Recovery of Ni from the Acid Leaching Solution of Electroplating Sludge through Preparing Ni-Fe Alloy with the Addition of Saccharin Na First and then Thiourea

作者：Wang, Yu; Li, Lei^*; Wang, Hua

来源：Electrochemistry, 2019, 87(1): 8-13.

DOI：10.5796/electrochemistry.17-00101

• Leaching Solution of Electroplating Sludge
• Ni Recovery
• Ni-Fe Codeposition
• High Concentration of Fe-2(+)

A novel method of Ni recovery from the acid leaching solution of electroplating sludge through preparing Ni-Fe alloy with high Fe2+ content (i.e., 0.5 g/L) is proposed in this paper, and the corresponding electrodeposition process was studied using conventional electrochemical techniques and scanning electron microscopy. The obtained results showed that adding saccharin Na at concentrations from 0 to 14 g/L to the deposition bath increased the cathodic polarization potential of Ni-Fe co-deposition, with sensible grain refinement and disappearance of surface cracks observed after the addition of 14 g/L saccharin Na. Two different mathematical models of metal nucleation were tested, and the different morphologies of the deposits formed with and without saccharin Na suggested disparate nucleation mechanisms. The Ni-Fe deposition potential shifted positively in the presence of thiourea, and it should not be added together with saccharin Na during the nucleation stage for the grain refinement of the deposits. The iron contents in the deposits decreased with the increase of thiourea concentration ascribed to the thiourea complex which adsorbed on the cathodic surface preventing Fe (2+ )electrodeposition from the electrolytes.

• 出版日期2019
• 单位昆明理工大学