Electrodeposition of zinc from sodium zincate/hydroxide electrolytes in a spouted bed electrode

Abstract

Zinc has been electrodeposited from sodium zincate/hydroxide electrolytes in a spouted bed electrode (SBE). The anticipated application is the removal of zinc from steel degalvanizing electrolytes. A number of short-term (2 to 3 hours) batch experiments have been carried out to determine the effect of design and operating parameters (e.g., current density and temperature) on cell performance, as reflected in the measured cell voltage and current efficiency. A significant effort was devoted to discovering a suitable diaphragm material. A combination of two materials was found to give a stable and acceptable cell voltage. In short-term runs, this combination gave DC energy consumptions of 2.3 to 2.5 kWh/kg zinc at current densities of 2500 to 4000 A/m 2 . Two long-term runs were carried out, the longer being of 82-hour duration to grow particles from 0.4 mm to approximately 1 mm (i.e., by roughly a factor of 15 in mass) and from 1 mm to approximately 3 mm (factor of 27). Current efficiencies and energy consumptions were comparable to those in the shorter runs; the particles produced had a metallic appearance and were not friable. Auxiliary experiments were carried out to probe the potential distribution in the SBE.

Copper recovery in a spouted vessel electrolytic reactor (SBER)

“…The principal reactions that occur during copper electrowinning from acidic aqueous solutions are [10,12]: Main cathodic reaction:…”

“…Copper electrowinning from acidic solutions was examined in small, related devices by Jiricny et al [6], Stankovic and Stankovic [7], Masterson and Evans [8], and Scott [9]. Also, Evans and coworkers reported on zinc electrowinning in a spouted bed electrode [10]. In the work of Stankovic [7] and Evans and coworkers [8], the cathode particles were fluidized and the cathode and anode compartments were separated.…”

II. Electrodeposition/Removal of Nickel in a Spouted Electrochemical Reactor

“…17 In one series of investigations, copper 18,19,20,21 and zinc 22 electrowinning were investigated. A rectangular cell design with sidewall electrodes was employed in this work.…”

Spouted Bed Electrodes (Sbe) for Direct Utilization of Carbon in Fuel Cells

“…In this design a ceramic frit serves as a membrane or diaphragm that passes to the anode on the other side where they oxidize the carbon fuel. This arrangement is analogous to that used in our cylindrical SBER and the rectangular SBEs described above [30][31][32][33][34] for electrowinning metals from aqueous acidic solutions. In this latter case, the aqueous solution serves as both the particle transport medium and the electrolyte.…”