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11.
AK Mishra D. Bhattacharya 《Fragblast: International Journal for Blasting and Fragmentation》2005,9(1):47-59
The mineral industry is leading towards a technology driven optimization process. Drilling and blasting are such unit operations in a mine, which can alter the balance sheet of the mine if not planned properly. The development, improvement and utilization of innovative technologies in terms of blast monitoring instruments and explosives technology are important for cost effectiveness and safety of mineral industries.
The ever-growing demand for minerals has compelled the industry to adopt large opencast projects using heavy equipment. This has necessitated use of a few hundred tonnes of explosives in each blast. The bulk delivered fourth generation explosives have solved the problem of explosive loading to a large extent as it provides improved safety in manufacturing, transportation and handling. Bulk delivered emulsion is non-explosive until gasification is complete and a large quantity of explosive can be transported and loaded into blast holes efficiently and with safety. The priming of bulk delivered explosives in Indian mines uses the conventional PETN/TNT-based boosters. The conventional booster possesses safety problems in terms of handling and use, so Indian Explosives Ltd has developed an emulsion-based booster (Powergel Boost).
This paper explores the potential of an emulsion-based booster used as a primer to initiate bulk delivered emulsion explosives used in mines. An attempt has been made at a comparative study between the conventional booster and the emulsion-based booster in terms of the initiation process developed and their capability of developing and maintaining a stable detonation process in the column explosives. The study has been conducted using a continuous velocity of detonation (VOD) measuring instrument, the VODMate two channel system manufactured by Instantel Inc. of Canada. During this study three blasts were monitored. In each blast two holes were selected for study, the first hole was initiated using a conventional booster while the other one used an emulsion-based booster. The findings of the study advocates that the emulsion-based booster is capable of the efficient priming of bulk delivered column explosive with a stable detonation process in the column. 相似文献
The ever-growing demand for minerals has compelled the industry to adopt large opencast projects using heavy equipment. This has necessitated use of a few hundred tonnes of explosives in each blast. The bulk delivered fourth generation explosives have solved the problem of explosive loading to a large extent as it provides improved safety in manufacturing, transportation and handling. Bulk delivered emulsion is non-explosive until gasification is complete and a large quantity of explosive can be transported and loaded into blast holes efficiently and with safety. The priming of bulk delivered explosives in Indian mines uses the conventional PETN/TNT-based boosters. The conventional booster possesses safety problems in terms of handling and use, so Indian Explosives Ltd has developed an emulsion-based booster (Powergel Boost).
This paper explores the potential of an emulsion-based booster used as a primer to initiate bulk delivered emulsion explosives used in mines. An attempt has been made at a comparative study between the conventional booster and the emulsion-based booster in terms of the initiation process developed and their capability of developing and maintaining a stable detonation process in the column explosives. The study has been conducted using a continuous velocity of detonation (VOD) measuring instrument, the VODMate two channel system manufactured by Instantel Inc. of Canada. During this study three blasts were monitored. In each blast two holes were selected for study, the first hole was initiated using a conventional booster while the other one used an emulsion-based booster. The findings of the study advocates that the emulsion-based booster is capable of the efficient priming of bulk delivered column explosive with a stable detonation process in the column. 相似文献
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14.
Purbasha Bhattacharya Sarbani Patranabis-Deb 《Journal of the Geological Society of India》2016,87(3):287-307
The Meso to Neoproterozoic succession in the western Chattisgarh basin around Rajnandgaon has been classified into coarse siliciclastic dominated proximal and fine siliciclastic-carbonate dominated distal assemblages. The proximal assemblage, the Chandarpur Group, unconformably overlies the Neoarchean to Paleoproterozoic Dongargarh- Kotri volcanics (c.2.2-2.3 Ga), Bengpal Granite (c.2.5-2.6 Ga) and BIF of the Dalli-Rajhara Group (~2.4 Ga). The Chandarpur Group consists of 15-20 m thick conglomerate and feldspathic sandstone at the basal part of the succession, which is mapped as a lateral equivalent of the Lohardih Formation. The coarse clastics, conglomerate succession gradationally passes up to ~280 m thick succession of supermature sandstone, the Kansapathar Formation. The thick mudstone dominated heterolithic unit, the Gomarda Formation and its lateral equivalent, the Chaporadih Formation is not present in the western part of the Chattisgarh basin. The fine siliciclastic-carbonate assemblage of the Raipur Group conformably overlies the Chandarpur Group. The Raipur Group consists of Charmuria Limestone (~320 m), Gunderdehi Shale (~450 m), Chandi Limestone (~ 550 m) with Deodongar Member (~50 m) and Tarenga Shale. The sediments of Chandarpur Group were deposited in a shallow marine environment with occasional fluvial input in a relatively fluctuating sea level. The palaeoshoreline was NW-SE oriented with an open sea towards north which remained same throughout the deposition of the Chandarpur-Raipur sequence. It has also been inferred that the Lohardih Formation and the Kansapathar Formation represents a rifting phase followed by a stable subsidence stage when the basin evolved into a large epicontinental sea. The sequences further display signatures of passive margin sedimentation with multiple events of carbonate-shale rhythmite deposition. 相似文献
15.
The paper presents a computational procedure for reliability analysis of earth slopes considering spatial variability of soils under the framework of the Limit Equilibrium Method. In the reliability analysis of earth slopes, the effect of spatial variability of soil properties is generally included indirectly by assuming that the probabilistic critical slip surface is the same as that determined without considering spatial variability. In contrast to this indirect approach, in the direct approach, the effect of spatial variability is included in the process of determination of the probabilistic critical surface itself. While the indirect approach requires much less computational effort, the direct approach is definitely more rigorous. In this context this paper attempts to investigate, with the help of numerical examples, how far away are the results obtained from the indirect approach from that obtained from the direct approach. In both the approaches, it is required to use a model of discretization of random fields into finite random variables. A few such models are available in the literature for one-dimensional (1D) as well as two-dimensional (2D) spatial variability. The developed computational scheme is based on the First Order Reliability Method (FORM) coupled with the Spencer Method of Slices valid for limit equilibrium analysis of general slip surfaces. The study includes bringing out the computational advantages and disadvantages of the three commonly used discretization models. The sensitivity of the reliability index to the magnitudes of the scales of fluctuation has also been studied. 相似文献
16.
Prakash Abhishek Piazolo Sandra Saha Lopamudra Bhattacharya Abhijit Pal Durgesh Kumar Sarkar Saheli 《International Journal of Earth Sciences》2018,107(6):2265-2292
International Journal of Earth Sciences - In the present study we investigate the microstructural development in mullite, quartz and garnet in an anatectic migmatite hosted within a Grenvillian-age... 相似文献
17.
Biplab Bhattacharya Joyeeta Bhattacharjee Sandip Bandyopadhyay Sudipto Banerjee Kalyan Adhikari 《Journal of Earth System Science》2018,127(2):29
The present research is an attempt to assess the Barakar Formation of the Raniganj Gondwana Basin, India, in the frame of fluvio-marine (estuarine) depositional systems using sequence stratigraphic elements. Analysis of predominant facies associations signify deposition in three sub-environments: (i) a river-dominated bay-head delta zone in the inner estuary, with transition from braided fluvial channels (FA-B1) to tide-affected meandering fluvial channels and flood plains (FA-B2) in the basal part of the succession; (ii) a mixed energy central basin zone, which consists of transitional fluvio-tidal channels (FA-B2), tidal flats, associated with tidal channels and bars (FA-B3) in the middle-upper part of the succession; and (iii) a wave-dominated outer estuary (coastal) zone (FA-B4 with FA-B3) in the upper part of the succession. Stacked progradational (P1, P2)–retrogradational (R1, R2) successions attest to one major base level fluctuation, leading to distinct transgressive–regressive (T–R) cycles with development of initial falling stage systems tract (FSST), followed by lowstand systems tract (LST) and successive transgressive systems tracts (TST-1 and TST-2). Shift in the depositional regime from regressive to transgressive estuarine system in the early Permian Barakar Formation is attributed to change in accommodation space caused by mutual interactions of (i) base level fluctuations in response to climatic amelioration and (ii) basinal tectonisms (exhumation/sagging) related to post-glacial isostatic adjustments in the riftogenic Gondwana basins. 相似文献
18.
Dhruba Mukhopadhyay Tapas Bhattacharya Tapan Chakraborty Arun Kanti Dey 《Journal of Earth System Science》1990,99(2):249-268
In the western part of the North Singhbhum fold belt near Lotapahar and Sonua the remobilized basement block of Chakradharpur
Gneiss is overlain by a metasedimentary assemblage consisting of quartz arenite, conglomerate, slate-phyllite, greywacke with
volcanogenic material, volcaniclastic rocks and chert. The rock assemblage suggests an association of volcanism, turbidite
deposition and debris flow in the basin. The grade of metamorphism is very low, the common metamorphic minerals being muscovite,
chlorite, biotite and stilpnomelane. Three phases of deformation have affected the rocks. The principal D1 structure is a
penetrative planar fabric, parallel to or at low angle to bedding. No D1 major fold is observed and the regional importance
of this deformation is uncertain. The D2 deformation has given rise to a number of northerly plunging major folds on E-W axial
planes. These have nearly reclined geometry and theL
2lineation is mostly downdip on theS
2surface, though some variation in pitch is observed. The morphology of D2 planar fabric varies from slaty cleavage/schistosity
to crenulation cleavage and solution cleavage. D3 deformation is weak and has given rise to puckers and broad warps on schistosity
and bedding. The D2 major folds south of Lotapahar are second order folds in the core of the Ongarbira syncline whose easterly
closure is exposed east of the mapped area. Photogeological study suggests that the easterly and westerly closing folds together
form a large synclinal sheath fold. There is a continuity of structures from north to south and no mylonite belt is present,
though there is attenuation and disruption along the fold limbs. Therefore, the Singhbhum shear zone cannot be extended westwards
in the present area. There is no evidence that in this area a discontinuity surface separates two orogenic belts of Archaean
and Proterozoic age. 相似文献
19.
For a pure phase at equilibrium with a polycomponent melt, two sets of expressions can be derived; one expressing its activity as a function of enthalpy, entropy, heat capacity and temperature, and the other by coupling a Flory-Huggins' polymerisation model with the van Laar heat of mixing term. Interaction parameters for binary and ternary systems have been computed at 1 bar by equating these two expressions. Assuming the interaction parameter to be independent of temperature, equilibrium temperatures at higher pressures can be calculated by an iterative procedure. Such retrieval calculations were carried out in simple eutectic, volatile-free systems like CaAl2Si2O8-CaMgSi2O6, Mg2SiO4-TiO2, MgSiO3-TiO2, Mg2SiO4-CaMgSi2O6, NaAlSi3O8-SiO2 and CaAl2Si2O8-CaMgSi2O6-Mg2SiO4. The close agreement between the theoretically retrieved and the experimentally determined equilibrium temperatures testifies to the validity of the model at higher pressures. The successful application of the model to simple eutectic, binary and ternary systems involving vastly dissimilar phases without imposing added constraints implies that it can be possibly extended to hitherto unknown systems provided the thermodynamic parameters of the phases involved are known. 相似文献
20.
Landsat imagery have been interpreted visually and under Additive Colour Viewer to interpret the regional geology and geomorphology in parts of Subarnarekha-Baitarani basin. The area lies south of Singhbhum shear zone and represents Precamrain shield. Important Simlipal ultrabasic volcanic complex of Orissa is included in the area. Although detailed map of the area is available, yet an attempt has been made to interpret the imagery for evaluating the results provided in comparison to the existing maps. Delineation of main lithological groups is possible. Having some data from the existing maps, lithoiogical boundary delineation of Mica Schist-Phyllite-Quartzite, Granites and Gneisses, Dhanjori Lava, Anorthosite-Gabbro Complex and Dolerite dykes, all of Precambrian age, has been done. Laterite and Quaternary sediments are also picked up. Lineament mapping has been carried out from imagery, which is difficult to map in the field. N--S and NNW-SSE lineament system is very prominent in Simlipal complex whereas in other parts NNW-SSE and NNE-SSW trends are common. The major fault plane running NNE-SSW in the area is responsible for the present-day configuration of Subarnarekha river. Identification of different geomorphological units is perhaps best done on imagery. Several geomorphic units like structural Hill, Denudational Hill, Pediment, Buried Pediment, Lateritic Clay Plain, Laterite upland, Terrace Plain etc have been mapped. Valley fills are wellpicked up from imagery. Hydrogeological potentiality of the different geologic and geomorphic units have been evaluated qualitatively. Ground water occurrence, movement and potentiality are mainly controlled by structural, geological and geomorphological set-up of the area. Buried Pediment, Laterite upland, Laterite clay plain and alluvial fills are the potential zones from the view point of ground water occurrences. Comparative study of the different Landsat bands and band-filter combinations under Additive Colour Viewer has been undertaken to find out the enhancement capability in delineating features. It is found that small scale geological and geomorphological maps can be prepared from Landsat imagery. 相似文献