Ionic Mass Transfer at Point Electrodes Located at Cathode Support Plate in an Electrorefining Cell in Presence of Rectangular Turbulent Promoters

Abstract

Current density plays a major role in deciding the plant size, current efficiency, and energy consumption in electrorefining cells. In general, operating current density will be 40% of the limiting current density. Forced circulation of the electrolyte in the presence of promoters improves the mass transfer coefficient. In the present study, rectangular turbulence promoters are fitted at the bottom side of the cell to improve the mass transfer coefficient at the cathode support plate. The limiting current density technique is used to measure the mass transfer coefficient. The variables covered in the present study are the effects of flow rate, promoter height, and spacing among the promoters. The electrolyte consists of copper sulfate and sulphuric acid. At a regulated flow rate, the electrolyte is pumped from the recirculation tank to the cell through an intermediate overhead tank. The limiting current density increased with an increasing flow rate in the presence of promoters, and thus the overall mass transfer coefficient on the cathode support plate also improved. With an increase in the flow rate of the electrolyte from 6.67 × 10−6 to 153.33 m3/s, limiting current density increased from 356.8 to 488.8 A/m2 for spacing of 0.30 m, with a promoter height of 0.01 m. However, it is noteworthy that when the promoter height is increased from 0.01 to 0.07 m, the overall mass transfer coefficient is found to increase up to 60%, but with the further increase in the promoter height to 0.30 m the mass transfer coefficient starts to decrease. Therefore, the optimized cell parameters are established in this work. The current sustainable concept of employing rectangular turbulence promoters will bring benefits to any precious metal refining or electrowinning tank house electrolytes.

Evaluation of the Flexural Rigidity of Underground Tanks Manufactured by Rotomolding

“…In the study of Brar [14], he statistically evaluates the random geometric imperfection stability for an asymmetrical cylindrical vessel under external pressure, while the relevant EN standard controls the relevant safety at the limit of the stability capacity with respect to geometric imperfections. In [15], the authors focus on electrolyte and recirculation tanks considering the technology itself but not the stability, confirming the need for safe rigidly stable tanks, although this is outside of the scope of our study.…”

Study on Improving Electrochemical Machining Performances through Energy Conversion of Electrolyte Fluid

“…Generally, high-speed flowing of the electrolyte is regarded as an important way to eliminate machining products in time and improve machining performance. However, many studies have also shown that blindly increasing the electrolyte velocity cannot have a significant impact on the machining performance because ECM is a complex multi-physics coupling process [37,38]. This study proposes an interesting approach to improve machining performance through energy conversion of electrolyte fluid during ECM processes, as shown in Figure 1.…”

Recovery of precious metals from processed wastewater: conventional techniques nexus advanced and pragmatic alternatives

“…This process is categorized into electrodeposition/electrowinning or electrorefining. The recovery of precious metals via electrowinning involves the use of direct current between the anode and cathode electrodes so aid the reduction of the targeted metals specie in the effluent of the cathode and to extract the metal in its metallic form (Subbaiah et al 2022). However, in electrorefining, the anode consisting the metals associated with impurities is dissolved in an aqueous state by either direct or indirect electrooxidation, leading to the selective deposition of leached metal ions unto the cathode in its pure form (Rai et al 2021;Subbaiah et al 2022).…”

“…The recovery of precious metals via electrowinning involves the use of direct current between the anode and cathode electrodes so aid the reduction of the targeted metals specie in the effluent of the cathode and to extract the metal in its metallic form (Subbaiah et al 2022). However, in electrorefining, the anode consisting the metals associated with impurities is dissolved in an aqueous state by either direct or indirect electrooxidation, leading to the selective deposition of leached metal ions unto the cathode in its pure form (Rai et al 2021;Subbaiah et al 2022). This precious metal recovery approach has notable significant merits such as uniform selective and uniform deposition of metals, high purity grade, automation, faster reaction kinetics, and cost-effectiveness.…”