IR@CIMFR - Central Institute of Mining and Fuel Research (CSIR)
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Assessment of metal pollution in groundwater using a novel multivariate metal pollution index in the mining areas of the Singhbhum copper belt
No full textGroundwater samples were collected from 22 locations for 3 seasons in mining areas of Singhbhum copper belt. The concentrations of Al, As, Ba, Co, Cu, Fe, Mn, Ni, V and Zn were evaluated using inductively coupled plasma mass spectrometry to assess the metal pollution using conventional heavy metal pollution index (HPI) and multivariate indexing approaches. Considering all the seasons, metal concentrations exceeded the drinking water standards for Fe and Mn for most of the locations and Al, Cu, Ni and Zn at some of the locations. An assessment using principal component analysis suggested that metals in groundwater in the area are derived from both geogenic and anthropogenic sources. The PCA-based index (PMI) was computed using the factor scores, which does not need any permissible limits or standards for its calculation. A classification of the index is also done using the terciles (3 quantiles) to demarcate the locations into “low”, “moderate” and “high” pollution classes. Marked differences could be identified between the results of HPI and the PCA-based index, of which the latter was found to be robust and more suitable for the study
Coal Combustion Residues Characterization Using Scanning Electron Microscopy & Energy Dispersive X-Ray (SEM-EDXA) Analysis
No full textThe objective of the present study is to observe the surface morphology, structure and elemental composition of the ash particles produced from some thermal power stations of India using scanning electron microscopy (SEM) and energy dispersive x-ray analysis (EDXA). This information is useful to better understand the ash particles before deciding its utility in varied areas
ENVIRONMENTAL ISSUES OF COAL MINES AND ITS ALLIED INDUSTRIES: SUGGESTIVE MEASURES FOR ROOT LEVEL REMEDIES
No full textEnvironmental issues in the mining areas arise both from coal mining and coal burning activities. Coal burning can be either from the fires in the coal mines or from the thermal power stations or the sources such as domestic burning of coal in and around mining areas. Coal mining activities includes all such activities that are undertaken in order to get the coal from beneath the earth surface. Such activities often are the cause of pollution and also give birth to several other environmental issues that affect our society to a much greater extent. Whatever be the sources of this pollution it needs great attention in the present times as it is affecting our society by altering land, air and water environments. Coal will dominate the India's economy being the cheapest source of energy and so the coal mining cannot be ruled out. Concern for environment will now play major role for coal industry's future. Environmental concerns should address well several environmental impacts not only at the regional level which is the prime concern, but also at the national and international level. This paper is an attempt to address almost all the environmental issues at one platform and also make the people, directly or indirectly associated with this coal industry, aware of the various issues. Some remedial measures are also being suggested at the end to better deal with the situation
Corporate Social Responsibility For Sustainable Development
No full textCorporate social responsibility (CSR) can be a good tool for sustainable development in the mining regions of the country. Like all processes of management, CSR has evolved over a period of time and now is the buzzword in the business fraternity. Though numerous definitions can be seen for this term the central meaning, however, remains the same and goes like ‘the impact that the businesses have on the society and in turn the expectations of the society from them'. The companies nowadays seriously undertake corporate social responsibility activities as they feel their responsibility towards the society where it operates. This paper aims to have a close look at the community development initiatives of a few large-scale coal mining companies in India. With a few case studies, an attempt is being made to understand the term corporate social responsibility and its role in sustainable development. Case studies of a few coal mining companies, namely Eastern Coalfield Limited, Central Coalfield Limited and Northern Coalfield Limited have been considered here. These examples show how the businesses have realised their existence in economic, social and environmental terms and as such, they are equally showing their inclination for environment and the society besides looking for the profit
Impact of geo technical factors on strata behavior in longwall panels of Godavari Valley coal field-a case study
No full textUnderstanding the cantilevers formed by thick, massive beds in the near-seam overburden above longwall panels and the associated loads and strata fracturing effects developed during caving (main and periodic weightings) are key elements for the successful implementation of longwalls. Such caving mechanisms rely on the geotechnical conditions within the panel. In India, the majority of longwall downtime and/or roof failures were caused by a lack of knowledge on overburden caveability, in particular when the main and periodic weightings will impact the face and longwall support selection to effectively mitigate such weightings. Godavari Valley Coal Fields is no exception as longwall faces were adversely affected due to the presence of thick, massive beds in the near-seam overburden at both Godavarikhani (GDK) 7 and 9 Incline mines. In contrast, overburden weightings were negotiated successfully in GDK10A and Adriyala Longwall Project (ALP) mines by detailed geotechnical studies, the use of adequate longwall support capacities, and effective operational practices. Thirteen longwall panels with varying face width, at different depths have been extracted under massive sandstone beds of 18 m to 28 m thickness at GDK 10A and ALP mines. This study elucidates that the main roof weighting interval decreases with an increase in face width and attains a constant value with further increases in face width under the same geo- mining conditions. In addition, this study also concludes that with increases in face width, the periodic roof weighting interval decreases and shield loads increase. Similarly with increasing panel width to depth ratio, the main and periodic roof weighting intervals decrease but shield loads again increase. Lastly, the strata behaviour of the longwall face retreated along up-dip direction is demonstrated. The results of this paper improves the mechanistic understanding of the impact of face width, depth and main roof thickness on periodic weighting and associated roof control problems on the longwall face
Effect of fly ash on carbon mineralization of biochar and organic manures added to mine spoil
No full textMine spoil is deprived of organic carbon. Reclamation and re-vegetation of mine spoil initiate photosynthetic carbon fxation and add soil organic matter. Fly ash (FA) generated from coal-fred power stations can be used for reclamation of mine spoil. Our research was aimed to assess the efect on FA on carbon mineralization of organic manures and biochar added to mine spoil. Incubation experiments were conducted to assess the carbon mineralization of farmyard manure (FYM), chicken litter (CL), plant litter (PL), and biochar (BC) added to mine spoil in the presence and absence of FA. After 1 year of incubation, the cumulative CO2 emission was lower for the FA-added mine spoil and it was higher for PL (4.42 vs. 5.09 g CO2–C/kg soil, with and without FA, respectively) and CL (3.75 vs. 4.07 g CO2–C/kg soil) followed by FYM (1.86 vs. 1.97) and BC (0.67 vs. 0.54 g CO2–C/kg soil). The labile C pool was signifcantly lower for FA-added mine spoil, whereas the stable carbon pool was higher in FA-added soils: FYM (1.4 vs. 0.6 g CO2–C/kg soil) and CL (2.20 vs. 3.17 g CO2–C/kg soil). Substrate-induced respiration, microbial biomass carbon (MBC), and dissolved organic carbon (DOC) were signifcantly higher under PL, CL, and FYM. FA increased MBC, but decreased DOC. Overall, FA decreased CO2 emission from mine spoil probably due to the interaction of organic matter with the surfaces on FA and the resultant physical protection against microbial decomposition
Area Classification and Types of Protection for Explosive Atmospheres
No full textAn equipment is designed, manufactured, tested and certified for use in explosive atmospheres is generally known as Ex (Explosion proof) equipment. The area of use these equipment where explosive gas, mist, dust and vapour is categorized into different hazardous areas. Ex equipment is designed by using many protection methods to prevent explosion in hazardous areas. the basic knowledge of area classification (gas group, zone and temperature class), types of protection and source of ignition is mandatory. Based on knowledge, it can be leaded for design, testing, manufacturing, use, inspection, installation and maintenance of Ex equipment to maintain its integrity for safe operation in hazardous area. The paper describes the area classification and types of protection for hazardous areas
Petrographic and chemical reactivity assessment of Indian high ash coal with different biomass in fluidized bed co-gasification
No full textThe reactivity of coal and biomass has been evaluated by comparing the optical and chemical changes in feed material prior and after the co-gasification. The proximate, ultimate, GCV, low-pressure N2 sorption isotherm, micropetrography, SEM and EDX spectroscopy analyses are carried out to assess the reactivity of blends of high ash Indian coal and biomass. The relative changes in parameters like surface area, pore size, and pore volume have been correlated with reacted percentage area of coal macerals and cellulose-lignin cellular structures of biomass. The Optimas image processing software is being used to mark the reacted portion of organic constituents and calculated the reactivity percentage. The bottom ash of pure coal has shown the least reacted organic matters, indicating inefficiency of high ash coal due to a large amount of inorganic and inertinite contents that is resisting the oxidation. The reactivity percentage is determined by the petrographic and SEM images, and varies from 36.34 to 99.64% and 6.61–96.22%, respectively. It is summarised that the estimation of percentage alteration of macerals and other micro-organic constituents can be used as one of the practical approaches for the assessment of the reactivity of coal and biomass. The blending ratio 6:4 of coal and press mud has shown the highest reactivity (>99.64%). The values of petrographic and SEM reactivity have shown good correlations with the carbon contents, unreacted vitrinites, mineral matters and biomass remnants. These relations have been taken into account to formulate the proposed petrographic empirically calculated reactivity (RPEC). The focus has also been made to investigate the influence of feed composition on carbon conversion and heating value of the product gas
Studies on the Segregation of Minerals in Different Size and Gravity Fractions While Treating Indian Coal
No full textGondwana coal makes up to 98 per cent of the total reserves and 99 per cent of the production of coal in India. These coals are intimately mixed with mineral matter, causing a high level of impurities in the run-of –mine (ROM) coal. Beneficiation of high – ash non-coking coals of India has become the prerequisite for improving the overall economics and efficiency for downstream utilization industries. The association between specific mineral and organic constituents in a typical non-coking coal sample form the Eastern Coalfields, India was studied. For this, raw coals were fractionated by size and density and the variation of major minerals with respect to size and density was examined. Mineral species were identified by X-ray diffraction. The results showed that the concentration of quartz and kaolinite increases with increase of gravity of the coal while concentration of siderite is much lower size fractions of the coal
Co-gasification of high ash Indian coal-biomass blends in a pilot-scale fluidized bed gasifier
No full textConventional coal-based technologies are experiencing several disadvantages due to its high ash content as well as a significant amount of greenhouse gas emission. Focus is shifting towards the utilization of renewable resources like biomass. The efficient use of coal and biomass in a clean manner has been the driving force in developing gasification technologies. In the present investigation, an effort has been made to study the gasification performance of selected coal with two types of biomass, namely rice husk and sawdust in different proportions in a pilot-scale bubbling fluidized bed gasifier. Gasification was conducted with a mixture of air and steam at a temperature between 900–950 °C and atmospheric pressure. Mainly, three blends were prepared by adding 10, 20, and 40% of biomass with the selected coal. It was found that up to 40% of biomass loading, gasifier is operated in a trouble-free manner without the formation of tar or any agglomerate by maintaining proper fluidization with smooth and controlled variation in the process parameters like temperature, airflow, and steam flow rate. Due to the synergistic influence between coal and biomass, overall carbon conversion, gas yield, and gas heat value were found to increase with increasing biomass loading