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Reclamation of Copper from Electronic Industry Effluent Using Plant Root Adsorbent
Get PDFCopper ion contamination in electronic industrial effluent is a universal issue. The traditional way of copper removal from effluent has some disadvantages like expensive operational costs, and sludge generation after water treatment. Adsorption technique for copper(II) using synthetic adsorbent is one of the efficient ways of water treatment but it is expensive on a commercial scale. Due
to this, researchers across the globe are looking after to find an efficient, economical, and readily available biomass-based adsorbent for metal recovery. The present study was intended for the adsorption of copper onto Datura ( ) root powder using batch studies. It was found to be one of the efficient bio adsorbents with 947 mg/g copper adsorption capability. Batch experiments were performed by using 4 g/L of Datura root powder kept in contact with 100 ppm copper containing industrial effluent in 15 min contact time at pH 4. The result indicates 95% copper adsorption on the surface of Datura root powder. Kinetic study indicates that experimental data fit well in pseudo second-order rate reaction and follows Freundlich isotherm indicating multilayer adsorption process. FT-IR result indicates involvement of aromatic group (Phosphates) of Datura root binding with copper ions. Elution experiments were performed using 10% H SO in 60 min to remove copper from the loaded
adsorbent. The high copper adsorption capacity and the regeneration efficiency of Datura root powder suggest its applicability in copper reclamation from electronic industrial effluent
On the enhanced hardening ability and plasticity mechanisms in a novel Mn-added CoCrNi medium entropy alloy during high-pressure torsion
No full textMicrostructure and texture evolution during high-pressure torsion (HPT) of a novel Mn-added CoCrNi medium entropy alloy (Co33Ni33Cr19Mn15) is investigated for the first time. The alloy exhibited a rapid rise in hardness at relatively low shear strains (gamma <= 20). It is attributed to an extensive dislocation activity to achieve saturation in dislocation density of similar to 10(16) m(-2), combined TWIP and TRIP effects and microstructural refinement. At higher shear strain, hardness increased at much reduced rates owing to saturation of dislocation density, twin fault probability and the TRIP effect, besides continued grain refinement for severe nano-structuring led to subsequent strengthening. The FCC phase showed remarkable stability except a small degree of initial deformation-induced HCP martensitic transformation in an early stage of HPT. The ideal shear texture components were observed at low shear strain, and these continued to evolve up to 5 turns of HPT processing. For similar HPT processing conditions, the studied alloy showed superior hardness (similar to 650 Hv) compared to a wide spectrum of FCC materials, which is ascribed to a combination of the strengthening mechanisms of Taylor hardening, the TRIP and TWIP effects and Hall-Petch strengthening resulting from the nano-structured grains having an average size of similar to 35 nm. (c) 2022 The Author(s). Published by Elsevier B.V. CC_BY_4.
Design and Simulation Analysis of Dewatering Hydrocyclones
No full textPrediction of dewatering performance of an industrial hydrocyclone from laboratory model hydrocyclone founds utmost importance. In this case, the challenge lies with the predicting design and operating parameters of industrial-scale hydrocyclones for estimating the efficiency. The laboratory scale hydrocyclone experiments were conducted using silica sand sample at 10% solid concentration for dewatering purpose with a "Mozley" 2-in and 4-in hydrocyclone. The objective of this paper is to predict the design parameters for an industrial dewatering cyclone to achieve at higher solid concentration in the underflow. A model was developed using the equations provided in Nageswararao hydrocyclone model and all model parameters (D 50 constant, capacity constant, volume split constant, water split constant, and sharpness of efficiency curve) were estimated with the help of a simulator. The simulated results provide reasonable accuracy with 2-in and 4-in hydrocyclone dewatering experimental data. A new model was developed with data obtained with the 4-in hydrocyclone experimental work and all the model parameters were estimated. Then, the technique was extended to predict all the dimensions (diameter, cylindrical length, inlet diameter, cone angle, apex diameter, vortex finder) of a full scale dewatering cyclone operating at 100 TPH and 20% solid concentration also with an objective to achieve 45% solid concentration in underflow
Effect of prior copper-coating on the microstructural development and corrosion behavior of hot-dip galvanized Mn containing high strength steel sheet
No full textIn the present investigation, the role of copper (Cu) pre-coating has been studied for the development of good quality corrosion-resistant hot-dip galvanized (GI) coating on high strength C-Mn steel sheets. The Cu pre coated GI steel has a more pronounced texture coefficient (TC) of the preferred high atomically dense (0002) crystal plane of Zn coating as compared to the GI steel without pre-coating. It has been observed that the GI coating with Cu pre-coating shows excellent surface quality in comparison to the GI coating without Cu pre coating, which exhibits many bare spots on the final coating. Further, the Cu pre-coated GI steel has revealed the development of a continuous iron aluminide (Fe-Al) intermetallic interfacial layer that has a uniform distribution of dense and equiaxed Fe-Al crystals at its interface with the substrate. It can also be noticed that the Cu pre-coated GI steel has a superior corrosion resistance when compared to the GI steel without pre-coating. This is ascribed to the Cu pre-coated GI steel forming a continuous compact interfacial layer with the maximum atomically dense (0002) crystal plane and a high-quality defect-free coating
High strength metakaolin/epoxy hybrid geopolymers: Synthesis, characterization and mechanical properties
No full textInorganic/organic hybrid geopolymers were synthesized by using metakaolin (MK) and solid organic components comprising an epoxy resin - diglycidyl ether of bisphenol A (DGEBA), and a hardener -dicyandiamide (DICY). In this study, solid organics were chosen to obtain a homogeneous mix upon co-milling all the solid precursors viz. MK, DGEBA and DICY in a planetary ball mill prior to geopolymerisation. Inorganic/organic hybrid geopolymers synthesized were then characterized for thermal, structural and mechanical properties. Thermogravimetric analysis (TG-DTG) revealed that hybrid geopolymers restricted the degradation of organics (-72% and-79% organics loss corresponding to 10 mass% and 20 mass% DGEBA addition, respectively) compared to their milled counterparts (-95% and-100% organics loss corresponding to 10 mass% and 20 mass % DGEBA addition, respectively) suggesting strong inorganic/organic interactions. This was substantiated by structural characterization via X-ray diffraction (XRD) and Fourier-transform infrared (FTIR) spectroscopy. Major changes in DGEBA peak positions (FTIR) and disappearance of DICY peaks (XRD, FTIR) corroborated the MK-DGEBA-DICY reactions during geopolymerisation. Microstructural studies (scanning electron microscopy and transmission electron microscopy) coupled with elemental line scan and area maps, confirmed the homogeneous distribution of organics into the inorganic geopolymer matrix with no phase separation. Incorporating 20 mass% epoxy resulted in improved compressive strength from-20.2 MPa to-50.6 MPa (2.5 times superior vis-a-vis only MK-based geopolymer) and higher flexural strength of 5.4 MPa. The significantly enhanced mechanical properties of hybrid geopolymers were indicative of effective inorganic/organic interactions
Magnetron sputtered films prepared from sintered Ti-based target and evaluation of tribological properties under the ball on disc condition with varying thickness and load
No full textThe hard nanocomposite coatings comprised of titanium, silicon, boron, and carbon (Ti-Si-B-C) and titanium, silicon, boron, carbon, and nitrogen (Ti-Si-B-C-N) were deposited on SS 304 substrate using magnetron sputtering technique. The tribological properties of these Ti-Si-B-C and Ti-Si-B-C-N coatings were explored with the variation of load (200-600 g) and thickness (3-25 mu m) against high strength steel ball using a ball on a disc tribometer. The nanoindentation technique was used to investigate the wear tracks and its consequent effect on the mechanical behaviour of uncoated and coated films. The analyses of the phases, microstructure, states of valence, shift of electron, and elemental compositions of the coatings were carried out by HRTEM, FESEM, AFM, XPS, EDX, and Raman spectroscopy techniques, respectively. The 2D cross-sectional profiles and 3D topographies of the wear tracks were explored using a 3D profilometer. All these studies established that the 10 mu m thick titanium-based sputtered nanocomposite coatings on SS 304 are efficient wear-resistant materials that showed excellent protection of the substrates from wear up till application of 500 g load. A good correlation between the composition, structure, properties, and processing of materials has been discussed based on the obtained wear behaviour
Optimization of Selective Laser Melting (SLM) Additive Manufacturing Process Parameters of 316L Austenitic Stainless Steel
No full textSelective laser melting (SLM) is a widely applied process in the metal additive manufacturing industry. The microstructure and mechanical properties of SLM products can be significantly affected by the SLM process parameters. In the present work, optimization of SLM process parameters was performed using the Taguchi optimization method for 316L austenitic stainless steel. Laser power, scan speed, layer thickness, and hatch spacing were selected as the controllable process parameters and relative density, ultimate tensile strength, and elongation as the performance evaluation characteristics. The S/N ratio analysis determined the optimum process parameters of the SLM process in 316L stainless steel. ANOVA analysis predicted that scan speed significantly affected the relative density with a 42.38% contribution and laser power showed contributions of 31.17% and 45.67% for ultimate tensile strength and elongation, respectively. The linear regression model was developed for relative density, ultimate tensile strength, and elongation with the coefficient of determination of 90.17%, 93.06%, and 81.53%, respectively
Effect of Microstructural Evolution on Creep and Rupture Behavior of Inconel 617 Alloy
No full textThe Inconel 617 alloy has been creep-tested at different combinations of loads (80-350 MPa) and temperatures (650-800 degrees C), considering its use in the advanced ultra-super critical (AUSC) boiler. The values of Monkman-Grant and modified Monkman-Grant constants obtained by analyzing the creep data are considered as related to the observed microstructural instability during creep at similar to 650-800 degrees C. The presence of intragranular secondary gamma' precipitates has led to significantly higher strength inside the grains compared to that of their boundaries, found to have a scanty population of secondary (Cr,Mo)(23)C-6 precipitates. As a result, formation of creep cavities leading to intergranular fracture has been observed in the temperature range of 650-750 degrees C. The creep damage tolerance factor, lambda, found as similar to 2.5 by empirical damage analysis on the basis of test results is in tune with the predominance of creep cavitation in the temperature range of 650-750 degrees C. In contrast, both the obtained value of lambda similar to 10.51 and the mixed mode nature of the fracture surface observed for the sample creep tested at 800 degrees C are considered due to substantial localized plastic deformation or necking. Increased creep ductility with necking is ascribed primarily to the reduced the grain body strength caused by the absence of gamma' precipitates and the grain boundary sliding being restricted by the discrete secondary (Cr,Mo)(23)C-6 precipitates present in abundance along the grain boundary. Based on the plot of applied stress against Larson-Miller parameter, it is possible to predict that the Inconel 617 alloy would withstand the steam pressure of 30 MPa at 750 degrees C for a design life of 10(5) h experienced in a typical AUSC boiler tube
Synthesis and Characterization of Carbon Nanomaterial from Indian Bituminous Coal
No full textIntroduction: Carbon nanomaterials synthesis from low-cost precursors is a highly desirable approach for bulk application in material science and technology. Among the various nanomaterials, graphene-based carbon nanomaterials have attracted much attention in recent years. Graphene oxide (GO) is the oxygenated form of graphene. Oxygenated functionalities make the material hydrophilic and hence, the material can be dispersed in water and facilitated various types of functionalization through chemical modification to improve the material properties for wide applications. Coal is the most abundant combustible energy source. Although, coal possesses a very complex structure, however, it consists significant amount of polyaromatic structure. Due to the presence of an inherent polyaromatic structure (sp2-Carbon), coal becomes a promising candidate to replace graphite as a precursor material for the production of graphene /or graphene oxide.
Methods: A facile cost-effective approach is reported to synthesize graphene oxide from semi-bituminous coal. Low-grade coal contains high mineral matter and thus, the demineralization process was employed to enrich the carbon matter by separating the mineral contents. Next, the demineralized coal was treated with H2SO4, NaNO2, and a little amount of concentrated HNO3 followed by washing and centrifugation to obtain the graphene oxide product.
Results: The synthesized product was characterized by various instrumentation techniques and all the observed results indicate the formation of graphene oxide. The Raman spectra of the synthesized product show two peaks at 1350 cm-1 and 1590 cm-1, corresponding to the D band and G band, respectively with an ID/IG value of about 1.04. SEM analysis is evident that the synthesized product exhibits flake-like morphology with distinct edges, wrinkled surfaces, stacked and layered structures. XPS analysis confirms the formation of GO.
Conclusion: The graphene oxide prepared from coal could be a low-cost precursor for bulk application in material science and technology
Recycling of Ti6Al4V machining swarf into additive manufacturing feedstock powder to realise sustainable recycling goals
No full textThis paper addresses the imperative need to develop sustainable recycle technologies for high value machining swarf generated during the processing of Ti6Al4V alloy. A novel recycling process based on multi-stage ball milling is proposed. The process converts Ti6Al4V swarf into a powder feedstock suitable for additive manufacturing (AM). The powders produced from the cleaned swarf using an in-house designed and fabricated tumbler ball mill were characterised in terms of their morphology, particle size, flowability and spreadability. It was found that the dominant effect of milling with o 25 mm balls was particle size reduction (up to -40%) and the primary effect with smaller balls of o 6.25 mm was modification of particle morphology from irregular to rounded shape; thus, necessitating adoption of a multi-stage milling approach to achieve required size and morphology. Ti6Al4V powder having particle size in the range of 40-200 mu m and near-spherical morphology was obtained after multi-stage ball milling up to 18 h. The powder characteristics were comparable or superior to the powder produced by generally used gas atomization (GA) process. The suitability of the powders for AM was established through direct metal laser sintering (DMLS). The proper melting of the optimally prepared powder occurs at 1000 mm/s scanning speed and 310 W of laser power. The developed multi-stage ball milling process was assessed vis -`a-vis gas atomization using life cycle assessment (LCA). LCA revealed that the proposed ball milling method consumed lower energy (-59%), had lower eco-cost (-82%), and lesser global warming po-tential (GWP) (-68%)