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Search Results: 1 - 10 of 22370 matches for " Sunil Kumar Tripathy "
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Recovery of Chromite Values from Plant Tailings by Gravity Concentration  [PDF]
Sunil Kumar Tripathy, Y. Ramamurthy, Veerendra Singh
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2011, DOI: 10.4236/jmmce.2011.101002
Abstract: Large tonnages of chromite tailing were discarded during processing of chromite ore in the conventional circuit. A typical chromite plant tailing was treated in wilfley table for the recovery of chromite values. Optimisation study was carried out for the process parameters of wilfley table using empirical models, developed from the experimental data. It was found that grade and recovery (% Cr2O3) in the concentrate fraction majorly depended on the variation of deck tilt angle. To achieve high grade (>45%) with acceptable recovery (>40%), set of optimisation condition of parameters have derived which resulted large quantity of wash water (>5lpm of flow rate) is necessary. Validation of the empirical models were done with set of tests which resulted good agreement with the predict values (R2 is 0.96 and 0.99 for the grade and recovery respectively).
Application of High Tension Roll Separator for the Separation of Titanium Bearing Minerals: Process Modeling and Optimization  [PDF]
Srijith Mohanan, Sunil Kumar Tripathy, Y. Ramamurthy, C. Raghu Kumar
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2012, DOI: 10.4236/jmmce.2012.1110103
Abstract: The High Tension Roll Separator (HTRS) is one of the main electrostatic unit operations employed to separate titanium minerals like ilmenite, rutile and leucoxene which behave as conducting from zircon, sillimanite, garnet and monazite which behave as non-conducting minerals when a high potential difference is applied. Three process inputs, namely roll speed, feed material temperature and roll speed have been optimized. Experiments were conducted based on the Box- Behnken factorial design; the results were analyzed using response surface methodology (RSM). A new term, called Operational Quality Index (OQI) has been defined as a process output, which is maximized by quadratic programming, to obtain the optimum operating conditions. The maximum value of OQI obtained under the constraints of grade >96% and recovery >98% is 195.53, at the following operating conditions—Temperature: 102°C, Feed Rate: 1.75 tph and Roll Speed: 132 rpm. Under these conditions, the grade and recovery obtained are 96.6% and 98.9% respectively.
Characterisation and Pre-concentration of Chromite Values from Plant Tailings Using Floatex Density Separator  [PDF]
C. Raghu Kumar, Sunil Tripathy, D.S. Rao
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2009, DOI: 10.4236/jmmce.2009.85033
Abstract: Classification is a method of separation of fines from coarse particles and also lighter particles from heavier particles. The conventional classifiers, such as, hydrocyclone or mechanical classifiers, decreases the efficiency of the grinding and concentration circuits due to their imperfect separation. In the process of improving the efficiency of classification, a device that has been gaining popularity in recent years is the teeter-bed or hindered-bed separator such as Floatex density separator. Generally for processing chromite ores, different types of gravity methods are employed after crushing, grinding followed by classification. The Tata Steel Chrome Ore Beneficiation (COB) plant is generating 50 tph of tailings assaying 17% Cr2O3. A critical review on practice of the plant operating personnel is concerned in the grade-recovery characteristics of unit operations. But separation insight and influence of different operating and process parameters are essential to understand and control the process. The objective of the present investigation was to study the effect of the important operating variables on floatex density separator and preconcentration of COB plant tailings for the further beneficiation process and found that significant removal of iron bearing mineral such as goethite and silica is possible using FDS in a single stage operation. The maximum of 83% recovery of chromite is possible with 22 to 23% Cr2O3 content and thus obtained FDS underflow is suitable for flotation circuit. A low teeter water flow rate with a high bed pressure removes iron bearing mineral like goethite efficiently in an FDS.
Effect of desliming on the magnetic separation of low-grade ferruginous manganese ore
Sunil Kumar Tripathy,P. K. Banerjee,Nikkam Suresh
- , 2015, DOI: https://doi.org/10.1007/s12613-015-1120-0
Abstract: In the present investigation, magnetic separation studies using an induced roll magnetic separator were conducted to beneficiate low-grade ferruginous manganese ore. The feed ore was assayed to contain 22.4% Mn and 35.9% SiO2, with a manganese-to-iron mass ratio (Mn:Fe ratio) of 1.6. This ore was characterized in detail using different techniques, including quantitative evaluation of minerals by scanning electron microscopy, which revealed that the ore is extremely siliceous in nature and that the associated gangue minerals are more or less evenly distributed in almost all of the size fractions in major proportion. Magnetic separation studies were conducted on both the as-received ore fines and the classified fines to enrich their manganese content and Mn:Fe ratio. The results indicated that the efficiency of separation for deslimed fines was better than that for the treated unclassified bulk sample. On the basis of these results, we proposed a process flow sheet for the beneficiation of low-grade manganese ore fines using a Floatex density separator as a pre-concentrator followed by two-stage magnetic separation. The overall recovery of manganese in the final product from the proposed flow sheet is 44.7% with an assay value of 45.8% and the Mn:Fe ratio of 3.1.
Magnetic separation studies on ferruginous chromite fine to enhance Cr:Fe ratio
Sunil Kumar Tripathy,P. K. Banerjee,Nikkam Suresh
- , 2015, DOI: https://doi.org/10.1007/s12613-015-1064-4
Abstract: The Cr:Fe ratio (chromium-to-iron mass ratio) of chromite affects the production of chrome-based ferroalloys. Although the literature contains numerous reports related to the magnetic separation of different minerals, limited work concerning the application of magnetic separation to fine chromite from the Sukinda region of India to enhance its Cr:Fe ratio has been reported. In the present investigation, magnetic separation and mineralogical characterization studies of chromite fines were conducted to enhance the Cr:Fe ratio. Characterization studies included particle size and chemical analyses, X-ray diffraction analysis, automated mineral analysis, sink-and-float studies, and magnetic susceptibility measurements, whereas magnetic separation was investigated using a rare earth drum magnetic separator, a rare earth roll magnetic separator, an induced roll magnetic separator, and a wet high-intensity magnetic separator. The fine chromite was observed to be upgraded to a Cr:Fe ratio of 2.2 with a yield of 55.7% through the use of an induced roll magnetic separator and a feed material with a Cr:Fe ratio of 1.6.
Structural Investigations into Shwachman Bodian Diamond Syndrome SBDS using a Bioinformatics Approach
Babu A. Manjasetty,Sunil Kumar,Andrew P. Turnbull,Niraj Kanti Tripathy
Quantitative Biology , 2010,
Abstract: The functional correlation of missense mutations which cause disease remains a challenge to understanding the basis of genetic diseases. This is particularly true for proteins related to diseases for which there are no available three dimensional structures. One such disease is Shwachman Diamond syndrome SDS OMIM 260400, a multi system disease arising from loss of functional mutations. The Homo sapiens Shwachman Bodian Diamond Syndrome gene hSBDS is responsible for SDS. hSBDS is expressed in all tissues and encodes a protein of 250 amino acids SwissProt accession code Q9Y3A5. Sequence analysis of disease associated alleles has identified more than 20 different mutations in affected individuals. While a number of these mutations have been described as leading to the loss of protein function due to truncation, translation or surface epitope association, the structural basis for these mutations has yet to be determined due to the lack of a three-dimensional structure for SBDS.
Optimal Promotion and Replenishment Policies for Profit Maximization Model under Lost Units  [PDF]
Pradip Kumar Tripathy, Monalisha Pattnaik, Prakash Tripathy
American Journal of Operations Research (AJOR) , 2012, DOI: 10.4236/ajor.2012.22031
Abstract: Ever since its introduction in the second decade of the past century, the economic order quantity (EOQ) model has been the subject of extensive investigations and extensions by academicians. The physical characteristics of stocked items dictate the nature of inventory policies implemented to manage and control. The question is how reliable are the EOQ models when items stocked deteriorate one time. This paper introduces a modified EOQ model in which it assumes that a percentage of the on-hand inventory is wasted due to deterioration. There is hidden cost not account for when modeling inventory cost. We study the problem of promotion for a deteriorating item subject to loss of these deteriorated units. The objective of this paper is to determine the optimal time length, optimal units lost due to deterioration, the promotional effort and the replenishment quantity so that the net profit is maximized and the numerical analysis show that an appropriate promotion policy can benefit the retailer and that promotion policy is important, especially for deteriorating items. Furthermore crisp decision making is shown to be superior to crisp decision making without promotional effort cost in terms of profit maximization.
Lead Iodide Crystals as Input Material for Radiation Detectors  [PDF]
Sunil Kumar Chaudhary
Crystal Structure Theory and Applications (CSTA) , 2012, DOI: 10.4236/csta.2012.13004
Abstract: Lead iodide is an important inorganic solid for fundamental research and possible technological applications and is considered to be a potential room temperature nuclear radiation detector. In lead iodide the phenomenon of polytypism is posing an interesting problem of phase transformations amongst its various polytypic modifications. The transformations have also been observed even when the crystals are stored for few months. It causes deterioration in functioning of PbI2 devices. Taking into account the known structures of PbI2 and the data available on the mode of growth and storage of crystals, it has been concluded that purified melt grown crystals of PbI2 are the best suited for nuclear radiation detectors.
An Adaptive Data Aggregation Algorithm in Wireless Sensor Network with Bursty Source  [PDF]
Wireless Sensor Network (WSN) , 2009, DOI: 10.4236/wsn.2009.13029
Abstract: The Wireless Sensor network is distributed event based systems that differ from conventional communica-tion network. Sensor network has severe energy constraints, redundant low data rate, and many-to-one flows. Aggregation is a technique to avoid redundant information to save energy and other resources. There are two types of aggregations. In one of the aggregation many sensor data are embedded into single packet, thus avoiding the unnecessary packet headers, this is called lossless aggregation. In the second case the sensor data goes under statistical process (average, maximum, minimum) and results are communicated to the base station, this is called lossy aggregation, because we cannot recover the original sensor data from the received aggregated packet. The number of sensor data to be aggregated in a single packet is known as degree of ag-gregation. The main contribution of this paper is to propose an algorithm which is adaptive to choose one of the aggregations based on scenarios and degree of aggregation based on traffic. We are also suggesting a suitable buffer management to offer best Quality of Service. Our initial experiment with NS-2 implementa-tion shows significant energy savings by reducing the number of packets optimally at any given moment of time.
Optical and electronic properties of some binary semiconductors from energy gaps
Sunil K. Tripathy,Anup Pattanaik
Physics , 2015,
Abstract: II-VI and III-V tetrahedral semiconductors have significant potential for novel optoelectronic applications. In the present work, some of the optical and electronic properties of these groups of semiconductors have been studied using a recently proposed empirical relationship for refractive index from energy gap. The calculated values of these properties are also compared with those calculated from some well known relationships. From an analysis of the calculated electronic polarisability of these tetrahedral binary semiconductors from different formulations, we have proposed an empirical relation for its calculation. The predicted values of electronic polarisability of these semiconductors agree fairly well with the known values over a wide range of energy gap.
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