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

Abstract

A novel method of Ni recovery from the acid leaching solution of electroplating sludge through preparing Ni-Fe alloy with high Fe 2+ 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.

Resource utilization of electroplating wastewater: obstacles and solutions

“…38 Organic matter can also be adsorbed on the surface of the electrode, and they can influence the interfacial charge-transfer rate of metal ion. 39 Riastuti et al claimed that SDS could be adsorbed on the cathode to prevent the deposition of nickel. 40 Ethoxylated 2-naphthalenesulfonic acid had a negative effect on the deposition of tin on gold electrodes.…”

Effect of Cd2+ on Electrodeposition of Copper in Cyclone Electrodeposition

“…The addition of Cd 2+ weakened the electrochemical reaction of Cu 2+ on the cathode and reduced the attenuation rate of Cu 2+ in the solution, the ability The micro-morphology of cathode copper obtained by the electrodeposition of copper electrolyte without adding Cd 2+ showed that the copper crystal nuclei were one-by-one spherical nodules [34] without any cracks and pores (Figure 8a). With the addition of Cd 2+ , some clear grain refinements [36] were generated based on the spherical nodules [34]. The more Cd 2+ that was added, the finer the sediments that were generated on the compact surface and the larger the pores between each crystal (Figure 8b-f).…”

Low current density electropolishing and corrosion resistance study of 304 stainless steel

“…Saccharin has consistently been one of the most commonly used organic additives. [16][17][18] During the polishing process, it significantly enhances the wetting and dispersion properties of the polishing solution, contributing to a more uniform polishing process. Furthermore, this compound can form a protective film on the metal surface, reducing oxidation and other adverse reactions, effectively improving the quality of the passivation layer.…”