Dissolution Kinetics Of Nickel Research Articles

Dissolution Kinetics of Nickel(II) Hydroxide in a Mixed Ammonia–Carbonate Solution

Dissolution Kinetics of Nickel(II) Hydroxide in a Mixed Ammonia–Carbonate Solution

Kinetic study on leaching of nickel from Turkish lateritic ore in nitric acid solution

Dissolution kinetics of nickel from lateritic ore in nitric acid solution was investigated. Experimental parameters used were stirring speed (100-600 r/min), temperature (40-96 °C), nitric acid concentration (0.1-2 mol/L) and particle size (<106 µm). The shrinking core model was applied to the results of experiments investigating the effects of leaching temperature in the range of 40-90 °C and nitric acid concentration in range of 0.1-2 mol/L on nickel dissolution rate. The kinetic analysis shows that the nickel dissolution from lateritic ore could be described by diffusion model. The activation energy (Ea) for the dissolution reaction is calculated as 79.52 kJ/mol.

Optimization of process parameters and dissolution kinetics of nickel and cobalt from lateritic chromite overburden using organic acids

AbstractBACKGROUNDLeaching kinetics of the roasted (at 600°C) chromite overburden of Sukinda mines Orissa, India, was studied with optimized data generated through response surface methodology (RSM) coupled with Box‐Behnken design (BBD). The effects of oxalic, citric and gluconic acid concentration (50–150 mmol L−1), reaction temperature (60° to 80°C) and period (up to 3 h) on metal (nickel and cobalt) dissolution were examined.RESULTSExtraction of nickel and cobalt to the extent of 63.61% and 44.33%, respectively, was achieved using 150 mmol L−1 oxalic acid at 80°C in 3 h; compared with other acids, oxalic acid leached more of the metals. Associated apparent activation energy for Ni was 74 kJ mol−1, and that for cobalt was 84.37 kJ mol−1 during the first hour, and 80.99 kJ mol−1 for the remaining period since cobalt leaching followed biphasic kinetics.CONCLUSIONDissolution of nickel and cobalt from the roasted chromite overburden was highly dependent on the amenability of ore minerals to organic acid attack. Nickel leaching data fit the three‐dimensional diffusion mechanism of the type Ginstling Brounsthein (GB) equation while a mixed kinetic model consisting of spherical geometry and the GB equation was followed for cobalt. This work presents maximum recovery of nickel and cobalt from chromite overburden using organic acid reported to date. © 2013 Society of Chemical Industry

Dissolution kinetics of nickel from spent catalyst in nitric acid medium

In this study, the kinetics of nitric acid leaching of a spent NiO–Al2O3 catalyst was investigated. Influence of leaching parameters such as temperature (60–90°C), acid concentration (1.5–5M) and average particle size (75–601μm) was studied. For average particle size≤75μm, dissolution data followed surface reaction controlled shrinking core model at all temperatures and acid concentration. However, for higher particle sizes product layer diffusion controlled the overall kinetics. The estimated activation energy for the surface reaction controlled mechanism was 83.44kJ/mol and the empirical order of reaction with respect to [HNO3] was nearly 2. In general, the reaction mechanism shifted from surface reaction controlled to diffusion controlled when the extraction reached ∼90%. The shift in reaction mechanism was explained by calculating the theoretical reaction rates.

Kinetics of current-enhanced dissolution of nickel in liquid aluminum

The dissolution kinetics of nickel in liquid aluminum at temperatures in the range 767–867 °C were investigated under the influence of a DC current. The current had a marked effect on the dissolution rate constant. Correspondingly, the application of the current significantly decreased the activation energy of dissolution. The direction of the DC current was shown to have an effect on dissolution. When the electronic flow was in the direction of dissolution, a further increase in dissolution was observed and attributed to electromigration. Calculations of the effective diffusion coefficient, D eff, of Ni through one of the two intermetallic layers, Al 3Ni 2, were made for different current densities and temperatures. From measured electromigration enhanced flux, the effective charge, z ∗, on the diffusing Ni was calculated.

Dissolution Kinetics of Nickel in Lead-free Sn-Bi-In-Zn-Sb Soldering Alloys

AbstractThe dissolution process of nickel in liquid Pb-free 87.5% Sn-7.5% Bi-3% In-1% Zn-1% Sb and 80% Sn-15% Bi-3% In-1% Zn-1% Sb soldering alloys has been investigated by the rotating disc technique at 250-450°C. The temperature dependence of the nickel solubility in the solders obeys a relation of the Arrhenius type cs = 4.94 × 102 exp (-39500/RT) % for the former alloy and cs = 4.19 × 102 exp (-40200/RT)% for the latter, where R is in J mol-1 K-1 (8.314 J mol-1 K-1) and T in K. The solubility values of nickel in the alloys differ considerably, while the dissolution rate constants are rather close. The data presented can be used to evaluate (i) the thickness of the dissolved portion of the solid nickel material during soldering, (ii) the extent of saturation of a solder with nickel and (iii) the effect of dissolution on the growth rate of intermetallic layers at the Ni-solder interface.

Dissolution Kinetics of Nickel(II) and Nickel(III) Oxides in Acid Media

The rate of nickel(II) and nickel(III) oxide dissolution in sulfuric, hydrochloric, and nitric acids was measured as a function of the acid concentration and temperature, and a kinetic model of this process is suggested. The limiting step of the dissolution process is the passage of the complexes forming on the oxide surface into the solution.

Dissolution kinetics of nickel in liquid tin

Dissolution kinetics of nickel in liquid tin