Electrochemical Behavior of Ni Ion in SiO₂-CaO-MgO-Al₂O₃Molten Slag

Abstract

A novel electrolytic cell with Pt,O2(air)|ZrO2 used as reference electrode was constructed integrally by using a one-end-closed magnesia partially stabilized zirconia solid electrolyte tube. Various electrochemical measurement techniques such as cyclic voltammetry (CV), chronopotentiometry (CP) and chronoamperometry (CA) were applied, and thermodynamic software Factsage was combined to study the effects of NiO concentration and temperature on electrochemical behavior of Ni ion in SiO2-CaO-MgO-Al2O3 molten slag at temperatures not less than 1673 K. The results indicate that Ni in molten slag is in stable form of Ni2+ instead of Ni3+; reduction of Ni2+ in molten slag is a diffusion control reaction process with a single step; smaller concentration of NiO and higher temperature lead to better reversibility of Ni2+ reduction reaction; with CV, CP and CA electrochemical measurement techniques, diffusion coefficients of Ni2+ at 1723 K are derived, respectively. Further, diffusion activation energy of Ni2+ from data corresponding to CV and CA techniques is derived from Arrhenius equation factored in diffusion coefficient and temperature.

Nonmodified Laser-Induced Graphene Sensors for Lead-Ion Detection

“…To quantify the relationship, peak currents at the corresponding scanning rates are extracted, subtracted by the baseline, and plotted in Figure b. It shows the peak current of LIG has a positive linear relationship with v 1/2 , indicating the feature of the diffusion control system . Thus, the active area can be calculated by the Randles–Sevcik equation: I normalp = 268600 .25em n 3 / 2 normalS normalD 1 / 2 normalC .25em normalv 1 / 2 where I p is the peak current value ( A ), n is the number of electrons transfer in the redox reaction, S is the active area (cm 2 ), D is the diffusion coefficient (cm 2 ·s –1 ), C is the reactant concentration (mol·cm –3 ), and v is the scanning rate (V·s –1 ).…”

“…It shows the peak current of LIG has a positive linear relationship with v 1/2 , indicating the feature of the diffusion control system. 40 Thus, the active area can be calculated by the Randles−Sevcik equation: 41 where I p is the peak current value (A), n is the number of electrons transfer in the redox reaction, S is the active area (cm 2 ), D is the diffusion coefficient (cm 2 •s −1 ), C is the reactant concentration (mol•cm −3 ), and v is the scanning rate (V•s −1 ). In the testing system, n = 1, D = 6.3 × 10 −6 cm 2 •s −1 , and C = 1 × 10 −6 mol•cm −3 .…”

Yttria-Stabilized Zirconia Assisted Green Electrochemical Preparation of Silicon from Solid Silica in Calcium Chloride Melt

“…After the YSZ tube was ultrasonically cleaned with alcohol, the porous annular Pt CE (area about 6.28 cm 2 ) and RE (area about 1.88 cm 2 ) were prepared according to the method provided in literature. [26,28] The Pt leads (diameter 0.5 mm and length 800 mm) for the RE and the CE were each protected in a thin double-bore alumina tube.…”

Continuous cleaning process of molten copper slags in a channel reactor under the external electric field

“…Due to the molten slags ionic structures, it can improve the cleaning process by the application of the electro-capillary effect in accelerating the copper-matte drops settling [8][9][10][11][12][13]. The behaviors of matte droplets in the molten slags under a vertical electric field are studied by Choo et al, and the slags and matte composition can significantly affect the migration direction of the droplets [12][13].…”