IR@CIMFR - Central Institute of Mining and Fuel Research (CSIR)
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Detection of Old Mine Workings over a Part of Jharia Coal Field, India using Electrical Resistivity Tomography
No full textOld mine workings, mainly hidden galleries, goafs, shafts etc may pose a great threat to the local environment and also for future mine development. The present study mainly deals with delineation and mapping of old mine workings over Tikmani-Gareriya section, a part of east Basuria colliery, Jharia coal field, India using state-of-the-art 64 electrodes and 61 channel FlashRES-Universal electrical resistivity tomography (ERT). ERT data have been acquired along a line at 5m electrode spacing covering total profile length of 315m using Wenner, Schlumberger, Gradient and Dipole-Dipole arrays over a known old mine working. Further joint inversion of all combined arrays has also been carried out using 2.5D resistivity inversion program to combine the relative advantage of all arrays for producing superior results. The acquired data have been analysed using four different thresholds for all arrays with quality factors 15, 10, 5, and 1; each with 60mA current. 2D inverse resistivity models generated using Joint inversion of all combined arrays with quality factor 5 provides best result for delineation of coal pillars, galleries and goafs followed by Gradient, Schlumberger, Dipole-Dipole and Wenner arrays with same quality factor. Coal pillars have been identified with relatively high resistivity anomaly whereas galleries and goaf have been delineated with relatively low resistivity anomaly. The estimated range of resistivity variation of coal pillars have been well corroborated with published results. The results prove the efficacy of the ERT technique for detection of old mine workings
Impact of Fly Ash Placement in an Abandoned Opencast Mine on Surface and Ground Water Quality: A Case Study
No full textWe investigated potential contamination of surface and ground water due to placement of fly ash in an abandoned area of an active opencast mine. Leachates from the fly ash and pond ash did not exceed the effluent discharge limits for inland surface water. Even though iron was one of the major components of the ash, it did not exceed 0.3 mg/L in the leachates. Water quality studies carried out at the coal mine indicated that fly ash disposal there, was not affecting the groundwater, but that the water discharged from the active portion of the mine contained high concentrations of total hardness, total dissolved solids (TDS), sulphate, manganese, and iron, exceeding India’s effluent discharge limits. The nearby Ajay River was not contaminated but the confluence point where the mine water met the Ajay River contained high levels of TDS, sulphate, and manganese. Groundwater in the area surrounding the mine was not significantly impacted. Multivariate statistical analysis was carried out to determine the relationships between the different water quality parameters
Delineation of fracture zone for groundwater using combined inversion technique
No full textThis paper deals with severe issue of groundwater crisis over a part of hard rock terrain in the premises of Central Institute of Mining and Fuel Research (CIMFR), Dhanbad, Jharkhand, India. The goal of this study is delineation and mapping of fractured rock mass for groundwater exploration. Generally, fractured rock formation is the only source of groundwater in hard rock terrain. Electrical resistivity tomography (ERT) survey was conducted along three profiles over different parts of CIMFR premises using Wenner–Schlumberger and dipole–dipole arrays. Combined inversion of both arrays has been carried out during data analysis for better delineation of fracture rock masses in the complex geological environment. Two water-saturated fracture zones have been identified for the availability of groundwater, which has been confirmed by direct borehole drilling. This proves the effectiveness of ERT survey by combined inversion of both arrays for delineation of fracture zones
Groundwater prospecting by the inversion of cumulative data of Wenner–Schlumberger and dipole–dipole arrays: A case study at Turamdih, Jharkhand, India
No full textThe present study deals with groundwater prospecting in hardrock terrain. Initially, the Wenner–Schlumberger array and the dipole–dipole array data have been acquired using Syscal Junior Switch-48. Furthermore, data acquired using both arrays have been merged using Prosys-II data handling software for the inversion of the cumulative data for possible mapping of water-bearing fracture rock masses with different structural distribution in a complex geological environment. The data have been analysed using RES2DINV software, based on the smoothness constrained least-square technique. Two numbers of 2D electrical resistivity tomography profiles (AA′′ and BB′′) have been selected over an official colony of the Turamdih uranium mine for groundwater prospecting, which is located at about 24 km west of Jaduguda, Jharkhand, India. High-resistivity features associated with a dyke-like structure have been delineated in both the profiles. Three low-resistivity features have been delineated as water saturated alluvium/aquifers in profile AA′′. A low-resistivity feature associated with the water-saturated fracture zone has been identified in profile BB′′, which is well correlated with the surficial location of an ephemeral channel at the bottom of the hill across the slope. It is observed that geoelectric sections generated by the inversion of cumulative data of both arrays provide superior results compared with the Wenner–Schlumberger and dipole–dipole arrays, separately
Exploring new correlation between hazard index and heavy metal pollution index in groundwater
No full textHazard index and various heavy metal pollution indices in groundwater are generally poorly correlated though all of them aim to address water quality. A semi empirical approach has been proposed for correlating Hazard Index (HI) of groundwater samples with a recently introduced heavy metal pollution index, m-HPI. m-HPI has two components, a positive index (PI) and a negative index (NI). It is possible to correlate HI with PI and NI through multivariate non-linear regression (MVNLR). Correlation performance may be improved by optimizing the weightage factor of each heavy metal. Introduction of USEPA heavy metal reference dose (RfD) in the expression for weightage factor improves the correlation still further. The newly proposed approach has been successfully validated with seven sets of water samples of different origin comprising different sets of heavy metals. The derived correlation function is generic and has global applicability as optimized m-HPI (PI and NI) data of 305 groundwater samples spread over six different locations could be well correlated with corresponding HI through a single generic correlation function employing MVNLR model. The predictive capability of MVNLR model has been demonstrated for each site. This communication has brought for the first time two poorly correlated similar narratives such as HI and heavy metal pollution index (HMPI) on the same page and provided a very useful predictive tool
Dynamic simulation approach to assess influence of charging parameters on blast induced vibration
No full textBlast induced ground vibration is one of the key concerns from safety view of nearby structures. There are many direct and indirect parameters responsible for blast induced ground vibration. Explosive parameters including its charging quantity and quality is one of them. Velocity of detonation of explosives, its interaction with rock strata and charging condition of a blasthole influences blast outputs in the form of fragmentation as well as undesirable effects like ground vibration, flyrock, air-over-pressure/noise etc. Researchers around the globe have established empirical formulations to investigate effects of explosive parameters on blast induced ground vibration. Following paper focused on investigating influence of charging parameters on blast induced ground vibration. Numerical simulation using dynamic modelling package of FLAC3D have been used for this. Signature hole geometry with rock properties and explosive properties in the form of detonation pressure has been modelled. Detonation pressure of the explosive was estimated from recorded in-the-hole velocity of detonation and density data for different explosive types. Damping parameters in the form of damping coefficient and frequency has been given to deplete blast vibration velocity for the medium. This was estimated by back calculation from recorded blast vibration data. Influence of hole diameter, distance of blast face from monitoring point, column length of explosive charge and charge distribution on blast induced vibration were assessed. Blast induced ground vibration in the form of history of velocity peaks has been plotted against dynamic time of blast wave propagation. Results of the dynamic simulation shows effects of hole diameter and charge column length on blast vibration in the same line with explosive weight per delay considered in USBM predictor equation. Investigation of effects of distance on blast induced vibration shows dependency of blast vibration on directional distance rather than radial distance. Charge distribution effects shows considerable reduction in blast vibration magnitude for distributed charge than full column charge
Geochemical attributes, pore structures and fractal characteristics of Barakar shale deposits of Mand-Raigarh Basin, India
No full textPore structures in the shale matrix are an essential factor affecting the storage capacity of gas of shale beds as well as production performance. Twenty organic-rich shale samples at different depths were collected from Barakar Formation of Mand-Raigarh basin, to examine the pore structure and their fractal characteristic. Fractal dimension was calculated by following FHH theory to investigate the complexity of pore surfaces, storage mechanism and the pore network system. The complex pore system influenced by thermal cracking of organic matter, pore dissolution during geochemical weathering and tectonics of the basins having surface area 5.56–23.94 m2/g (avg. 14.21 m2/g). Whereas, the pore volume determined using the BJH model varying from 0.035 to 0.076 cc/g (avg. 0.053 cc/g). FTIR spectrum demonstrated that significant presence of aliphatic side chains and aromatic carbon structures existing in studied shale influencing the pore volume. It is summarized that pores and matrix of shale are built by complex mixtures of organic and inorganic content. Further, the pores are categorized into organic pores evolved during thermal cracking, inter-granular, intra-granular and inter-crystalline due to the large content of altered clays and minerals showing fissile nature. The SEM-EDX derived facies indicating the involvement of different chemical constituents following the trend of alteration as well as carbon enrichment. The D1 and D2 values obtained through FHH model range from 1.17 to 2.45 and 2.54–2.70, the fractal values particularly D2 are ∼3 demonstrating the pore surfaces and structure of studied shales beds are complex and heterogeneous. This study helps to enhance the exploration and advancement in the shale gas resources from Ib-River of Mand-Raigarh Basin, Indi
Dehydration of isopropanol to propylene over fullerene[C60] containing niobium phosphate catalyst: Study on catalyst recyclability
No full textSynthesis of lower olefins from biomass is an attractive area of research as the petroleum feedstocks are limited day to day. A fullerene [C60] based niobium phosphate acid catalyst has been tested for isopropanol dehydration in gas phase for production of propylene and a thorough study has been undertaken on its recyclability. The physicochemical properties of the catalyst before and after reaction have been studied by several techniques, namely FTIR, FESEM, BET surface area, HRTEM, NH3-TPD, TGA, XRD and O2-TPO. The BET result suggests the trapping of coke within the micropores which retard the catalytic activity. Interestingly, the NH3-TPD profile demonstrates the abrupt increase in acidity of the used catalyst due to the widening of narrow pores while, CP-MAS 31 P NMR spectra show increase in population of hydrogen phosphate species may be caused by the decomposition of surfactant phosphoric acid complex. However, the UV–vis spectra support structural change by the oxidation of fullerene during regeneration leads to decrease in the acidity. The catalytic activity is evaluated in the temperature range 453–573 K, shows consistent performance up to 6th regenerated cycle with low activation energy (30 ± 5 kJ/mol). Furthermore, a detailed discussion of the reaction kinetics and reaction mechanism has also been demonstrated
Investigation on the Combustion Behavior of Coal at Various Level of Washing in TGA and Drop Tube Furnace
Get PDFCleaning of coal resulted in ash reduction, heat value enhancement, increased reactive maceral content and change in ash composition influencing combustion performance.
With washed fractions, trends of improved combustion behavior were observed in thermo-gravimetric analyser, which was not always reflected correspondingly in bench
scale combustor, i.e. drop tube furnace (DTF). Lower burnout efficiency in DTF was observed when top port char particles were totally masked by defused mineral matter.
Higher burnout efficiency was observed with tenui ballon/ sphere type of char structure partially covered by defused mineral matter. Overall improvement of combustion
performance also led to CO2 emission reduction
Experimental process parameters optimization and in-depth product characterizations for teak sawdust pyrolysis
No full textPyrolysis is an efficient thermochemical route to obtain biofuels in the form of bio-oil, biochar and pyrolytic gas from the processing of biomass. Pyrolysis experiments were performed with teak sawdust to determine the yield and main characteristics of solid, liquid and gaseous products. Experiments were carried out in the temperature range of 400–700 °C in 100 °C intervals, nitrogen flow rate of 150–250 mL/min, packed bed height in between 2 and 8 cm and particle size in between 0.18 and 0.60 mm. The maximum bio-oil and biochar yield were observed at 600 °C (48.8%) and 400 °C (37.42%), respectively. Physical properties (viscosity, density, carbon residue, pH and HHV) of bio-oil were determined and the chemical properties were investigated using FTIR and GC–MS. Further, biochar was characterized with proximate, ultimate, HHV, FTIR, SEM-EDX, BET surface area and XRD analysis. Non-condensable gases coming out during pyrolysis were analyzed using gas chromatography and amount of H2, CH4, CO and CO2 were determined. According to characterization results, bio-oil can be used as biofuel after up gradation or as source of valuable chemicals, biochar can be utilized as solid fuel or seems to be suitable in waste stream purification as it has very high BET surface area. In addition, pyrolytic gases have significant amount of methane and hydrogen that provides good combustion properties