| Popis: |
Dezincification is the selective corrosion of zinc in brass that leaves the copper behind and does not result in the full dissolving of the brass followed by copper redeposition. Both procedures may occur under different conditions. This work investigated the influence of concentration and applied potential on the characteristics of zinc powder (purity, apparent density, morphology, particle size distribution, and particle zeta potential) produced by the electrochemical process from waste brass. In the electrochemical process, we used hydrochloric acid HCl in three different concentrations (0.1, 0.2, and 0.3) M. The time of the electrochemical process was 30 min, and the distance between poles was 3cm for all experiments, With the pH scale of all solutions equal to 1. The voltages that were used were (1, 1.5, 2, 2.5, and 3) V. We made Fifteen experiments were conducted to obtain the best result for the highest solubility of zinc ion in an electrolyte. Atomic absorption spectrometry (AAS) analysis was used to determine the concentration of Cu++ and Zn++ ions that deposited in the electrolyte after electrodeposition, with the highest value of Zn obtained being 1500 ppm for a concentration of 0.3 M HCl in 1 V, rather than 736, 454 for 0.2 M in 2 V, and 0.1 M in 2.5 V, respectively. After knowing the most solutions that contain zinc ions by examining the AAS. We take the solutions and re-deposition them electrically using graphite electrodes for a period of 25 minutes, where the zinc is deposited on the graphite electrode in the form of silver-colored layers tilted to light gray. This precipitate is then scraped off on filter paper and weighed to determine the apparent density. In graphite cathode, the apparent density ranged from (0.89 - 0.42) gm./cm3 in 0.3M, (0.69 - 0.34) gm./cm3 in 0.2M, and (0.55 - 0.24) gm/cm3 in 0.1M. All results showed that the morphology of zinc powder analyzed by SEM was dendritic and mossy. purity of zinc produced were determined by XRF analysis for different concentrations, that increase with increased the concentration and applied potential from 1 to 3 V, the high value of purity of Zinc powder was %98.58 in 1V and 0.3M concentration for graphite cathode. |
