IR@CIMFR - Central Institute of Mining and Fuel Research (CSIR)
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Heavy metal geochemistry and toxicity assessment of water environment from Ib Valley Coalfield, India: Implications to contaminant source apportionment and human health risks.
No full textThe present study aims to investigate the hydrogeochemical evolution of heavy metals and assesses impacts of mining activities on the groundwater resources and potential human health risks in the coal mining areas of Ib valley coalfield. In this perspective, a total of one hundred and two mine water and groundwater samples were collected from different locations. The water samples were analysed for some selected heavy metals i.e. Mn, Cu, Pb, Zn, Ni, Co, As, Se, Al, Sr, Ba, Cd, Cr, V and Fe using ICP-MS. In addition, pH and SO42− concentration were also measured following APHA procedure. The water pH in the Ib valley coalfields ranged from 3.26 to 8.18 for mine water and 5.23 to 8.52 for groundwater, indicating acidic to alkaline nature of water. Mn in mine water and Zn in groundwater environment were observed as the most dominant metals. The water hazard index (WHI) reflects that around 80% of mine water are non-toxic (WHI10) and 15% extremely toxic (WHI>15). Relatively high pH and low concentration of dissolved metals and SO42− in groundwater as compared to mine water indicate lesser impact of mining activities. The calculated drinking water quality index (DWQI) suggests that Mn, Al, Ni and Fe in mine water and Mn, Fe, Ni and Pb in groundwater were the major objectionable metals which caused the water quality deterioration for drinking uses. Further, the non-carcinogenic health risk assessment for adult male, female and child populations identifies Co, Mn, Ni as the key elements making the water hazardous for human health. Comparatively higher ratio of ingestion rate and body weight in child population might be causing higher health risks in child population as compared to adult male and adult female populatio
Integrated MEUF, MENF and MERO for phenol remediation: A process intensified technology.
No full textThe study focuses on micellar-enhanced pressure-driven membrane separation (RO, NF, UF), for phenol removal. The rationale was to develop, a simple and efficient technique for complete remediation of phenol. For this, experiments toward integration of the pressure-driven membrane processes and comparative performance analysis were undertaken. Effect of micellar aggregation, nature of surfactant, phenol loading, and process parameters on processes like nanofiltration and reverse osmosis were studied. Cost–benefit analysis was also carried out to assess the techno-commercial viability of the process. Comparative phenol removal efficiency obtained follows the order MENF > MEUF > MERO. Combined MEUF and MENF demonstrated sustained high removal efficiencies of up to 95% and above. Subsequently surfactant regeneration and its reuse were investigated. Competitive phenol removal efficiencies in the range of 80–87% were attained using regenerated surfactant when tested up to 4 operational cycles. Several useful insights about surfactant-mediated pressure-driven transport and techno-economic analysis were gained through this study
Influence of Contaminated Ammonium Nitrate on Detonation Behaviour of Bulk Emulsion Explosives and Numerical Analysis of Detonation-Induced Damage Zone
No full textBulk emulsion explosives are widely used industrial explosives for mining and civil infrastructure work. Ammonium nitrate is an important ingredient for bulk emulsion explosives and plays an important role in the detonation behaviour. Considering the growing demand for bulk emulsion explosives, an in-depth investigation is necessary to understand how the impurities in ammonium nitrate can affect the detonation behaviour and safe handling of bulk emulsion explosives. Herein, we have demonstrated the influence of contaminated ammonium nitrate on the detonation behaviour and characteristics of bulk emulsion explosive. Furthermore, the particle size of the internal phase of the all prepared bulk emulsion explosives was analyzed using optical microscopy to confirm the effect of contaminated ammonium nitrate. Time dependent chemical-induced gassing behaviour and detonation velocity of prepared bulk explosive samples were also studied. Importantly, numerical modeling was used to stimulate the detonation-induced rock damage zone and assess the impact of ammonium nitrate contamination. Additionally, a real-time rock damage pattern of different prepared samples was further investigated to understand the impact of contamination on the detonation induced crack development phenomena of different bulk emulsion samples
Investigation and mapping of toxic fumes produced by detonation of ANFO explosives in underground space
No full textPost-blast fumes are hazardous and known to cause severe health related issues of workers. Further, these harmful gases have a significant impact on the surrounding environment. Thus, it is imperative to have an in-depth understanding of the real time detonation fume generation in underground space to avoid hazardous health risk of the worker. In this context, the mapping of toxic fume concentrations generated by the detonation of ANFO explosives in the actual field is a fascinating area of research that has a great environmental impact. This article examined the real-time analysis of toxic fumes generated by ammonium nitrate fuel oil (ANFO) explosives at various locations of a metalliferous underground mine. Furthermore, detonation parameters of various ANFO explosive compositions were also studied at the mining site. On-site blasting studies were performed with ANFO explosives, and post-detonation fume measurements enabled us to map the CO and NOx concentrations in underground spaces. Toxic fumes like CO and NOx were analyzed before and after each blasting operation at different intervals, and found within the allowed limit as per the Directorate General of Mines Safety guidelines. Additionally, an empirical correlation has been established to evaluate the maximum detonation velocity based on the alteration of ammonium nitrate and fuel oil composition
Support design in underground coal mines using modified rock mass classification system (RMRdyn) for enhanced safety– an approach from stable and failed roof cases
No full textBord and pillar method of mining continues to be a major operation in India with about 160 mines producing 35 MT of coal. Owing to the exhaustion of near-surface deposits, environmental impacts and land acquisition issues associated with surface mining, underground coal mining is expected to take a leap in the next decade. Weak and layered roof strata in underground mining play a significant role in roof failures in development headings affecting both safety and productivity. Despite well-defined support design guidelines based on CMRI-ISM RMR, roof failures are still a cause of great concern. In this research, firstly, a risk matrix has been framed on the basis of stable and unstable roof conditions for evaluating the potentiality of roof failure. This was followed by the development of a modified Rock Mass Classification System (RMRdyn) considering Seismic velocity of rocks as one of the key parameters. A modified empirical relationship for rock load (RL) and a handy nomogram has been developed based on input parameters, namely, P-wave velocity, structural features, slake durability and groundwater condition. A guideline for roof support design has been framed based on rock load computed for RMRdyn values ranging from 25 to 70. The developed models have been validated by statistical tools. The study also presents the risk classes to enable rock engineers to design more rational support systems in coal mine development headings
Development of a mine‑functionalized fluorescent silica nanoparticles from coal fly ash as a sustainable source for nano fertilizer
No full textScaling up the synthesis of fluorescent silica nanoparticles to meet the current demand in diverse
applications involves technological limitations. The present study relates to the hydrothermal
synthesis of water‑soluble, crystalline, blue‑emitting amine‑functionalized silica nanoparticles
from coal fly ash sustainably and economically. This study used tertiary amine (trimethylamine) to
prepare amine‑functionalized fluorescent silica nanoparticles, enhancing fluorescence quantum
yield and nitrogen content for nanofertilizer application. The TEM and FESEM studies show that
the silica nanoparticles have a spherical morphology with an average diameter of 4.0 nm. The x‑ray
photoelectron and Fourier transform infrared spectroscopy studies reveal the presence of the amine
group at the surface of silica nanoparticles. The silica nanoparticles exhibit blue fluorescence with
an emission maximum of 454 nm at 370 nm excitation and show excitation‑dependent emission
properties in the aqueous medium. With the perfect spectral overlap between silica nanoparticle
emission (donor) and chlorophyll absorption (acceptor), fluorescent silica nanoparticles enhance plant
photosynthesis rate by resonance energy transfer. This process accelerates the photosynthesis rate to
improve the individual plant’s quality and growth. These findings suggested that the fly ash‑derived
functionalized silica nanoparticles could be employed as nanofertilizers and novel delivery agent
Optimization of Blast Design Parameter for Ring Blasting in Underground Hard Rock Mine Using Numerical Simulation
No full textSublevel stoping is the most popular and practiced mining method in underground hard rock mines. Proper planning and its execution is the key requirement for stope extraction using this method. The stope extraction has been a challenging task since decades. The major reason is the unavailability of free faces as compared to opencast bench blasting. The geological and geotechnical parameters change gradually even within the stope itself. So, the blast design parameters should be planned according to the scenario of the upcoming ring. The blast design parameters like burden, toe spacing, inclination of blastholes, diameter of blastholes, charge density of explosive, etc., play an immense role in the rock damage. For the proper breakage of rock, the movement of burden is the prime objective. To study this, an explicit dynamic based modeler of M/s Ansys was used. The burden values were varied from 20 to 65 times of blasthole diameter to assess the optimum burden value during the study. The models were simulated for the rock having uniaxial compressive strength as 35 MPa and 102 mm blasthole diameter. Three holes were simulated having depth around 14–14.5 m. Different blast design parameters and respective blast-induced ground vibration have also been measured at the experimental site. The core samples of the rock present at the experimental site have been used for the evaluation of geotechnical parameters. These geotechnical parameters were used in the simulation models. The volume of rock excavated along the free face has been calculated in each model by varying the burden. It has been found that the burden value can varies from 35 to 40 times blasthole diameter (3.6–4.1 m) to achieve a greater volume of rock along the free face for 102 mm blasthole diameter and rock of 35 MPa uniaxial compressive strengt
Evaluation of Optimum Burden for the Excavation of Narrow Vein Ore Deposits Using Numerical Simulation
No full textBurden is one of the major influencing blast design parameters which should be optimised for the extraction of narrow vein ore bodies. Numerical simulation-based approach has been used for the optimisation of burden in this paper. Different models were prepared under varying parametric conditions including width of the vein, blasthole diameter and burden. The RHT concrete constitutive model was used for the analysis of damage contour. The volume of the excavated rock along the free face (EV) was quantified from the model output in all the scenario. The study showed that EV initially increases with the increase in burden for a particular width of vein. Furthermore, EV starts decreasing after a point termed as pivot point. The value of burden at this pivot point was considered as optimal in this study. The best fit curve between EV and burden for three blasthole diameter and seven different width of vein were plotted. In all instances, the outputs of the model followed the second-degree polynomial equation. The study also suggests that the optimum burden reduces with the increase in the width of the vein. It has also been found that the optimum burden follows power trend with the increase in width of the ore body irrespective of blasthole diameter. Based on the optimum burden obtained from the output of simulation along with different blasthole diameter and width of the ore body, an empirical relationship has been established. The developed empirical relationship has a good agreement with the experimental trial data
Targeting ash generated from coal combustion as secondary source of rare earth elements
No full textThe demand of Rare Earth Elements (REEs) has increased for the development of clean and green technologies. Conventional geological sources of REE are insufficient to overcome the high demand of REE; hence, the secondary resources are being actively explored. Coal ashes (CAs), a potentially hazardous material, is one of the best secondary sources containing high concentration of REE. The present study aims to explore the abundance of REE in coal and coal ash from different Thermal Power Stations (TPS). The mineralogy and surface morphology of all samples have been determined. The coals mostly consist of quartz and kaolinite, whereas CAs predominantly contain quartz and mullite. Both coal and CAs are dominated by LREE elements, followed by MREE and HREE. The outlook coefficient (Cout) is close to “1” and the critical percentage (Cp) is more than 30%. Coal ash from some of the TPS is identified as secondary source for REE. Fractionation study of REE from coal to CA is carried out to understand the feasibility of CA. A Pearson correlation has been plotted for individual REE elements with other parameters to understand the affinity of REE to different phases of CA
V2X, GNSS, radar, and camera-based intelligent system for adaptive control of heavy mining vehicles during foggy weather
No full textOne of the most challenging scenarios for drivers of open-pit mines is driving in dense fog. As a result, drivers cannot see the road, which causes significant vehicle colloidal accidents. To overcome the problem, an intelligent vision enhancement system has been developed by real-time processing and integrating data from the vehicle-to-everything (V2X) module, global navigation satellite system (GNSS), radar, and infrared cameras to enhance the visibility range of the operative road to the driver and mitigate the chances of accidents. Final images after image processing and object detection are displayed using a dashboard screen in front of the driver for adaptive control and safe operation. Performance analysis of the visual computing algorithm has been carried out in a mine based on image quality parameters. Field-tested images’ average contrast value, peak signal-to-noise ratio, structural similarity index, visual information fidelity, and universal quality index were 0.87, 19.36, 0.39, 0.82, and 0.56, respectively, and the calculated accurateness of the convolution neural network (CNN)-based object detection model was 90%. These values indicate the output of the image processing algorithm provided better-enhanced images in the foggy condition. With the help of image processing algorithms, the camera view is able to provide a clear vision of more than 30 m in dense fog. Further, using V2X technology, the augmented visibility range has been increased up to 200 m. The 3D augmented reality (AR) view and 2D navigation view provide other surrounding vehicle locations. Untagged objects like rocks or bunds are also detected and displayed using radar