To develop high‐performance Cr‐free refractories for copper smelting and verify the feasibility and advantages of ZrO 2 as a substitute for Cr 2 O 3 , the high‐temperature corrosion behavior of MgO–ZrO 2 refractories with 0–15 wt.% ZrO 2 (Z0–Z15) exposed to Cu slags containing 20–30 wt.% Cu x O (C20–C30) was investigated. The results show that ZrO 2 addition decreased slag infiltration and corrosion. The corrosion layer thickness of Z0 in C20 slag decreased from 132 to 52 μm for Z15, owing to the higher density of the refractories, their lower solubility in slag, and the higher slag viscosity caused by ZrO 2 dissolution. In contrast, increased CuO content intensified corrosion, and the corrosion layer of Z15 reached 97 μm in C30 slag due to reduced slag viscosity and enhanced interfacial wettability. Thermodynamic simulations confirm that ZrO 2 has a lower solubility (3.2 wt.%) in C20 slag than MgO (6.1 wt.%), and its solubility is second only to Cr 2 O 3 (0.7 wt.%) among common refractory oxides. This work elucidates the corrosion mechanism of MgO–ZrO 2 refractories in copper slags, demonstrates the core merits of ZrO 2 as a green alternative to Cr 2 O 3 without Cr 6+ leaching risks, and provides a theoretical basis for the design of Cr‐free refractories for copper smelting.
Liu et al. (Sat,) studied this question.