Using polyethylene glycols as alternative inhibitors in copper electrorefining

Effect of additives on monovalent copper electrodeposition in ammoniacal alkaline solutions

“…Although PEG appears superior to gelatin based on the SEM observations, the addition of PEG to the electrolyte tended to cause nodule formation as shown in Fig. 8 (c), and a similar tendency was reported by Stelter et al (2002) in acidic sulfate solutions. This might be caused by the strong interaction between the PEG and copper surface, which was suggested by the results of the preliminary experiment mentioned in the first paragraph of this section.…”

“…In addition, the polarization became more significant as the concentration of the additives increased. These tendencies are close to those observed in the copper sulfate/sulfuric acid solution by Stelter et al (2002) and Nakano et al (2003) and are attributed to the increasing number of lone pairs of electrons working as the active sites for the adsorption to the copper surface.…”

“…These additives are used for a prolonged period; however, the way in which these additives function during the electrolysis is not fully understood. Thus, a number of fundamental and/or systematic studies have been undertaken by several researchers (e.g., Alodan and Smyrl, 1998, Ando et al, 2002, Nakano et al 2003, as well as research into alternative additives (Varvara et al, 2001, Stelter et al, 2002 and similar studies into zinc electrowinning (e.g., Kerby et al, 1977, Karavasteva and Karaivanov, 1993, Ogai et al, 1999. In addition, leveling and brightening effects are among the most important topics in the field of electroplating from previous years.…”

“…Because the effects of the optimization of these variables were found to be insufficient, we examined gelatin (purified glue) and polyethylene glycol (PEG; one of the most viable potential alternatives to glue) as additives (Stelter et al, 2002, Nakano et al, 2003. The effectiveness of these agents was evaluated through electrochemical measurements, observations of the surface morphology, and examination of the impurity content of the copper deposit.…”

Process Optimization in Copper Electrorefining

“…Especially in near net shape casting technologies enhanced corrosion and erosion performance is required followed by thin wall thickness design of functional components such as submerged entry nozzles or casting channels. [1,2] In addition the processing of these advanced refractories has to fulfil all the requirements for a large geometry component manufacturing whereby the task of low shrinkage during firing dominates.…”