From theory to practice: Dissociation of AsMA under reactive metal perturbations for the harmlessness and resourcefulness of copper slag

Abstract

Upgrading copper slag into value-added products provides an untapped opportunity to address arsenic pollution in the environment and promote waste recycling, but the problem of excessive arsenic in products remains a huge engineering challenge. Herein, we employ DFT calculations to explore the dissociation mechanism of AsMA and propose a universal descriptor for screening As removal agents for the first time. The dissociation of AsMA is related to the disturbance of the Mo-As bond by Ba and follows the “Perturbation – Re-stabilization – Dissociation” mechanism. The BΨ value of Ba is near the minimum value of −0.1058 in the universal descriptors, which renders it potential candidates for As removal agents. As expected, Ba can increase As removal efficiency by approximately 45 % when employing the Si-Ca-Ba alloy compared to other Ca-based alloys. This work offers contributions to the As removal technology for copper slag value-added products while also highlighting the DFT calculations used in guiding engineering practices.