Browsing by Author "A.S. Naik"

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Demineralization of Gondwana coal with Pseudomonas mendocina strain B6-1: a case study of coal from Gopinathpur top and bottom seams of Mugma mine, Dhanbad, Jharkhand (India)
(Springer Verlag, 2016) Prakash K. Singh; Asha Lata Singh; Mahendra P. Singh; A.S. Naik; Dharmshila Singh; Spardha Rai; Aniruddha Kumar
In the present investigation an attempt has been made to demineralize the Gondwana coal of Gopinathpur top and bottom seams of Mugma mine, Raniganj coalfield, Dhanbad with the help of Pseudomonas mendocina strain B6-1. The change in the amount of ash yield and decrease in the concentration of selected minor elements like Na, K, Mn and Ca and environmentally sensitive selected trace elements such as Cd, Pb, Se, Ni, Mn, and Zn have been studied as a function of time of bacterial treatment as well as with variation in the bacterial biomass. After 28 days of bacterial treatment there was variable amount of decrease observed in ash yield as well as in the concentration of minor and trace elements. The removal of the elements was further enhanced with the increase in the bacterial biomass from 10 to 25 mg/mL. Due to over exploitation of superior grade coals in the country, the remaining coal resources, available for current use, are inferior in grade and contain high level of impurities and there is ample scope of bio-beneficiation of these coals using bacterial biomass. © 2016, The Author(s).
Distribution and geochemistry of selected trace elements in the lignites of Cambay basin, Gujarat, western India
(Geological Society of India, 2016) P.K. Singh; Vijay Kumar Singh; Pramod Kumar Rajak; M.P. Singh; A.S. Naik
In the present investigation all the working lignite seams of Cambay basin of Gujarat have been studied to see the distribution and geochemistry of selected major/minor elements like Fe, Ca, Na, K, Mg, and Mn and trace elements like Cu, Co, Cr, Cd, Ni, Pb and Zn. The vertical variation of these elements along the seam profiles has been studied to see the pattern of distribution of these elements and also to know the horizons of their enrichment and the probable cause. Further, these elements have been correlated among themselves and also with organic and inorganic matter of lignite. The correlation study indicates that in Tadkeshwar upper seam Fe has its affinity with huminite while Mg and Na have their affinity with liptinite and in Tadkeshwar lower seam Na has an affinity with liptinite. In Vastan upper seam Mn and Cu are associated with inertinite and Na with huminite while in Vastan lower seam Cu relates to huminite and Cd to liptinite and huminite. In Rajpardi seam Ca and Co are associated with huminite. The study provides information on the mode of occurrence of elements of less studied lignites of western India. © 2016, Geological Society of India.
Environmental geochemistry of selected elements in lignite from Barsingsar and Gurha mines of Rajasthan, Western India
(Geological Society of India, 2015) Prakash K. Singh; P.K. Rajak; M.P. Singh; A.S. Naik; Vijay Kumar Singh; S.V. Raju; Sanjay Ojha
The present paper contains the result of investigation carried out on selected trace elements in the less studied lignite deposits of Rajasthan, Western India. The study has been made on two new lignite deposits–Barsingsar and Gurha. The former has elevated ash content (mean 20.8%) than the latter one (mean 5.1%) and both of them have high volatile matter (mean 43.7% and 49.9% respectively). The lignite samples have been studied for selected elements like Fe, Ca, Mg, Mn, K, Na, Cu, Co, Ni, Cr, Zn, Pb, Cd and As. The elements like Cd, Co, Ni, Pb and Cu occur in high concentration when compared to the Clarke values for brown coal. Ca and Mg relate positively with organic matter in Barsingsar lignite indicating their organic source while K, Cu, Co, Pb and Cd indicate their inorganic origin. Ca might have come in contact with the organic matter during humification and would have become a part of humate. The elements like Cu, Co, Ni, Cr, Cd and Pb showing strong affinity with inertinite could have got associated with the mineral matter present in the fusinite and funginite macerals. In Gurha lignites Pb and Co have shown their affinity with inorganic matter which could have been drawn from sulphides and clay minerals. © 2015, Geological Society of India.
Eocene lignites from Cambay basin, Western India: An excellent source of hydrocarbon
(Elsevier B.V., 2016) P.K. Singh; V.K. Singh; P.K. Rajak; M.P. Singh; A.S. Naik; S.V. Raju; D. Mohanty
In the present paper lignites from the Cambay basin have been studied for their hydrocarbon potential. The samples were collected from three lignite fields–Vastan, Rajpardi and Tadkeshwar, and were investigated by petrography, chemical analyses and Rock-Eval pyrolysis. The results are well comparable with the empirically derived values. The study reveals that these ‘low rank C’ lignites are exceedingly rich in reactive macerals (huminite + liptinite) while inertinite occurs in low concentration. These high volatile lignites generally have low ash yield except in few sections. The Rock-Eval data indicates the dominance of kerogen type-III with a little bit of type-II. The study reveals that the lignites of Vastan (lower and upper seams) and Tadkeshwar upper seam are more gas-prone while Rajpardi and Tadkeshwar lower seams are oil-prone. Further, the fixed hydrocarbons are several times higher than the free hydrocarbons. The relation between TOC and fixed hydrocarbon indicates that these lignites are excellent source rock for hydrocarbon which could be obtained mainly through thermal cracking. The empirically derived values reveal a high conversion (94–96%) and high oil yield (64–66%) for these lignites. © 2015 China University of Geosciences (Beijing) and Peking University
Maturity Parameter of Carbonaceous and Coaly Matter Revealed through Raman Spectroscopy
(Geological Society of India, 2024) A.S. Naik; Govind Kumar; Vishvajeet Singh; Prakash K. Singh; Manju Kumari; D. Mohanty; R.K. Majhi; N. Upadhyay
This article presents the results of ten coal samples of sub-bituminous rank collected from working mines in Chhattisgarh, India, and subjected to proximate and ultimate analysis, organic petrology and Raman spectroscopic study to reveal their maturity parameters and structural characteristics of carbonaceous materials. Vitrinite reflectance measurement was also performed to understand the maturity parameter, with values ranging from 0.35% to 0.57%. The research is unique as it combines petrological, geochemical and spectroscopic technique on coals of Hasdeo basin. Conventional parameter, volatile matter ranges from 21.83 and 33.68% suggesting low maturity. The ash yield values range from 12.04 and 26.61%. Petrographically, the coals are vitrinite rich ranging from 53.95 to 63.47% while the inertinite group range from 17.9 to 29.2%. The liptinite concentration the samples remain below 10%. The maceral constitution of the coals indicates carbonaceous materials undergoing early diagenetic phase. The Raman results showed the presence of the D and G bands, two prominent spectral signatures, which are typical of natural materials rich in carbon. The Raman shift recorded for the D band ranges from 1348 to 1385 cm-1 and for the G band, the Raman shift was recorded between 1607 to 1616 cm-1. The ratio of the various parameters derived from the two bands aid to understand the material response to the changing physical and chemical variables in the geological setup. The intensity ratio of the ID /IG band ranged from 0.15 to 0.79 (average 0.50), while the (G-D1) parameter ranges from 225 to 260 indicating heterogeneity in the samples. However, the ratio of AD1 /AG did not show any regularity, with values ranging from 0.07 to 1.85. The investigation elucidates that by integrating Raman spectroscopy analysis with vitrinite reflectance (VRo), we can discern distinctive structural attributes characteristic of immature kerogen. Furthermore, the petrological, proximate, and ultimate data collectively corroborate the carbonaceous, coaly material in its early stages of coalification. © 2024 Geological Society of India, Bengaluru, India.
Mineralogical Studies of Mahanadi Basin coals based on FTIR, XRD and Microscopy: A Geological Perspective
(Springer, 2021) A.S. Naik; B. Behera; U.K. Shukla; H.B. Sahu; P.K. Singh; D. Mohanty; K. Sahoo; D. Chatterjee
This paper is an attempt to investigate the mineral matter constituents in Permian coals of Mahanadi basin, India. Twenty two bulk samples from the working mines have been selected for the study. Analytical techniques such as X-Ray diffraction, Fourier transform infrared spectroscopy coupled with coal microscopy have been used in this study for rapid characterization. The chief mineral phases are quartz, kaolinite, orthoclase, muscovite, and chlorite in order of increasing abundance in all the samples. Petrographic analysis reveal the dominance of Vitrinite (36.17%) followed by the Inertinite (32.33%), Liptinite (14.30%) group of macerals and mineral matter (17.18%). Mineral matter in the voids and cell lumens is common mode of occurrence in the coals which can be attributed to syngenetic and epigenetic types. The proximate analysis suggest the coals have high ash yield (8.37% to 38.46% on air dried basis) with high volatile matter (10.8% to 35.51% on air dried basis) making it suitable for thermal power plants. © 2021, GEOL. SOC. INDIA.
New Occurrence of Sapphirine-spinel-bearing Granulite from NW of Chilka Lake, Eastern Ghats Belt, Odisha
(Geological Society of India, 2019) D. Prakash; B. Vishal; A.S. Naik; R. Yadav; S.K. Rai; S. Tewari; M.K. Yadav; S. Tiwari; S. Dash; C. Pattnaik
A new locality of sapphirine-spinel-bearing granulites from the Kaithapalli area which lies NW of Chilka Lake, Odisha is reported. The area tectonically forms a northern part of Eastern Ghats belt. It occurs as small enclaves within the khondalite and pelitic granulite. The mineral assemblage includes spinel-sapphirine-garnet-cordierite-orthopyroxene-sillimanite-biotite-k-feldspar-plagioclase-quartz. Development of reaction textures and symplectites are common in the sapphirine-spinel granulites which have been used to describe reaction history. The relative XMg values among various minerals are as follows: cordierite > biotite > sapphirine > orthopyroxene > garnet > spinel. The P-T evolution of these sapphirine-spinel granulites constrained through the pseudosection modelling in the NCKFMASH model system using Perple_X software indicate conditions of ultra-high temperature (UHT) metamorphism. The P-T estimates computed by isopleths define a retrograde trajectory with decompression of c.2.5 kbar from P-Tmax of c.10.5 kbar at c.950 o_C. The sequence of reactions as deduced from the symplectite assemblages, together with pseudosection modelling, from the Kaithapalli area, offer greater opportunities for providing a better picture of petrological evolution of northern part of the Eastern Ghats Belt (EGB). © 2019, Geological Society of India.
Organic Petrological Facets and the Evolution of Paleomire, Matasukh Lignite Deposits, Rajasthan, India
(Springer, 2023) A.S. Naik; Vishvajeet Singh; D. Mohanty; R.K. Majhi; Govind Kumar; N. Upadhyay; Manju Kumari; Shweta Rai
The present research work attempts to understand the organo-petrological facets of the lignite hosted in the Tertiary successions in Rajasthan. The maceral diversity was analyzed qualitatively and quantitatively which recorded huminite as the dominant microscopic constituent followed by inertinite and liptinite. The rank parameter of coal evaluated through vitrinite reflectance measurement random (VRo) shows the values vary between 0.19 to 0.27% suggesting lignite in rank. The petrographic investigation point towards the primary phase of degradation of organic matter corroborated through the dominance of huminite suggesting frequent flooding and the presence of funginite, demonstrating intense fungal activity in the mire. The paleodepositional model records elevated values of gelification Index (GI) ranging from 1.63 to 3.88 with well-preserved cell structures pointing towards an early phase of coalification. The model and plot of GI and TPI show that the paleomire developed in a limnic setting. © 2023, Geological Society of India.
Peat swamps at Giral lignite field of Barmer basin, Rajasthan, Western India: understanding the evolution through petrological modelling
(Springer Verlag, 2016) Prakash K. Singh; P.K. Rajak; M.P. Singh; V.K. Singh; A.S. Naik; Alok K. Singh
The lignite samples collected from Giral lignite field of Barmer basin have been subjected to petrological investigation. The data generated has been discussed to understand the evolution of the paleomires of these lignites. The present study reveals that these low rank C coals are chiefly composed of huminite group macerals, mainly telohuminite and detrohuminite, while liptinite and inertinite group macerals occur in subordinate amounts. Not much variation in the maceral composition from Seam-I to Seam-VIII has been observed. Barmer lignites are characterized by a very high GI (>10) and moderate TPI indicating topogenous mire in the basin which was permanently flooded. The GI and TPI values and the petrography-based facies critical models indicate that these lignites originated mostly under wet forest swamp to clastic marsh having telmatic to limno-telmatic conditions with a moderate rate of subsidence and a very slow fall in ground water table. Further, the GWI and VI values are suggestive of mesotrophic to rheotrophic hydrological conditions having the dominance of herbaceous to marginal aquatic vegetation. There were spells of periodic drowning of peat especially during the formation of Seam-VII. Moderately high concentration of calcium in these lignites along with the presence of framboidal pyrite indicate enhanced sulphate-reducing bacterial activity present in carbonate and sulphate-rich waters in the basin during peat formation. © 2016, The Author(s).
Petrographic characteristics and carbon isotopic composition of Permian coal: Implications on depositional environment of Sattupalli coalfield, Godavari Valley, India
(2012) Prakash K. Singh; M.P. Singh; P.K. Prachiti; M.S. Kalpana; C. Manikyamba; G. Lakshminarayana; Alok K. Singh; A.S. Naik
The present paper entails a study carried out on selected samples of coal and carbonaceous shales of Permian age from the Sattupalli open cast coal mine of Godavari valley, Andhra Pradesh to know their petrographic and chemical characteristics. Based on these characteristics, the depositional environment has also been discussed. The study reveals that these coals are sub-bituminous in rank and are chemically characterized by low to medium moisture (4.3 to 8.6wt %) and volatile matter (24.5 to 32.6wt %) while the ash yield varies between 16.4 and 35.3wt %. Petrographically these coals are rich in inertinite. Liptinites occur in very small concentration. Collotelinite, collodetrinite and vitrodetrinite are the main vitrinite macerals whereas fusinite, inertodetrinite and semi-fusinite constitute the major proportion of inertinites. Mean ∂ 13C value measured for coal is -22.58±0.20‰ and for carbonaceous shale it is -23.64±0.57‰ while in the organic matter of Barakar sandstones the ∂ 13C is -25.2±2.1‰.Dry periods are reflected by the abundance of inertinite in some samples while more anoxic conditions are indicated by high concentration of vitrinite in some samples. Seam-II of Sattupalli coalfield initially formed in dry condition and gradually flooding took place due to rise in the water table. During the formation of the upper part of the seam, again a relatively dry phase prevailed. Moreover, a positive correlation of ∂ 13C org with TOC and a negative one with TIC indicate that ∂ 13C org is being modified by ∂ 13C DIC.. © 2011 Elsevier B.V.
Petrographic characteristics and paleomires of Mand-Raigarh coals, Mahanadi Gondwana Basin, Chhattisgarh, India
(Springer Verlag, 2016) A.S. Naik; M.P. Singh; N. Volkmann; P.K. Singh; D. Mohanty; D. Kumar
Mand-Raigarh coalfield is one of the largest coalfields in the Mahanadi basin. The Geological Survey of India carried out initial study primarily on exploration. However, detailed petrographic and geochemical characters of the coals have not been done so far. This investigation is an attempt for petrographic and geochemical appraisal of the coals. Moreover, effort is also made for possible interpretation on development of coal facies. The results drawn from 30 composite coal samples suggest coals are rich in vitrinite, with collotelinite as the dominant maceral while liptinite macerals register low concentration. Dominant mineral assemblages found were clay minerals, pyrite was recorded as disseminated, framboidal and euhedral forms, carbonates recorded were mainly siderites. The vitrinite reflectance random (VRo) mean values range from 0.44 % to 0.56 %, and the rank of coal is suggested as high volatile ‘B’ to ‘A’ sub-bituminous in rank. The rock–eval pyrolysis reveal TOC content varying from 37 % to 68.83 %, while low hydrocarbon generating potential is evident from low S2 and Tmax values. The Hydrogen Index (HI) versus Oxygen Index (OI) plot reveal that the samples belong to Kerogen type—II–III with input dominantly from terrestrial source, some samples also fall in Kerogen type—II domain indicating lacustrine input. Vitrinite reflectance result indicate that the samples are immature and approaching oil window, which is in agreement with data of the Rock–Eval parameters. The gelification index (GI) and tissue preservation index (TPI) indicate that the coal developed in a telematic set up with high tree density. The ground water index (GWI) and vegetation index (VI) demonstrate that the peat developed as an ombrogenous bog. © 2016, The Author(s).
Petrological and geochemical investigations of Rajpardi lignite deposit, Gujarat, India
(2012) Prakash K. Singh; M.P. Singh; Alok K. Singh; A.S. Naik; Vikas K. Singh; Vijay K. Singh; P.K. Rajak
The present paper entails the petrographic and chemical characteristics of the lignite samples drawn from the Rajpardi lignite deposit of Bharuch district, Gujarat. This lignite contains a high concentration of huminite which is dominated by telohuminite, followed by detrohuminite. Liptinite and inertinite macerals are very low in concentration. The dominant microlithotype is humite. Its elevated volatile matter and high hydrogen content depicts its perhydrous nature. The study reveals that this lignite originated in a limno-telmatic to telmatic condition. The paleomire is further characterized as a wet moor having moderate to high flooding with good tissue preservation and increasing bacterial activity.
Study of Hydrocarbon Source Potential of Kapurdi Lignites of Barmer Basin, Rajasthan, Western India
(Springer, 2021) P.K. Rajak; V.K. Singh; Aniruddha Kumar; Vishvajeet Singh; Ankita Rai; Shweta Rai; K.N. Singh; Mamta Sharma; A.S. Naik; Neeraj Mathur; Prakash K. Singh
The present investigation is an attempt to study hydrocarbon source potential of early Paleogene lignites of Kapurdi, Barmer Basin. The samples collected from the working mines have been subjected to petrographic and geochemical analyses. The petrographic study includes both maceral as well as microlithotype analyses whereas geochemical study includes proximate and ultimate analyses. Besides, rock eval pyrolysis, FTIR and NMR studies have also been carried out. The analytically generated data were also correlated and checked with empirical equations. The study shows that these lignites of Barmer Basin are rich in kerogen type-III organic matter and contain high concentration of reactive macerals (huminite + liptinite) to the tune of ∼98% (mineral matter free basis) and they have attained low maturity (Rmax is 0.43%). These lignites have a fairly high conversion factor (95–97%) and oil yield (65–67%) which is also supported by the rock-eval data. Further, 1H and C13 shifts of NMR also suggest a high potential of hydrocarbon of Kapurdi lignites. © 2021, GEOL. SOC. INDIA.
The petrology of coals from the Rampur seam-IV and the Lajkura seam, Ib River Coalfield, Mahanadi Valley, Orissa, India
(2013) G.P. Singh; M.P. Singh; A.S. Naik
This article entails results of the study designed to characterize the coals of Ib River coalfield of Mahanadi Valley, Orissa. The study reveals that durain is the dominant lithotype of these coals, which has imparted a dull appearance. This is reflected in its microscopic constituents by the dominance of the macerals of inertinite group and high mineral matter content. This is followed by vitrinite, while liptinites occur in small quantity. Further, it is evolved that these coals are sub-bituminous in rank and have originated from forest and open moors under oxic conditions with intermittent flooding. © 2013 Taylor & Francis Group, LLC.
The prediction of the liquefaction behavior of the east kalimantan coals of indonesia: An appraisal through petrography of selected coal samples
(2013) P.K. Singh; M.P. Singh; A.K. Singh; M. Arora; A.S. Naik
The present study is undertaken to investigate the coals of East Kalimantan for their oil proneness and their suitability for hydrogenation. These coals are Sub-bituminous/Low rank A and per-hydrous in nature. They also have elevated sulphur content. Petrographically, they have high huminite (90.7-98.1%) and poor concentration of liptinite and inertinite. The study reveals that the coalification is characterized by loss of hydrogen and oxygen in this region. The richness of hydrogen, in relation to carbon, is probably responsible for vitrinite suppression and makes these coals per-hydrous and oil prone. The role of petrofactor has also been evaluated to predict reactivity of these coals during hydrogenation. There is a good correlation between petrofactor and conversion. These coals do possess favorable characteristics for hydrogenation and have a high conversion (∼95%) and oil yield (>65%). © 2013 Taylor & Francis Group, LLC.