Modeling and Optimization of Charge Materials Ranges in Converter Furnace with Enhanced Passivation Time in Copper Electrorefining Process: A Mixture Design Approach

In this study, the design of experiments is used to study and model the time of passivation in copper electrorefining as a function of the charge of melting furnace through the preparation of copper casting anodes. As a result of optimization for the proposed optimized anodes, the charge percent values of concentrate (Co), refinery scrap (RS), and non-refinery scrap (NRS) were proposed equals to ۶۹.۱, ۰.۵۷۴ and ۳۰.۳۲ (wt.%), respectively. Experimental data confirmed the enhanced passivation time of the proposed anode was ۶۵۲۰ s. Also, it was observed that the molar ratio of As/(Bi+Sb) and Ag/(Se+Te) are the key factors in passivation time. Finally, the relation of passivation time (seconds) with the charge of melting furnace is proposed as:  t (s)= - ۳۷۲۸.۹۸ × Co + ۴۶۴۰.۰۰ × RS + ۳۱۴۱.۰۰ × NRS + ۱۷۷۶۳.۲۷ × Co × RS + ۲۵۵۴۷.۶۵ × Co × NRS - ۱۷۵۸.۰۰ × RS × NRS. Moreover, adding of As ingot in casting anodes as a dose dependent of non-refinery scrap portion in the input charge of the melting unit can effectively prolong the time of passivation.

Keywords:

Copper electrorefining , Passivation time , Casting anode , Design of experiment