Refractory Challenges in Nickel and Cobalt Processing Furnaces

The primary metallurgy of nickel and cobalt, as well as copper, is closely interlinked, and follows processing of sulfidic ore concentrates. Commonly these furnaces are lined with magnesia-chrome-based materials. The selection of the processing route, furnace type and slag system will be dictated by the specific ore type available; this will determine the individual refractory wear mode. This paper evaluates the common refractory wear mechanisms of infiltration, spalling and chemical attack by various slag systems, as well as sulfur attack as observed when processing primary sulfidic ores. All these wear parameters discussed in the paper lead to a severe degeneration of the brick microstructure and a decreased lining life. In addition to post-mortem studies, thermochemical calculations and corrosion testing provide better understanding of the wear mechanisms. Based on such research results, combined with specific process knowledge, appropriate brick lining solutions for nickel and cobalt processing furnaces can be recommend.