IR@CIMFR - Central Institute of Mining and Fuel Research (CSIR)
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Role of oxygen vacancy in cobalt doped ceria catalyst for styrene epoxidation using molecular oxygen
No full textThe oxygen vacancy formation and refillment of oxygen vacancy by molecular oxygen are the key steps of catalyst redox cycle towards styrene epoxidation reaction. Well dispersed, Isomorphically substituted and energetically favorable cobalt based redox cycle in ceria lattice caused lower oxygen formation energy, oxygen adsorption energy and activation energy than pure ceria for the reaction ensuring excellent catalytic activity. DFT studies show that inclusion of cobalt in ceria leads to lower the oxygen removal energy. Oxygen vacancy formation resulted into the rise of the spin magnetic moment of cobalt to 2.70 μB indicating reduction of Co+3 to Co+2 as well as fall of oxygen adsorption energy. A mechanistic proposal is presented in which Co3+/Co2+, Ce4+/Ce3+, oxygen vacancies are involved in adsorption, activation reaction of oxygen and styrene on the surface of the catalyst. The Co(4)-CeO2 catalyst also demonstrated reactivity towards stilbene, cyclooctene under similar reaction condition. The catalyst was regenerated up to three cycles
Studies on the characterization of Indian coals using FE-SEM and EDS and its relevance to coal washability
No full textThe basic objective of coal washability is to establish the set of maximum possible separation performance for a given coal feed and to access to cut gravity for achieving clean coal of desired quality. The conventional float-sink (F-S) analysis is time taking, hazardous and at the same time costly. Indian coals are of drift origin and vary widely in the washability characteristics and there is also wide variation from seam to seam at the same mine. The washery is to be fed with coals from multiple sources/seams, which are having wide washabiltiy characteristics. The standard practice of washability will not help the washery t improve its performance as a result on alternative online analyzer especially for a commercial coal washing plants which maximize the reliability of actual coal washability in conjunctin with particle size distribution, ash, etc is the need of the hour.
Researchers worldwide, are trying to establish the washability characteristics of coal through different routes X-ray/gamma, basically imaged based/processing to solve the problem. An automated coal washability analyser is being under developmental stage which will give near real time F-S data that would maximize the yield at desired ash level and impact positively on the profitability of the plant operation. The results are very promising with the actual standard float and sink data to the coal analysed with the X-ray analyser, which are being highlighted in the present paper
Evolution of Applicability of robotics in underground mine services
No full textMining is one of the most hazardous and hostile occupations in the world. Even though a lot of hazards are associated with this industry, mining of both fuel and mineral based deposit from earth is necessary for the economic growth of the nation, maintaining a low cost of production by avoiding import and gaining independence from other mineral rich and technologically advanced nation for its day to day requirements of minerals. But, the industry must keep in mind that it should adopt the policy of safety first than production in the context of a large number of dangers which are associated with mining activity and must take necessary action to avoid such unwanted events from happening. Though safety standards in current mining industry scenario have improved by providing training sessions to miners regarding safe and better work practices and using better machines for stabilization of mining structure and extraction. But still disaster tends to happen in mines worldwide and rescue of miners and mining machinery is the first task that is performed by industry by sending rescue team without prior knowledge about underground mine environmental condition since post-disaster installed mine environment monitoring is either damaged or destroyed. Subsequently, sending mine rescuers will be dangerous and may cause even bigger disaster from happening which is evident in past. Therefore, the mining industry is now relying upon robotics for mine disaster rescue management to assist human rescuers and avoid further exposure to dangerous post-disaster underground mine environment. This paper gives an overview of applicability of robotics in mine disaster rescue management
Porosity controls and fractal disposition of organic-rich Permian shales using low-pressure adsorption techniques
No full textThe pore structure characteristics of the Lower and Upper Permian shales belonging to the Barren Measures and Raniganj Formations, respectively, were investigated using the low-pressure N2 adsorption-desorption experiments. It was found that the kaolinite content of the Barren Measures shales strongly influenced the Brunauer-Emmett-Teller specific surface area (BET SSA). However, it was the Rock-Eval temperature maxima (Tmax) for the Raniganj Formation shales that influenced the BET SSA values. These shales are dominantly mesoporous and display a negative correlation between BET SSA and average pore radius. Nitrogen adsorption-desorption isotherms are of type IIB and type IV, displaying H2, H3, and hybrid H3-H4 hysteresis patterns. A strong positive correlation exists between average pore radius and the difference in volumes of gas adsorbed at the last-two-highest relative pressures measured. Samples with steeper isotherm slopes at the higher relative pressure range were those with the highest average pore radii. Porosity fractal dimension, D2 displayed a positive correlation with BET SSA and Tmax, and a negative correlation with average pore radius. It is thus concluded that shales with the lowest average pore sizes and highest thermal maturities are marked by larger SSA and more complex pore structures. One of the tested samples (CG 1019) with the highest D2 value is associated with the lowest D1 fractal dimension value. That counter intuitive relationship may reflect analytical constraints of the nitrogen adsorption method at lower relative pressures
Modification in spinach response to UV-B radiation by nutrient management: Pigments, antioxidants and metabolites
No full textFertilizers are extensively used essentially to meet the food demand of increasing population. Further, they help the plants in alleviating the deleterious effects of UV-B radiation. In this study, we explored this in spinach (Spinacia oleracea L.). S. oleracea plants were grown under ambient and elevated UV-B at different combinations and concentrations of NPK: (i) recommended level of NPK (RNPK); (ii) 1.5 times recommended level of NPK (1.5 × NPK); (iii) 1.25 times recommended level of N plus recommended PK (1.25N+PK); and (iv) 1.25 times recommended level of NPK (1.25 × NPK) to assess the amelioration potential of nutrient combination. Higher availability of NPK provided more protection to plants against oxidative stress as is obvious from reduction in MDA content under elevated UV-B which can be attributed to low oxidative stress due to higher induction of antioxidants. Protection provided to chlorophyll by nitrogen was enhanced by phosphorus and potassium in 1.5 × NPK and 1.25 × NPK compared to RNPK and 1.25 × N+ PK. Maximum increase in PAL activity in plants at 1.5 × NPK did not translate into flavonoid accumulation in same at initial age of observation. Maximum alleviation against UV-B radiation was observed at 1.5 × NPK which can be attributed to better ROS scavenging capacity, more metabolite production and maintaining photochemical efficiency
Study on Altered Depiction of Pond Water Quality During Post-Immersion of Idols
No full textFestivals are an integral part of rich and diverse cultural heritage of India. But this cultural activity also has a centre of pollution. The activities of immersing idols and throwing other materials of various rituals are the sources of pollution which deteriorate the quality of ponds, lakes and rivers in India. Artificial paints used for idols comprise heavy metals, which are potentially hazardous on bioaccumulation and biomagnifications as they enter into the food chain. The present study has been made to ascertain the truth that idol immersion is source of water pollution and addresses the contamination of chemical pollutants caused by such activities. The result reveals that the water quality parameters, such as total hardness, total suspended solids, total dissolved solids, biochemical oxygen demand, chemical oxygen demand and chloride were found to be drastically increased after the immersion of idols in the pond. The integrated quality analysis using sensitivity functions defined for each parameter over the quality interval constituted by the lower permissible limits, desirable limits and maximum permissible limits of the accepted standards has been carried out for detecting the overall quality alteration due to idol immersion for assessing the damage to the environment in numerical value
Assessment of occupational health exposure to particulate matter around opencast coal mines, India: a case study
No full textParticulate matter concentrations in terms of occupational health, namely inhalable, thoracic, and alveolic, were measured using GRIMM aerosol spectrometer in Basundhara Grajanbahal Area, Sundergarh, India. At mining sites, average inhalable, thoracic, and alveolic particle concentrations were found to be 1.8 to 2, 1.8, and 1.2 to 1.6 times the concentrations at residential sites, respectively. Ratio of thoracic/inhalable, alveolic/inhalable, and alveolic/thoracic varied in the range 73–91%, 42–73%, and 55–80% at residential sites and 69–84%, 37–52%, and 49–63% at mining sites, respectively. From correlation analysis, significant positive correlations among particulate matter concentrations, positive correlation of particulate matter concentrations with relative humidity, and negative correlation with temperature and wind speed were obtained
Coal Winnowing: An Innovative Technique for Dry Coal Beneficiation
No full textThermal Power plants in India burn high ash content coal of 40-60 ash % due to the paucity of low ash coal. Combustion of high ash coals creates a lot of environmental issues like atmospheric pollution, generation of high quantities of fly/bottom ash, water and soil pollution. The common practice for reduction of mineral matter and undesirable pollutants in coal is by wet washing or cleaning. The disadvantages of wet coal cleaning are high water requirement, increase in moisture content of washed coal thereby decrease in heat value, chemical breakdown of coaly material, physical degradation & generation of excessive fines, disposal of slurry water in addition to high capital investment, high processing cost and cumbersome handling. A new dry coal beneficiation system namely "COAL WINNOWING SYSTEM" has been designed & developed. Various coals from Wardha Valley Coalfields of WCL had been experimented in Coal winnowing system. Studies on Coal of size fractions; 50-25 mm, 25-13 mm, 13-6 mm were conducted. One experiment conducted with size fractions of 25-13 mm WCL -Marki Mangli mine coal shows overall ash percentage reduction from 47.4% to 43.1% with cleans yield of 79.5%. The parameters like air velocity, horizontal distribution of particles and handling of higher sized coal, 100-50 mm was optimized. Studies on ROM coal from New Sasti Mines, Wardha Valley Coalfield, Maharashtra on size fraction of 100-75 mm shows overall ash percentage reduction from 55.8% to 37.0% with cleans yield of 48.17%.Winnowing Index is calculated and Tromp curve has been drawn for different size fractions of coal. The probable error (Ep) values for different size fractions are between 0.065 to 0.155 which seems better than the Allair Jig which has Ep value 0.18 during bench scale test in the laboratory. These studies show that Coal winnowing technique can be effectively applied to physically separate the coal & shale/stone particles. The developed technique can be easily applied to dry coal cleaning of non-coking coals for
thermal power plant use and will be more useful in as the coal will have low moisture, no chemical breakdown, no physical degradation as well as low capital investment, low processing cost and easy handling
Evaluation of gas resource potentiality, geochemical and mineralogical characteristics of Permian shale beds of Latehar-Auranga Coalfield, India
No full textThe shale beds associated with Permian coal-bearing Barakar Formation of the Latehar-Auranga coalfield (north Koel Valley), India have been investigated for the hydrocarbon prospects and their critical reservoir properties. The shale core samples were collected from boreholes drilled in three different blocks like Gowa, Jagaldaga and Banhardih. The shale core samples are examined for in-situ gas content, desorbed gas composition, geochemical, Rock-Eval, scanning electron microscopy (SEM), X-ray diffraction (XRD), high pressure CH4 adsorption isotherm, porosity and permeability aspects. The shales are rich in carbonaceous and silty materials with alternate bands of intercalations; suggesting deposition of the sediments and organic matters by slow or wavering river currents under the reducing environment. The van Krevelen diagram of H/C and O/C atomic ratio of the shales has demonstrated type III/IV kerogens; specifying that organic matters transformed from the fluvio-terrestrial depositional conditions to the diagenesis and catagenesis stages and placed in wet to dry gas window (H/C ratio < 0.5). The values of in-situ gas, lost gas, desorbed gas and residual gas contents are ranging from 1.06–7.02, 0.21–0.98, 0.35–4.16 and 0.42–2.45 cc/g, respectively. The Langmuir volume (VL) is varying between 5.6 and 0.9 cc/g, when values of VL compared to the in-situ gas revealed low to moderate gas saturation (26.86–73.75%) of the shale beds. The negative trend of Langmuir pressure (PL) with depth suggests affinity of CH4 to the shale pore surfaces. The plot of lower hydrocarbons ratios like (C2/C1) × 1000 and (C3/C1) × 1000 shows the dry thermal origin of desorbed gas. The Rock-Eval pyrolysis constituents like S1, S2, S3, PI, Tmax, TOC, HI, OI and Calc. VRo% varies from 0.11–0.47, 3.45–28.34 mg HC/g, 0.11–0.89 mg CO2/g, 0.00–0.07, 414–456 °C, 1.28–16.26 wt%, 39.54–821.45 mg HC/g TOC, 1.52–20.00 mg CO2/g TOC and 0.29–1.05% respectively. The plots of hydrogen index (39.54–821.45 mg HC/g TOC) with calculated VRo (0.29–1.05%) and Tmax (414–456 °C) are signifying types I, II, III and IV kerogen in the shales prone to generate oil, wet and dry gas placed in immature to mature regions. The positive linear correlation of the VL with kaolinite and illite contents suggests that mainly clays contribute to the formation of shale matrix. The SEM images show six types of pore: i) lenticular open pores along the fissility, ii) altered pores due to weathering, iii) intergranular pores, iv) intermingled pores between crystal lattices, v) partially filled pores associated with clays and minerals, and vi) evolved pores by cracking of the organic compounds. The values of porosity and permeability have been measured under reservoir simulated confining pressure, and are ranging from 0.87–8.18% and 0.08–1.45 mD, respectively. This shows poor connectivity between the pores and fracture mechanisms controlled by the clay and minerals. It is summarized that the studied shales of Latehar-Auranga Coalfield have a low to moderate gas potential, based on their in-situ gas, TOC content (1.28–16.26 wt%), sorption capacity, Tmax values and thermal maturity. Moreover, the significant residual volume, low porosity and low permeability are the most critical properties for shale gas resource development at the Latehar-Auranga coalfield
Studies on the Utilization of Non-Coking Coal after Beneficiation for Pulverized Coal Injection
No full textPulverized Coal Injection (PCI) is a process that involves injecting large volumes of fine coal particles into the raceway of a blast furnace (BF). This provides not only a supplemental carbon source but also speeds up the production of liquid iron besides reducing the need for metallurgical coke for reactions in the blast furnace. About 30% of coking coal can be saved by injecting fine coal particles into the blast furnace. Non-coking coals, being cheaper than the others, is mostly preferred for blast furnace injection for cost saving by reducing coke rate. About 20-25% of the Indian non-coking coal reserves constitute less than 30% ash. They are mostly being fed to thermal plants, some of these coals may be beneficiated to obtain clean coal of less than 10% ash for use for pulverized coal injection. This will not only help in conserving the scarce coking coal reserves but also help to save considerable foreign exchange. This paper presents the detailed laboratory investigations in terms of characterization and washabiliy carried out on typical coal sample from Eastern Coalfields and suggests the concept of beneficiation for the improvement in the quality of run-off-mine (ROM) coal. The characterization studies of the clean coal strongly support its use as pulverized coal injection in steel making. The clean product also meets the other specifications of PCI like low to medium volatile content, very low phosphorous and sulfur and suitable grindability index