Influence of As, Sb, Bi and O on Copper Anode Behaviour - Part 2: Anode Dissolution Behaviour and Anode Sludge Generation

摘要

This article is the second of a three articles series of results from a three year research project funded by the "Sponsor Group Copper Electrorefining". Investigated were dissolution/passivation behaviour, anodic current efficiencies, anode sludge formation and distribution coefficients of impure anodes with varying Sb, As, Bi and O contents processed at three current densities. Main focus of this article is the influence of As, Sb, Bi, O and the current density on the dissolved anode mass respectively the anode current efficiency and the generated amount of anode sludge. For a better assessment of the experimental results literature about the mineralogical structure of anodes depending on their chemical composition was reviewed and the significant aspects related to the tested anodes were summarized. The anode current efficiencies varied between 100.4 percent and 103.7 percent dependent on the anode composition. The factor with the highest impact is oxygen, which influence is approximately four times higher than the influence of As respectively As centre dot O. Investigating the factors influencing the amount of anode sludge revealed that it is influenced by a lot of factors, but mainly by As and partly by O and the current density. Several prediction charts were designed forecasting the dissolution of anodes and the amount of anode sludge produced within the parameter set.