Nickel Sulfate Solution Research Articles

Development of Wear Resistant Nano Dispersed Composite Coating by Electrodeposition

This study concerns the development of wear resistant coatings of Ni-Al2O3 composite on steel substrates by electrodeposition. Each of the coating experiments was performed in an electrolytic bath, containing a nano-sized dispersion of Al2O3 particles in nickel sulfate and boric acid solution. Composition of the coating mixture was systematically varied with respect to the contents of the dispersed particles, while the amount of the dissolved nickel sulfate, and boric acid and the applied current were kept constant during the experimental measurements. The coated substrates were characterized for their morphology, Vickers hardness, and scratch resistance properties. It was observed that hardness and scratch resistance of the coated substrates increased with an increase in the Al2O3 content in the coating. It was noted that hardness of the composite coating decreased after heat treatment at 400oC in air atmosphere.

Synthesis and Characterization of Uniform Fine Particles of Nickel Compounds

AbstractNickel oxalate particles were prepared by mixing aqueous solutions of nickel sulfate and oxalic acid at 25 and 85 °C. Effect of composition of the reacting solutions and pH of the resulting dispersion was evaluated on morphology of the precipitated particles. Besides these parameters, isoelectric point of the nickel oxalate played a major role in the particles build up. On control heating at 340 °C, the nickel oxalate particles converted into nickel oxide particles while preserving their particles' integrity to a maximum extent. Selected batches of the as‐prepared and heat‐treated particles were characterized by various physical methods.

Kinetics analysis of Ni-TiO2 composite system during initial stages of electro-crystallization

The initial stage of Ni-TiO2 composite system electrodeposition on glassy carbon electrode from an acidic solution of nickel sulfate was investigated using cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS). Analysis of current density-time transients was performed using the nonlinear fitting procedure and electrochemical impedance spectroscopy was simulated by Z-view software. Besides, the surface morphology of Ni-TiO2 co-deposition at the initial stage was observed by scanning electron microscopy (SEM). The results show that, in the case of low overpotential (−790 mV vs SCE), the presence of TiO2 particles in the plating bath makes the nucleation relaxation time tmax decreased clearly. Meanwhile, the electro-crystallization of Ni-TiO2 system follows a Scharifker-Hills (SH) progressive nucleation/growth mechanism. While in the case of higher overpotential, the presence of the TiO2 particles in solution makes the nucleation relaxation time tmax increased. At −850 mV (vs SCE), the co-deposition of Ni-TiO2 system meets SH instantaneous nucleation/growth mechanism. The results of impedance spectra show that the appearance of the characteristic inductive loops represents the nucleation/growth of nickel and the presence of TiO2 particles reduces the charge transfer resistance of solution. The SEM observation confirms that TiO2 particles can be considered as favorable sites for nickel nucleating.

Recovery of Nickel from Spent Industrial Catalysts Using Chelating Agents

The extraction of nickel from a spent primary steam reformer catalyst from an ammonia plant was carried out by chelation using ethylenediaminetetraacetic acid (EDTA) as the chelating agent. Ni recovery was optimized by varying the particle size distribution of catalyst (pretreatment of spent catalyst), stirring speed, temperature (particularly in an autoclave, where temperatures ranging from 100 to 200 °C were used), EDTA concentration, and solid-to-liquid ratio. Approximately 95% Ni recovery was achieved in the Ni extraction carried out under hydrothermal conditions in an autoclave, at temperatures of 150 °C and higher, over a 4-h period. The resulting Ni−EDTA complex was then “dechelated” using a mineral acid (H2SO4 and HNO3), resulting in the formation of a nickel nitrate or sulfate solution and the precipitation of EDTA (about 97% of the initial weight of EDTA was recovered). However, the chelation performance of Ni was shown to decrease with every successive recovery of EDTA (in the case of dechelati...

Fabrication and wear properties of co-deposited Ni-Cr nanocomposite coatings

Ni-Cr nanocomposite coatings with different Cr particles contents were developed by electrodeposition method from a nickel sulfate solution containing different concentrations of Cr nanoparticle with an average particle size of 40 nm. The characteristics of the coatings were assessed by scanning electron microscopy and microhardness test. The friction and wear performances of Ni-Cr nanocomposite coatings and pure Ni film were comparatively investigated, with the effect of the Cr content on the friction and wear behaviors to be emphasized. The results indicate the microhardness, friction and wear behaviors of Ni-Cr nanocomposite coatings are closely related with Cr particles content. The Ni-Cr nanocomposite coating with a lower Cr content of 4.0% shows somewhat increased microhardness and wear resistance than the pure Ni coating, while the Ni-Cr nanocomposite coating with a higher Cr content has much better wear resistance than the pure Ni coating. The effect of Cr nanoparticles on the microhardness and wear resistance was discussed.

Biosorption of nickel with barley straw

Wastewater containing nickel sulphate generated from a nickel plating industry is of great concern. In the present work, biosorption of nickel by barley straw from nickel sulphate solution was investigated. Nickel uptake at room temperature (23 ± 0.5 °C) was very sensitive to solution pH, showing a better uptake value at a pH of 4.85 ± 0.10 among the tested values. The nickel biosorption isotherm fitted well the Langmuir equation. When the ionic strength (IS) of the solution was increased from less than 0.02–0.6 M, nickel uptake was reduced to 12% of that obtained at IS of less than 0.02 M. Barley straw showed a higher nickel uptake (0.61 mmol/g) than acid washed crab shells (0.04 mmol/g), demonstrating its potential as an adsorbent for removal of nickel.

Molecular environment of Ni after its use for removal of CMP nanoparticle

X-ray absorption spectroscopy (XAS) is employed to investigate the molecular environment around nickel that, in the form of nickel sulfate solution, has been added to precipitate nanoparticles in chemical mechanical polishing (CMP) waste water. After phase separation, for the liquid-phase sample, both the white line intensity in the normalized Ni K-edge X-ray absorption near edge structure (XANES) spectrum and the amplitude of the extended X-ray absorption fine structure (EXAFS) spectrum are enhanced due to the presence of solvation of water molecules, as compared to the solid-phase sample. Meanwhile, with the presence of water molecules, the coordination number increases; yet the Debye–Waller factor slightly decreases. The lack of chemical reduction of Ni 2+ in the CMP solution is suggested as the main reason why the charge neutralization precipitation method through the use of Ni 2+ is less effective than the system using Cu 2+ to precipitate nanoparticles as previously reported.

Effect of temperature on sorption of metals by silica-supported 2-(aminomethyl)pyridine. Part I: Binding equilibria

The effect of temperature on acid and metals binding was studied using a commercial chelating adsorbent CuWRAM® (by Purity Systems Inc., USA) which contains 2-(aminomethyl)pyridine (AMP) ligands on a polyamine–silica composite. The binding equilibria in synthetic copper and nickel sulfate solutions and authentic multimetal process solutions were measured at 25–90 °C in batch experiments using potentiometric and spectroscopic methods. Experimental data were correlated with a non-ideal competitive adsorption (NICA) model. According to the results, the binding enthalpy is negative for both sulfuric acid and metal sulfates. Basicity and metals binding strength of the adsorbent thus decrease with temperature. The affinity for copper remains sufficiently high even at 90 °C to ensure high uptake selectivity from a concentrated ZnSO 4 solution. At the same time the amount of metal adsorbed remains constant or even increases with increasing temperature.

Electro-deposition and characterizations of nickel coatings on the carbon–polythene composite

Nickel coating on the carbon-polythene com- posite plate was prepared by electrodeposition in a nickel sulfate solution in this work. The morphology and cross- sectional microstructure of the nickel coating were exam- ined by scanning electron microscope (SEM) and optical microscope (OM), respectively. The influence of bath temperature on the nickel deposition rate was investigated experimentally. The adhesion between the coating and the substrate was evaluated by the pull-off test. The corrosion behavior of the coating in an aqueous solution of NaCl was studied by electrochemical methods. The results showed that the nickel electrodeposition rate could reach up to 0.68 lm min -1 on average under conditions of cathodic current density of 20 mA cm -2 and bath temperature of 60 C. It was confirmed that increasing the bath tempera- ture up to 50 C had a positive effect on the nickel deposit rate, while an adverse effect was observed beyond 60 C. The adhesion strength between the nickel coating and the substrate can be more than 2.3 MPa. The corrosion potential of the bright coating in the NaCl solution was more positive than that of the dull coating, and the anodic dissolution rate of the bright coating was also far lower at the same polarization potential compared with the dull

Poly(N-methylaniline)/nickel modified carbon paste electrode as an efficient and cheep electrode for electrocatalytic oxidation of formaldehyde in alkaline medium

This research in finding a cheap and efficient catalyst for electrooxidation of formaldehyde give us an attempt to make and examine the behavior of poly(N-methylaniline)/nickel modified carbon paste electrode (Ni/P(NMA)/MCPE) in absence and presence of formaldehyde. This involves in situ electropolymerization of N-methylaniline at carbon paste electrode, which is following to the incorporation of Ni(II) to polymeric layer by immersion of modified electrode in 1.0 M nickel sulphate solution. The electrocatalytic oxidation of formaldehyde was studied by cyclic voltammetry and chronoamperometry methods. The effects of scan rate and formaldehyde concentration on the electrocatalytic oxidation of formaldehyde were also investigated at the surface of Ni/P(NMA)/MCPE. The diffusion coefficient ( D = 14.1 × 10 −5 cm 2 s −1), and some kinetic parameters such as the transfer coefficient ( α = 0.45) and also second-order rate constant ( k = 8.96 × 10 −4 cm 3 mol −1 s −1) of formaldehyde were calculated.

Influence of pH value on microstructure and thermal stability of Ni–P electroless coating prepared in acidic condition

Three kinds of Ni–P electroless coatings were prepared in nickel sulphate solution at different pH values of 4.5, 5.5 and 6.5 with the purpose of ascertaining the influence of pH value on microstructure, internal stress statue and thermal stability of the coatings. Laser curvature (LC) method was used to measure the residual stress level in the coatings. Scanning electronic microscopy (SEM) and transmission electronic microscopy with energy dispersive spectrum (TEM/EDS) were used to examine the surface morphology and internal phase structure of the coatings, respectively. Differential scanning calorimeter (DSC) was used to analyze the phase transformation and thermal stability of the coatings at high temperature. Results showed the Ni–P coating prepared at pH 5.5 with nano-crystal mixed in amorphous structure had the worst thermal stability. The relatively higher stability of Ni–P coatings prepared at pH 4.5 and 6.5 was ascribed to the lower tensile stress level and much finer grain size, respectively. Besides, inverse Hall–Petch effect of annealing strengthening might also contribute to the integrity of Ni–P coating prepared at pH 6.5.

The adsorption of sulfur dispersing agents on sulfur and nickel sulfide concentrate surfaces

The adsorption behavior of sulfur dispersing agents, including lignosulfonate, Quebracho, o-phenylenediamine (OPD), and humic acid on elemental sulfur and nickel sulfide concentrate was investigated. The charge changes on elemental sulfur surface were characterized by the measurement of the electrokinetic sonic amplitude (ESA) signal. The adsorption behavior of OPD was investigated by measuring the interfacial tension between liquid sulfur and nickel sulfate solution at 140 °C. The adsorption of lignosulfonate on the molten sulfur surface was calculated by the Gibbs Equation. The adsorption of lignosulfonate, Quebracho, and humic acid on the nickel concentrate was studied at ambient temperature. The adsorption mechanism of sulfur dispersing agents on both elemental sulfur and nickel concentrate were discussed. The stability of OPD in the nickel concentrate slurry was discussed.

Electroless Ni–P coating of different magnesium alloys

Abstract Coating of AZ31B, AE 42 and ZRE1 wrought magnesium alloys was carried out using electroless Ni plating technique in a solution of nickel sulphate, sodium hypophosphite, ammonium hydrogen fluoride and glycine with a zinc immersion pre-treatment. The results of SEM/EDX investigations and X-ray diffraction indicate that the coat exhibit a typical surface morphology with compact nodules with good adherence to the substrate. The coat was composed of amorphous structure, which transformed to a mixture of crystalline Ni and Ni 3 P precipitates after heat treatment at 673°K for 1 h. The phosphorous (P) content increased gradually from the substrate towards the surface reaching a maximum of 10 wt.% to 18 wt.% on the surface depending on the substrate alloy and the thickness of deposit. The hardness of the coat was found to increase with the P content and also after heat treatment. The electrochemical corrosion test in NaCl solution indicated a great improvement in the corrosion resistance of the Mg substrates and that a noble behaviour of Ni–P was obtained regardless of the heat treatment process. The forming ability test indicates that hot rolling of the coated substrate does not succeed to keep a continuous coat due to cracking of the coat in both as-coated and heat treated specimens.

Electrical Conductivity of Concentrated Aqueous Solutions of Divalent Metal Sulfates

The electrical conductivities of aqueous solutions of cobalt sulfate, copper sulfate, cadmium sulfate, manganese sulfate, nickel sulfate, and zinc sulfate have been measured as a function of concentration, m = (0.005 to 2.5) mol·kg−1, and temperature, T = (278.15 to 308.15) K. Densities were measured for all electrolyte solutions at 298.15 K, and the molar conductivities are reported. The conductivity data were analyzed by the empirical Casteel−Amis equation.

Variation in the chemical composition and yield of essential oil of rose‐scented geranium (Pelargonium sp.) by the foliar application of metallic salts

AbstractThe effects of foliar application of metallic salts (0.5% aqueous solution of sodium chloride, calcium chloride, iron sulphate, zinc sulphate, copper sulphate and nickel sulphate) on the chemical composition and yield of essential oil of rose‐scented geranium (Pelargonium sp.) was studied in a pot experiment. The content of linalool, geraniol and 10‐epi‐γ‐eudesmol in the geranium oil significantly increased and that of geranial and β‐bourbonene decreased by the foliar application of metallic salts as compared to control plants. The increase in the content was 53.3%, 15.8%, 6.6%, 109.2%, 13.3% and 54.2% in linalool and 17.8%, 26.8%, 39.1%, 36.6%, 24.8% and 38.8% in geraniol over the control by the application of sodium chloride, calcium chloride, iron sulphate, zinc sulphate, copper sulphate and nickel sulphate, respectively. The content of 10‐epi‐γ‐eudesmol was increased by 24.2%, 16.3%, 36.9%, 24.2%, 17.1% and 23.7% over the control by the application of sodium chloride, calcium chloride, iron sulphate, zinc sulphate, copper sulphate and nickel sulphate, respectively. The level of cis‐ and trans‐rose oxide in geranium oil significantly increased and that of neral decreased by the application of sodium chlorides, zinc sulphate and nickel sulphate as compared to control. cis‐3‐Hexenol, isomenthone, neo‐isomenthol, citronellol and citronellyl formate 2‐phenylethyl tiglate and geranyl tiglate content in geranium oil was not significantly affected by the foliar application of metallic salts. The herbage and oil yield of geranium significantly increased by the foliar application of metallic salts as compared with control plants. The increase in yield was 9.9%, 9.4%, 30.6%, 29.7%, 28.6% and 21.6% in herbage and 41.9%, 23.4%, 29.6%, 29.6%, 41.9% and 41.9% in oil yield over control by the application of sodium chloride, calcium chloride, iron sulphate, zinc sulphate, copper sulphate and nickel sulphate, respectively. The oil content in the geranium was enhanced by the application of sodium chloride, calcium chloride, copper sulphate and nickel sulphate, whereas application of iron sulphate and zinc sulphate had no significant effect on the oil content. Copyright © 2008 John Wiley & Sons, Ltd.

Solvent extraction recovery of nickel from spent electroless nickel plating baths by a mixer-settler extractor

The treatment of spent electroless nickel plating baths has attracted much attention from the standpoints of environmental protection and nickel recycling. In order to design a nickel recovery process from the spent baths, the continuous extraction and stripping of nickel in the spent baths were carried out using a mixer-settler extractor. 2-Hydroxy-5-nonylacetophenone oxime (LIX84I) and 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (PC88A) were used as the extractant and the accelerator, respectively. The effects of the accelerator, flow rates and total stage number were investigated. It was found that the extraction efficiency was significantly increased by adding the accelerator. The extraction and stripping efficiencies were affected by the flow rates of the organic and aqueous phases, and its mechanism was qualitatively discussed on the basis of the stoichiometric relation of the extraction and the hydrodynamic properties of the mixer. A high nickel extraction efficiency (99.9%) was achieved using a countercurrent three-stage extraction process, while the most concentrated nickel sulfate solution (0.49 kmol/m 3) was obtained with the stripping efficiency of 98.4% in a countercurrent two-stage stripping. This continuous extraction–stripping technique is expected to be effective for recycling nickel from the spent baths.

Interaction of micas with nickel sulfate solutions

The interaction of natural biotites with dilute nickel sulfate solutions at various pHs are studied by X-ray powder diffraction, thermogravimetric analysis, and chemical analysis. K ⇆ Ni, Mg ⇆ Ni, and to a lesser extent Fe ⇆ Ni ion exchange is shown to occur. Nickel can both enter octahedral layers and act as an interlayer cation. Tetrahedral layers have a virtually invariable composition. The mechanoactivation of biotites enhances exchange reactions.

Extraction of pure metallic nickel from ores and plants at Ussangoda, Sri Lanka

Samples of serpentine from Ussangoda in the Hambantota District were found to contain 2-3% nickel of minable quality. Laterite from the same location contained 0.4% nickel. Nickel and several other metals in these rocks dissolved almost completely into hot 50% sulphuric acid. Nickel, cobalt, and any zinc that form complexes with ammonia were separated into the aqueous phase by addition of excess ammonia and filtration of precipitated hydroxides of magnesium, iron, manganese, chromium and aluminium. Acidification of the filtrate yielded a solution of nickel sulphate admixed with small amounts of cobalt and zinc. Electrolysis of the filtrate with a conducting tin oxide glass cathode after removal of cobalt yielded pure nickel. The process can also produce nickel ammonium sulphate. Extraction of metallic nickel from a nickel hyperaccumulating plant growing in Ussangoda is also demonstrated. The possibility of nickel mining in Sri Lanka and the importance of petrological, geochemical and ecological studies of the serpentine area at Ussangoda and other localities are discussed.

Characterization of Supported NiSO4 and Effect of TiO2–ZrO2 Composition on Catalytic Activity for Acid Catalysis

A series of catalysts, NiSO4/TiO2–ZrO2 having different TiO2–ZrO2 composition, for acid catalysis was prepared by the impregnation method using an aqueous solution of nickel sulfate. The addition of TiO2 to ZrO2 improved the surface area of the catalyst and enhanced its acidity remarkably because of the formation of new acid sites through the charge imbalance of Ti–O–Zr bonding. The binary oxide, TiO2–ZrO2 calcined above 600 °C resulted in the formation of crystalline orthorhombic phase of ZrTiO4. Therefore, NiSO4/TiO2–ZrO2 calcined at 500 °C exhibited a maximum catalytic activity for acid catalysis, and then the catalytic activity decreased with the calcination temperature. The correlation between catalytic activity and acidity held for both reaction, 2-propanol dehydration and cumene dealkylation. NiSO4 supported on 50TiO2–50ZrO2 (TiO2/ZrO2 ratio = 1) among TiO2–ZrO2 binary oxides exhibited the highest catalytic activity for acid catalysis.

Hyperfiltration of nickel sulphate solutions through silty sandstone and its effect on hydraulic conductivity

Hyperfiltration (reverse osmosis) and subsequent precipitation of minerals from the hyperfiltrated solution are processes that potentially decrease the hydraulic conductivity of porous media. These processes were demonstrated by hyperfiltrating NiSO 4 solutions through fine-grained sandstone. The mineral precipitates occur in very small (mm sized) layers at the high-pressure side of the samples where they create zones of lowered hydraulic conductivity (2–3 orders of magnitude lower than initial). The total amount of precipitates is very small compared to the dissolved mass which was passed through the membrane. Hyperfiltration-induced precipitates and the resulting lowering of hydraulic conductivities were observed at solute saturations as low as 10%. Nevertheless, at saturations higher than 50% the conductivity reduction strongly increased. Full reversibility of the hydraulic conductivity reduction by extensive re-flushing with water was only obtained at low initial solute saturations (10%). This indicates that precipitated minerals in many pores are susceptible only to very slow, diffusion-controlled re-dissolution.