quently, there is inconsistency between the industrial and genetic potential of certain groups of Kuznetsk Basin coal and their role and significance in Russia’s coke industry. In this context, we consider the Sapozhnikov method, whose informative potential has not been fully appreciated. In terms of the clinkering properties of an individual coal component, this method indi cates the impossibility of further transformation of the coal in the absence of a plastic layer. On that basis, the potential of the method may be further explored. A new method arising out of this research permits assess ment of the coking properties of individual coal com ponents (in other words, their capacity for coke for mation) [8]. On the basis of measured parameters (determined in accordance with State Standards GOST 1186 and GOST 6382)—the coal’s plasticlayer thickness, its yield of volatiles, and the yield of semicoke (plasto metric beads)—the following technological parame ters may be determined from the formulas of [9]: the yield of plastic mass (Vpm), the gasliberation coeffi cient of the coal (Kgl), the pyrolytic coefficient (Kp), the semicoke yield coefficient (Ksc), and the coke yield coefficient (Kco). The method in [9] involves discrete assessment of coke formation in terms of numerical coefficients (the gasliberation coefficient, the pyrolytic coefficient, and the semicoke yield coefficient), which represent individual aspects of the thermal transformation from coal to coke. On the basis of measured values of Vpm, d d the yield of volatile V c , and the yield of semicoke V sc , we may determine the coking properties of the coal, in the form Kco. In physical terms, Kco assesses the coking proper ties of the coal on the basis of the calculated volume of the plastic mass and the residual products that are con verted to semicoke, which is responsible for the forma tion of the coke body. In Kuznetsk Basin coal of different rank (Table 1), we see different values of Vpm, Kgl, Kp, Ksc, and Kco,
GZh (2GZh) GZh (2GZh) GZh (2GZh) GZh (2GZh) GZh (2GZh)
Bolshevik mine, bed 29
Bolshevik mine, bed 29
Raspadskaya mine, bed 11
bed 10
bed 77a
7.9
Zh (2Zh) Zh (2Zh) Zh (2Zh) K (K1) K (1K)
ChertinskayaYuzhnaya mine, bed 6
Shurapskii field, Kemerovskii bed
Osinnikovskaya mine, commercial
Taibinskii mine, Pr. Vnutrennogo III bed
Ol’zherasskii mine, commercial
COKE AND CHEMISTRY
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K (2K) K (2K) K (2K)
Edel’veis mine, IV Vnutrennii bed
Sarbalinskii field, bed 1
No. 11
Neryungrinsk coal
9.5
9.0
4.8
4.6
Krasnogorskaya mine, VI Vnutrennii bed
K (1K)
4.8
Novobachatskii mine, Vnutrennii bed K (1K)
4.4
7.8
5.8
8.5
12.0
9.2
8.2
9.8
8.9
9.8
7.9
4.3
8.6
4.9
6.4
9.0
19.6
19.7
22.1
23.5
25.0
25.8
28.0
32.5
32.2
36.5
38.0
38.9
31.3
38.0
39.4
37.5
39.0
39.0
38.7
38.1
42.9
35.8
A d, % V daf, %
ChertinskayaKoksovaya mine, com Zh (2Zh) mercial
Zh (2Zh)
GZhO (2GZhO)
Bolshevik mine, bed 30
Raspadskaya mine, bed 77a
GZh (1GZh)
Yubileinaya mine, commercial
Zh (1Zh)
G(2)
Novokazanskii min, bed 48
Shurapskii field, Kemerovskii bed
G(1G)
Rank
Taibinskii mine, commercial
Source of coal
Table 1. Data for coal
73
70
58
61
64
56
57
84
59
84
82
83
57
82
84
82
81
84
81
81
85
70
Vt
20
23
37
34
31
40
38
12
34
10
9
12
37
11
9
11
12
13
14
14
3
25
1.52
1.47
1.31
1.22
1.12
1.08
1.0
0.99
0.98
0.86
0.86
0.86
0.97
0.87
0.86
0.86
0.83
0.82
0.82
0.78
0.72
0.77
14
13
17
16
16
13
17
29
20
32
29
26
15
24
21
18
21
18
13
18
14
11
14
13
17
16
16
13
17
29
20
32
29
26
15
24
21
18
21
18
13
18
14
11
ΣLC, % Ro, % y, mm V pm, % K gp
0.60
0.81
0.79
0.63
0.51
0.60
0.52
0.47
0.52
0.40
0.33
0.41
0.27
0.30
K co
1.24
0.01
0.04
0.00
0.03
0.16
0.02
0.22
0.32
0.36
0.24
0.34
0.41
0.29
0.41
0.30
K gc
0.09
0.17
0.84
0.36
0.40
0.89 –0.08
0.77
0.69
0.57 –0.10
0.63 –0.06
1.00 1.23 0.86
0.97
1.06 0.81
0.93 0.86
0.85 0.85
0.70 0.46
0.80 0.56
1.18 0.90 0.89
0.80 0.65
1.13 0.81
1.08 0.82
0.89 0.79
0.66 0.53
0.84 0.82
0.73 0.83
0.65 0.83
0.73 0.76
0.58 0.74
0.46 0.74
0.59 0.70
0.41 0.68
0.41 0.60
Kp
14
13
18
15
14
9
14
34
16
36
31
23
10
20
15
12
15
10
6
11
6
5
1.0
0.93
0.92
0.88
0.86
0.78
0.81
1.0
0.85
0.93
0.90
0.92
0.76
0.89
0.83
0.78
0.81
0.76
0.67
0.74
0.62
0.62
APM, % TVC
0.93
0.84
0.89
0.77
0.69
0.57
0.63
1.00
0.68
0.91
0.89
0.71
0.58
0.68
0.58
0.53
0.59
0.45
0.37
0.46
0.33
0.34
TUC
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7.8 9.5 8.1
7.7 6.1
KS (1KS) KS (1KS) KS (1KS) KS (1KS)
KS (2KS) SS
Krasnyi Brod mine, commercial
Yuzhnaya mine, commercial
Tomusinskii mine
Mezhdurechenskii mine, commercial KS (1KS) KS (2KS)
Novobachatskii mine, commercial
Lenin mine, bed 16
Sarbalinskii field, bed 3
Anzherskaya mine, commercial
Mezhdurechenskii mine, commercial TS
17.9
16.3
18.2
18.7
22.2
20.8
18.3
20.2
18.2
25.2
24.2
26.2
18.7
18.0
18.8
23.0
26.3
26.5
52
30
55
52
58
49
39
42
42
40
29
28
69
68
41
45
50
38
Vt
42
64
38
41
36
45
57
53
53
55
66
66
26
25
51
47
43
55
1.48
1.27
1.51
1.43
1.34
1.28
1.27
1.19
1.18
1.03
1.00
1.01
1.52
1.49
1.31
1.10
0.98
0.93
5
4
8
6
9
9
9
7
6
8
6
9
11
12
10
10
11
10
5
4
8
6
9
9
9
7
6
8
6
9
11
12
10
10
11
10
ΣLC, % Ro, % y, mm V pm, %
1.15
1.16
0.51
0.42
0.51
0.02
K gp
0.25
0.08
0.93
0.91
0.81
0.47
0.40
0.60
0.35 –0.42
0.63
0.47
0.59
0.63
0.67 –0.13
0.47
0.48
0.43 –0.08
0.35 –0.52
0.46 –0.51
0.83
0.93
0.76
0.65
0.60
0.52
Kp
K gc
0.01
0.42
0.35
0.38
0.50
0.31
0.35
0.25
0.31 –0.74
0.55
0.41
0.50
0.54 –0.07
0.58 –0.71
0.40 –0.15
0.42 –0.34
0.35 –0.43
0.29 –0.80
0.37 –0.88
0.72
0.81
0.66 –0.15
0.55 –0.13
0.49
0.42 –0.40
K co
2
1
5
3
5
6
6
3
3
3
2
4
11
9
8
6
7
5
0.75
0.63
0.82
0.75
0.82
0.75
0.71
0.37
0.64
0.65
0.58
0.63
0.91
0.91
0.74
0.70
0.70
0.64
0.35
0.31
0.55
0.41
0.48
0.54
0.58
0.40
0.42
0.35
0.29
0.37
0.72
0.81
0.66
0.55
0.49
0.42
APM, % TVC TUC
Note: Here V pm is the yield of plastic mass, %; K p is the pyrolytic coefficient; K gp is the genetic preference; K co is the coke yield coefficient; K gc is the geneticcompatibility coefficient (for a blend); APM is the active plastic mass, %; TVC is the technological value coefficient; and TUC is the technological utility coefficient.
7.7
8.7
5.0
9.6
5.9
KSN
Shurapskii field, Volkovskii bed
6.1
6.3
KSN
KSN
Shurapskii field, Volkovskii bed
5.9
5.4
9.2
11.0
9.2
6.6
A d, % V daf, %
Shurapskii field, Podvolkovskii bed
OS (1OS)
KO (2KO)
AnzherskayaYuzhnaya mine, com mercial
Sarbalinskii field, bed 3a
KO (1KO)
Novobachatskii mine, commercial
OS (1OS)
KO (1KO)
Shurapskii field, Kemerovskii bed
Sarbalinskii field, bed 1
KO (1KO)
Rank
Ol’zherasskii mine, commercial
Source of coal
Table 1. (Contd.)
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Table 2. Correlation of coal characteristics and classification parameters Characteristics Ro Vt ΣLC Vdaf y
V pm
K gl
Kp
K sc
K co
K gp
K gc
0.83 –0.61 0.67 –0.88 –0.61
–0.52 0.71 –0.67 0.65 1.00
0.20 0.35 –0.27 –0.05 0.70
0.92 –0.70 0.75 0.99 –0.61
0.43 0.17 –0.08 –0.30 0.48
0.28 0.69 –0.65 0.04 0.36
0.10 0.72 –0.72 0.20 0.17
with different variation within and among ranks, according to calculations by the formulas in [9]. Information regarding the coking properties of coal is insufficient to form a complete idea regarding its technological potential, since the coal is blended with other coal components in a coal batch, from which blastfurnace coke is produced. Therefore, we need to know the genetic potential of each individual coal component, which will determine its behavior in the blend. In other words, we need to know its genetic compatibility Kgc. The genetic compatibility was expressed as the genetic preference of the coal in [10]. It essentially reflects the natural inertness of the coal, as seen in bed coking in the predominance not only of the inert com ponent in the coal’s organic mass but also of the accom panying mineral impurities. All the coal components participate in clinkering and coke formation: vitrinite (Vt), inertinite (I), semivitrinite (Sv), liptinite (L), and mineral impurities (M). On heating, these components will behave differently. The proportions of these com ponents in the coal with determine the transformation and quality of the newly formed material. The petrographic microcomponents may be divided into three groups: those that are actively transformed; those that are inertly transformed; and those that disin tegrate. The active group includes vitrinite, liptinite, and one third of the semivitrinite (Vt + L + 1/3Sv); the inert group includes inertinite and two thirds of the semivitrinite (I + 2/3Sv); and the disintegrating group consists of mineral impurities (M), represented by clay (Mgl), sulfide (Ms), carbonate (Mk), and silicate (Mkr) impurities. The genetic preference Kgp is determined by the principle in [10]. In the present case, the formula appears as follows Kgp = RoΣCCf (1) Here the sum ΣCCf corresponding to the proportion (%) of free clinkering components is determined from the formula ΣCCf = ΣCC – ΣLC/ΣCC, where ΣCC = Vt + L + 1/3Sv and ΣLC = I + 2/3Sv. The content of organic macerals is determined when the coal has mineral components. In a coal blend (coal batch), two factors interact: the coal’s capacity for coking (Kco) and its genetic preference (Kgp), which corresponds to the natural potential responsible for the coal’s behavior in the
blend. The technological potential of the blend will be characterized by the compatibility of the individual coal components on coking (Table 1). The genetic compatibility Kgc is calculated as Kgc = Kgp – Kco, (2) gc Here K may take positive or negative values: positive values indicate donor properties of the coal; negative values indicate acceptor properties in relation to the other batch components. If Kgc is zero, the coal is completely selfsufficient in coking. We conclude from correlation analysis of the charac teristics employed (Vpm, Kp, Ksc, Kco, Kgp, Kgc with the classification parameters in State Standard GOST 25543–88 (Ro, ΣLC, Vdaf, y) and the vitrinite content Vt in the coal (Table 2) that the plasticmass volume Vpm depends on Vt (r = 0.61) and has a stronger negative relation with the fusinized components (r = –0.67). This confirms the observations in [2]. At the same time, the influence of metamorphic development on Vpm is more pronounced in terms of Vdaf (r = 0.59) than Ro. This is also readily comprehensible. The strongest relation is between the characteris tics Ro, Vt, ΣLC, V daf, and y and the parameters Kgl and Ksc. This shows that the genetic and technological parameters of the coal have a strong but unequal influ ence on coke formation (r = 0.52–1.0) and the prod uct quality (r = 0.61–0.99). There is a natural relation between Kp and the plasticlayer thickness (r = 0.70) and between the indices Kgp and Kgc and the petro graphic composition of the coal (r = 0.65–0.72). The relation between Kco and the classification parameters Ro, ΣLC, Vdaf, and y requires separate con sideration. Such a relation is only seen with Ro and y (r = 0.43 and 0.48, respectively). Japanese researchers have established a relation between the hardness of semicoke and coke and the metamorphic stage, as noted in [6]. However, “in a series of clinkering coals, no clear relation was observed between the hardness of the coke and the plasticlayer thickness in the initial coal” [6]. These observations probably reflect a weak depen dence of Kco on Ro and y. This corresponds to the pres ence of only traces of the initial coal structure in the coke, whereas whole fragments of coal microstructure are retained in the semicoke. Thus, Kco essentially assesses the technological value of an individual coal component for blastfur nace coke production, while Kgc assesses the techno COKE AND CHEMISTRY
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ASSESSING THE VALUE OF COKING COAL IN TERMS
logical value of the coal blend. Overall, using these characteristics, we may estimate the coking properties of the coal and the coking ability of the coal blend. The clinkering properties of coal and the clinkering ability of the coal blend may be estimated on the basis of the plasticmass volume V pm and the volume of active plastic mass (APM) APM = V pmKp, (3) p where K is the pyrolytic coefficient of the coal or coal blend. The data in Table 1 indicate that the proposed characteristics permit differentiation of coal samples in terms of clinkering properties and clinkering ability. On the basis of Kco, we may calculate the technological utility coefficient (TUC) of coal in bed coking co
co
TUC = K i K st .
(4)
co
The standard value K st for GZh and Zh coal is cal culated for Osinnikovskaya Zh coal, for which Kco = 0.89 when Kgp = 0.90 [9]. For K and KO coal, the stan co dard value K st is calculated on the basis of Neryungrin skii K coal, with Kco = 0.86 when Kgp = 1.23 (Table 1). There is a correlation (at a level of 0.91) between TUC and the technological value coefficient TVC calcu lated by the method developed at the Eastern Coal Chemistry Institute [1]. In that method, the ratio of TVCi for the coal component to the standard value TVCst for classic coal batch is determined. The high correlation between TVC and TUC confirms the proposed approach to determining the coking properties of coal. The new approach, based on the calculation of Kco and Kgc, may be regarded as a direct method of deter mining the technological value of coal components and assessing their suitability for the production of coke and, in particular, blastfurnace coke. The relevance of our proposal is evident in the light of the definition of the coking ability in State Standard GOST 17070. According to that definition, the coking ability of coal is the ability of ground coal to cake, with the subsequent formation of coke of established size and strength. In other words, nothing is said about the properties of the coal. Likewise, the clinkering proper ties of the coal are characterized as the ability of ground coal to bind inert material, with the formation of a bound nonvolatile residue, in standard conditions. In other words, the focus is on the ability of coal to produce a bound nonvolatile residue; nothing is said about large pieces (in other words, coke). Thus, the proposed approach greatly reduces the subjective element in assessing the coking properties of coal and reveals its natural potential by means of the genetic compatibility. This approach also refines the terminology employed in the analysis and eliminates ambiguous interpretations. Space constraints prevent a discussion regarding the influence of the coal’s mineral content on its cok COKE AND CHEMISTRY
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No. 11
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ing properties and other related observations. These topics will be addressed in future articles. CONCLUSIONS (1) On the basis of research data, we introduce a terminological distinction between the coking proper ties of individual coal components and the coking ability of coal blends. Likewise, we distinguish between the clinkering properties of individual coal components and the clinkering ability of blends. (2) The genetic compatibility of a coal is proposed as a means of characterizing its behavior in coking batch. (3) The coefficients Kco and Kgc characterize the technological value of individual coal components for coke production. The technological utility coefficient TUC permits assessment of their relative suitability for bed coking. REFERENCES 1. Stukov, M.I., Kiselev, B.P., and Kukolev, Ya.B., Meto dika dlya opredeleniya koeffitsientov tekhnologicheskoi tsennosti ugol’nogo syr’ya, ispol’zuemogo v RF dlya proiz vodstva koksa (Procedure for Determining the Techno logical Value Coefficients of Russian Coking Coal), Yekaterinburg: FGUP VUKhIN, 2009. 2. Stankevich, A.S., Stepanov, Yu.V., and Gilyazetdinov, R.R., Predicting Coke Strength on the Basis of the Chemical and Petrographic Parameters of Coal Batch, Koks Khim., 2005, no. 12, pp. 14–21. 3. Ivanov, V.P., Sushkov, R.Yu., Torgunakov, A.A., and Pantykin, S.A., Kuznetsk Basin Coking Coal: Reserves and Technological Value, Koks Khim., 2008, no. 9, pp. 12–18. 4. Bol’shaya sovetskaya entsiklopediya (Comprehensive Soviet Encyclopedia), Moscow: Sovetskaya Entsiklo pediya, 1985. 5. Taits, E.M. and Andreeva, I.A., Methody analiza i ispytaniya uglei (Methods of Coal Analysis and Testing), Moscow: Nedra, 1983. 6. Gryaznov, N.S., Osnovy teorii koksovaniya (Principles of Coking Theory), Moscow: Metallurgiya, 1976. 7. Sukhorukov, V.I., Nauchnye osnovy sovershenstvovaniya tekhniki i tekhnologii proizvodstva koksa (Scientific Principles for Improving Coke Production), Yekaterin burg, 1999. 8. Stankevich, A.S., Gilyazetdinov, R.R., Popova, N.K., and Koshkarov, D.A., Model for Predicting CSR and CRI on the Basis of the Chemical and Petrographic Parameters of Coal Batch, Koks Khim., 2008, no. 9, pp. 37–44. 9. Ivanov, V.P., Sposob pryamogo opredeleniya koksuemosti spekayushchikhsya uglei: NouKhau No. 012.10.A (Direct Method of Determining the Coking Properties of Coal: Practical Report 012.10.A), Novokuznetsk: Depozitarii KROO Kuzbasskaya Inzhenernaya Aka demiya. 10. Ivanov, V.P., Assessing the Technological Value of Coking Coal on the Basis of Genetic and Technological Prefer ences, Koks Khim., 2008, no. 6, pp. 2–9.
