Selective Leaching of Arsenic from Copper Concentrates in Hypochlorite Medium
The selective leaching of arsenic using sodium hypochlorite was evaluated in order to reduce its concentration in a copper concentrate. The best conditions achieved in the synthetic concentrate were applied to the industrial concentrate. First, the individual behaviors of pure samples of enargite an...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-10-01
|
| Series: | Minerals |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2075-163X/13/11/1372 |
| _version_ | 1797458344042037248 |
|---|---|
| author | Maria Cecilia Hernández Oscar Benavente Antoni Roca Evelyn Melo Víctor Quezada |
| author_facet | Maria Cecilia Hernández Oscar Benavente Antoni Roca Evelyn Melo Víctor Quezada |
| author_sort | Maria Cecilia Hernández |
| collection | DOAJ |
| description | The selective leaching of arsenic using sodium hypochlorite was evaluated in order to reduce its concentration in a copper concentrate. The best conditions achieved in the synthetic concentrate were applied to the industrial concentrate. First, the individual behaviors of pure samples of enargite and chalcopyrite were evaluated under a hypochlorite medium. The enargite reaction is significantly faster than chalcopyrite, allowing for greater selectivity to ClO<sup>−</sup> (0.1–0.3 M), pH 12–12.5; 20 to 40 °C, reaction time <60 min. Under these conditions, the reagent consumption for pure compounds approaches the stoichiometric consumption and presents a selectivity factor of 5/1. Furthermore, concentrate leaching in a sodium hypochlorite medium, containing enargite, releases arsenic ions into the solution, while copper and iron remain in the solid phase, as CuO and Fe(OH)<sub>3</sub>, respectively. A novel copper concentrate cleaning process by selective leaching is proposed, which transforms unacceptable copper concentrate for smelters (>0.5%As) into clean concentrates (<0.2%As) or low penalty concentrates (0.2 < %As < 0.5). The estimated consumption for the cleaning process is in the order of 0.4–0.6 kg Cl<sub>2</sub> equivalent per kg of concentrate. |
| first_indexed | 2024-03-09T16:35:44Z |
| format | Article |
| id | doaj.art-ec939855eab843f48fd0fa4cf54e24c1 |
| institution | Directory Open Access Journal |
| issn | 2075-163X |
| language | English |
| last_indexed | 2024-03-09T16:35:44Z |
| publishDate | 2023-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Minerals |
| spelling | doaj.art-ec939855eab843f48fd0fa4cf54e24c12023-11-24T14:57:27ZengMDPI AGMinerals2075-163X2023-10-011311137210.3390/min13111372Selective Leaching of Arsenic from Copper Concentrates in Hypochlorite MediumMaria Cecilia Hernández0Oscar Benavente1Antoni Roca2Evelyn Melo3Víctor Quezada4Metallurgical and Mining Engineering Department, Universidad Católica del Norte, Antofagasta 1240000, ChileMetallurgical and Mining Engineering Department, Universidad Católica del Norte, Antofagasta 1240000, ChileDepartment of Materials Science and Physical Chemistry, Universitat de Barcelona, 08007 Barcelona, SpainMetallurgical and Mining Engineering Department, Universidad Católica del Norte, Antofagasta 1240000, ChileMetallurgical and Mining Engineering Department, Universidad Católica del Norte, Antofagasta 1240000, ChileThe selective leaching of arsenic using sodium hypochlorite was evaluated in order to reduce its concentration in a copper concentrate. The best conditions achieved in the synthetic concentrate were applied to the industrial concentrate. First, the individual behaviors of pure samples of enargite and chalcopyrite were evaluated under a hypochlorite medium. The enargite reaction is significantly faster than chalcopyrite, allowing for greater selectivity to ClO<sup>−</sup> (0.1–0.3 M), pH 12–12.5; 20 to 40 °C, reaction time <60 min. Under these conditions, the reagent consumption for pure compounds approaches the stoichiometric consumption and presents a selectivity factor of 5/1. Furthermore, concentrate leaching in a sodium hypochlorite medium, containing enargite, releases arsenic ions into the solution, while copper and iron remain in the solid phase, as CuO and Fe(OH)<sub>3</sub>, respectively. A novel copper concentrate cleaning process by selective leaching is proposed, which transforms unacceptable copper concentrate for smelters (>0.5%As) into clean concentrates (<0.2%As) or low penalty concentrates (0.2 < %As < 0.5). The estimated consumption for the cleaning process is in the order of 0.4–0.6 kg Cl<sub>2</sub> equivalent per kg of concentrate.https://www.mdpi.com/2075-163X/13/11/1372copper concentrateselective leachingenargitehypochlorite medium |
| spellingShingle | Maria Cecilia Hernández Oscar Benavente Antoni Roca Evelyn Melo Víctor Quezada Selective Leaching of Arsenic from Copper Concentrates in Hypochlorite Medium Minerals copper concentrate selective leaching enargite hypochlorite medium |
| title | Selective Leaching of Arsenic from Copper Concentrates in Hypochlorite Medium |
| title_full | Selective Leaching of Arsenic from Copper Concentrates in Hypochlorite Medium |
| title_fullStr | Selective Leaching of Arsenic from Copper Concentrates in Hypochlorite Medium |
| title_full_unstemmed | Selective Leaching of Arsenic from Copper Concentrates in Hypochlorite Medium |
| title_short | Selective Leaching of Arsenic from Copper Concentrates in Hypochlorite Medium |
| title_sort | selective leaching of arsenic from copper concentrates in hypochlorite medium |
| topic | copper concentrate selective leaching enargite hypochlorite medium |
| url | https://www.mdpi.com/2075-163X/13/11/1372 |
| work_keys_str_mv | AT mariaceciliahernandez selectiveleachingofarsenicfromcopperconcentratesinhypochloritemedium AT oscarbenavente selectiveleachingofarsenicfromcopperconcentratesinhypochloritemedium AT antoniroca selectiveleachingofarsenicfromcopperconcentratesinhypochloritemedium AT evelynmelo selectiveleachingofarsenicfromcopperconcentratesinhypochloritemedium AT victorquezada selectiveleachingofarsenicfromcopperconcentratesinhypochloritemedium |