Iron ore grindability improvement by microwave pre-treatment

P. Kumar,B.K. Sahoo,S. De,D.D. Kar,S. Chakraborty,B.C. Meikap 한국공업화학회 2010 Journal of Industrial and Engineering Chemistry Vol.16 No.5

The influence ofmicrowave pre-treatment on grindability of iron ore (Orissa, India) was investigated by grindability tests. SEM analysis characterized the micro-fractures in microwave treated sample. This may be due to the thermal stress cracking resulted from microwave energy pre-treatment. XRD analysis showed the crystalline content of the sample. It was found that the microwave treated iron ore has peak more than that of untreated ore, i.e. the crystallinity increased with the microwave exposure time. The calculation of HGGI indicated increase in the ease of grinding or decrease in grindability index of the microwave treated ore. Grindability test showed that the microwave treated iron ore grinds much more rapidly initially than the untreated ore. The results showed that the breakage function of both microwave untreated and treated iron ore is dependent of the particle size. The grindability increased significantly as a result of microwave pre-treatment with the specific rate of breakage (Si) increasing by an average of 50%. It was concluded that microwave assisted grinding produced good results particularly for grinding characteristics. 2010 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

Highly Efficient Photocatalytic Studies on Bi36 Fe2 O57 Ceramic Synthesized by Chemical Route

Manish Kumar Verma,Vinod Kumar,Upakar Patel,Vishnu Shankar Rai,Anup Kumar,Arup Kumar De,Aditya Kumar Prajapati,Dinesh Prajapati,Kedar Sahoo,Tapas Das,N. B. Singh,K. D. Mandal 한국전기전자재료학회 2023 Transactions on Electrical and Electronic Material Vol.24 No.5

Bi36 Fe2 O57 (BFO) polycrystalline ceramic was synthesized by economical chemical route. The single-phase formation of BFO ceramic was confirmed by powder X-ray diffraction studies. Nanosized formation of BFO ceramics established by XRD and TEM analysis. The bimodal distribution of grain size is observed with size ranging from 50 to 600 nm. It observed that the Bi36 Fe2 O57 photocatalyst exhibited higher catalytic activity for the degradation of Methylene Blue (MB) under visible-light irradiation The oxidation state of elements present in the BFO ceramic, was confirmed by XPS studies. The pseudocapacitive nature of BFO ceramic was observed by cyclic Voltammetry. The dielectric constant of BFO ceramic was found 375 at 1 kHz at 300 K. The dielectric loss was found 0.51 at 100 kHz and 300 K.

Rheological characteristics of coal–water slurry using microwave pretreatment – A statistical approach

B.K. Sahoo,B.C. Meikap,S. De,M. Carsky 한국공업화학회 2011 Journal of Industrial and Engineering Chemistry Vol.17 No.1

The present study addresses the treatment of microwave energy for rheological characteristics of coal–water slurries (CWS) performed in an online Bohlin viscometer. Detailed experimental investigations were carried out for high ash Indian coal (Jamadoba washery, 38% ash). Experiments were conducted at high power level (900 W) for all the test samples in microwave oven. The exposure times were fixed at 30, 60, 90 and 120 s. Before and after treatment, the test samples were ground and sieved into different fractions for chemical and physical analysis. Central composite design (CCD) was applied to study the influence of particle diameter, solid concentration, microwave (MW) exposure time and shear rate on apparent viscosity for rheology characteristics of coal–water slurry. A quadratic model was developed for apparent viscosity using Design-Expert software. The model was used to calculate the optimum operating conditions for minimization of apparent viscosity. The apparent viscosity (22.83 mPa s)produced at these operating conditions showed an excellent agreement with the amounts predicted by the models.

Design and Construction of Nitrogen Liquefier

B. K, Choudhury,R. K. Sahoo,S. K. Sarangi 국제문화기술진흥원 2015 International Journal of Advanced Culture Technolo Vol.3 No.2

The design and construction of nitrogen liquefier begins with the process design of the cycle. The simulation of the cycles has been done using the software Aspen HYSYS. The compressor unit is available in the laboratory. Two number of high effectiveness, vacuum brazed aluminum plate fin heat exchangers are designed and fabricated. Turboexpander is designed and all of its components are fabricated. A suitable modification has been done with a precession needle valve to operate as a long stem JT valve. For separating the liquid, a phase separator is designed and fabricated. All the components are assembled inside a double walled cold box with pipes as per the process need. The necessary pressure, temperatureand other measuring instruments, valves and safety devices are mounted on the liquefier. After successful running of the liquefier, for the mass flow rate of 296 kg/hr for gaseous nitrogen, it is expected to deliver 17.44 lit/hr of liquid nitrogen.

An investigation into the influence of microwave energy on iron ore–water slurry rheology

B.K. Sahoo,S. De,B.C. Meikap 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.25 No.-

The transporting of slurries in pipelines depends largely on rheological behavior of the solid–liquid suspension. These rheological properties of slurries are very much influenced by the slurry concentration, particle size distribution and, surface characteristics. The present invention is concerned with the effect of these parameters on slurry rheology using microwave (MW) energy. Microwave pretreatment for rheological behaviour of iron ore-water slurries (IWS) were carried out in an online Bohlin viscometer. Detailed experimental work for Indian iron ore were conducted at power level of 900 W and 30, 60, 90 and 120 s various exposure times in microwave oven. The microwave treated and untreated test samples were ground for rheological characteristic of slurries. It was seen that microwave-treated ore have better rheological properties as compared to untreated ore. This type of slurry is shear thinning and easy to transport as it exhibited pseudo-plastic behavior. The result showed that microwave-treated iron ore have a density lower than that of untreated ore after grinding. Statistical design analysis was employed to develop empirical equations and found to be encouraging and highly considerable.

Potentially Multidentate Tripodal Amine Catechol Ligands as Chelators for Ga(III) and In(III)

Sahoo, Suban K.,Baral, Minati,Bera, Rati Kanta,Kanungo, B. K. Korean Chemical Society 2009 Bulletin of the Korean Chemical Society Vol.30 No.9

The binding abilities of two multidentate tripodal amine catechol ligands, cis,cis-1,3,5-tris[(2,3-dihydroxybenzylamino) aminomethyl]cyclohexane (TMACHCAT, $L^1)\;and\;N^1,N^3,N^5$-tris(2-(2,3-dihydroxybenzylamino) ethyl)cyclohexane-1,3,5-tricarboxamide (CYCOENCAT, $L^2$) with Ga(III) and In(III) have been investigated by potentiometric and spectrophotometric methods in an aqueous medium of 0.1 M KCl at 25 ${\pm}\;1\;{^{\circ}C}.$ The ligands $L^1\;and\;L^2$ formed various monomeric species $MLH_3,\;MLH_2$, MLH and ML (M = $Ga^{+3}\;and\;In^{+3}$) and showed potential to form strong encapsulated tris(catechol) type complexes. The coordination modes, binding ability and selectivity of the ligands towards Ga(III) and In(III) have been discussed with the help of experimental evidences, and supported with molecular modeling calculations.

Effect of Formaldehyde Treated Rape Seed Oil Cake Based Diet Supplemented with Molasses on Growth Rate and Histopathological Changes in Goats

Sahoo, B.,Walli, T.K.,Sharma, A.K. Asian Australasian Association of Animal Productio 2006 Animal Bioscience Vol.19 No.7

An experiment with twenty crossbred goat kids (male) of 2-3 months old, weighing about 12 kg was conducted to study the effect of feeding formaldehyde treated rape seed oil cake based diet supplemented with molasses on growth rate and histopathological changes of different organs. Goats were randomly divided into four groups of 5 animals each and were individually fed for a period of 120 days. The animals in group I (URC) and II (URCM) were fed concentrate mixture (CM-I) containing untreated rape seed oil cake (30%) while, the animals in group III (TRC) and IV (TRCM) were offered concentrate mixture (CM-II) containing formaldehyde treated rape seed oil cake. Further, molasses as energy source was additionally supplemented with the concentrate mixture at the rate of 8% of concentrate mixture on dry matter basis to animals in group II and IV. All the animals were maintained on roughage (Berseem hay:wheat straw = 2:1) and concentrate in 50:50 ratio. Average daily gain (g/d) of animals in group IV was significantly (p<0.05) higher than that in group I., but at par with group II and III. Feed conversion efficiency was also significantly (p<0.05) higher in group IV (10.14) than group I and II but at par with group III. The growth rate however increased by 50.2% in group IV showing more consistency in maintaining highest growth rate due to better balance of nutrients. At the end of four months of feeding trial, two animals from each group were sacrificed for histopathological study of different organs. Significant histopathological changes in liver, heart, lungs tissue of animals fed untreated rape seed oil cake diet were recorded which were totally absent in the organ of animals fed formaldehyde treated cake. The liver tissue of goats receiving control diet (containing untreated rape seed oil cake) were found to be associated with engorged central vein and blood vessels. Hepatocytes were swollen, pale and degenerated with cellular infiltration and fibrosis of portal areas. The muscles of heart were found to have intermyofibral edema. Emphysema accompanied by dilated and ruptured alveoli was also recorded in lung tissue. However, histopathological examination of various tissues of goats fed formaldehyde treated cake diet did not exhibit any degenerative changes. Additional supplementation of molasses with or without treated cake diet, apparently did not have any significant effect on ameliorating the above degenerative changes.

Potentially Multidentate Tripodal Amine Catechol Ligands as Chelators for Ga(III) and In(III)

Suban K. Sahoo,Minati Baral,Rati Kanta Bera,B. K. Kanungo 대한화학회 2009 Bulletin of the Korean Chemical Society Vol.30 No.9

The binding abilities of two multidentate tripodal amine catechol ligands, cis,cis-1,3,5-tris[(2,3-dihydroxybenzylamino) aminomethyl]cyclohexane (TMACHCAT, L1) and N1,N3,N5-tris(2-(2,3-dihydroxybenzylamino) ethyl)cyclohexane-1,3,5-tricarboxamide (CYCOENCAT, L2) with Ga(III) and In(III) have been investigated by potentiometric and spectrophotometric methods in an aqueous medium of 0.1 M KCl at 25 ± 1 °C . The ligands L1 and L2 formed various monomeric species MLH3, MLH2, MLH and ML (M = Ga+3 and In+3) and showed potential to form strong encapsulated tris(catechol) type complexes. The coordination modes, binding ability and selectivity of the ligands towards Ga(III) and In(III) have been discussed with the help of experimental evidences, and supported with molecular modeling calculations.

Nanofiller as Vulcanizing Aid for Styrene-Butadiene Elastomer

Sahoo, N.G.,Das, C.K.,Panda, A.B.,Pramanik, P. The Polymer Society of Korea 2002 Macromolecular Research Vol.10 No.6

The use of ZnO and stearic acid is very well known in sulfenamide accelerated sulfur vulcanization of diene elastomers. Zn-ion coated nano filler has been developed and tested, in styrene-butadiene rubber (SBR) as sulfur vulcanizing activator cum reinforcing filler. In this study Zinc oxide has been replaced by the Zn-ion coated nano silica filler with an aim to study the dual role of this nanofiller in SBR. The presence of Zn-ion on the nano silica filler surface activates the sulfur vulcanization by involving Zn++ in to the sulfurating complex formed with thiazole from sulfenamide. The increase of Zn-ion, on the nanofiller, decrease the scorch safety of the elastomer compound but increase the tensile strength, state of cure and tear strength and attain maximum at its 10% level. The presence of stearic acid increases the rate of vulcanization. Replacement of stearic acid with mono-stearate, however, increases the vulcanization rate but decrease the ultimate state of cure. A mechanistic scheme involving dual function of this nanofiller has been suggested.

Nanofiller as Crosslinker for Halogen-Containing Elastomers

Sahoo, N.G.,Kumar, E.Shiva,Das, C.K.,Panda, A.B.,Pramanik, P. The Polymer Society of Korea 2003 Macromolecular Research Vol.11 No.6

A Zn ion-coated nanosilica filler has been developed and tested, in chlorosulfonated polyethylene (CSPE) and polychloroprene (CR), as a vulcanizing activator, cum was reinforcing filler. In this study, ZnO was replaced by the Zn ion-coated nanosilica filler with an aim of studying the dual role of this nanofiller in CSPE and CR. In the case of CSPE vulcanizates, the presence of MgO deteriorated the state and rate of cure when the Zn ion-coated nanosilica filler was used, but in the case of CR it improved the state of cure and enhanced the modulus and tensile strength. The Zn ion-coated filler proved to be a better reinforcing-cum-curing agent than was externally added ZnO and NA-22 also proved to be a better curative in the presence of the Zn ion-coated nanosilica filler for both CSPE and CR.