IR@CIMFR - Central Institute of Mining and Fuel Research (CSIR)
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Determination of concentration of total sodium and potassium in surface and ground water using a flame photometer
No full textIn this paper, we have investigated 18 water samples collected from various sources, e.g., surface, underground and river water, as specimens for their sodium and potassium ions content in and around Dhanbad, a mining town, using the flame photometry. We have plotted the contour maps to show the spatial distributions of the dissolved sodium and potassium cations in the groundwater and surface water sources in and around the Dhanbad city to identify the relative contributions of human and natural phenomena to it. Along with it, water quality index (WQI) is calculated to evaluate whether the collected surface, ground and river water samples are fit for human consumption for the residents of those areas. The water of Maithan Dam has been observed to have the least sodium and potassium concentrations of 16 mg/l and 7 mg/l, respectively, which make it most suitable for human consumption. The water of Rani Talab Pond has the highest sodium and potassium contents of 49 mg/l and 24 mg/l. WQI values of all the samples are found to be less than 50, which indicates they are safe to consume by the humans. Reduction in the use of pesticides, potassium permanganate and water softeners is recommended to maintain WQI of the Dhanbad city within safe limit
Failure Analysis Of FRP Composite Bonded Socket Joint
No full textPipes and pipe joints are the backbone of many engineering applications such as oil and gas industries, mining applications, aerospace industries, structures, automotive industries etc. Adhesively bonded laminated Fiber Reinforced Polymer ( FRP) composite pipe joints have many advantages over conventional pipe joints (e.g. welded), as adhesive joints are less corrosive and this type of joint provide more uniform load transfer. In the present work finite element simulation of functionally modified adhesive bonded FRP composite socket joint has been carried out. The grading is given along bond-length for bonded socket joint of laminated Fiber Reinforced Polymer composite pipes. The loading condition is axial tensile at one free end and other end is constrained (fixed in all directions). The geometries and boundary conditions are taken from [1]. Different kinds of failures in the socket joint such as cohesion failure in the adhesive mid layer, adhesion failure in the tube-adhesive interface and adhesion failure in socket-adhesive interface have been analyzed using different failure criteria as Tsai-Wu failure criteria for adhesion failure and parabolic yield criteria for cohesion failure. Failure indices of the socket joint has been determined and critical region of the joint has been found at the edges and near the middle of the bonded tubular socket joint. Different functional grading has been applied and failure index profiles for different modulus functions have been drawn to compare these profiles obtained with failure index for isotropic adhesive to determine an appropriate function for modulus grading which reduces the stress concentrations effectively and increases the strength and life of the bonded tubular joint. Quadratic (parabolic), Biquadratic and Cosine functions are applied to compensate the stress pinnacle or stress singularities. The stress peaks at edges and near the middle of the socket joint are found to be more than the other portion of the socket joint. Flexible adhesives having lowest values of elastic modulus at edges and near the middle of the joint are used to reduce the stress peaks, and highest values of elastic modulus are the regions where stress values are less we used stiffer adhesive
Impact of the Combined Application of Biochar and Compost on Mine Soil Quality and Growth of Lady’s Finger (Abelmoschus esculentus)
No full textAmelioration of mine soil is challenging because of the lack of biologically active organic matter. The study was aimed to recycle yard waste into compost and biochar and to use them to reclaim mine soil. Biochar prepared at 350 °C showed the highest stable organic matter yield index and was used for the experiments. Lady’s finger was grown on mine soil amended with biochar (1%–5%), compost (2%–10%), and biochar-compost mixtures (2%–10%). Mine soil pH increased in all treatments. Mine soil dehydrogenase activity (42%–224%), microbial biomass carbon (4%–257%), and hydrolase activity (3%–230%) increased by combined application of biochar and compost. Lady’s finger plant height, biomass, and fruit yield were superior in biochar–compost mixtures compared to biochar and compost alone treatment. Thus the use of compost along with biochar could be recommended for reclamation of mine soil
Underground coal gasification techniques for different geo-mining conditions
No full textUnderground coal gasification (UCG) technique provides facilities for converting underground coal into synthetic gas by remote ignition and injecting steam as well as air into the coal seam. This product, which is also known as syngas, is a mixture of combustible gases like carbon monoxide, hydrogen and methane; and non-combustible gases like carbon dioxide, nitrogen and water vapour. This syngas is utilised for generation of emission-free power, ultra-clean diesel and manufacture of ammonia, fertiliser and other various valuable chemical products. The UCG technique is not only cost-effective but also environment friendly. This technique can also be employed for recovering coal from areas where conventional mining is either difficult or uneconomical. Due to this remarkable feature, UCG technique is going to play a greater role in coming years with the depletion of easy exploitable coal day by da
A Versatile VMPO Catalyst Prepared In Situ for Oxidative Ammonolysis of Isomeric Picolines and Xylenes
No full textThe V2O5–MoO3–P2O5 (VMPO) catalyst has been prepared in situ by thermal decomposition of vanado-molybdophosphoric acid (PMoV) on TiO2 support at 475°C. The TiO2 supported VMPO catalysts are characterized by FT–IR, XRD, BET surface area, NH3–TPD, and H2–TPR. Morphology of the catalyst has been studied by TEM. The accumulated data indicate decomposition of PMoV and presence of phosphate and pyrophosphate phases of molybdenum and vanadium after calcination. TPD and TPR studies exhibit the moderate acidity and presence of V4+ in the material, respectively. The VMPO catalyst has been used for ammoxidation of six different compounds including three isomeric picolines and three isomeric xylenes to the corresponding nitriles with the yield of 90–96%
Gasification studies of high ash Indian coals using Aspen plus simulation
No full textA simulation model of high ash Indian coal based Fluidized Bed Gasifier has been developed using Aspen Plus simulation software and the predicted results were validated against the experimental data available in literature for three different types of coals having different ash content which was as high as 48.9%. The hydrodynamic parameters as well as reaction kinetics were both adapted from standard literature data. To complete the gasification modeling, various unit operation blocks available in Aspen Plus was used. The three different coal samples which consisted of different proximate and ultimate analysis values was used for the simulation. Parameters such as steam to coal ratio and temperature were varied while the coal feed rate and air to coal (A/C) ratio were kept constant throughout the simulation process as per the standard literature data. The model predicted very well in determining the final synthesis gas compositions. The simulation experiment also yielded various more critical information which otherwise was not found in the followed literature. The simulation shows that the production of H2 increases with higher steam to coal ratio but follows a decreasing trend after a certain temperature while the amount of CO and CH4 was found to increase with temperature but follows a slight average decreasing trend on increasing the steam to coal ratio. The amount of CO2 formed was found to have increased in the temperature range of 750–950°C which further decreased with the increasing temperature. The carbon conversion efficiency was also found to have increased with increasing temperature as well as steam to coal ratio
Spontaneous Combustion in Relation to Drying ofLow Rank Coal
No full textThe water molecules associated with coal play a significant role in spontaneous ignition and combustion of coal. This paper deals with studies to evaluate the impact of moisture content on crossing point temperature (CPT) and ignition point temperature (IPT) of some low-rank coal and lignite after various stages of drying. Experimental data suggest (i) existence of critical moisture content value determining the propensity of a particular coal toward self-heating and (ii) content of moisture and nature of oxygen-bearing functional groups to be the most influencing factors in self-heating. The auto-oxidation cum self-heating characteristics of coal become more conducive with increase in the ratio of quantity of hydroxyl to carboxyl functional groups. The FTIR studies further corroborate that the initial stages of auto-oxidation cum self-heating occur presumably at the surface of the coal
Innovative Directional Controlled Blasting Technique for Excavation of Unstable Slopes Along a Busy Transportation Route: a Case Study of Konkan Railway in India
No full textMany cases of derailments, train accidents and traffic interruptions due to the slope failure and rockfall have been reported in the past on Konkan Railway trackline because of unstable rock slopes. The authorities installed stability enhancement measures such as wire netting, rock bolting and shotcreting which were found insufficient. The failed geotechnical measures prompted authorities to excavate the unstable slopes. Rock blasting is generally not preferred for the excavation of slopes along the transportation route. Stabilisation and widening of slopes by blasting need closure of the route for a considerable time. Discontinuing traffic on Konkan Railway route was undesirable as it connects two important port cities Mumbai and Mangalore. The paper presents an innovative directional controlled blasting (DCB) technique for excavating three unstable slopes (i.e. cuttings) in hilly terrain without disturbing the traffic. New empirical formulae for small geometry blasting to estimate burden and throw have been developed. A unique sequence of firing and excavation with powder factor varying between 0.04 and 0.39 kg/m3 irrespective of the actual free face was used for rock blasting. The process controlled the throw of blasted material over the track and resulted in a smooth and stable wall. The slope angle has been changed from 80 to 82° to 45–47° and probability of wedge, planar and toppling failures was eliminated. About 100 such accident-prone slopes (52 km cumulative length, 7% of total route) situated at discrete locations along Konkan Railway route were stabilised using the technique. No incident of rockfall and slope failures along these slopes has been observed after the stabilisation
Impact of the Combined Application of Biochar and Compost on Mine Soil Quality and Growth of Lady’s Finger (Abelmoschusesculentus)
No full textAmelioration of mine soil is challenging because of the lack of biologically active organic matter. The study was aimed to recycle yard waste into compost and biochar and to use them to reclaim mine soil. Biochar prepared at 350 °C showed the highest stable organic matter yield index and was used for the experiments. Lady's finger was grown on mine soil amended with biochar (1%-5%), compost (2%-10%), and biochar-compost mixtures (2%-10%). Mine soil pH increased in all treatments. Mine soil dehydrogenase activity (42%-224%), microbial biomass carbon (4%-257%), and hydrolase activity (3%-230%) increased by combined application of biochar and compost. Lady's finger plant height, biomass, and fruit yield were superior in biochar-compost mixtures compared to biochar and compost alone treatment. Thus the use of compost along with biochar could be recommended for reclamation of mine soil
Ameliorative effect of Lantana camara biochar on coal mine spoil and growth of maize (Zea mays)
No full textThe aftermath of surface mining is a wasteland deprived of vegetation, soil structure and biodiversity. The unearthed overburden material is nutrient deprived and can only support the growth of invasive weeds such as Lantana camera which often cause allelopathy. The aim of the study is to prepare biochar from these noxious weeds and use it as an amendment for the mine spoil reclamation. Lantana biochar (LB) was prepared and applied to mine spoil, and Zea mays L. growth on biochar amended mine spoil was monitored for three months. Biochar application in a coal mine spoil using LB is comparatively de novo approach for reclamation practitioners. LB was prepared at varying temperature (250, 350 and 450℃) and residence times (30, 45 and 60 min) and characterized. After characterization, the most recalcitrant biochar at 450℃ for 60 min was chosen for application for the study. A pot trial was conducted to study the effect of LB at 0, 5, 10, 20 and 30 g kg−1 dosage on the yield of Zea mays and mine spoil properties. Significant ameliorative effects were observed with increase in organic carbon content (2.9 times), cation exchange capacity (2 times), water holding capacity (0.13 times) and decrease in bulk density (0.5 times) in the mine spoil. The seedling vigour index and germination also increased significantly (p < .05) at 30 g kg−1 biochar treatment compared to control. The study concluded that LB has the potential to remediate coal mine spoils and promote re‐vegetation in degraded land