Experimental Study on the Recovery of Arsenic and Iron from Arsenic–Iron Precipitate by Carbon Thermal Magnetization Reduction
Arsenic–iron precipitate was treated using a carbon thermal magnetization reduction method in order to recover arsenic and iron. Arsenic–iron precipitate mixed with coke powder was roasted at a low temperature; arsenic was recovered in the form of As<sub>2</sub>O<sub>3</sub>,...
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MDPI AG
2023-02-01
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| Online Access: | https://www.mdpi.com/2075-4701/13/2/407 |
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| author | Xuepeng Li Dachun Liu Juan Wang Jun Chang Ziyang Wang |
| author_facet | Xuepeng Li Dachun Liu Juan Wang Jun Chang Ziyang Wang |
| author_sort | Xuepeng Li |
| collection | DOAJ |
| description | Arsenic–iron precipitate was treated using a carbon thermal magnetization reduction method in order to recover arsenic and iron. Arsenic–iron precipitate mixed with coke powder was roasted at a low temperature; arsenic was recovered in the form of As<sub>2</sub>O<sub>3</sub>, and iron was recovered in the form of Fe<sub>3</sub>O<sub>4</sub>. The volatilization rate of arsenic was 97.45%, and the content of arsenic in the precipitate was decreased to 0.60%. Iron and arsenic were recovered in the form of Fe<sub>3</sub>O<sub>4</sub> and As<sub>2</sub>O<sub>3</sub> with a purity of 99.91 wt.% under the conditions of a roasting temperature of 650 °C, coke powder addition of 25 wt.%, a roasting time of 180 min, and an argon flow rate of 10 L/min. The volatilization of arsenic was controlled by a chemical controlling step at 20–100 min, and this was switched to a diffusion controlling step at 120–180 min by kinetic experiments. The reaction mechanism of arsenic and iron under carbon thermal magnetization reduction was as follows: in the early stage of the reaction, a large amount of FeAsO<sub>4</sub> was decomposed into As<sub>2</sub>O<sub>3</sub> and Fe<sub>3</sub>O<sub>4</sub>; in the middle and late stages of the reaction, FeAsO<sub>4</sub> was continuously decomposed and reduced, and the content of Fe<sub>3</sub>O<sub>4</sub> was continuously increased until all iron was magnetized to generate Fe<sub>3</sub>O<sub>4</sub>, and the decomposed As<sub>2</sub>O<sub>3</sub> volatilized into dust. Arsenic reacted with CaO to generate Ca<sub>3</sub>(AsO<sub>4</sub>)<sub>2</sub>, and this may be the reason why arsenic could not be removed completely. |
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| spelling | doaj.art-5b5b907cfb59497b807a61d09aed1ec02023-11-16T22:08:52ZengMDPI AGMetals2075-47012023-02-0113240710.3390/met13020407Experimental Study on the Recovery of Arsenic and Iron from Arsenic–Iron Precipitate by Carbon Thermal Magnetization ReductionXuepeng Li0Dachun Liu1Juan Wang2Jun Chang3Ziyang Wang4College of Materials and Chemical Engineering, Tongren University, Tongren 554300, ChinaCollege of Metallurgy and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, ChinaCollege of Data Science, Tongren University, Tongren 554300, ChinaCollege of Materials and Chemical Engineering, Tongren University, Tongren 554300, ChinaCollege of Materials and Chemical Engineering, Tongren University, Tongren 554300, ChinaArsenic–iron precipitate was treated using a carbon thermal magnetization reduction method in order to recover arsenic and iron. Arsenic–iron precipitate mixed with coke powder was roasted at a low temperature; arsenic was recovered in the form of As<sub>2</sub>O<sub>3</sub>, and iron was recovered in the form of Fe<sub>3</sub>O<sub>4</sub>. The volatilization rate of arsenic was 97.45%, and the content of arsenic in the precipitate was decreased to 0.60%. Iron and arsenic were recovered in the form of Fe<sub>3</sub>O<sub>4</sub> and As<sub>2</sub>O<sub>3</sub> with a purity of 99.91 wt.% under the conditions of a roasting temperature of 650 °C, coke powder addition of 25 wt.%, a roasting time of 180 min, and an argon flow rate of 10 L/min. The volatilization of arsenic was controlled by a chemical controlling step at 20–100 min, and this was switched to a diffusion controlling step at 120–180 min by kinetic experiments. The reaction mechanism of arsenic and iron under carbon thermal magnetization reduction was as follows: in the early stage of the reaction, a large amount of FeAsO<sub>4</sub> was decomposed into As<sub>2</sub>O<sub>3</sub> and Fe<sub>3</sub>O<sub>4</sub>; in the middle and late stages of the reaction, FeAsO<sub>4</sub> was continuously decomposed and reduced, and the content of Fe<sub>3</sub>O<sub>4</sub> was continuously increased until all iron was magnetized to generate Fe<sub>3</sub>O<sub>4</sub>, and the decomposed As<sub>2</sub>O<sub>3</sub> volatilized into dust. Arsenic reacted with CaO to generate Ca<sub>3</sub>(AsO<sub>4</sub>)<sub>2</sub>, and this may be the reason why arsenic could not be removed completely.https://www.mdpi.com/2075-4701/13/2/407arsenic–iron precipitatearsenicarsenic trioxideferroferric oxide |
| spellingShingle | Xuepeng Li Dachun Liu Juan Wang Jun Chang Ziyang Wang Experimental Study on the Recovery of Arsenic and Iron from Arsenic–Iron Precipitate by Carbon Thermal Magnetization Reduction Metals arsenic–iron precipitate arsenic arsenic trioxide ferroferric oxide |
| title | Experimental Study on the Recovery of Arsenic and Iron from Arsenic–Iron Precipitate by Carbon Thermal Magnetization Reduction |
| title_full | Experimental Study on the Recovery of Arsenic and Iron from Arsenic–Iron Precipitate by Carbon Thermal Magnetization Reduction |
| title_fullStr | Experimental Study on the Recovery of Arsenic and Iron from Arsenic–Iron Precipitate by Carbon Thermal Magnetization Reduction |
| title_full_unstemmed | Experimental Study on the Recovery of Arsenic and Iron from Arsenic–Iron Precipitate by Carbon Thermal Magnetization Reduction |
| title_short | Experimental Study on the Recovery of Arsenic and Iron from Arsenic–Iron Precipitate by Carbon Thermal Magnetization Reduction |
| title_sort | experimental study on the recovery of arsenic and iron from arsenic iron precipitate by carbon thermal magnetization reduction |
| topic | arsenic–iron precipitate arsenic arsenic trioxide ferroferric oxide |
| url | https://www.mdpi.com/2075-4701/13/2/407 |
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