







































 
 

 

6 
© 2025 by the authors; licensee Asian Online Journal Publishing Group 
 

Asian Review of Environmental and Earth Sciences 
Vol. 12, No. 1, 6-13, 2025 

ISSN(E) 2313-8173 / ISSN(P) 2518-0134 
DOI: 10.20448/arees.v12i1.6917 

© 2025 by the authors; licensee Asian Online Journal Publishing Group 

 
 

 
 
 
Unsolved problems in the study of coal formation processes and the manifestation 
of hazardous properties of coal seams 

 
Filatieva Elvira1   

Filatiev Mikhail2   

Antoshchenko Nikolay3   

Fursova Olha4   

Maksyuk Inna5   

 

 
( Corresponding Author) 

 
1Department of Fire Safety, Vladimir Dahl Lugansk State University, Ukraine. 
1Email: elafilatyeva@gmail.com   
2,3,4,5Department of Technosphere Safety, Lugansk State University, Ukraine. 
2Email: Mfilatev@gmail.com   
3Email: antm1949@gmail.com    
4Email: metmashdtu@gmail.com   
5Email: innagroys@gmail.com  

 
Abstract 

To establish problems, the solution of which for a specific stage of coal formation will allow a 
scientifically sound prediction of the occurrence and manifestation of hazardous properties of a 
specific coal seam during mining operations. The methodology is based on modern concepts of 
coal formation processes to confirm or establish the discrepancy between the processes occurring 
at different stages. Hazardous properties of coal seams during mining operations are formed not 
only at the stage of metamorphic transformations, and their occurrence is genetically associated, 
to a large extent, with previous processes of accumulation of the source material, which was 
subjected to successive transformation at the peat, brown coal, coal, or anthracite stages of coal 
formation. Based on the conducted research, scientifically substantiated proposals have been 
developed to clarify the general scheme of coal formation, which significantly changes the 
understanding of the formation of hazardous properties of mine seams and indicates the need to 
solve a number of urgent scientific problems associated with improving the regulatory framework 
for safe mining operations and clarifying geological processes at individual stages of coal 
formation. 

 
Keywords: Coal formation, Hazardous properties, Problems, Processes, Regulatory frameworks, Safety. 

 
Citation | Elvira, F., Mikhail, F., Nikolay, A., Olha, F., & Inna, M. 
(2025). Unsolved problems in the study of coal formation processes 
and the manifestation of hazardous properties of coal seams. Asian 
Review of Environmental and Earth Sciences, 12(1), 6–13. 
10.20448/arees.v12i1.6917 
History:  
Received: 5 May 2025 
Revised: 12 June 2025 
Accepted: 27 June 2025 
Published: 18 July 2025  
Licensed: This work is licensed under a Creative Commons 

Attribution 4.0 License  
Publisher:  Asian Online Journal Publishing Group 

Funding: This study received no specific financial support 
Institutional Review Board Statement: Not applicable. 
Transparency: The authors confirm that the manuscript is an honest, 
accurate, and transparent account of the study; that no vital features of the 
study have been omitted; and that any discrepancies from the study as planned 
have been explained. This study followed all ethical practices during writing. 
Competing Interests: The authors declare that they have no competing 
interests. 
Authors’ Contributions: All authors contributed equally to the conception 
and design of the study. All authors have read and agreed to the published 
version of the manuscript. 

 

Contents 
1. Introduction ......................................................................................................................................................................................... 7 
2. Materials and Methods ...................................................................................................................................................................... 7 
3. Results and Discussion ...................................................................................................................................................................... 7 
4. Conclusions ....................................................................................................................................................................................... 12 
References .............................................................................................................................................................................................. 12 
 

 
 
 

 

mailto:elafilatyeva@gmail.com
mailto:Mfilatev@gmail.com
mailto:antm1949@gmail.com
mailto:metmashdtu@gmail.com
mailto:innagroys@gmail.com
https://creativecommons.org/licenses/by/4.0/
https://creativecommons.org/licenses/by/4.0/
https://www.doi.org/10.20448/arees.v12i1.6917
https://orcid.org/0000-0002-1041-0535
https://orcid.org/0000-0001-5608-6737
https://orcid.org/0000-0001-8901-8263
https://orcid.org/0000-0002-9622-2622
https://orcid.org/0000-0002-0096-7372


Asian Review of Environmental and Earth Sciences, 2025, 12(1): 6-13 

7 
© 2025 by the authors; licensee Asian Online Journal Publishing Group 

 

 

Contribution of this paper to the literature 
The possibilities of forming dangerous properties of coal seams are considered not only at the 
stage of metamorphic transformations but also in relation to their occurrence, which is 
genetically connected with previous processes of accumulation of the initial material, subjected 
to successive transformations at different stages of coal formation. 

 
1. Introduction 

The hazardous properties of coal seams (release of flammable and explosive gases, sudden outbursts of coal and 
gas, occurrence of endogenous fires, increased dust formation and its explosiveness, and some other features) 
during mining operations are considered in modern regulatory documents depending on the degree of 
metamorphic transformations of coals. As one of the main indicators of the degree of metamorphism and, in most 
cases, the only one, the yield of volatile substances (mass or volume) during thermal decomposition of coals without 
access to air is accepted [1-7]. 

In essence, the indicators 𝑉𝑑𝑎𝑓and 𝑉𝑣
𝑑𝑎𝑓

, according to the methods of their laboratory determinations based on 
analytical samples of coal, they are a mixture of gaseous fluids released from dry ash-free mass under artificially 
created conditions with elevated temperature. The mixture of gases released during the thermal destruction of coal 
has no direct relation to the occurrence of hazardous properties of coal seams. Fluids, including moisture, which 
determine hazardous properties during mining operations, have already been removed at the stage of preparing 

analytical samples by crushing to a size of 7 μm and drying the coal at a temperature above 100℃ [8]. For this 
reason, the influence on the occurrence and manifestation of hazardous properties of seams should be considered 

regardless of the indicators 𝑉𝑑𝑎𝑓or 𝑉𝑣
𝑑𝑎𝑓

, but on the elemental composition of coals and fluids that were formed 
and preserved (including possibly only partially) during geological processes before mining operations. 
 

2. Materials and Methods 
It follows from the state of the issue under consideration that problems related to the reliable prediction of 

hazardous properties of coal seams during mining operations have not been fundamentally resolved to date. This is 
confirmed by the ongoing and periodically recurring accidents at enterprises in coal-mining countries around the 
world caused by gas flares and explosions in mine workings, sudden emissions of coal and gas in production and 
development faces, the occurrence of endogenous fires, and some other manifestations of hazardous properties. 
Prevention of such accidents largely depends on the degree of validity of the requirements of regulatory documents 
governing the safe operation of coal deposits. 

The effectiveness of measures taken to prevent accidents depends on the reliability of forecasts regarding the 
hazardous properties of mine seams. Therefore, research aimed at improving the regulatory framework for safe 
mining operations remains highly relevant for all coal-mining countries worldwide. 
 

3. Results and Discussion 
The formation of methane and carbon dioxide at the peat stage could not have significantly influenced the 

formation of the hazardous properties of coal seams, since their release occurred almost entirely into the 
atmosphere. 

Water formation did not occur at the peat and brown coal stages, since geological transformations of the initial 
substance at the diagenesis stages consisted only of its removal. Similar processes of only moisture removal 
continued at the Carboniferous stage, which refers to metamorphic transformations. The absence of water 
formation processes at the Carboniferous stage is confirmed by experimental data on the graphs of the decrease in 
maximum moisture capacity and stable hydrogen content (≈ 4.5÷5.5%) depending on carbon in the range of its 
change from approximately 75 to 88% (Figure 2). 

 

 
Figure 1. Dependence of the maximum moisture capacity of coal seams (a) and the hydrogen content in the combustible part of the fuel (b) 
on carbon for hard coals and anthracites. 
Note: 1 – averaging curves; × – experimental data on maximum moisture capacity according to Handbook of the Quality [9]; ● – joint experimental data 

on coal moisture in coal seams according to catalogue [1] and carbon content in the combustible part according to data from Handbook of the 

Quality [9](a); ×- experimental data on hydrogen content according to reference book [10]; 𝑅2, σ – coefficients of determination and standard 
deviation, respectively. 

 



Asian Review of Environmental and Earth Sciences, 2025, 12(1): 6-13 

8 
© 2025 by the authors; licensee Asian Online Journal Publishing Group 

 

 

The transition to the anthracite stage is characterized by a carbon content of more than 88% and an increase in 
moisture capacity after reaching minimum values (Figure 1a). The possibility of the formation and release of water 
at the anthracite stage is additionally indicated by a decrease in hydrogen content, also at a carbon content of more 
than 88% (Figure 1b). The ambiguous change in moisture content in coals allows the break in the curve, from 
decreasing to increasing, to be considered as the beginning of the anthracite stages of metamorphism [11]. 

Using only the indicators of the degree of metamorphic transformations, including 𝑉𝑑𝑎𝑓and 𝑉𝑣
𝑑𝑎𝑓

, it is 
impossible to reliably predict the gas content of coal seams in advance (Figure 2). Its quantitative values are 
random quantities, since the total amount of gases formed at individual stages of coal formation and their share 
subsequently released into the host rocks or onto the earth's surface are not taken into account. 

 

 
Figure 2. Dependence of gas content of Donbass mine seams (CH4) on the yield of volatile substances ( 𝑉𝑑𝑎𝑓) according 
to statistical processing. 

Note: 1,2 – respectively, the upper and lower boundaries of the change in the gas content of anthracites according to the joint data processing 
[12-14]; 3 – the expected lower boundary of the gas content during the transition from hard coals to anthracites; 4,5 – respectively, the 
upper and lower boundaries of hard coals; 6 – the averaging rectilinear boundary of the maximum values of gas content according to the 
results of data processing [13]; 7 – the conditional boundary of the division of hard coals by the degree of metamorphism into two parts, 
respectively, with an increase and decrease in gas content; I , II , III – gas content zones, respectively, for anthracites, transition and hard 

coals; ● – experimental data obtained during the joint data processing [1, 15]. 
Source: Antoshchenko and Shepelevich [16]. 

 
If conditions exist for the removal of all formed gases, then the methane content of coal seams is quantitatively 

equal to zero. If some part is retained, the maximum gas content of anthracite coal seams can reach 45 m3 per ton of 
dry ash-free combustible mass (m3/tdacm), and that of coal seams - 35 m3/tdacm. This difference indirectly 
confirms that at the anthracite stages, some additional methane is formed under the influence of elevated 
temperature. 

The formation of carbon dioxide (CO2) in significant quantities at the coal and anthracite stages is unlikely. 
This conclusion follows from the graph showing the decrease in the average oxygen content alongside a 
simultaneous increase in carbon in the combustible part of the fuel as the degree of metamorphic transformations 
increases (Figure 3). 

 

 
Figure 3. Dependence of oxygen content on carbon content for coal and anthracite seams. 

Note: 1 - averaging curve; × - experimental data [10]; R2 and σ - respectively, the coefficients of 
determination and the standard deviation. 

 



Asian Review of Environmental and Earth Sciences, 2025, 12(1): 6-13 

9 
© 2025 by the authors; licensee Asian Online Journal Publishing Group 

 

 

Table 1. Results of statistical processing of experimental data [10] on the quantitative increase in carbon content (СГ) and decrease in oxygen (ОГ) at individual stages of 
metamorphic transformations. 

S
ta

g
es

 o
f 

m
et

am
o
rp

h
ic

 t
ra

n
sf

o
rm

at
io

n
s 

o
f 

co
al

s 
an

d
 a

n
th

ra
ci

te
s 

Average carbon content

ГС , % 

Average oxygen 

content ГО , % 

T
h

e 
d

if
fe

re
n

ce
 

b
et

w
ee

n
 t

h
e 

in
cr

ea
se

 i
n

 t
h

e 
av

er
ag

e 
ca

rb
o
n

 
co

n
te

n
t 

an
d

 
th

e 
d

ec
re

as
e 

in
 

o
x

y
g

en
, 
∆
С
Г

 - 

∆
О
Г
, 
%

 

T
h

e 
m

ai
n

 
co

m
p

o
n

en
ts

 o
f 

th
e 

co
m

b
u

st
ib

le
 

m
as

s 
th

at
 t

o
o
k

 
p

ar
t 

in
 t

h
e 

fo
rm

at
io

n
 o

f 
fl

u
id

s 

V
it

ri
n

it
e 

re
fl

ec
ta

n
ce

 
v

ar
ia

ti
o
n

 
ra

n
g

e 
R

o,
 %

 

N
o
te

s 

A
t 

th
e 

b
eg

in
n

in
g

 o
f 

th
e 

st
ag

e 

A
t 

th
e 

en
d

 o
f 

th
e 

st
ag

e 

In
cr

ea
se

 i
n

 t
h

e 
co

n
te

n
t 

o
f 

∆
С
Г
 

A
t 

th
e 

b
eg

in
n

in
g

 o
f 

th
e 

st
ag

e 

A
t 

th
e 

en
d

 o
f 

th
e 

st
ag

e 

R
ed

u
ct

io
n

 o
f 

co
n

te
n

t 

∆
О
Г
 

    

I 75.00 84.24 9.24 14.77 5.18 9.59 -0.35 ОГ 0.40÷1.06 
Transitional stage from brown 

coal to hard coal 

II 84.24 87.83 3.59 5.18 2.89 2.29 1.30 ОГ, НГ 1.06÷1.43 Carboniferous stage 

III 87.83 92.75 4.92 2.89 1.12 1.77 3.15 ОГ, НГ, SГ 1.43÷2.17 
Transitional stage from hard 

coals to anthracites 

IV-IX 92.75 97.23 4.48 1.12 0.39 0.39 3.75 
ОГ, НГ, 

SГ, NГ, 

СГ 

2.17÷3.54 Anthracite stages 

X >97.23 -* -* <0.73 -*  >3.75 -* >3.54 - 

Note: * - No data. 



Asian Review of Environmental and Earth Sciences, 2025, 12(1): 6-13 

10 
© 2025 by the authors; licensee Asian Online Journal Publishing Group 

 

 

To establish a quantitative relationship between the increase in carbon content and the simultaneous decrease 
in oxygen in the combustible mass at each stage of metamorphic transformations, an empirical relationship was 
used [17]: 

С̄Г = 100 − 33,1 ⋅ е−0,70⋅𝑅𝑜, %             (1) 

where: С̄Гand 𝑅𝑜are, respectively, the average carbon content in the combustible mass and the corresponding 
vitrinite reflectance index, %. 

Dependence (1) is established on the basis of a generalization of experimental data obtained by different 
researchers. It practically functionally reflects the interdependence between the average carbon content and 
vitrinite reflection (R2 = 0.94). This allows us to compare the growth of carbon content and the decrease in oxygen 
in the combustible mass at each characteristic stage of metamorphic transformations (Table 1). Such stages were 
preliminarily determined by the intersection points of the averaging pairs of curves of the dependences of the main 
components (oxygen, hydrogen, organic sulfur, nitrogen) as the metamorphic transformations intensify (growth 

СГ). 
Each intersection point of two averaging curves indicates a change in the ratio between the content of the main 

components in the combustible (organic) mass, which undoubtedly affects the manifestation of hazardous properties 
of the mine layers. In this way, ten characteristic stages of metamorphic transformations of mine layers were 
established by the factor of changing the ratio between all the main components. Their boundaries are clearly 
defined by the average carbon content and the sum of the remaining components. Using the dependence of the 
average carbon content on the vitrinite reflectance (1), the ranges of change in the content of the main components 
at characteristic stages were also established by the vitrinite reflectance index (Figure 4). 

This allowed us to separately consider the quantitative dependencies of the increase in the average carbon 
content and the decrease in oxygen at each characteristic stage of metamorphism by the factor of change in the 
elemental composition (Table 1). The first stage is, to some extent, a transitional one from brown coals to hard 

coals (𝑅𝑜= 0.40 ÷ 1.06%). This follows from the upper limit of the vitrinite reflectance index (𝑅𝑜= 0.60%) for 
brown coals during their classification by genetic and technological parameters [18]. At the first stage, the 

increase in the average carbon content (∆СГ) was due exclusively to the removal of oxygen (∆ОГ). The average 

possible quantitative increase in ∆СГwas 9.24%, and the decrease in ∆ОГ occurred by 9.59%. The difference between 
these indicators (0.35%) is within the permissible limits of accuracy for determining the desired values; therefore, 
other main components (hydrogen, organic sulfur, nitrogen) did not participate in the formation of fluids at this 
stage of metamorphism. 

 

 
Figure 4. Dependences of the average carbon content (a), the sum of the remaining main components of the combustible part (b) and their 
individual change (c) at different stages of metamorphic transformations on the vitrinite reflectance. 
Note: 1,2 – averaging curves, respectively, of the dependences of the carbon content ( ГС ) and the sum of the remaining main components (∑ 

); 3,4,5,6 – averaging curves, respectively, of the dependences of the individual content of oxygen (О̄Г), hydrogen ( Н̄Г), sulfur (

ГS ) and nitrogen ( ГN ); 1′,2′,3′,4′-9′ - intersection points of the averaging curves of the individual change in each main component of the 

combustible part; I, II, III, IV, V, VI, VII, VIII, IX, X - stages of metamorphic transformations, distinguished by the average content of the main 
components. 

 

The second stage is characterized by the transformation of only coal seams (𝑅𝑜= 1.06 ÷ 1.43%). At this stage, 

the growth of carbon content (∆СГ= 3.59%) somewhat outpaces the reduction of oxygen (∆ОГ= 2.29%), which 
indicates the possible participation of other main components in the formation of fluids. Based on the graph of the 
experimental data (Figure 1b), the formation of fluids at this stage also occurred due to the reduction of the 
elemental content of hydrogen in the combustible mass. The upper limit of the carbon content at stage II (87.83%) 

, , ,Г Г Г ГО Н N S



Asian Review of Environmental and Earth Sciences, 2025, 12(1): 6-13 

11 
© 2025 by the authors; licensee Asian Online Journal Publishing Group 

 

 

corresponds to the minimum humidity (Figure 1a). This indicates that the next stage, Stage III, is a transition from 
hard coals to anthracites. 

According to the classification of coal quality by genetic and technological characteristics [18] hard coals, by 

the upper value 𝑅𝑜, are classified if they are less than 1.6%. The lower limit for anthracites is the value 𝑅𝑜, equal to 

1.4%. The absence of a specific boundary between hard coals and anthracites by the criterion 𝑅𝑜, confirms the 

presence of a transitional stage III between them. The range of change in the indicator 𝑅𝑜, by the factor of the ratio 
of average values of the main components for the transitional stage, was within 1.43 ÷ 2.17% (Table 1). According 
to the coal chemical map [19] by the brittleness criterion (output of dust class 1 ÷ 0 mm, cm3), coals of the L and 

SA grades are classified as transitional from hard coals to anthracites. These grades correspond to values 𝑅𝑜, in the 
range of 1.50-2.20% [20]. In the case under consideration, close values of the ranges of change in the vitrinite 
reflectance index for the transition stage were obtained both by the change in the ratio of the elemental content of 
the main components and by the consumer and physical-mechanical (brittleness, dust yield) properties of coals. 
This indicates a fairly reliable determination of the boundaries of the transition stage from hard coals to anthracites 
using different criteria characterizing metamorphic transformations. An increase in the difference between the 

growth of carbon content at this stage (∆СГ= 4.92%) and a decrease in oxygen (∆ОГ= 1.77%) to 3.15% (Table 1) 
indicates that carbon did not participate in the formation of fluids, including carbon dioxide. According to the 
graphs (Figure 4) and the results of statistical processing (Table 1), the main components of the combustible mass 
that participated in the formation of fluids were oxygen, hydrogen, and organic sulfur. 

At anthracite stages from IV to IX, the oxygen content in the combustible mass decreased slightly from 1.12% 
to 0.68%–0.80%. Due to the small differences at these stages between the lower limits of the oxygen content 
(0.12%), its average value for all anthracite stages, which is 0.73%, was adopted for analysis (Table 1). 

From a comparison of the significant increase in carbon content at the anthracite stages (∆СГ= 4.48%) and the 

insignificant decrease in oxygen (∆ОГ= 0.39%) with its approximately constant and low average absolute value 
(0.73%), it follows that there is a practical absence of the possibility of the formation of common compounds 
containing carbon and oxygen. 

Due to some slowdown in the growth of carbon content and the constancy of a small amount of oxygen content 
at anthracite stages IV-IX (Figure 4), the formation of carbon compounds with other main components (hydrogen, 
sulfur, and nitrogen) is possible. The formation of such compounds is confirmed by studies [19]. 

Stage X is characterized by a high carbon content (more than 97.23%). The sum of all other main components 
accounts for less than three percent. This indicates a decrease in the role of the elemental content of the main 
components in the formation of fluids that determine the hazardous properties of anthracite coal seams. For this 
reason, hazardous properties are determined, to a greater extent, by the amount of gas formed at previous stages of 
coal formation and preserved until the anthracite stages. 

The share of nitrogen and sulfur in the formation of fluids at all stages of metamorphic transformations can be 
assessed based on the graphs showing the dependence of their content on carbon in the combustible mass (Figure 
5). 

 

 
Figure 5. Dependence of nitrogen (a) and sulfur (b) content in the combustible part of the fuel on the carbon content for coal seams and 
anthracites. 
Source: × - experimental data [10]. 

 
Changes in nitrogen and sulfur content are random for seams that have undergone the same metamorphic 

transformations according to the carbon content criterion. 
The nitrogen content changed insignificantly and was within the limit of two percent, regardless of the carbon 

content. When the content reaches СГ more than 90% (at the anthracite stages), a certain tendency towards a 
decrease in nitrogen content is observed, and for some coal seams, its content is less than one percent (Figure 5a). 

The nitrogen content in coals from different basins may differ significantly, but in most cases does not exceed 

three percent. There are anomalous cases of increased nitrogen content. For example, for the seam of
5

  mine No. 

3 "Kochegarka" in the Donetsk basin, the nitrogen content reached 4.2% [19] and for the seams of the Dolinskaya 
suite in the Karaganda basin, 8.6% [21]. Such fluctuations in the nitrogen content are obviously associated to a 
large extent with differences in the composition of the original material and the conditions of its accumulation. 

Regardless of the increase in the degree of metamorphic transformations (growth СГ), the sulfur content for the 
coal seams of the Donetsk basin fluctuates widely from 0.7 to 7.0% (Figure 5b). 



Asian Review of Environmental and Earth Sciences, 2025, 12(1): 6-13 

12 
© 2025 by the authors; licensee Asian Online Journal Publishing Group 

 

 

Unpredictable relationships between the carbon content and nitrogen and sulfur do not affect the accuracy of 
controlling the carbon (about one percent) of the sum of all other components of the combustible (organic) mass. 
For this reason, the equality: 

СГ= 100 - ∑ 
Г

О , НГ, 𝑁Г, 𝑆Г, %              (2) 

Remains true for any mine seam, regardless of the degree of its metamorphic transformations and the different 
ratios between the main components. 

Different ratios between the main components can significantly affect the manifestation of hazardous properties 
of coal seams. The high probability of such an effect is indicated by a significant change in the consumer qualities of 
coals with different oxygen contents. With an equal degree of metamorphic transformations of coal seams, coals 
with a lower oxygen content are distinguished by higher sintering, solubility in hydrocarbons, and heat of 
combustion. Taking the yield of volatile substances as the only criterion for the degree of metamorphic 

transformations, it is impossible to establish different oxygen contents with the same reference values 𝑉𝑑𝑎𝑓. For 
this reason, the terms "reduction" and "oxidation" of fossil coals were introduced to characterize the consumer 
qualities [19]. Differences in consumer properties were explained by genetic differences in coal types. It was 
proposed to distinguish four types of coal: type "a" - slightly reduced coals; type "b" - intermediate; type "c" - 
reduced; type "bb" - highly reduced. It was believed that the mineral part of coal is also genetically related to the 
composition and properties of the organic matter. 

According to the developed methodology [19], the type of hard coals by reduction is determined based on a 

comparison of the yield of volatile substances (𝑉𝑑𝑎𝑓) and the oxygen content in organic matter (Oo) for two coal 

seams. Additional indicators of reduction are considered to be the indicators of total sulfur (𝑆𝑡
𝑑) and the main oxides 

in the ash. The coal seams, which with approximately equal values of 𝑉𝑑𝑎𝑓, the oxygen content and the indicators 
of the content of total sulfur and main oxides in the ash (Fe2O3, CaO, MgO) also differed slightly from each other 
were considered to be of the same type. 

The different types mainly included coal seams with coals, the yield of volatile substances of which was 
approximately the same, but there were some differences in the oxygen content. 

To date, the permissible differences in the values of the index have not been determined 𝑉𝑑𝑎𝑓, At which two 
compared mine layers must be classified as belonging to the same degree of metamorphic transformations. The 
permissible differences in oxygen content, at which mine layers must be classified as of the same or different types, 
have also not been established. 
 

4. Conclusions 
Preliminary analysis indicated that the reasons for the existing uncertainties in establishing the genetic types 

of coals may be due to provisions adopted during the development of the methodology that are insufficiently 
scientifically substantiated [19]. The main ones are: 

• The yield of volatile substances, taking into account the methods of determination, does not correspond to 
the classical (generally accepted) characterization of metamorphism as a change in the composition and 
properties of coals in the process of geological transformations of coal seams [22-24]. 

• Metamorphism and thermal decomposition of coals are different stages of their transformation. The 
quantitative and qualitative composition of the volatile substances formed during thermal decomposition has 
no direct relation to the previously occurring metamorphic processes in natural conditions, in which part of 
the gaseous products had already been removed. Thermal destruction is the result of a new (next) artificial 
stage of transformation of the original organic matter raised to the earth's surface [16]. 

• Using only the yield of volatile substances as an indicator of metamorphism, it was not possible to confirm 
the fulfillment of Hilt's rule for many mine seams [19]. 

• The organic mass consists of five main components. When establishing the reduction of coals and the 
uniformity of coal seams, only the oxygen content is taken into account [19], which is genetically related to 
the total individual content of carbon, hydrogen, nitrogen, and sulfur. In this case, organic sulfur is not 
considered a genetic component of the organic mass. 

• Mineral impurities, roughly determined by the ash yield, are not indicators of metamorphic transformations 
of coals due to their preliminary enrichment during the preparation of analytical samples. To partially 
eliminate the influence of mineral impurities on the consumer qualities of fuel, coals are enriched until the ash 
yield is, as a rule, less than 10% [8]. 

It follows from the above analysis that the yield of volatile substances and the oxygen content in the organic 
mass do not unambiguously characterize either the types of coal seams by the supposed reduction of coals or the 
manifestation of hazardous properties during mining operations. In order to establish the true causes of changes in 
the properties of coal seams and their tendency to manifest hazardous phenomena, taking into account the genetic 
interdependence between the main components, it is necessary to consider individual relationships between them 
for each coal seam, and not limit ourselves to determining the content of only oxygen and total sulfur. 

 

References 
[1] Guide to Dust, Guide to dust control in coal mines. Moscow: Nedra Publishing House, 1979. 
[2] Order of the Federal Service for Environmental, Technological and Nuclear Supervision of December 8, 2020 No. 506. On approval of the 

Federal norms and rules in the field of industrial safety: "Instructions for aerological safety of coal mines. Moscow, Russia: Federal Service 
for Environmental, Technological and Nuclear Supervision, 2020. 

[3] G. t. Design, Guide to design of coal mine ventilation. Moscow: Osnova, 1994. 
[4] Guidelines for the Prevention, Guidelines for the prevention and extinguishing of endogenous fires in coal mines of Ukraine: KD 12.01.402. 

Donetsk: NIIGD, 2000. 
[5] Instructions for Forecasting, Instructions for forecasting and preventing sudden methane breakthroughs from the soil of mine workings. 

Russia: MakNII, 1987, p. 29. 
[6] SOU, SOU. Kiev: Standard of the Ministry of Coal Industry, 2009. 



Asian Review of Environmental and Earth Sciences, 2025, 12(1): 6-13 

13 
© 2025 by the authors; licensee Asian Online Journal Publishing Group 

 

 

[7] Catalogue of Dynamic, Catalogue of dynamic faults of rocks in coal mines. Russia: USSR Coal Industry Institute, All-Russian Research 
Institute of Mining Geomechanics and Mine Surveying, 1983. 

[8] I. V. Avgushevich, E. I. Sidoryuk, and T. M. Bronovets, Standard methods for testing coals. Coal classifications. Moscow: Reklama 
Master, 2018. 

[9] Handbook of the Quality, Handbook of the quality of hard coals and anthracites of the Donetsk and Lviv-Volyn basins. Moscow: Nedra, 
Donetsk Coal Research Institute, 1972. 

[10] Handbook on the Quality and Beneficiation, Handbook on the quality and beneficiation of coals and anthracites of the Ukrainian SSR 
(Donbass within the borders of the Ukrainian SSR, Lvov-Volyn basin). Characteristics of the quality of coals and anthracites of the Ukrainian 
SSR. Moscow: Nedra, 1965. 

[11] V. A. Uspensky, "Experience of material balance of processes occurring during metamorphism of coal seams," Oil and Gas Geology. 
Theory and Practice, vol. 1, pp. 1-10, 2006.  

[12] M. E. Zheldakov and E. I. Ivanova, Handbook on the quality of anthracites of the Soviet Union. Moscow: Nedra, 1980. 
[13] Catalogue of Methane Content, Catalogue of methane content and outburst hazard of the main coal seams of the Donetsk and Lviv-Volyn 

coal basins within the boundaries of operating mines. Donetsk: MUP USSR, CBNTI, 1990. 
[14] G. A. Babansky, "Method for calculating methane content of highly metamorphosed anthracites and methods for constructing 

methane content maps of formations," in Proceedings of MakNII, Occupational safety in coal mines, Moscow, Nedra, 1972, vol. 22, pp. 
20-28.  

[15] Catalogue of Seams, Catalogue of seams of the Donetsk coal basin with characteristics of mining and geological factors and phenomena. 
Moscow: Institute of Mining named after A.A. Skochinsky (IGD im. A.A. Skochinsky), 1982. 

[16] N. I. Antoshchenko and V. D. Shepelevich, Methane in coal seams from formation to release», monograph. Alchevsk: DonSTU, 2006. 
[17] E. S. Rudnev, V. A. Galchenko, E. N. Filatieva, and N. I. Antoshchenko, "On the methodology for selecting indicators for 

predicting the hazardous properties of coal seams," Technical Engineering Zhytomyr Polytechnic State University, vol. 2, no. 88, pp. 
148-167, 2021.  

[18] GOST 25543-2013, Interstate standard. Brown coals, hard coals and anthracites. Classification by genetic and technological parameters. 
Moscow, Standartinform: Official Publication, 2014. 

[19] Geological and Coal-Chemical, Geological and coal-chemical map of the Donets Basin. Moscow, Ugletekhizdat: Donetsk Coal Research 
Institute (DonUGI), 1954. 

[20] E. S. Rudnev, V. A. Galchenko, E. N. Filatieva, and N. I. Antoshchenko, "On the development of a general methodology for 
predicting the hazardous properties of coal seams," News of the Donetsk Mining Institute, vol. 2, no. 49, pp. 135-148, 2021.  

[21] Y. M. Chernousov, Geology of coal deposits. Moscow: Higher School, 1977. 
[22] GOST 17070-2014, Interstate standard. Coals. Terms and definitions. Moscow, Standartinform: Official Publication, 2015. 
[23] E. A. Kozlovsky, Mining encyclopedia. Moscow: Soviet Encyclopedia, 1987. 
[24] V. S. Beletsky, Mining encyclopedic dictionary. Donetsk: Eastern Publishing House, 2001. 

 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  

Asian Online Journal Publishing Group is not responsible or answerable for any loss, damage or liability, etc. caused in relation to/arising out of the use of the content. 
Any queries should be directed to the corresponding author of the article. 
 


