IR@CIMFR - Central Institute of Mining and Fuel Research (CSIR)
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Development of a new noncarcinogenic heavy metal pollution index for quality ranking of vegetable, rice, and milk
No full textA new heavy metal pollution index (HMI) has been proposed for ranking noncarcinogenic heavy metal pollution in vegetable, rice, and milk. HMI comprises a pair of one positive index (Pqi) and one negative index (Nqi). Pqi represents metals present above the maximum allowable concentration, while Nqi corresponds to those below. Higher the Pqi, greater is the pollution. In the case two similar food items have same or close Pqi, Nqi decides the relative degree of contamination; lower the Nqi, lesser is the pollution. Three different databases of 12 heavy metals in 57 vegetable samples (15 different species), 12 in 14 rice samples, and 10 in 24 milk samples were separately used for developing and calibrating the newly proposed HMI. All the samples were collected from mineral-rich country sides of Jharkhand state in India. USEPA Hazard Index (HI) was used as the referral standard for calibrating HMI using a Multi-Variate Linear Regression (MVLR) model. It is also possible to apply the same model to other types of food items. If properly calibrated, HMI may not only be independently used for ranking heavy metal pollution in food but may also be used for theoretically predicting maximum allowable metal concentrations in food items for which reliable experimental data are not available
Development of a petrographic classification system for organic particles affected by self-heating in coal waste. (An ICCP Classification System, Self-heating Working Group – Commission III)
No full textSelf-heating of coal waste is a major problem in the leading coal-producing and consuming countries, independent of the recent or past coal exploitation history. The phenomenon of self-heating is dependent on many factors such as the properties of organic matter (maceral composition and rank), moisture and pyrite content, climate effects, and storage conditions (shape of the dump or compaction of the coal waste). Once deposited, coal waste undergoes oxidation, which can lead to self-heating with the overall temperatures exceeding 1000 °C. During these self-heating processes, both organic and mineral matter undergo oxidative and thermal alterations, being influenced, among others, by the rate of heating as well as by the access of air and moisture. The morphological features of organic matter in coal waste at microscopic scale reflect the thermal conditions within the waste dump. Since 2008, several exercises designed to establish a petrographic classification system of oxidatively- and thermally-altered morphological forms of organic particles present in self-heated coal waste dumps have been carried out within the Self-heating of Coal and Coal Waste Working Group (Self-Heating WG), in Commission III of the International Committee for Coal and Organic Petrology (ICCP). Based on the degree of oxidative and thermal alteration, all assessed organic particles were divided into unaltered particles (huminite, vitrinite, liptinite, and inertinite macerals), altered particles, and newly formed particles (pyrolytic carbon, bitumen, chars, graphite, and coke). Altered particles were further divided according to their optical properties (porous, massive; isotropic, anisotropic). For altered particles the following specific features were distinguished: fractures, fissures, cracks; brighter rims; darker rims; plasticised edges; bands; devolatilisation pores; paler in colour particles. The final petrographic classification of oxidatively- and thermally-altered morphological forms of organic particles in coal waste dumps was established as a result of the successively performed Round Robin Exercises 2008–2017. The selected criteria and categories proved the high performance of the analysts characterised by a minor bias. The proposed petrographic classification system based on petrographic methods represents a useful way to characterize the undesirable phenomena occurring in coal waste dumps. Microscopic analyses and application of the petrographic classification system for organic particles affected by self-heating in coal waste offers the identification, documentation and monitoring of coal waste oxidation, self-ignition and combustion processes. It also enables a selection and application of appropriate measures to delay or even prevent undesired environmental impacts. The established classification system may assist in the air quality monitoring and assessment of burning waste dump sites and, thus, provide a relevant support in the environmental management of the disposal sites related to coal mining. The classification system can provide an important instrument for environmental protection agencies to increase the effectiveness of measures applied in fire hazard combating. The proposed classification of oxidatively- and thermally-altered morphological forms of organic particles in coal waste dumps can be applied on self-heating coal waste or mining dumps research, being a useful tool for coal waste managements performed by environmental agencies responsible for the landfill managements and monitoring of waste dumps
Offsetting anthropogenic carbon emissions from biomass waste and mineralised carbon dioxide
No full textThe present work investigates biomass wastes and their ashes for re-use in combination with mineralised CO2 in cement-bound construction products. A range of biomass residues (e.g., wood-derived, nut shells, fibres, and fruit peels) sourced in India, Africa and the UK were ashed and exposed to CO2 gas. These CO2-reactive ashes could mineralise CO2 gas and be used to cement ‘raw’ biomass in solid carbonated monolithic composites. The CO2 sequestered in ashes (125–414 g CO2/kg) and that emitted after incineration (400–500 g CO2/kg) was within the same range (w/w). The CO2-reactive ashes embodied significant amounts of CO2 (147–424 g equivalent CO2/kg ash). Selected ashes were combined with raw biomass and Portland Cement, CEM 1 and exposed to CO2. The use of CEM 1 in the carbonated products was offset by the CO2 mineralised (i.e. samples were ‘carbon negative’, even when 10% w/w CEM 1 was used); furthermore, biomass ashes were a suitable substitute for CEM 1 up to 50% w/w. The approach is conceptually simple, scalable, and can be applicable to a wide range of biomass ashes in a closed ‘emission-capture’ process ‘loop’. An extrapolation of potential for CO2 offset in Europe provides an estimate of CO2 sequestration potential to 2030
Formation of thermogenic gases with coalification: FTIR and DFT examination of vitrinite rich coals
No full textThe evolution of thermogenic gases during coalification has not yet been theoretically attempted. Examinations on Indian Permian vitrinites of various ranks ranging from Cwt% 76 to 92 were performed. Fourier Transform Infra-red spectroscopy (FTIR) provided insight into the structural changes where the aliphatic CH increases with increase in percentage of carbon up to ~85% and then decreases. In contrast, the aromatic CH, the ratio of aromatic CH to aliphatic CH and aromaticity (fa) increase monotonically with the advancement of rank. A relationship between fa and atomic H/C ratio as fa = 1.12–0.45H/C was established to predict fa from elemental analysis. The structural data from FTIR served as an input to construct six representative hypothetical models of coal of varying Cwt% (76, 80, 83, 86, 87 and 89). Density Functional Theory (DFT) has been applied to these coal models and the formation of principal thermogenic gases, viz. CO2 for the low-(76%C)and CH4 for the high-rank (87%C), with simultaneous increase in the rank was demonstrated considering the smaller structural units extracted from the relevant coal models. The suggested reaction pathways are supported by the negative values of changes in free energies of the reactions computed from the Gaussian thermo-chemistry. The studies could, therefore, show that gas evolution as a natural (spontaneous) process with feasibility of rank advancement
Prediction of rock load emphasizing excavation damage of in situ rockscaused by blasting in coal mines
Get PDFRoof failure in coal mines is strongly related to the frequency of laminations and their movement when
the load acts upon them. Detachment of roof bolts from mine roof due to improper estimation of extent
of weak zone is one of the major problems in underground coal mines, thus affecting the safety and productivity of workings. The most popular and practiced method for roof support design in Indian coal mines is the Central Mining Research Institute-ISM geomechanical classification system. Irrespective of such an established system of support design, accidents due to roof fall still persist. Here we review various available classification systems for rock load estimation and identify their limitations. The study has been extended taking into consideration the case study of KTK-6 incline of Singareni Collieries Company Limited by proposing a modified rock mass classification system based on seismic wave velocity as a key descriptor. A
modified rock mass rating (RMR) system (RMRdyn) with inclusion of seismic velocity as one of the parameters is proposed for the estimation of rock load. Enhancement in rock load by 20% has been found for
RMRCMRI-ISM values less than 40 according to the new rock load relation. This resulted in under-supporting
of the roof and thus might have caused failures. For cases with RMRCMRI-ISM values more than 60, the earlier
equation overestimates rock load by about 25% resulting in over-supporting. Thus, estimation of rock load from the proposed new equation appears to be more rational as it takes into account the actual damage
zone
Efficient utilization of Indian Coking Coal: Opportunities and challenges
Get PDFThe preservation of coking coal and the reduction of coke cost are gaining much importance in iron and steel industry. An effort is being made worldwide to maximize the use of inferior quality of coking coal in cokemaking without sacrificing the coke quality to minimize the coke cost. In general, Indian coking coals contain lower content of vitrinite (≤ 50%) and higher content of ash (≥ 15%) as compared to imported coking coal. Indian coking coals have poor washability characteristics also. Therefore, for making coal blend for coke making, selection of an appropriate proportion of Indian coking coals with imported coking coals is a major challenge for Indian steel industries. Proper selection of Indian coal not only reduces the coking coal import but also minimizes the coal blend cost with added benefits of the increase in the captive mine life. This paper touches the opportunities and challenges for efficient utilization of Indian coking coal as a component in the coal blend to produce the desired quality of cok
Coal Seam Reservoir Characteristics for Coalbed Methane in North and South karanpura Coalfields, Jharkhand
No full textMethane in coal is a major safety hazards since the beginn ing of underground coal mining. If methane accumulates in the range of 5 to 15% in underground working, it form s highly explosive mixtures. Science last three decades methane from coal seam is being extracted and utilized as an energy resource. Following the coalbed methane (CBM) exploration and production growth around the globe, the exploration and R& D institutions have taken interest to develop CBM as an energy resources in India. Till date 32 CBM block have been awarded for exploration and production by Government of India to different industrie
A geo-spatial approach to perceive the groundwater regime of hard rock terrain- a case study from Morappur area, Dharmapuri district, South India
Get PDFThe goal of the present study is to identify the groundwater regime of Morappur area at Dharmapuri district, India. The study area covers an area of 410 sqkm. The area belongs to a hard rock terrain where the primary porosity is feeble and the secondary porosity offered by fracture, joints and shear zones etc, contributes to the groundwater regime. The availability of surface water resources is sparse and hence the groundwater repositories are intensely utilized. In the current study area, the availability of groundwater is limited due to scanty rainfall and poor recharge. The entire study area underlain by hard crystalline rocks of Archaean age, Charnokite and Hornblende epidote gneiss are the main rock types encountered in the area. The over exploitation of these resources more than the adequate recharge has resulted to decrease in the groundwater level. In this context, it is very much important to identify and understand the groundwater regime of this area for the better groundwater monitoring and conservation of this precious resource. Remote Sensing and GIS are playing a vital role in the advancement of hydro-geological studies. The use of conventional methods alone has its own limitations in comprehending the groundwater regime of the area. The integrated study using remote sensing, field studies together with GIS has helped to understand the role of structural, lithological and geomorphic units in controlling the groundwater occurrence and movement in the present study area. Various thematic maps were prepared from the satellite images and they were integrated and incorporated in a GIS platform along with collateral information to study the groundwater regime of Morappur area. The outcome of this study clearly shows the importance of the geospatial studies in identifying the role of satellite imageries and geospatial techniques to understand the groundwater regime of a hard rock terrain
Whole body vibration exposure and its effects on heavy earthmoving machinery (HEMM) operators of opencast mines – a review
No full textOperators of opencast heavy earthmoving machinery (HEMM), during their 8-hour shift duration, are regularly succumbed to the high level of whole body vibration (WBV) amplitudes. Due to long and continuous working in the field, the operators of HEMM may yield to adverse health effects and results in hazardous conditions if the magnitudes repeatedly exceed the permissible limits. Based on extensive literature review, the authors of the paper put forward the recognized harmful adverse health effect of short and longterm WBV exposure of HEMM operators in surface mining and also with the same view with the findings of various researchers in this field and feels that for the safety of operators, long-term understanding of WBV should be carried out instead of short term vibration monitoring
Alternative Coke from Inferior Coal for Ferro-Alloy Industry
No full textCarbothermic reduction of iron oxide is an important reaction in Ferro-alloy production process. Coke and bio-char are the main resource carbon for these industries. Carbon not only takes part in reduction reaction but also have important role in maintaining required carbon percentage in metal and contribution in energy supply for the process. Thus the price of carbonaceous material has significant contribution to the overall cost of Ferro-alloy production. Suitable low cost carbon materials are always in demand for such industries. In the present study low rank Indian coal has been carbonised in medium temperature level for producing an alternative semi-coke for this purpose. The coal sample has been first fractionated in two parts based on particle size distribution. Larger size samples are directly carbonised in a laboratory scale coke oven using non-recovery type coke making technique. Finer fractions are first carbonised, then agglomerated into small briquettes and subsequently de-volatilised for lowering volatile matter content, enhancement of fixed carbon and improvement of other properties