IR@CIMFR - Central Institute of Mining and Fuel Research (CSIR)
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Identification of indicator species at abandoned red mud dumps in comparison to residential and forest sites, accredited to soil properties
No full textPlant community structure studies on derelict sites are providing significant insights into vegetation dynamics to ensure the success of future revegetation projects in such areas. Therefore, the present study was conducted to evaluate the changes in soil physico-chemical and biological properties at abandoned red mud dumps (RMD) compared to residential (RS) and forest (FS) sites, coupled with their consequent impacts on the plant community structure. An attempt was also made to identify the indicator species that thrive only under unfavourable red mud conditions. Soil at RMD showed relatively high bulk density, alkalinity, salinity and exchangeable sodium percentage along with poor nutrient status and low microbial activity. Though toxic metals (Cd, Cr and Pb) were higher at RMD, their phytoavailabilities were lower compared to FS site. Number of herb-, shrub- and woody species at RMD were although low, but a significant number of species were acclimatized to the unfavourable soil conditions. Shrub species were maximally affected at RMD, followed by woody- and herbaceous species. Important value index of sensitive species was low while that of tolerant species was higher, and was accredited to altered soil properties. Presence of invasive species such as Acacia nilotica, Caesalpinia bonduc, Stylosanthes scabra and Urena lobata at only RMD may be used as an indication for high toxic metal contamination along with high alkalinity, salinity and poor nutrient contents. Principal component and canonical correspondence analyses revealed that woody and herbaceous species were mainly affected by soil alkalinity, salinity, exchangeable cations, bulk density, porosity, moisture content and phytoavailable metals. Shrub species were primarily influenced by soil organic carbon, nitrogen, available phosphorus, bulk density, porosity, moisture content, soil biological parameters, total (Fe, Mg, Cd, Cr and Pb) and phytoavailable metals. Domination of herbaceous species in the plant community indicated their tendency towards a definite selection strategy in response to altered soil properties. The identified tolerant herbaceous species may be suitable candidates for future red mud reclamation strategies
Design of Support System and Stability Evaluation for Underground Workings of Gare Palma Coal Mine – A Case Study
No full textIn underground coal mines, a number of fatal accidents have been occurred due to roof fall. The roof fall mainly occurs in newly exposed working sections of coal mines during development and final extraction of coal. The main factor which contributes to the roof failure in coal mines is the re distribution of stresses and geotechnical discontinuity. If a proper support system is not provided in time the layers get detached and fall down causing major causalities in the mines. Rock mass rating (RMR) plays important role in design and selection of adequate support system. In Indian coal mines, Central Mining Research Institute- Indian School of Mines - Rock Mass Rating (herein after referred to as (CMRI-ISM RMR) is mostly used for formulating design guidelines for supports. In this paper study for stability of II seam working was assessed. Later on study was extended to determine rock load for II seam applying empirical and numerical approaches and finally design of support has been formulated
Water quality assessment and correlation study of physic-chenical parameters of Sukinda chromite Mining Area Odisha , India
No full textThe Sukinda Chromite Valley of Odisha state is endowed with the highest reserve of chromite ore in India and produces 98% of the chromite ore of the country. Cr (VI) is a highly toxic form of chromium metal being used in different industries like leather tanning, electroplating, dye and pigment. Due to open cast mining process in Sukinda chromite valley, huge quantity of over burden dump (OB) are being generated and during rainy season Cr (VI) leached from the OB dump and contaminate the ground water as well as surface water of the surrounding area. Different water samples were collected from mines, surface water and groundwater and analyzed for their physico-chemical properties including heavy metals and Cr (VI). The result shows that at some locations, the total Cr and Cr (VI) concentration exceeded the permissible limit of 0.05 mg/L as per Indian water quality standards, despite mine water treatment at mine sites. The concentration of total Cr in mine water ranged from 0.32 to 1.46 mg/L before treatment and between 0.02 and 0.42 mg/L after treatment. Total chromium for surface water varied from 0.04 to 0.38 mg/L and for groundwater varied from 0.001 to 0.678 mg/L which exceeds the permissible limit of 0.1 mg/L for inland surface water. Cr (VI) content in these water samples also exceeds the permissible limit of 0.05 mg/L. Pearson’s correlation analysis revealed that the Cr exhibited a significant positive correlation with pH (0.688), temperature (0.428), Total hardness (0.568) and sulphate (0.686). Cr (VI) also showed the similar results with total chromium
Assessment of groundwater quality of Pratapgarh district in India for suitability of dirinking purpose using water quality index (WQI) and GIS technique
No full textAn attempt has been made to develop a water quality index (WQI) model in geographic information system (GIS) environment, using 12 groundwater quality parameters (pH, TDS, F−, Cl−, NO3 −, SO4 2− HCO3 −, Ca2+, Mg2+, Na+, K+, and TH) at 55 different locations of the Pratapgarh district. The analytical results show alkaline nature of the groundwater resources of the Pratapgarh district. HCO3 − and Cl− are the dominant anions, while cation chemistry is dominated by Mg2+ and Na+. The computed WQI values in the groundwater range from 52 to 345 (avg. 115) and indicate that the groundwater quality varied from good to unsuitable for drinking. High WQI has been found at sites 3, 4, 7, 10, 20, 40, 41, and 50 primarily due to high TDS, F−, Cl−, NO3 −, SO4 2−, Mg2+, Na+, and TH. Western and eastern parts of the Pratapgarh district show low TDS along the Ganga and Gomti Rivers, respectively, due to aquifer recharging. Groundwaters of more than one-third area are not suitable for drinking. Analysis of the data reveals that rock weathering and agricultural activities govern the groundwater chemistry of the study area
Techno economic analysis of chemical looping system for Indian power plants
No full textChemical looping combustion (CLC) has been developed as a major new generation CO2 capture technology which involves inherent CO2 separation and high system conversion efficiency. The technology is well-known to have low energy penalty, as compared to other technologies. This paper intends to carry out a numerical investigation on the flow characteristics of the chemical looping combustion (CLC) process using the cold model fabricated and commissioned by CSIR-CIMFR, Dhanbad. It attempts to visualise the hydrodynamic viability of the system, which is very important to know the effect of the configuration of the system on circulation of the oxygen carrier particles. Cost analysis for a power plant implemented with chemical looping based capture system in Indian condition has also been presented. The pressure drop profile, volume fraction distribution of particles and fluidisation patterns are analysed and found to give expected results. The effects of gas phase and solid phase velocity are also studied, through which, similarity in flow pattern of ilmenite as well as air can be seen in both the plots. Through the cost analysis, higher temperature in both air reactor as well as fuel reactor has been found to increase plant efficiency while residence time in both reactor was found to have a little effect on the plant efficiency. As cost for O&M for gasifier was found to be more, change and modification of the gasifier unit will play a major role towards increasing the plant efficiency with incorporation of chemical looping as a carbon capture system
A safe depillaring design for shallow depth of cover with influence of surface ground movements: a study in Jharia Coalfield
No full textExtraction of coal from a shallow depth of cover especially under multi-seam mining condition requires intensive precautions in respect to safe working and impact on surface structures. A detailed geotechnical investigation is imperative for the design of a suitable support system during depillaring operation. A study has been exercised in Maheshpur colliery of Jharia Coalfield to assess the stability between the parting of VIIIA and VIIIB seams through numerical modeling. The support systems have been framed for split galleries, slices, and goaf edges with the help of well-established Central Mining Research Institute-Indian School of Mines rock mass rating (CMRI-ISM RMR) and NGI-Q system. A suitable method of depillaring has been designed keeping in view the safety of surface structures in respect to subsidence
Vision improvement system using image processing technique for adverse weather condition of opencast mines
No full textThis paper deals with a vision improvement system (VIS) developed using real-time image processing technique by CSIR-Central Institute of Mining and Fuel Research, Dhanbad aiming at providing comparatively clear vision to the operators of HEMM (Heavy Earth Moving Machinery) in foggy weather condition in opencast mines. It can also be used in deteriorated visibility situation due to mist, haze, smog, etc. while driving other vehicles also. In adverse weather, mining processes cannot be carried out during one-third of a day due to problem of perceptibility which reduces production rate of opencast mines. The developed system amplifies colour, sets the brightness and contrast to the input video to make objects more visible by reducing the effect of fog, mist, haze and smog. In order to enable quick real time operation, a fast CPU with dedicated graphics processing unit is used which is well suited for intensive data processing; because of its high computational efficiency and robustness, the developed system is able to operate at high frame rate and it is suitable for real-time driving assistance in adverse weather conditio
Synthesis of middle distillate through low temperature Fischer-Tropsch (LTFT) reaction over mesoporous SDA supported cobalt catalysts using syngas equivalent to coal gasification
No full textAbstract
A series of silica doped alumina (SDA) [Si-Al2O3] having high surface area and narrow pore size distribution are synthesized with varying amount of silica and used as a support material to facilitate incorporation of Co, Mg and Zr into it. These supported Co-Mg-Zr/SDA materials are used as catalysts for selective synthesis of middle distillate through Fischer-Tropsch synthesis (FTS) reaction. Trace quantity (∼0.05 wt %) of ruthenium (Ru) has also been used as a promoter for Co -Mg-Zr/SDA catalyst to improve the reducibility, selectivity towards middle distillate and increasing the catalyst life. The detail characterizations of catalysts indicate that Ru promotion and narrow pore size distribution facilitate CO conversion and middle distillate selectivity. Synthetic syngas of composition (H2 = 28.63%, CO = 14.27%, CO2 = 9.25%, CH4 = 1.0%, and N2 = 46.85%), which may be obtained after coal gasification and H2 enrichment process by water gas shift (WGS) reaction has been used as a reactant for middle distillate synthesis. The role of Ru and silica proportion on Co-Mg-Zr/SDA is investigated through Low Temperature Fischer-Tropsch (LTFT) synthesis at 220 °C temperature and 30 bar pressure. The surface acidity of the Ru/Co-Mg-Zr/SDA catalyst plays an important role for middle distillate selectivity and CO conversion. To determine the durability of catalysts, 300 h continuous experimental run has been conducted at Gas Hourly Space Velocity (GHSV) of 500 h−1. Among the catalysts in the present study, Ru/Co-Mg-Zr/SDA(7.5) catalyst shows highest CO conversion (94.2%) with 85% selectivity of C6-C19 hydrocarbon
Assessment of groundwater quality of Pratapgarh district in India for suitability of drinking purpose using water quality index (WQI) and GIS technique
No full textAn attempt has been made to develop a water quality index (WQI) model in geographic information system (GIS) environment, using 12 groundwater quality parameters (pH, TDS, F−, Cl−, NO3 −, SO4 2− HCO3 −, Ca2+, Mg2+, Na+, K+, and TH) at 55 different locations of the Pratapgarh district. The analytical results show alkaline nature of the groundwater resources of the Pratapgarh district. HCO3 − and Cl− are the dominant anions, while cation chemistry is dominated by Mg2+ and Na+. The computed WQI values in the groundwater range from 52 to 345 (avg. 115) and indicate that the groundwater quality varied from good to unsuitable for drinking. High WQI has been found at sites 3, 4, 7, 10, 20, 40, 41, and 50 primarily due to high TDS, F−, Cl−, NO3 −, SO4 2−, Mg2+, Na+, and TH. Western and eastern parts of the Pratapgarh district show low TDS along the Ganga and Gomti Rivers, respectively, due to aquifer recharging. Groundwaters of more than one-third area are not suitable for drinking. Analysis of the data reveals that rock weathering and agricultural activities govern the groundwater chemistry of the study area
Role of MineVue Radar for Proving Abandoned and Unapproachable Mine Galleries for the Safety of Surface Structures
No full textDuring the pre-nationalisation period due to unscientific mining, large number of old workings exist below important structures at various coal fields in India. Mostly these old workings exist below National Highways and Railway track. These workings are generally at shallow depth. It has been observed that subsidence and pot holing are common in those areas. As a result the safety of vehicles and passenger trains plying over these areas endangered. Since the old workings are more than 60 years old in most of the cases the proper plan and survey documents are not available. So it is extremely difficult to exactly locate the underground mine workings/galleries/voids from the surface such that precautionary measures can be initiated for the safety of roads and railway tracks. Eastern Coalfields Limited (ECL) has indicated that there may be some old workings below the national highway (NH-2) near Dalmia colliery of SalanpurArea of ECL. The most sophisticated system, MineVue Radar was used for delineation of abandoned mine workings or mine galleries below NH-2. Two voids of size 1.8 m height at depth of 40 m and another of size 1.35 m height at a depth of 33.5 m were delineated and confirmed using direct core drilling method. After that, Mine management was informed about these voids to take precautionary measures for the safety of NH-2. Thus, this system has played an important role for the safety of important surface structures. This paper deals the application of MineVue radar system for delineation of mine galleries below NH-2