IR@CIMFR - Central Institute of Mining and Fuel Research (CSIR)
Not a member yet
2618 research outputs found
Sort by
Petrographic and geochemical analysis of Barmer Basin Paleogene lignite deposits: Insights into depositional environment and paleo-climate
No full textThe current study attempts to characterize the samples from Kapurdi, Giral and Sonari lignite mines of Barmer Basin within Rajasthan Tertiary Lignite deposits using petrographic and geochemical techniques. The data generated has been studied in order to better understand the geochemical properties, hydrocarbon potential, depositional environment and paleo-climatic condition of the paleo-mires of these lignites. The proximate analysis of the samples reveals that the average ash content of the Barmer Basin is 11.93 %, the average moisture content is 14.08 %, average volatile matter yield is 42.03 % and the average fixed carbon is 31.95 %, which suggesting that the physical properties of lignite are dominated by volatile matter on dry basis. The ultimate investigation reveals the chemical properties of the lignite with the average carbon content found to be 58.79 wt%, hydrogen value 3.83 wt%, nitrogen percentage 1.60 wt% and sulphur content 2.75 wt%. This clearly indicates high sulphur concentration in Barmer lignite deposits, based on dry basis. The lignite samples subjected to FTIR studies identified aliphatic Cdouble bondH group, aromatic Cdouble bondO group, hydroxyl Osingle bondH and Aldehyde HCdouble bondO group. The Rock-Eval pyrolysis studies have been carried out to know the coalification profile of the deposits and hydrocarbon source rock potential. The varying behaviour between brown coal lithotype are primarily reflected by changes in oxygen index values, whereas hydrogen index values demonstrate a more pronounced correlation with coal type rather than the level of maturation. The results show the average total organic carbon (TOC) 47.29 %, S1 peak 2.18 mg HC/g, S2 peak 88.70 mg HC/g, S3 peak 19.22 % mg CO2/g, Tmax 410.53 °C, hydrogen index 219.2 mg HC/g TOC and oxygen index 46.33 mg CO2/g TOC. According to petrographic investigations, the huminite macerals dominate followed by liptinite and inertinite maceral groups in mineral matter-free basis. In all the three different lignite mines, the huminite group dominates with preserved sub-maceral ulminite indicating less transformation of structured plant matter. Reconstruction of depositional environment and paleo-climatic condition of the paleo-mires has been attempted by using organic petrographic indices. The high gelification index (GI) and low tissue preservation index (TPI) values suggest a prolonged wet environment during the decomposition of organic material, accompanied by a gradual subsidence process. The ground water influence index (GWI) and vegetation index (VI) denote ombrotrophic to mesotrophic hydrological conditions of basin at the time of deposition
A hybrid of GNSS remote sensing and ground-based laser technology for geo-referenced surveying in mining.
No full textRapid, precise and frugal surveying is a strategic factor
in the present mechanized mining environment owing
to rapid surface profile transformation in a short period.
Determination of global coordinates with high accuracy
using the satellite-based global navigation satellite system
(GNSS) has been studied in the mining arena and is
gradually becoming an essential component. A case study
of Khanak Stone Mine, Haryana, India, is discussed
here, highlighting the combination of GNSS system
and terrestrial laser scanner for the preparation of a
surface profile of a rugged terrain with the key objec�tive to determine the precise in situ rock excavation in
periodical phases. The actual tonnage of rock produced/
transported from the mine has been calculated by de�termining the in situ density and bulk density in the
laboratory. The study reveals that this survey of appro�ach is apt to achieve quality plan and to obtain the goal
of actual tonnage of rocks excavated
Control of microstructural and mineralogical characteristics on thermo-elastic behavior of coal-bearing sandstone under mild to high-temperature regimes: Experimental investigation and development of AI prediction models
No full textThis experimental study aimed to investigate the potential control of microstructural-mineralogical characteristics on thermal properties and its relation with the deformational behaviour in mild to high temperature (25°–800°C) regime of coal-bearing sandstone from an underground coal mine fire region. Barakar sandstone from Jharia Coalfield, India, one of the world's largest underground coal mine fire regions, was chosen. The thermal parameters and their relations to the mineralogical, microstructural, and damage characteristics of Barakar sandstone have been discussed. Thermal conductivity (λ), thermal diffusivity (κ), and specific heat capacity (Cp) of heat-treated samples were determined using the transient plane source method. Additionally, detailed petrography, scanning electron microscopy, and electron probe micro-analyser were used to understand the thermal effect on mineralogy and microstructures. The deformational behaviour with elevated temperature was investigated through the universal testing machine. The obtained results suggest three characteristic temperature regimes: mild temperature regime (25°–300°C), transitional temperature regime (300º–500°C) and high temperature regime (500º–800°C). Moreover, prediction models for thermal properties have also been developed using multi-gene genetic programming (MGGP), considering physical properties as input parameters. In view of experimental constraints to determine the thermos-elastic properties of a rock due to tedious experimental processes, the proposed prediction models shall be very useful to indirectly estimate the thermal properties of sandstone rocks using easily determined physical parameters. The outcome of the present study may be useful to understand the subsidence induced by underground coalmine fire, which is
Fluoride and Metals in the Agricultural Soils of Mica Mining Areas of Jharkhand, India: Assessing the Ecological and Human Health Risk
No full textThe concentration of metals and fluoride in the agricultural soils of the mica mining areas of Jharkhand was estimated for human health risk assessment and source apportionment studies. The elemental concentrations of As, Co, Cu, Fe, Ni, Pb and Zn in the study area exceeded the world average values. The sources of the metals and fluoride in soil were suggested to be from both natural and human-induced activities as per principal component analysis (PCA) and cluster analysis (CA). The sources of Al, Fe, Mn and F in the soil were ascribed to the mica mining–related activities as indicated by PCA and CA. Potential ecological risk assessment suggested moderate risk with respect to Cd, Cu and Pb at few locations. Considering metals and fluoride content of the soils, non-cancer risk assessment suggested considerable risk to the child population which was largely due to Al and Fe. Taking into account all the pathways and elements, the HIs for the study area were calculated to be 0.586 and 3.58 for the adult and child residents, respectively. The carcinogenic risk assessment evaluated the cancer risk to be within the target risk of 1 × 10−4, suggesting insignificant cancer risk to the residents
Electrical Resistivity Tomography study above inaccessible old mine workings for safe erection of high voltage electricity power transmission terrestrial towers: a case study
No full textOld and abandoned mine workings become inaccessible with time owing to safety issues thereby demanding insight review of strata overlying such areas. Electrical Resistivity Tomography (ERT) survey was carried out at locations within Kajora area of Eastern Coalfield Limited (ECL) in Raniganj coalfield, India to assess the present strata condition for the proposed high voltage electric transmission layout. Parallel 2D ERT profiles were carried out with 20 m offset covering the study area. Considering the sensitiveness in horizontal direction i.e., identification of vertical structures, the Dipole-Dipole array methodology was implemented. The acquired data sets were filtered and processed using Prosys-II software. L-curve criteria for misfit data was used for proper interpretation of subsurface features. Non-linear least-squares regularized optimization method and 3D ERT volumetric model were performed by combining 2D ERT parallel profiles data sets for better resolution of underground old mine working and accurately map the status of mine workings. High resistivity magnitude ranging between 200 Ωm to 1600 Ωm indicated intact bedrock and solid pillar. Depillared workings area (either dry-filling or air-filled) was identified through anomalous high resistivity magnitude of more than 1600 Ωm. The data generated were also validated with underground working plan and available borehole data. Combination of 2D ERT and 3D ERT techniques against each profile was found to be effective for detection of strata condition for safe installation of terrestrial high voltage electric transmission towers
Prediction of Cutting Speed of Surface Miner for Coal and Limestone Production under Varied Rock Mass Conditions
No full textThe key function of surface miner is to mechanically excavate in-situ rock. Strength properties i.e. the resistance of the rock to break limits the cutting speed and in turn overall performance of the surface miner. Quantitative account of rock properties in relation to cutting speed of surface miner is essential for precise estimation of its net performance. A study encompassing operating parameters (cutting speed and depth of cut) of surface miner and rock/rock mass parameters were conducted in a few coal and limestone mines located in different parts of India. Intact rock and rock mass parameters were correlated with cutting speed of surface miners and also confirmed through principal component analysis. A multiple regression equation is developed based on these outcomes to predict cutting speed taking depth of cut into consideration. An empirical relation is also developed to predict the production after arriving at suitable operating conditions. An easy to use nomogram is developed for fixing the optimum cutting speed based on the studies carried out
Nanopore Characteristics of Barakar Formation Shales and Their Impact on the Gas Storage Potential of Korba and Raniganj Basins in India
No full textLithologically diverse shales were collected from two different proliferous basins, namely, the Korba (SM) and Raniganj Basin (BK) in India, and were experimented with at an isothermal condition using CO2 and N2 as probe gases in the low-pressure gas adsorption method, demonstrating the disparity between shale pore attributes and surface roughness. The Korba Basin is one of the potential sites for gas storage and production in India and needs to be explored in terms of pore statistics. Literature reviews demonstrate that pore characteristics in shale changes with depth, organic matter, and mineral composition, which can elucidate the gas storage potential for anthropogenic CO2 storage. Gas adsorption capacity and surface roughness are directly associated with the difference in organic and mineral compositions, which certainly affects the phase distribution of flow regimes in shale reservoirs. The result determines that micropore and mesopore attributes are in good correlation with the TOC and clay minerals, respectively. SM shale shows 30–37% higher micropore attributes and 17–19% lower mesopore attributes than those of BK shales. Furthermore, the siderite content shows a variance in the pore size distribution in BK shales. The fractal dimension (Ds) is evaluated based on the N2 adsorption isotherm curve using the Frenkel–Halsey–Hill model. SM shales show a strong correlation with both micropores and mesopores at low relative pressure regimes, while BK shales depict their dominance with mesopores at the high relative pressure regime. Therefore, this research provides a preliminary attempt to determine the influence of changes in the depth, surface roughness, and organic and mineral compositions on shales. However, a complete extrapolation of other reservoir factors, viz., seam thickness, shale–water interaction, and permeability variation at reservoir conditions, is vital to unlocking the technical and environmental feasibility of CO2 storage and gas production in these basins
A Case Study of Tunnel Stability in Quaternary Deposits Using Pipe Roof Supports
No full textIn numerical modeling, boundary conditions play a vital role for stability analysis of a tunnel. The top boundary is kept free to simulate vertical movement of material during tunnel excavation in case of a tunnel being excavated at shallow depth through soil like material. On the other hand, the top boundary is kept restricted in case of a deep tunnel. In this view, it becomes important so as to categorize the tunnel as shallow or deep while designing support system for a tunnel. The present paper is a case study which has been carried out for the execution of a part of a railway tunnel being excavated through quaternary deposits below 40–60 m of overburden in Rishikesh–Karnaprayag rail link project in Himalayan region, India. Crown Stability of a tunnel is essential for better re-distribution of induced stresses around the tunnel periphery and the surrounding ground so as to attain a stable equilibrium stage of stresses. The inlet tunnel portals of the Main and Escape tunnel were forced to locate on river-borne material due to constraints related to the geometry of Railway line, its curve and elevation. Large displacements are usually associated with tunnelling through such a kind of loosened and highly weathered rock mass, which could result in settlement of the ground surface. However, other parameters such as shape and size of the tunnel, height of overburden material and consistency of the material which may also result in ground subsidence. The adopted support system for stability of the arched portion of tunnel was modeled in the form of Pipe-roofs which are pre-excavation supports generally installed from crown to the spring levels. The paper describes a methodology of pipe-roof design and the behavior of ground monitored with the help of tunnel instrumentation to validate the efficacy of the installed supports. The study reveals that the pre-excavation support behaves as an arch beam throughout the tunnel's perimeter which enhances the stability of the surrounding ground beyond the formed arch beam, multifold. The Analysis leads for the determination of shallow and deep tunnel based on a limiting value of overburden observed through numerical analysis compared with monitoring results of ground deformations, above that overburden value the tunnel behaves as deep and below the given value, the tunnel behaves as a shallow tunnel
New insights into the coal-associated methane architect: the ancient archaebacteria
No full textExploration and marketable exploitation of coalbed methane (CBM) as cleaner fuel has been started globally. In addition, incidence of methane in coal basins is an imperative fraction of global carbon cycle. Significantly, subsurface coal ecosystem contains methane forming archaea. There is a rising attention in optimizing microbial coal gasification to exploit the abundant or inexpensive coal reserves worldwide. Therefore, it is essential to understand the coalbeds in geo-microbial perspective. Current review provides an in-depth analysis of recent advances in our understanding of how methanoarchaea are distributed in coal deposits globally. Specially, we highlight the findings on coal-associated methanoarchaeal existence, abundance, diversity, metabolic activity, and biogeography in diverse coal basins worldwide. Growing evidences indicates that we have arrived an exciting era of archaeal research. Moreover, gasification of coal into methane by utilizing microbial methanogenesis is a considerable way to mitigate the energy crisis for the rising world population