STRUCTURE PROPERTY CORRELATION OF MODIFIED Al-Mg ALLOYS FOR AEROSPACE APPLICA...
kushank bajaj_ppt_thesis
1. “Characterization of Coals from Seam-I,
Ramagundam coalfield, Pranhita-Godavari
valley with special emphasis on the
assessment of microstructures under
Scanning Electron Microscope”
Supervised by:
Prof. M.P. Singh
Department of Geology
Banaras Hindu University
Presented by:
Kushank Bajaj
M.Sc.(Tech) Geology
Banaras Hindu
University
2. Grade:
Rank:
Type:
OVERVIEW
Study area
GRADE & RANK: Proximate analysis
TYPE : Coal facies
• Megascopic: on the basis of lithotypes
• Lithotype under SEM-EDX
• Maceral & Microlithotype: Depositional
environment
PLUGGING OF MICROSTRUCTURES:
Problem
• Microstructures in coal
• SEM: A qualitative assessment
• Possible quantitative assessment
Conclusions
www.nyfo.fws.gov
https://www.uky.edu/KGS/coal/coalkinds.htm
COAL CHARACTERIZATION
6. UHV=8900-138(ASH +MOISTURE %) Kcal/Kg
Grade UHV(Kcal/Kg)
A Exceeding 6200
B Exceeding 5600 but not exceeding 6200
C Exceeding 4940 but not exceeding 5600
D Exceeding 4200 but not exceeding 4940
E Exceeding 3360but not exceeding 4200
F Exceeding 2400but not exceeding 3360
G Exceeding 1300but not exceeding 2400
Sample Moisture% ASH %
UHV
(Kcal/Kg) Grade
RG_1 3.42 39.30 3004.98 F
RG_2 1.14 13.07 6939.54 A
RG_3 2.57 38.36 3251.47 F
RG_4 2.18 24.49 5219.12 C
RG_5 1.63 18.83 6076.31 B
RG_6 2.24 17.81 6133.21 B
RG_7 1.81 38.69 3311.62 F
GRADE: USEFUL HEAT VALUE
Average Grade of coal seam: D- Grade
Indian grading of non-coking coal
Grading of Seam- I, Ramagundam coalbelt
8. MEGASCOPIC CHARACTERIZATION: Lithotypes ; using
I.C.C.P RULES & DIESSEL’S CLASSIFICATION
Bright coal (RG_1), b. Banded Bright coal (RG_2), c. Banded Dull
coal (RG_3), d. Banded Bright coal (RG_4), e. Banded Bright coal
(RG_5), f. Banded Bright coal (RG_6), g. Banded Bright coal (RG_7)
Macroscopic seam profile of Seam-I, Ramagundam coal belt, Godavari
Valley Coalfield.
9. COAL LITHOTYPES
Variation of Carbon and Oxygen weight percentage in different lithotypes
Vitrain: Forest plant mat.
& high bacterial activity
Durain: High water level,
inundation of mineral matter
Clarain: Frequent variation
in climate condition,
alternate dry & flooding
Fusain: dry/ forest fire
16. Microstructures Width of
pathway (um)
Length of
pathway
(um)
Orientation Association
Fracture porosity
Macroporosity
Face, butt cleat and 3rd cleat 100-200 >100 90o to bedding Restricted to bright
Microfractures
Vertical microcleats
Horizontal microcleats
Blocky fractures
Conchoidal fractures
Striae
5-20
0.5-2
1-1.5
0.05-0.1
0.1
50-500
50-300
50-200
1-100
5-100
90o to bedding
Parallel bedding
Irregular
Irregular
60-900 to bedding
Restricted to bright
Restricted to bright
Restricted to bright
Restricted to bright
Restricted to bright
Phyteral porosity
Cavities associated with organic
components
2-4 >10 Parallel to bedding Restricted to dull
Matrix porosity
In between maceral fragments
In between minute particles
In between clays
0.05-50
0.01-0.05
0.1-2
0.05-50
0.01-0.05
1-20
Irregular
Irregular
Parallel to bedding
Restricted to dull
Restricted to dull
Restricted to dull
Characterization of microstructures observed in coal using SEM, modified after Gamson, Beamish, and Gas 1993
Pore sizes Coal rank
(ASTM Designation)
Micropores
d<2 nm
high volatile bituminous coal A and higher
Mesopores
2 nm< d < 50 nm
high volatile bituminous coal (C+B)
Macropores
d>50 nm
lignites + sub-bituminous
17. The plugging influences:
Ability of gas flow
Pore availability of gas adsorption
Tendency to shrink and swell
Potential of enhanced gas recovery & CO2 sequestration
PROBLEM: PLUGGING OF MICROSTRUCTURES BY
MINERAL MATTER!
18. a. Disseminated mineral
matter in the middle
portion. Conchoidal
fractures in vitrain bands.
b. Unfilled cavity pores
ranging from 0.17 to 6.23
µm in telinite fragment.
c. Numerous macropores
ranging from 100 to 10 µm,
mineral matter is present as
plugging material in some
pores and in blanket form.
d. Red sphere shows
conchoidal microfractures
plugged with mineral
matter in thin bands of
vitrain. The yellow sphere
show a macropore.
a. 6.23 um
0.17 um
b.
c. d.
QUALITATIVE ANALYSIS OF MICROSTRUCTURES
19. e. f.
e. Conchoidal microfractures in
vitrain filled my mineral
matter.
f. Blanket of mineral matter on
vitrain bands. Unfilled pores
of various sizes ranging from
40 to 5µm.
a. b.
a. Durain showing phyteral
porosity within compressed
fibrous parenchyma of
wood.
b. Homogenized structure in
durain with nominal
superficial mineral matter.
20. c.
e. f.
d.
c. & d. Fibrous parenchyma
of wood showing pitted
vessels in a linear
equidistant fashion.
Fusain showing its
characteristic phyteral
porosity
e. Massive impregnation of
mineral matter in durain.
Very little matrix porosity
within mineral matter.
f. EDX spectra of mineral
found in durain showing
high content of Si & Al
(17.16 and 7.64 wt %).
21. QUANTITATIVE ANALYSIS OF MICROSTRUCTURES
ACQUISITION OF
SEM IMAGES
• SE images for
morphology & BSE
for plugged pores
MOSAIC
• Using image
interpretation
software or Arc GIS
SEGMENTATIO
N OF UNFILLED
AND PLUGGED
PORES
• Contour tool in Arc
GIS.
PORE
DISTRIBUTION,
GEOMETRY & %
OF PLUGGED
STRUCTURES
• Using
computational
methods
22. Megascopically, these coals are Banded Bright in nature.
As per the grading based on Useful Heat Value (UHV), the coals have been classified as
Grade-D non coking coals.
Rank of coal samples as per German (DIN) and North America (ASTM) classification,
based on volatile matter (dry ash free basis) is found to be High Volatile Bituminous.
Elemental analysis using EDX on different humic lithotypes is in accordance to our
knowledge of lithotypes being environment specific.
On the basis of different coal petrographic models, the coal seam –I of Ramagundam coal
belt, Godavari valley is inferred to have formed in a fluvial environment with low rate of
subsidence. Alternating oxic to anoxic conditions of forest swamp to reed marsh with
increasing anoxic conditions prevailed during the time of seam formation.
Characterization of microstructures under SEM shows that:
Dull bands are dominated by phyteral porosity where as bright bands are dominated
by fracture porosity and macropores.
Most of the microstructures are plugged with mineral matter.
CONCLUSIONS
23. REFERENCES
• ASTM D-388. Standard Classification of Coals by Rank.
• BIS, 2003. Methods of test for coal and coke (2nd revision of IS: 1350). Part I, Proximate analysis. Bureau of
Indian Standard, 1-29.
• Diessel, C.F.K., 1986. On the correlation between coal facies and depositional environments. Proceeding 20th
Symposium of Department Geology, University of New Castle, New South Wales, 19-22.
• Diessel, C.F.K., 1992. Coal Bearing Depositional Systems. Springer-Verlag, Berlin, 721p.
• Gamson, Paul D, B Basil Beamish, and Coalseam Gas. 1993. “Coal Microstructure and Micropermeability
and Their Effects Natural Gas Recovery” 72: 87–99.
• https://www.uky.edu/KGS/coal/coalkinds.htm
• Mukhopadhyay, G. et al., 2010. Stratigraphic correlation between different Gondwana Basins of India.
Journal of the Geological Society of India, 76(3), pp.251–266.
• Mukhopadhyay, P. K. (1986). Petrography of selected, Wilcox and Jockson group Lignite from Tertiary of
Taxas in Finkelman, R. B., Casagrade, D. J. (Eds) Geology of Gulf Coast Lignites 1986, Annu, Meet.
Geological Society of America, Coal Geol. Div. Field Trip. Pp 126-145
• Singh, M.P. & Singh, P. K 1996: Petrographic characterization and evolution of the Permian coal deposits of
the Rajmahal basin, Bihar, India. International Journ. coal Geol., Elsevier, The Netherlands. 29: 93-118
• Various authors., 2015. Annual report. S.C.C.L., 2015
• www.nyfo.fws.gov
