Arsenic, a hazardous material that is toxic for humans, enters the human body through soil, water, and air. Furthermore, metal smelting is known to produce arsenic-containing hazardous secondary resources (AHSRs), which cause irreversible damage to the total environment. Therefore, a novel, clean, and efficient arsenic fixation technology has been developed in this study for arsenic removal, which involves directional oxidation and vacuum gasification of AHSRs. Oxidation results revealed that physical phases containing arsenic (As, As2O3, As2Te3 and Cu3As) are selectively oxidized to As2O3 completely and thus classified as oxidative modulation products (OMPs). Meanwhile, approximately 98.82% As2O3 of OMPs convert into volatiles in the following gasification. Characterization results showed that As2O3 with 96.72% purity and uniform microscopic distribution was obtained in the form of monoclinic crystalline needle-like crystals. The proposed approach organically combines oxidation and volatilization properties of each element to facilitate clean and efficient separation as well as recovery of As2O3. No hazardous gas or wastewater is discharged during the entire process, thereby ensuring that arsenic is recycled in a sustainable and clean manner. Overall, this study provides a clean and low-carbon approach for recycling secondary resources containing arsenic.
Keywords: Arsenic resources; Green production; Harmless disposal; Selective oxidation; Vacuum distillation.
Copyright © 2022 Elsevier B.V. All rights reserved.