Pressure Oxidation of Arsenic (III) Ions in the H3AsO3-Fe2+-Cu2+-H2SO4 System
| Autor: | D. A. Rogozhnikov, Sergey Mamyachenkov, K. A. Karimov, Stanislav Naboichenko, Maksim Tretiak, Oleg Dizer |
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| Rok vydání: | 2021 |
| Předmět: |
Materials science
oxidation Inorganic chemistry 0211 other engineering and technologies COPPER chemistry.chemical_element 02 engineering and technology 010501 environmental sciences OXIDATION 01 natural sciences Ion Catalytic effect iron General Materials Science KINETICS Arsenic 021102 mining & metallurgy 0105 earth and related environmental sciences Mining engineering. Metallurgy IRON arsenic TN1-997 Metals and Alloys Foundation (engineering) catalytic effect semi-empirical equation CATALYTIC EFFECT Copper chemistry kinetics copper SEMI-EMPIRICAL EQUATION ARSENIC Pressure oxidation |
| Zdroj: | Metals, Vol 11, Iss 975, p 975 (2021) Metals Volume 11 Issue 6 |
| ISSN: | 2075-4701 |
| DOI: | 10.3390/met11060975 |
| Popis: | The processing of low-grade polymetallic materials, such as copper–zinc, copper–lead– zinc, and poor arsenic-containing copper concentrates using hydrometallurgical methods is becom-ing increasingly important due to the depletion of rich and easily extracted mineral resources, as well as due to the need to reduce harmful emissions from metallurgy, especially given the high content of arsenic in ores. Ferric arsenates obtained through hydrothermal precipitation are the least soluble and most stable form of arsenic, which is essential for its disposal. This paper describes the investigation of the oxidation kinetics of As (III) ions to As (V) which is required for efficient puri-fication of the resulting solutions and precipitation of low-solubility ferric arsenates. The effect of temperature (160–200 °C), the initial concentration of Fe (II) (3.6–89.5 mmol/dm3), Cu (II) (6.3–62.9 of mmol/dm3) and the oxygen pressure (0.2–0.5 MPa) on the oxidation efficiency of As (III) to As (V) was studied. As (III) oxidation in H3AsO-Fe2+-Cu2+-H2SO4 and H3AsO-Fe2+-H2SO4 systems was controlled by a chemical reaction with the apparent activation energy (Ea (≈84.3–86.3 kJ/mol)). The increase in the concentration of Fe (II) ions and addition of an external catalyst (Cu (II) ions) both have a positive effect on the process. When Cu (II) ions are introduced into the solution, their catalytic effect is confirmed by a decrease in the partial orders, Fe (II) ions concentration from 0.43 to 0.20, and the oxygen pressure from 0.95 to 0.69. The revealed catalytic effect is associated with a positive effect of Cu (II) ions on the oxidation of Fe (II) to Fe (III) ions, which further participate in As (III) oxidation. The semi-empirical equations describing the reaction rate under the studied conditions are written. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This work was financially supported by the Russian Science Foundation Project No. 20‐ 79‐00321. |
| Databáze: | OpenAIRE |
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