The Enhancement of Enargite Dissolution by Sodium Hypochlorite in Ammoniacal Solutions
The dissolution of both copper and arsenic from a copper concentrate was investigated in oxidative ammonia/ammonium solutions at moderate temperatures and atmospheric pressure. The main parameters studied were temperature, pH, concentrations of different ammonia salts, the presence of sodium hypochl...
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| Online Access: | https://www.mdpi.com/1996-1944/14/16/4529 |
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| author | Lilian Velásquez-Yévenes Hans Álvarez Víctor Quezada Antonio García |
| author_facet | Lilian Velásquez-Yévenes Hans Álvarez Víctor Quezada Antonio García |
| author_sort | Lilian Velásquez-Yévenes |
| collection | DOAJ |
| description | The dissolution of both copper and arsenic from a copper concentrate was investigated in oxidative ammonia/ammonium solutions at moderate temperatures and atmospheric pressure. The main parameters studied were temperature, pH, concentrations of different ammonia salts, the presence of sodium hypochlorite, pretreatment with sodium chloride, and curing period. In all ammoniacal solutions studied, increasing the temperature enhanced the dissolution of copper, but the dissolution of arsenic remained marginal. Mixing the copper concentrate with sodium chloride and leaving it to rest for 72 h before leaching in ammoniacal solutions significantly increased the dissolution of copper and slightly increased the dissolution of arsenic from the concentrate. A maximum of 35% of Cu and 3.3% of As were extracted when ammonium carbonate was used as the lixiviant. The results show relatively rapid dissolution of the concentrate with the addition of sodium hypochlorite in ammonium carbonate solution, achieving a dissolution of up to 50% and 25% of copper and arsenic, respectively. A copper dissolution with a non-linear regression model was proposed, considering the effect of NaClO and NH<sub>4</sub>Cl at 25 °C. These findings highlight the importance of using the correct anionic ligands for the ammonium ions and temperature to obtain a high dissolution of copper or arsenic. The results also showed that the curing time of the packed bed before the commencement of leaching appeared to be an important parameter to enhance the dissolution of copper and leave the arsenic in the residues. |
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| format | Article |
| id | doaj.art-b8ca1f07d9ab4359be85e5b5aa7bfb2d |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-10T08:38:25Z |
| publishDate | 2021-08-01 |
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| spelling | doaj.art-b8ca1f07d9ab4359be85e5b5aa7bfb2d2023-11-22T08:28:52ZengMDPI AGMaterials1996-19442021-08-011416452910.3390/ma14164529The Enhancement of Enargite Dissolution by Sodium Hypochlorite in Ammoniacal SolutionsLilian Velásquez-Yévenes0Hans Álvarez1Víctor Quezada2Antonio García3Escuela de Ingeniería Civil de Minas, Facultad de Ingeniería, Universidad de Talca, Curicó 3340000, ChileLaboratorio de Investigación de Minerales Sulfurados, Departamento de Ingeniería Metalúrgica y Minas, Universidad Católica del Norte, Avenida Angamos 0610, Antofagasta 1270709, ChileLaboratorio de Investigación de Minerales Sulfurados, Departamento de Ingeniería Metalúrgica y Minas, Universidad Católica del Norte, Avenida Angamos 0610, Antofagasta 1270709, ChileLaboratorio de Investigación de Minerales Sulfurados, Departamento de Ingeniería Metalúrgica y Minas, Universidad Católica del Norte, Avenida Angamos 0610, Antofagasta 1270709, ChileThe dissolution of both copper and arsenic from a copper concentrate was investigated in oxidative ammonia/ammonium solutions at moderate temperatures and atmospheric pressure. The main parameters studied were temperature, pH, concentrations of different ammonia salts, the presence of sodium hypochlorite, pretreatment with sodium chloride, and curing period. In all ammoniacal solutions studied, increasing the temperature enhanced the dissolution of copper, but the dissolution of arsenic remained marginal. Mixing the copper concentrate with sodium chloride and leaving it to rest for 72 h before leaching in ammoniacal solutions significantly increased the dissolution of copper and slightly increased the dissolution of arsenic from the concentrate. A maximum of 35% of Cu and 3.3% of As were extracted when ammonium carbonate was used as the lixiviant. The results show relatively rapid dissolution of the concentrate with the addition of sodium hypochlorite in ammonium carbonate solution, achieving a dissolution of up to 50% and 25% of copper and arsenic, respectively. A copper dissolution with a non-linear regression model was proposed, considering the effect of NaClO and NH<sub>4</sub>Cl at 25 °C. These findings highlight the importance of using the correct anionic ligands for the ammonium ions and temperature to obtain a high dissolution of copper or arsenic. The results also showed that the curing time of the packed bed before the commencement of leaching appeared to be an important parameter to enhance the dissolution of copper and leave the arsenic in the residues.https://www.mdpi.com/1996-1944/14/16/4529enargite dissolutionammonia saltssodium hypochloritepretreatment with NaClcuring time |
| spellingShingle | Lilian Velásquez-Yévenes Hans Álvarez Víctor Quezada Antonio García The Enhancement of Enargite Dissolution by Sodium Hypochlorite in Ammoniacal Solutions Materials enargite dissolution ammonia salts sodium hypochlorite pretreatment with NaCl curing time |
| title | The Enhancement of Enargite Dissolution by Sodium Hypochlorite in Ammoniacal Solutions |
| title_full | The Enhancement of Enargite Dissolution by Sodium Hypochlorite in Ammoniacal Solutions |
| title_fullStr | The Enhancement of Enargite Dissolution by Sodium Hypochlorite in Ammoniacal Solutions |
| title_full_unstemmed | The Enhancement of Enargite Dissolution by Sodium Hypochlorite in Ammoniacal Solutions |
| title_short | The Enhancement of Enargite Dissolution by Sodium Hypochlorite in Ammoniacal Solutions |
| title_sort | enhancement of enargite dissolution by sodium hypochlorite in ammoniacal solutions |
| topic | enargite dissolution ammonia salts sodium hypochlorite pretreatment with NaCl curing time |
| url | https://www.mdpi.com/1996-1944/14/16/4529 |
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