Short-Process Preparation of High-Purity Metallic Arsenic from Arsenic-Bearing Solid Waste of Nonferrous Metals: Key Technologies and Applications

Wei Sun

Central South University,
NO.932, Lushan South Road, Yuelu District, Changsha, China

High-purity metallic arsenic serves as a critical raw material for semiconductor manufacturing and exhibits significant potential in strategic emerging industries. The key challenge in its production lies in the efficient separation of arsenic from analogous impurities (e.g.,Sb, Se). Conventional chloride-mediated reduction processes, which utilize arsenic trioxide (As2O3) or crude arsenic as feedstocks, are plagued by limitations such as inefficient impurity separation, multi-step complexity, and elevated operational costs. Based on the geochemical mineralization mechanisms of arsenic, this study innovatively proposes a high-fidelity mineralization precipitation theory for arsenate double salts, resolving the critical challenge of efficiently separating arsenic from alkalis and analogous impurities in highly alkaline or saline solutions. Furthermore, a key one-step reduction roasting method is developed to prepare 3N-grade metallic arsenic (99.9% purity) from arsenate salt precursors, thereby establishing a short-process and high-efficiency technical route for producing high-purity metallic arsenic directly from arsenic-bearing solid wastes.Case studies on arsenic-alkali slag, copper smelting flue dust, and anode slime demonstrate that the arsenate double-salt precursors synthesized through high-fidelity mineralization precipitation exhibit impurity levels (Sb, Se) below 0.1 wt%. Subsequent reduction roasting of these precursors yields 3N-grade metallic arsenic with impurity concentrations under 0.05 wt%. This research establishes a theoretical framework for the valorization of arsenic-bearing solid wastes while providing a scalable technological pathway for high-purity metallic arsenic production.