IR@CIMFR - Central Institute of Mining and Fuel Research (CSIR)
Not a member yet
2618 research outputs found
Sort by
Estimation of Optimum Burden for Blasting of Different Rock Strata in an Indian Iron Ore Mine
No full textBurden movement plays very important role in the bench blasting for the effective utilization of the explosive energy. The optimum burden for a blast face varies with the nature of the strata and explosive quantity & quality. There are various experimental and empirical approaches for the estimation of optimum burden. However, there is a need for the site-specific estimation suited with the strata condition for estimation of optimum burden at the blast faces having huge variations in the rock types. Two different approaches have been used in this paper for computation of optimal burden of different rock strata of an Indian iron ore mine. The first approach is based on assessment of rock mass properties and explosive properties for the blast. The assessed properties are put in different empirical equations of Kuz-Ram model. To achieve optimal burden desired fragment size has been computed by back calculation from the empirical model. The second approach is based on the assessment of critical vibration limit for different rock strata. The determination of critical vibration is done using the assessment of rock mass properties. The prediction of distance up to which critical vibration limit will be achieved using the designed charging parameters, gives the optimum burden. The computed burden has been compared for both the approaches, which gives a good correlation with correlation coefficient of 0.78. The experimental blasts of different rock strata were conducted using the computed optimal burden. The blast output with optimal burden and charging parameters have been improved in terms of fragmentation, blast face movement and reduction of back-break
Investigation of ambient air quality category by the application of air quality index in and around chandrapura Thermal Power Station in Jharkhand - A Case Study
No full textThermal power station produces huge quantities of particulate matters in the form of fly ash and bottom ash as well as gaseous pollutants like SO2, NOx, CO, etc., which have been continuously discharged to the open atmosphere.
Air is our life and ambient air is also our life. We have to survive here according to our life-span created by the almighty/God and have to protect us from the hazardous atmosphere. So for safer ambient air, it must be cleaned and free from dirt. Ambient air monitoring studies have been carried out in and around Chandrapura thermal power station of Damodar valley Corporation (DVC), to evaluate the Concentration of those pollutants, which usually affects the surrounding atmosphere that of residential colonies, townships, schools, and hospitals. Here, interpretation of data restricted to only three parameters, namely, SPM, SO2, and NOx.
The paper deals with laboratory analysis with respect to ambient air quality studies and discusses its result of the case study as well as interpretation of data by the application of air quality index (AQI)
Importance and Sensitivity of Variables Defining the Performance of Pre-split Blasting Using Artificial Neural Networks
No full textBlast induced damage to the final wall of rockmass in any civil or engineering application is a major concern to the rock excavation engineers. There are at least four distinct techniques practised by blasting engineers to minimise the damage to the parent rock during blasting that are classified as contour blasting. One of the methods to achieve a smooth wall or rock surface in blasting is pre-splitting, where blastholes in the final row are mildly loaded with explosives and fired first in sequence before the rest of the holes in a round of blast to achieve a split in rockmass. Since blasting is one of the most adopted methods for achieving a final wall in a desired shape, while maintaining the rockmass integrity, the design of pre-split blast assumes importance. There are several variables that determine the final shape of the pre-split face including the rock type, the drill diameter, the explosive characteristics, the orientation of major joints with respect to drill hole, the linear charge density, the spacing of drill holes and inclination of the drill holes. This study attempts to determine the importance and sensitivity of variables in pre-split blasting using historical data from open excavations of a hydroelectric project in India. Keeping in view the multitude of variables, low correlation of independent variables with responses and high level of interactions between the variables that define the blast results, it was found suitable to use ANN to determine the importance and sensitivity of the variables involved. A new method to determine the blast induced damage to rockmass, namely, undamaged area (AUD%), is introduced. Half Cast Factor (HCF%) and AUD% were calculated for a high wall and trenches by digital image analysis technique using the Fragalyst software. Joint spacing and linear charge density emerged as most controlling variables in determining the final result of pre-blast. The relative importance of other variables assuming significance in the case of both the designed outputs is also discussed. A comparative analysis of HCF% and AUD% on the basis of results obtained from ANN analysis is also presented. A futuristic approach concept has also been introduced
Hydrocarbon generation and kinetics: A case study of Permian shales, India
No full textReconstructing hydrocarbon generation history for predicting the onset of oil/gas generation is an important step for petroleum system modeling, and for the purpose, source rock kinetic analysis is required. For evaluating the controlling factors that influence shale rock kinetics, Lower Permian Barren Measures Formation shales from two Damodar Valley sub-basins, India are evaluated in terms of their source rock properties and kinetics. Rock-Eval open-system programmed-pyrolysis is applied at heating-rates of 5, 15 and 25 °C/min to determine the shales’ reaction kinetics. The results substantiate the importance of petrographic composition in controlling the shale source rock potentiality and reaction kinetics. North Karanpura Basin shales are shown to have liquid hydrocarbon generation potential, owing to their richness in type I-II kerogen. In contrast, the Raniganj Basin shales are richer in type III-IV kerogen and gas prone. The shales are grouped in distinct clusters on an E versus LnA (activation energy versus pre-exponential factor) kinetic distribution. The type I-II kerogen-bearing samples display the highest reactivity, while the type III-IV kerogen-bearing shales, and those with higher thermal maturity levels, display lower reactivity. The least reactivity is associated with a heat-altered shale from the Raniganj Basin, which also displays the highest Rock-Eval S2 Tmax, S4 Tpeak, and lowest HI (hydrogen index) value. This indicates the significant impact of igneous intrusions by removing hydrocarbons from shales and lowering their residual reactivity. The dominance of type I-II kerogen and presence of framboidal pyrite in the North Karanpura Basin shales also indicates some marine influence during their deposition
Forecasting sector-wise electricity consumption for India using various regression models
No full textElectricity is an important and one of the most domi�nant energy sources used in the world. It governs a
major share in the Indian as well as world economy.
Thus, forecasting its consumption can be useful in bet�ter planning of its future production and supply. In
the present study, electricity consumption in seven dif�ferent sectors, namely industry, domestic, agriculture,
commercial, traction and railways, others along with
total electricity consumed is forecasted using regres�sion analysis. The study uses four regression model�ling approaches to forecast electricity consumption by
sectors in India. These are linear, logarithmic, power
and exponential regression models. The accuracy of
the models is tested using R2
(coefficient of determina�tion) and MAPE (mean absolute percentage error)
values. The model having the highest R2
and lowest
MAPE value is selected for better accuracy results.
The result/forecast is then compared with the availa�ble data published by the Central Electricity Authority,
Government of India
Parametric stability analysis for optimum size of rib/snook in mechanized depillaring
No full textMechanised depillaring (MD) has been proved to be a panacea for faster extraction of the developed pillars which is blocking access to deeper deposits and locking more than 3200 Mt of coal, developed by Bord and Pillar mining method in Indian coalfields. Depillaring of these square/rectangular-shaped developed pillars by continuous miner creates irregular-shaped ribs/snooks. Stability assessment of such ribs/snooks becomes a challenging task due to various issues faced in estimation of load acting upon it and their strength. Area-based approach for the design of rib/snook is found to be the most suitable criteria during MD. Field investigations supported for parametric investigation for a competent size of rib/snook with varying nature of roof and depth of cover. Taking help from previous studies to design such ribs/snooks on numerical models using FLAC3D, a parametric study is carried out using 3DEC. Strength of such ribs/snooks and load acting upon them is calculated with the help of calibrated numerical models in order to estimate their factor of safety. This paper presents a review of the previous researches and a novel numerical simulation technique for estimation of a competent size of rib/snook in a given geo-mining condition
TGA/DSC study to characterise and classify coal seams conforming tosusceptibility towards spontaneous combustion
No full textThermogravimetric analysis/differential scanning calorimeter (TGA/DSC) technique along with basic coalcharacteristics study is carried out for eighty coal samples of Indian coalfields, to determine spontaneouscombustion propensity behaviour of coal. TGA study of coal samples indicates that there is an increase inthe mass of coal samples in the temperature range 150–350 ℃, which may be due to oxygen adsorptionand absorption. The correlation and principal component analysis states that the component of proxi-mate analysis (Mad,VMd, FR, and VR) have an acceptable correlation with the TGA experiments resultsi.e., Tgshand Tgign. Multiple fixed nonlinear regression analysis shows that thermogravimetry (TG) exper-iment results Tgignmay be the best index to categorise/classify the coal as per their susceptibility towardsspontaneous combustion. The authors proposed four groups of classification as per their propensitytowards spontaneous combustion depending upon the moisture (Mad), volatile matter (VMd), and TG ignition temperature from differential thermogravimetric (DTG) curve (Tgign) using hierarchal clustering analysis. The coal samples of different seams from Indian coalfield may be classified into four different clusters, viz. very highly/extremely susceptible (Tgign 320 ℃). The field observations and TGA/DSC experiment results with the following statistical analysis substantiate a similar assessment
Thermally processed biochar: preparation, characterisation and their application for cadmium removal from surface and groundwater
No full textThe thermally modified Parthenium biochar was used as an efficient adsorbent for removal of Cd from water. Parthenium biochar (PBC) prepared at 500°C was thermally activated by re-heating it at 700°C. PBC and thermally modified biochar (TMPBC) was characterised by FTIR, SEM-EDS, BET-surface area and XRD. The surface area of TMPBC (3.44 m2g−1) was higher than PBC (1.89 m2g−1). The optimum conditions for Cd adsorption was found to be pH, 5.0; biochar dose, 2.5 (g L−1); time, 30 min; temperature 25°C; initial Cd concentration, 100 mg L−1. Cadmium removal parameters were assessed using kinetic (pseudo first and second order) and adsorption models (Langmuir, Freundlich, and Redlich-Peterson). Cd removal followed pseudo second order kinetic model. The Cd removal capacity of TMPBC (129.2 mg g−1) was significantly higher than PBC (59.3 mg g−1). Cd removal by TMPBC (97–99%) was also demonstrated for a surface and underground waters. FTIR, XRD and SEM-EDS analysis confirmed the ion exchange and otavite precipitation mechanisms of Cd removal by biochar. The thermal modification technique could be an alternative for commercially available activated carbons; however this needs to be explored with different biomasses and other elements
Torrefaction of agro-wastes (palmyra palm shell and redgram stalk): characterization of the physicochemical properties and mechanical strength of binderless pellets
No full textTo increase the utilization of agro-waste as solid fuel, torrefaction is an important process to improve the fuel properties. In the present investigation, palmyra palm shell (PPS) and redgram stalk (RS) were torrefied in a specially designed stainless-steel tubular reactor with varying temperatures (230 °C, 260 °C, and 300 °C) under a nitrogen atmosphere at two residence times of 30 and 60 min. The influence of torrefaction temperature and residence time on mechanical properties and moisture reabsorption tendency of the binderless pellets were investigated. With increasing the torrefaction temperature up to 300 °C (60-min residence), the mass and energy yield decreased, and the fixed carbon, high heating value, and energy density increased. The fuel ratio (FR) increased from 0.25 or 0.23 to 1.35 and 0.52 for PPS and RS, respectively. The combustibility index increased up to a certain temperature (260 °C); however, at 300 °C, it decreased. Grindability of the torrefied biomass increased; about 99.89% and 95.28% of the smallest particles’ fraction pass through a < 75-µm sieve for PPS and RS, respectively, at 300 °C and 60 min as compared to the raw agro-wastes. The moisture reabsorption tendency of untorrefied and torrefied PPS and RS pellets was measured under the controlled environment of 60% RH at 40 °C. FTIR study supported the hydrophobicity of the torrefied material than the raw biomass. This study demonstrated that the torrefied PPS and RS have fuel properties comparable with India lignite, and this renewable fuel could be sustainably used for power generation and domestic applications
