A pilot-scale trial of an improved galvanic deoxidation process for refining molten copper

laboratory-scale galvanic deoxidation technology developed by earlier worke rs has been improved, with the aim of developing a prototype pilot-scale de oxidation unit. Each deoxidation cell consists of a one end-closed yttria-s tabilized zirconia (YSZ) tube coated with a Ni-YSZ cermet anode on the inne r walls. The YSZ tube is immersed, with its closed end in the metallic melt , and an oxygen-chemical-potential gradient across the tube is established by passing a reducing gas through the tube. The melt is then deoxidized by short circuiting it with the anode. Through laboratory experimentation, the nature of the anode/electrolyte interface adhesion was identified to be an important factor in obtaining enhanced deoxidation kinetics. The kinetics of oxygen removal from the melt was increased by an order of magnitude with an improved anode/electrolyte interface. A pilot-scale refining unit consi sting of 53 cells with the improved anode/electrolyte interface was manufac tured, and a field evaluation of the galvanic deoxidation of copper was con ducted. The deoxidation-process model was modified to include multiple deox idation cells, which were required for the pilot-scale trials, and to analy ze the effect of electrolyte/electrode adhesion on deoxidation kinetics. Pr eliminary studies on process component lifetimes were conducted by investig ating the thermal cycling, corrosion behavior of the electrolyte, and stabi lity of the cermet anode structure. Based on the results of the field trial and the analyses of the process component lifetime, future work needed tow ard commercializing the technology is discussed.