Faculty Publications
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Item 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. © 2021Item Biocorrosion Behavior of Epoxy-Based Multilayer Nanocomposite Coatings(Springer Science and Business Media Deutschland GmbH, 2023) Shetty, P.; Arya, S.B.; Shetty K, V.S.Marine structures are prone to biocorrosion, so developing a suitable coating system to combat corrosion is essential. The present work is focused on the development of a multilayered epoxy-based nanocomposite (NC) coating system reinforced with ZnO filler in the first layer coat (NC1), ZnO and Cu2O in the second layer (NC2), and the third layer consisting of a varying percentage of TiO2 with 5 wt%, 10 wt%, and 15 wt% of TiO2 designated as NC3, NC4, and NC5, respectively, as top coat on the bare steel. Brush coating was employed to fabricate the coatings. Surface morphology and mechanical properties, wettability, corrosion, and biocorrosion behavior of the bare steel and coated substrates were examined. Mechanical properties such as linear scratch hardness and posi adhesion test values of the coatings were found to be in the order NC1 < NC2 < NC3 < NC4 < NC5. The NC3-coating system comprising three layers of coating reinforced with 5 wt% TiO2 imparting hydrophobicity offered maximum resistance to microbial adhesion with 93% and 91% reduction in corrosion rate than the bare metal in natural and artificial seawater, respectively, after the 7th day of immersion. The bacterial and fungal cell counts in the biofilm after the 7th day of immersion were reduced by four and three orders of magnitude, respectively, in the nanocomposite against the bare substrate providing good biofouling resistance. NC3 coating also prevented the release of metal ions into the seawater and acted as a barrier for the leaching of metals from the coating underneath, thus, proving to be safe for the marine environment. © 2023, The Author(s), under exclusive licence to Springer Nature Switzerland AG.