Mass transport studies at rotating cylinder electrode during zinc removal from dilute solutions

摘要

The mass transport in the rotating cylinder electrode (RCE) for the Zn(II) recovery from dilute solutions was investigated. Global mass transport data were obtained by monitoring the (first order) concentration decay of dissolved zinc in sulfate media at pH 2. The electrolyses were performed at holding potential of -1.7 V vs. sat. MSE at Reynolds numbers comprised between 15 470 ≤ Re ≤ 123 680. Based on the analysis of Sh = aRe~bSc~(0.356) correlation, the value of the constant a, associated with shape and cell dimensions, was 0.65; while the constant b, associated with hydrodynamic regime, exhibits a value of 0.48, which obeys to smooth zinc deposits on RCE interface. The mass transport in the Zn(II)/Zn cathode interface process differs with other deposition process, which usually gives roughness deposits.