Browsing by Author "Mohanraj, G.T."

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Characterization study and recovery of copper from low grade copper ore through hydrometallurgical route
(Elsevier B.V., 2022) Mohanraj, G.T.; Rahman, M.R.; Arya, S.B.; Barman, R.; Krishnendu, P.; Meena, S.
Characterization studies were conducted on low grade copper ore with the aid of standard approaches. The Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDS) study specifies the semi-quantitative data of qualitatively analyzed chemical elements present in the ore sample. Optical Microscopy (OM) and X-Ray Diffraction (XRD) endorse the presence of chalcopyrite (CuFeS2) and pyrites along with other different mineral phases in the ore sample. Thermo Gravimetric Analysis (TGA) and Mossbauer spectroscopy studies confirm the formation of CuO and Fe2O3 after roasting at 700 °C. The better copper recovery from low grade copper ore was achieved through optimized leaching parameters. It was found that the particle size of −63+53 µm can be leached up to 94.96 % of copper using a lixiviant reagent mixture (30 vol. % hydrogen peroxide and 0.5 M sulfuric acid) under magnetic stirring for 30 min at a constant speed of 300 rpm, by keeping the liquid/solid (L/S) ratio at 20/2 ml/g. Moreover, the solvent extraction process works well with the pregnant leach solution, whereby, 98.9 % of copper extraction is possible, and the loading time is less than a minute. Meanwhile, 93.91 % of overall copper extraction efficiency was achieved through optimized leaching parameters and solvent extraction method. © 2021
Comparison of the Experimental and Modelling Results of Mechanical Characteristics of LM6 and LM9 Alloy for Tractor Application
(Springer, 2023) Shetteppanavar, C.C.; Shinde, R.B.; Hanumanthappa, H.; Mohanraj, G.T.; Shanmugam, B.K.S.; Srivatsav, S.K.Y.; Kavitha Kumar, A.R.B.K.
In India, the development of composite and alloys material has provided the required characteristics material. In this study, an attempt has been made to compare the performance of LM6 and LM9 alloy for an automobile application. These alloys are studied based on the tensile strength and fatigue test required for the pullet used in tractor application. The tensile test results showed that the LM9 alloy specimen has higher strength than the LM6 alloy specimen. Furthermore, results showed that the fatigue strength of the LM9 alloy specimen was found to be higher than the LM6 alloy specimen. Further, the tensile and fatigue materials behaviour of LM6 and LM9 specimens were compared through ANSYS modelling. From the experimental and modelling results, it was clear that the modelling results are in close agreement with the tensile and fatigue experimental results. The mechanical characteristics such as tensile and fatigue strength of the LM9 specimen were found to be much better than the LM6 specimen. The microstructural analysis also showed higher silicon particles providing higher strength for LM9 specimens than LM6 specimens. The pulley material made out of LM9 alloy will avoid the shear failure occurrence of the pulley. © 2022, The Institution of Engineers (India).
Design and fabrication of optimized magnetic roller for permanent roll magnetic separator (PRMS): Finite element method magnetics (FEMM) approach
(Elsevier B.V., 2021) Mohanraj, G.T.; Rahman, M.R.; Joladarashi, S.; Hanumanthappa, H.; Shanmugam, B.K.; Vardhan, H.; Rabbani, S.A.
In the present work, an attempt has been made to develop a PRMS in a cost effective and environmental friendly way through FEMM analysis of magnetic roller (active part of PRMS). The FEMM analysis indicates that, the optimized magnetic roller having magnet-to-steel disk thickness ratio of 5 mm: 2.5 mm was proved to be gainful in beneficiating paramagnetic minerals due to the best magnetic field value from the roller surface that is, 0.89 to 2.59 T. Prediction analysis was performed on FEMM data using artificial neural network (ANN) modelling technique. Further, the design calculations of lab scale PRMS in terms of power requirements and belt tensions were addressed. The fabricated PRMS was tested on paramagnetic mineral (hematite ore) assayed 51.24% of Fe, 10.20% of SiO2, and 2.98% of Al2O3 for different roller speeds and the belt thickness. The result showed that, at 0.5 mm belt thickness with 180 rpm roller speed the fabricated lab scale PRMS works well in terms of improvement in the Fe content up to 59.5% at the concentrate along with the Fe recovery of 71.41%. The obtained results suggest that, the FEMM analysis is more suitable to optimize the effective magnetic roller for the PRMS. © 2021 The Society of Powder Technology Japan
Effect of Wollastonite Filler on the Experimental and Microstructural Analysis of Epoxy Composite Reinforced with E-glass Fibre
(Springer, 2022) Lokesh, K.S.; Pinto, T.; Shrinivasa Mayya, D.; Shanmugam, B.K.; Panduranga, B.P.; Hanumanthappa, H.; Mohanraj, G.T.
In the present study, the polymer composite was produced with epoxy, E-glass and wollastonite as the matrix, reinforcement and filler material, respectively. The present study investigates the effect of the filler material on the mechanical performance of developed composite specimens. The reinforcement material selected was woven and chopped-type fibre material. The filler material composition in the woven and chopped-type specimens was individually varied with 0%, 1%, 3%, 5% and 7%. The specimen was subject to mechanical testing, viz., tensile and flexural strength tests. Further, the wear rate of the normal specimen was tested to 5, 10 and 15 min. Additionally, the specimen was subjected to SEM (scanning electron microscope) analysis after attaining fracture for each study. The results showed that the specimen with 1% filler material had better tensile strength. It was also found that the flexural strength was good and was increasing with the filler material. The wear rate was reduced with the increase in filler material composition in the specimen. The results show that the woven fabric specimen shows better mechanical performance than the chopped specimen. © 2022, The Institution of Engineers (India).
Evaluation of the Wear Behaviour of Thermally Aged E Glass Reinforced Epoxy Composite Filled with Wollastonite Using Taguchi L27 Technique
(Springer, 2022) Lokesh, K.S.; Pinto, T.; Mayya, D.S.; Shanmugam, B.K.; Panduranga, B.P.; Hanumanthappa, H.; Mohanraj, G.T.
In the present study, the E glass reinforced epoxy composite filled with wollastonite was developed. Taguchi’s L27 technique was selected for developing and analysing the effects of control factors on the wear behaviour of composites. The control factors considered for the present study was filler (%), time (minute) and temperature (°Celsius). The wear experiments were carried out using pin on disc arrangements for different experimental conditions. After the wear test, the microstructural analysis was carried out on the specimens using scanning electron microscope (SEM) analysis. The regression coefficient of 98.8% and probability plot shows that the model was accurate and valid. From the optimization results, it was clear that the 7% filler percentage (high level), 5 min sliding time (low level) and 50 °C temperature (high level) will yield high wear resistance and lower material loss due to the wear of the composites. Further, a confirmation test with the optimized condition was conducted and validated using the SEM image. The results also showed that the Taguchi technique effectively studies the effects of the control factors for obtaining the maximum wear resistance of the composites. © 2022, The Institution of Engineers (India).
Mineralogical studies of low grade iron ore from Bellary-Hospet region, India
(2019) Mohanraj, G.T.; Krishneindu, P.; Choudhary, R.P.; Meena, S.S.; Yusuf, S.M.; Rahman, M.R.
Detailed mineralogical characterization study has been conducted on low grade iron ore sample from Bellary-Hospet region, Karnataka, India by using XRD, optical microscopy and M�ssbauer spectroscopy techniques for identifying the eminence of iron ore sample. Liberation analysis was carried out by particle size analysis and specific gravity measurement. Chemical analysis results showed that, -125+90? size fraction assaying up to 57.34% Fe, 8.55% SiO 2 and 8.6% Al 2 O 3 . XRD analysis revealed the presence of major hematite phase along with kaolinite, gibbsite, quartz and goethite in the sample. Microscopic study confirms the transformation of magnetite to hematite by martitization. M�ssbauer spectrum reveals the existence of hematite ?-Fe 2 O 3 phase with small distortion in crystal structure. � 2019 Author(s).
Mineralogical studies of low grade iron ore from Bellary-Hospet region, India
(American Institute of Physics Inc. subs@aip.org, 2019) Mohanraj, G.T.; Krishneindu, P.; Choudhary, R.P.; Meena, S.S.; Yusuf, S.M.; Rahman, M.R.
Detailed mineralogical characterization study has been conducted on low grade iron ore sample from Bellary-Hospet region, Karnataka, India by using XRD, optical microscopy and MÃ¶ssbauer spectroscopy techniques for identifying the eminence of iron ore sample. Liberation analysis was carried out by particle size analysis and specific gravity measurement. Chemical analysis results showed that, -125+90Î¼ size fraction assaying up to 57.34% Fe, 8.55% SiO 2 and 8.6% Al 2 O 3 . XRD analysis revealed the presence of major hematite phase along with kaolinite, gibbsite, quartz and goethite in the sample. Microscopic study confirms the transformation of magnetite to hematite by martitization. MÃ¶ssbauer spectrum reveals the existence of hematite Î±-Fe 2 O 3 phase with small distortion in crystal structure. Â© 2019 Author(s).
Numerical approach for optimization of magnetic roller and evaluating the performance of permanent magnet roller separator through design of experiment
(Elsevier B.V., 2022) Mohanraj, G.T.; Joladarashi, S.; Hanumanthappa, H.; Shanmugam, B.K.; Vardhan, H.; Naik, G.M.; Bhat Panemangalore, B.P.; Rahman, M.R.
The present study is focused on numerical analysis of magnetic roller (Mr) using finite element method magnetics (FEMM) software for different magnet disc-to-steel disc (MD-to-SD) width ratios. The numerical (FEMM) results reveal that, the optimized Mr with the MD-to-SD width ratio of 5 mm: 2.5 mm was proved advantageous because of the effective magnetic field (Mf) value of 0.89–2.59 T. The artificial neural network (ANN) modelling technique was used for the prediction analysis of obtained numerical results. Furthermore, by using optimized Mr, the lab-scale permanent magnet roller separator (PMRS) was developed and parametric optimization has been carried out using Taguchi-based L27 orthogonal array design. The significance of parameters on the overall quality of the product has also been evaluated quantitatively by the analysis of variance (ANOVA) method. It was found that the belt thickness was the most influential factor in the product of desired Fe grade and recovery %. The obtained regression coefficient (i.e., R2 = 87.13 and 91.69% for Fe grade and Fe recovery %, respectively) and normal probability plot show the highest correlation between the experimented and predicted data. The results suggested that the numerical approach was suitable for designing optimized Mr for the processing of paramagnetic minerals. © 2022 Faculty of Engineering, Alexandria University
Tunable dual color emission from the opposite faces of silicon nanoparticle embedded gel-glass
(Elsevier B.V., 2023) Das, B.; Hossain, S.M.; Mohanraj, G.T.; Chowdhury, S.R.; Siddique, A.B.; Rahman, M.R.; Ray, M.
A luminescent silicon nanoparticle embedded gel-glass, prepared by room temperature hydrolysis and reduction of aminosilane, exhibits intriguing dual photoluminescence (PL) from opposite faces of the glass. The face, which is excited with UV, exhibits excitation energy dependent blue-green emission. As the excitation energy is varied from 350 nm to 450 nm the PL peaks shift from 435 nm to 506 nm. The opposite surface, on the other hand emits nearly excitation independent green light – the PL peak shifts by ∼17 nm as the excitation energy is varied from 350 nm to 450 nm. The luminescent properties provide interesting insights into the light emission mechanism from nanostructured silicon. Spectral filtering by reabsorption and photon reabsorption-reemission in a size distributed nanoparticle system having different optical gaps play a combined role in the observed dual emission. We show that the dual emission can be tuned by simply varying the thickness of the glass. Such dual emission renders the luminescent glass amenable for several applications as a novel solid state display material. © 2023 Elsevier B.V.