Recovery of value-added products from copper slag by pyrometallurgy: Transfer and structure of arsenic compounds

A large-scale application of copper slag, a potential resource for manufacturing iron, has not yet been encouraged. The issue of removing impurity elements is one of the factors restricting its progress. Based on density functional theory (DFT), this work speculates the structure of liquid As compounds at 1800 K. The calculations show that the unique sp-d hybridization type electronic structure between As and transition metals makes As metallic, and the interaction of C-As within the clusters plays a crucial role in maintaining the clusters' stability. However, CPMD proved that the cluster would be destroyed when exposed to a significant quantity of C. Considering the diversity of copper slag, As is most commonly found in Cu-containing molten iron in the form of FeCAs3. In contrast for the high Mo-containing copper slag employed in this paper, FeCAs3 and MoCAs3 will coexist in the Cu-containing molten iron. Additionally, the results of simulations and classical thermodynamics are consistent, offering a theoretical framework for industrial arsenic removal to support the resourcefulness of copper slag.