scholarly journals Sulphur study of the Palaeogene coals from Jaintia Hills, Meghalaya, NE India: Implications for palaeoenvironment, utilisation prospects, and environmental impacts

2021 ◽  
Vol 38 (2) ◽  
pp. 115-121
Author(s):  
Manabendra Nath
Keyword(s):  
Volatile Matter ◽  
Northeast India ◽  
Sulphur Content ◽  
Coal Seams ◽  
Ne India ◽  
Combustion Emissions ◽  
Increasing Trend ◽  
Jaintia Hills ◽  
Marine Influence ◽  
Produce Acid

Coal samples of Eocene age (Shella Formation) from four different mines (Bapung, Jaintia, Sutunga, and Lakadong) of the Jaintia Hills of Meghalaya, Northeast India, were collected and investigated to observe the sulphur content and to understand the palaeoenvironment, utilisation prospects, and environmental impact. The study reveals that these coal samples contain sulphur in higher concentration (4.46% to 7.26%) both organic and inorganic forms. There are 3 coal seams exposed in the area. The organic sulphur is higher (2.53%-5.49%) than the inorganic forms (1.26%-1.77%). The upper seam is found to contain higher concentration of sulphur than the lower seam. Intra seam pyritic sulphur also shows an upward increasing trend. The high sulphur content in the coal seams suggests the marine influence in the peat-forming swamps. These coals are classified as High Sulphur coal (>1%) which is the main obstacle in the utilization although high volatile matter and hydrogen content strongly suggest that these coals are good for liquefaction. Moreover, during coal combustion emissions of sulphur dioxide produce acid rain, affecting the environment of the mine areas.  

scholarly journals Comparative characteristics of the petrographic composition and quality of coal series С12 and С13 of the Prydniporovia Block

2021 ◽  
Vol 30 (1) ◽  
pp. 145-152
Author(s):  
Vyacheslav S. Savchuk ◽  
Vasyl F. Prykhodchenko ◽  
Dmytro V. Prykhodchenko ◽  
Valeriia V. Tykhonenko
Keyword(s):  
Volatile Matter ◽  
Matter Content ◽  
Coal Seams ◽  
Combustion Heat ◽  
Petrographic Composition ◽  
Genetic Features ◽  
History Of ◽  
Coal Composition ◽  
Technological Indices

Taking into consideration the whole history of geological development of the Western Donbas, data on composition and grade of С12 series coal involved information about the geotectonic development of the Basin. To satisfy the objectives, a system of research methods, covering petrographic, computational, statistical, chronological, comparative and other methods, has been applied. In the process of identification of the petrographic composition and grade of series С12coal on the territory of the Prydniprovia Block, and determination of lateral regularities of their change as well as change in stratigraphic section of the Lower Carboniferous, data of petrographic as well as chemical and technological indices of the coal seam c1 were generalized along with data of all seams of С13 series. The activities helped define genetic features of series С12coal as well as stratigraphic and lateral regularities of changes in the coal composition. The differences in the petrographic composition as well as in the chemical and technological characteristics of series С12 and С13 are indicative of dissimilar conditions of formation of their peat depositions. It has been determined that compared with С13 series coal, the coal of С12 series contains more humidity and fewer mineral impurities. It is characterized by higher values of sulfur content, volatile-matter content, and combustion heat. The ultimate composition of coal seams of С12series is characterized by smaller values of carbon and oxygen contents as well as greater hydrogen content. The conclusions on common features and differences in the petrographic composition as well as chemical and technological features of coal seams of С12and С13 series, and regularities of their changes over the area of the seam occurrence was assessed.

scholarly journals Failure Mechanisms and the Control of a Longwall Face with a Large Mining Height within a Shallow-Buried Coal Seam

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Haijun Wang ◽  
Yingjie Liu ◽  
Yuesong Tang ◽  
Hao Gong ◽  
Guoliang Xu
Keyword(s):  
Tensile Stress ◽  
Coal Mine ◽  
Horizontal Displacement ◽  
Longwall Face ◽  
Mining Equipment ◽  
Coal Seams ◽  
Increasing Trend ◽  
Support Force ◽  
Coal Wall ◽  
Mining Height

The capabilities of mining equipment and technology in China have been improving rapidly in recent years. Correspondingly, in the western part of the country, the mining heights of longwall faces in shallow-buried coal seams have shown an increasing trend, resulting in enhanced mining efficiency. However, the problems associated with the possible failure of the coal wall then increase and remain a serious difficulty, restricting safe and efficient mining operations. In the present study, the 12401 longwall face of the Shangwan Coal Mine, Inner Mongolia, China, with a mining height of 8.8 m, is taken as an example to study the mechanisms underlying failure phenomena of coal walls and their control methods. Our results show that the failure region inward of the longwall face is small in shallow-buried coal seams, and the damage degree of the exposed coal wall is low. The medium and higher sections of the coal wall display a dynamic failure mode, while the broken coal blocks, given their initial speed, threaten the safety of coal miners. A mechanical model was developed, from which the conditions for tensile failure and structural instability are deduced. Horizontal displacement in the lower part of the coal wall is small, where no tensile stress emerges. On the other hand, in the intermediate and higher parts of the coal wall, horizontal displacement is relatively large. In addition, tensile stress increases first with increasing distance from the floor and then decreases to zero. Experiments using physical models representing different mining heights have been carried out and showed that the horizontal displacement increases from 6 to 12 mm and load-bearing capacity decreases from 20 to 7.9 kN when the coal wall increases in height from 3 to 9 m. Furthermore, failure depth and failure height show an increasing trend. It is therefore proposed that a large initial support force, large maximum support force, large support stiffness, and large support height of a coal wall-protecting guard are required for the improved stability of high coal walls, which operate well in the Shangwan coal mine.

scholarly journals Morphological and molecular characterization of Theloderma moloch (Anura: Rhacophoridae) from Indo-Burma biodiversity hotspot of northeast India

2017 ◽  
Vol 17 (3) ◽  
pp. 148-159
Author(s):  
Samuel Lalronunga ◽  
C. Lalrinchhana
Keyword(s):  
16S Rrna ◽  
First Record ◽  
Northeast India ◽  
Biodiversity Hotspot ◽  
Arunachal Pradesh ◽  
Ne India ◽  
Himalayan Foothills ◽  
India And China ◽  
Morphological And Molecular Characterization

Specimens of a rare rhacophorid frog of the genus Theloderma were collected from Hmuifang, Mizoram, India. Based on their morphology and molecular analysis (16S rRNA), the specimens were identified as Theloderma moloch, a rare species previously recorded only from the Himalayan foothills of India and China. The present record significantly extends the known range of the species and is a first record for the state of Mizoram and Indo-Burma biodiversity hotspot. The uncorrected p-distance between the specimen from Mizoram, NE India and the specimen from Arunachal Pradesh, India (KU169993) and Tibet, China (KU243081) are 0.0% and 1.2% respectively.

Hilt's Law and the Volatile Contents of Coal Seams

1949 ◽  
Vol 86 (5) ◽  
pp. 303-312 ◽  
Author(s):  
O. T. Jones
Keyword(s):  
High Pressures ◽  
Volatile Matter ◽  
Physical Factors ◽  
Recent Theory ◽  
Coal Seams ◽  
South Wales ◽  
Coal Measures ◽  
Depth Of Burial

AbstractDr. Trotter's recent theory of devolatilization of coal seams is criticized on structural grounds and the “square law” suggested is shown to be no improvement on many other expressions of varied types. The data are best represented both for South Wales and the Kent Coalfield by Hilt's law. The influence of depth of burial on coal vegetation is discussed; loss of volatile matter is probably promoted by temperatures, but is almost certainly retarded by high pressures. The Hilt rate is controlled by the chemical-physical factors and may be influenced also by varying rates of sedimentation during the accumulation of the Coal Measures.

scholarly journals Forming conditions of the Graikas lignite, N. Peloponnese

2001 ◽  
Vol 34 (3) ◽  
pp. 1195 ◽  
Author(s):  
Σ. ΚΑΛΑΪΤΖΙΔΗΣ ◽  
Σ. ΠΑΠΑΖΗΣΙΜΟΥ ◽  
Κ. ΧΡΗΣΤΑΝΗΣ
Keyword(s):  
Influence Factor ◽  
Volatile Matter ◽  
Low Rank ◽  
Early Pleistocene ◽  
Silty Clay ◽  
Inorganic Matter ◽  
Pyrite Content ◽  
Marine Influence ◽  
Clay Layers ◽  
Coal Petrography

In Northern Péloponnèse (southern Greece) several lignite seams occur, many of which were exploited in the past decades. In the small Graikas basin, in the upland Aigialia, a 2.5-m-thick lignite seam outcrops within the Pliocene/ Pleistocene sediments. The pre-Neogene margins and the basement of the basin consist of radiolarites, pelagic limestones, and flysch of the Pindos isopic zone. The sediments filling the basin include marly, sandy and clay layers, which deposited under marine, brackish and lacustrine conditions, during the rifting of the Corinth graben (Late Pliocene-Early Pleistocene). The seam consists of lignite and clay-rich lignite layers, of matrix lithotype, with total thickness of 1.4 m, intercalating with thin marly, silty, clay and humic clay layers. Fourteen lignite samples were obtained for proximate and ultimate analyses and coal-petrography studies. The ash contents of the Graikas lignite range up to 46.2% on dry base revealing intense inorganic input. The total sulphur contents are also high up to 4%. The fixed carbon and volatile matter contents (33.2-46% and 53.9-66.8% on daf, respectively), as well as the H/C and O/C atomic ratios and the reflectance of Eu-ulminite Β (Rm 0.26-0.30%), indicate a low rank (soft brown coal, Weichbraunkohle). Micropetrographic studies revealed a Huminite content >73%, Liptinite <23%, and Inertinite <12%. Attrinite and Densinite are the most prevailing macérais, while Texto-ulminite A and Eu-ulminite A show moderate values. Inertodetrinite and Semi-fusinite dominate within the Inertinite macerai group. Cutinite and Liptodetrinite are the most abundant macérais of the Liptinite group. Mainly clay and carbonate minerals constitute the inorganic matter (7-30%). However, pyrite content is also significantly high, up to 10%, revealing anoxic marine influence. Factor analysis suggests that peat accumulation started under anoxic conditions and intense bacterial activity. The peat-forming vegetation was mostly herbaceous with minor contribution of arboreal vegetation. Moreover, negative correlation is revealed between the gelification degree and the inorganic input. Coal-facies diagrammes suggest low preservation of the organic tissues and highly scattered gelificationindeces. The peat in the Graikas basin started accumulating in a lagoonal environment under brackish conditions behind a barrier. Progressively, sea regraded and the conditions became limnic to limnotelmatic

scholarly journals Indigenous rice of Northeast India harbor rich genetic diversity as measured by SSR markers and Zn/Fe content

2019 ◽  
Author(s):  
Vanlalsanga No Surname ◽  
Sagolshem Priyokumar Singh ◽  
Yengkhom Tunginba Singh
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Microsatellite Markers ◽  
Oryza Sativa L ◽  
Northeast India ◽  
Rice Cultivars ◽  
High Genetic Diversity ◽  
Fe Content ◽  
Ne India ◽  
Improvement Programs

Abstract Background Rice (Oryza sativa L.) is one of the most important crops of the world and a major staple food for half of the World’s human population. The Northeastern (NE) region of India lies in the Indo-Burma biodiversity hotspot and about 45% of the total flora of the country is found in the region. Local rice cultivars from different states of NE India were analyzed for genetic diversity and population structure using microsatellite markers, and their zinc and iron content. Results A total of 149 bands were detected using twenty-two microsatellite markers comprising both random and trait-linked markers, showing 100% polymorphism and high value of expected heterozygosity (0.6311) and the polymorphism information content (0.5895). Nali Dhan cultivar of Arunachal Pradesh possessed the highest genetic diversity (0.3545) among studied populations while Moirangphou Khonganbi of Manipur exhibited the lowest genetic diversity (0.0343). The model-based population structure revealed that all the studied 65 rice cultivars were grouped into two clusters. Cluster I was represented by 36 cultivars and cluster II by 29 cultivars. Badalsali cultivar of Assam possessed the highest Zn content (75.8 μg/g) and Kapongla from Manipur possessed the lowest (17.98 μg/g). The highest and the lowest Fe content was found in Fazu (215.62 μg/g) and Idaw (11.42 μg/g) of Mizoram. Conclusion The result suggested rice cultivars of NE India possessing high genetic diversity (Nali Dhan), high Zn (Badalsali) and Fe (Fazu) content can be useful as a source of germplasm for future rice improvement programs.

scholarly journals CHARACTERIZATION OF COAL SEAMS IN THE ARANTIGA AND SELUANG MINE BENGKULU USING PROXIMATE ANALYSIS DATA

2020 ◽  
Vol 6 (3) ◽  
pp. 197-204
Author(s):  
Rafi Maulana ◽  
Ordas Dewanto ◽  
A Raka Abriyansyah
Keyword(s):  
Bituminous Coal ◽  
Analysis Data ◽  
Volatile Matter ◽  
Proximate Analysis ◽  
Total Sulfur ◽  
Coal Seams ◽  
Fixed Carbon ◽  
Caloric Value ◽  
Average Value ◽  
Coal Type

Indonesia as a country that has ample large coal reserves spread across the Sumatera and Kalimantan islands. The huge potential in the region needs further research to be able to find out the quality and excellence of coal resources in order to know the characteristics in detail, then the research was carried out in the Bengkulu Province area by testing coal sample based on Proximate analysis to obtain accurate coal quality results and analysis of coal characteristics in the area can be carried out. The results show that the coal seams in the Arantiga mine have an average value Inherent Moisture is worth 7.49 %, ASH is worth 9.82 %, Volatile Matter is worth 40.99 %, Fixed Carbon is worth 41.70 %, Total Sulfur is worth 0.34 %, Gross Caloric Value is worth 6305 kcal/kg and including of High Volatile A Bituminous coal type, while the Seluang mine has an average value Inherent Moisture is worth 2.07 %, ASH is worth 22.92 %, Volatile Matter is worth 20.26 %, Fixed Carbon is worth 54.78 %, Total Sulfur is worth 0.55 %, Gross Caloric Value is worth 6365 kcal/kg dan and including of Medium Volatile Bituminous coal type.

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