0000000000235585
AUTHOR
J.y. Hihn
The use of non-cavitating coupling fluids for intensifying sonoelectrochemical processes
Abstract For the first time, we have investigated the beneficial effects of non-cavitating coupling fluids and their moderate overpressures in enhancing mass-transfer and acoustic energy transfer in a double cell micro-sonoreactor. Silicon and engine oils of different viscosities were used as non-cavitating coupling fluids. A formulated monoethylene glycol (FMG), which is a regular cooling fluid, was also used as reference. It was found that silicon oil yielded a maximum acoustic energy transfer (3.05 W/cm2) from the double jacketed cell to the inner cell volume, at 1 bar of coupling fluid overpressure which was 2.5 times higher than the regular FMG cooling fluid. It was also found that the…
Adsorption of gelatin during electrodeposition of copper and tin-copper alloys from acid sulfate electrolyte
International audience; An acid Cu–Sn deposition bath was developed, and copper and copper–tin coatings were electrodeposited on polycrystalline platinum. The effect of gelatin on copper and copper–tin electrodeposition from acid sulfate solutions has been investigated by a variety of electrochemical methods (voltammetric studies and electrochemical quartz crystal microbalance) as well as by morphologic technique (scanning electron microscopy). The electrochemical results have shown that the overpotential is required when gelatin is added, indicating the presence of interaction between the additive and the coating. From the results of X-ray photoelectron spectroscopy, PM-IRRAS and cyclic vo…
Effects of ultrasound and temperature on copper electro reduction in Deep Eutectic Solvents (DES).
Abstract This paper concerns a preliminary study for a new copper recovery process from ionic solvent. The aim of this work is to study the reduction of copper in Deep Eutectic Solvent (choline chloride–ethylene glycol) and to compare the influence of temperature and the ultrasound effects on kinetic parameters. Solutions were prepared by dissolution of chloride copper salt CuCl 2 (to obtain Copper in oxidation degree II) or CuCl (to obtain Copper in oxidation degree I) and by leaching metallic copper directly in DES. The spectrophotometry UV–visible analysis of the leached solution showed that the copper soluble form obtained is at oxidation degree I (Copper I). Both cyclic voltammetry and…
Comparison of electropolishing behaviours of TSC, ALM and cast 316L stainless steel in H 3 PO 4 /H 2 SO 4
Abstract In recent decades, new manufacturing processes have been developed such as Thermal Spray Coating (TSC) and Additive Layer Manufacturing (ALM), which reduce or avoid machining of parts with complex geometries. This study aims to develop an Electropolishing (EP) process for TSC and ALM 316L Stainless Steel (SS). EP is an anodic dissolution process currently used in industry to reduce surface roughness and obtain a bright and smooth finish. The EP mechanism was studied, in a mixture of H3PO4 and H2SO4, for TSC, ALM and “cast” SS in order to determine the best conditions (time, temperature, potential). Special attention was paid to surface characterization by combining several techniqu…
An ultrasonic-assisted process for copper recovery in a des solvent: Leaching and re-deposition
Abstract The continuous growth of the electronic equipment market has led to an increased amount of scraping that it becomes necessary to recover. A hydrometallurgical method for copper and precious metal recovery from e-waste must consist of a number of steps: leaching, ion separation and subsequent electrochemical re-deposition of the target metal. Although this task is achievable in aqueous solutions, it requires strong acid or cyanide solutions. The aim of the study is to develop a new environmentally benign process by using a Deep Eutectic Solvent (DES), a form of cheap and safe ionic liquid, as an electrolyte for both leaching and electrodeposition. The experiments were conducted in a…