Reactivation Process of Activated Carbons: Effect on the Mechanical and Adsorptive Properties
Carbon reactivation is a strategy to reduce waste and cost in many industrial processes, for example, effluent treatment, food industry, and hydrometallurgy. In this work, the effect of physical and chemical reactivation of granular activated carbon (AC) was studied. Spent activated carbon (SAC) was...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-04-01
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| Series: | Molecules |
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| Online Access: | https://www.mdpi.com/1420-3049/25/7/1681 |
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| author | Rita B. Cevallos Toledo Carlos F. Aragón-Tobar Sebastián Gámez Ernesto de la Torre |
| author_facet | Rita B. Cevallos Toledo Carlos F. Aragón-Tobar Sebastián Gámez Ernesto de la Torre |
| author_sort | Rita B. Cevallos Toledo |
| collection | DOAJ |
| description | Carbon reactivation is a strategy to reduce waste and cost in many industrial processes, for example, effluent treatment, food industry, and hydrometallurgy. In this work, the effect of physical and chemical reactivation of granular activated carbon (AC) was studied. Spent activated carbon (SAC) was obtained from a carbon in pulp (CIP) leaching process for gold extraction. Chemical and physical reactivations were evaluated using several acid-wash procedures (HCl, HNO<sub>3</sub>, H<sub>2</sub>SO<sub>4</sub>) and thermal treatment (650–950 °C) methods, respectively. The effect of the reactivation processes on the mechanical properties was evaluated determining ball pan hardness and normal abrasion in pulp resistance. The effect on the adsorptive properties was evaluated via the iodine number, the gold adsorption value (<i>k</i> expressed in mg Au/g AC), and Brunauer–Emmett–Teller (BET) surface area. Initial characterization of the SAC showed an iodine number of 734 mg I<sub>2</sub>/g AC, a <i>k</i> value of 1.37 mg Au/g AC, and a BET surface area of 869 m<sup>2</sup>/g. The best reactivation results of the SAC were achieved via acid washing with HNO<sub>3</sub> at 20% <i>v</i>/<i>v</i> and 50 °C over 30 min, and a subsequent thermal reactivation at 850 °C over 1 h. The final reactivated carbon had an iodine number of 1199 mg I<sub>2</sub>/g AC, a <i>k</i> value of 14.9 mg Au/g AC, and a BET surface area of 1079 m²/g. Acid wash prior to thermal treatment was critical to reactivate the SAC. The reactivation process had a minor impact (<1% change) on the mechanical properties of the AC. |
| first_indexed | 2024-03-10T20:38:28Z |
| format | Article |
| id | doaj.art-1eb151c9f3264333acfbc2af4f7b480f |
| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-03-10T20:38:28Z |
| publishDate | 2020-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-1eb151c9f3264333acfbc2af4f7b480f2023-11-19T20:51:24ZengMDPI AGMolecules1420-30492020-04-01257168110.3390/molecules25071681Reactivation Process of Activated Carbons: Effect on the Mechanical and Adsorptive PropertiesRita B. Cevallos Toledo0Carlos F. Aragón-Tobar1Sebastián Gámez2Ernesto de la Torre3Department of Extractive Metallurgy, Escuela Politécnica Nacional, Quito 170517, EcuadorDepartment of Extractive Metallurgy, Escuela Politécnica Nacional, Quito 170517, EcuadorDepartment of Extractive Metallurgy, Escuela Politécnica Nacional, Quito 170517, EcuadorDepartment of Extractive Metallurgy, Escuela Politécnica Nacional, Quito 170517, EcuadorCarbon reactivation is a strategy to reduce waste and cost in many industrial processes, for example, effluent treatment, food industry, and hydrometallurgy. In this work, the effect of physical and chemical reactivation of granular activated carbon (AC) was studied. Spent activated carbon (SAC) was obtained from a carbon in pulp (CIP) leaching process for gold extraction. Chemical and physical reactivations were evaluated using several acid-wash procedures (HCl, HNO<sub>3</sub>, H<sub>2</sub>SO<sub>4</sub>) and thermal treatment (650–950 °C) methods, respectively. The effect of the reactivation processes on the mechanical properties was evaluated determining ball pan hardness and normal abrasion in pulp resistance. The effect on the adsorptive properties was evaluated via the iodine number, the gold adsorption value (<i>k</i> expressed in mg Au/g AC), and Brunauer–Emmett–Teller (BET) surface area. Initial characterization of the SAC showed an iodine number of 734 mg I<sub>2</sub>/g AC, a <i>k</i> value of 1.37 mg Au/g AC, and a BET surface area of 869 m<sup>2</sup>/g. The best reactivation results of the SAC were achieved via acid washing with HNO<sub>3</sub> at 20% <i>v</i>/<i>v</i> and 50 °C over 30 min, and a subsequent thermal reactivation at 850 °C over 1 h. The final reactivated carbon had an iodine number of 1199 mg I<sub>2</sub>/g AC, a <i>k</i> value of 14.9 mg Au/g AC, and a BET surface area of 1079 m²/g. Acid wash prior to thermal treatment was critical to reactivate the SAC. The reactivation process had a minor impact (<1% change) on the mechanical properties of the AC.https://www.mdpi.com/1420-3049/25/7/1681reactivationactivated carbonmechanical propertiesadsorption |
| spellingShingle | Rita B. Cevallos Toledo Carlos F. Aragón-Tobar Sebastián Gámez Ernesto de la Torre Reactivation Process of Activated Carbons: Effect on the Mechanical and Adsorptive Properties Molecules reactivation activated carbon mechanical properties adsorption |
| title | Reactivation Process of Activated Carbons: Effect on the Mechanical and Adsorptive Properties |
| title_full | Reactivation Process of Activated Carbons: Effect on the Mechanical and Adsorptive Properties |
| title_fullStr | Reactivation Process of Activated Carbons: Effect on the Mechanical and Adsorptive Properties |
| title_full_unstemmed | Reactivation Process of Activated Carbons: Effect on the Mechanical and Adsorptive Properties |
| title_short | Reactivation Process of Activated Carbons: Effect on the Mechanical and Adsorptive Properties |
| title_sort | reactivation process of activated carbons effect on the mechanical and adsorptive properties |
| topic | reactivation activated carbon mechanical properties adsorption |
| url | https://www.mdpi.com/1420-3049/25/7/1681 |
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