Binchuan Li , Xinwei Luan , Xiaoge Wang , Daxue Fu , Yongfeng Chang , Shuang Cui , Kuiren Liu , Xiaocai He , Jianshe Chen , Qing Han
{"title":"Immobilization of hazardous components in zinc leaching residue by autothermal roasting with pyrite","authors":"Binchuan Li , Xinwei Luan , Xiaoge Wang , Daxue Fu , Yongfeng Chang , Shuang Cui , Kuiren Liu , Xiaocai He , Jianshe Chen , Qing Han","doi":"10.1016/j.cep.2025.110391","DOIUrl":null,"url":null,"abstract":"<div><div>In this paper, pyrite is innovatively used as sulfur source, and its combustion heat is used to achieve effective detoxification of zinc leaching residue. Realize the treatment of waste with waste. The effects of several factors on the immobilization of hazardous components like Zn, Pb, As, and Cd were systematically investigated. The results show that under the condition of a roasting temperature of 975 °C, roasting time of 2.5 h, sulfur content of 20 %, and air flow of 0.8 m<sup>3</sup>·h<sup>-1</sup>, the leaching concentrations of Zn, Pb, As, and Cd in the roasted residue were 15.9 mg·L<sup>-1</sup>, 0.1 mg·L<sup>-1</sup>, 1.72 mg·L<sup>-1</sup>, and 0.84 mg·L<sup>-1</sup>, respectively, all of which are below the limits of hazardous waste identification standard. Thermodynamic analysis of the pyrite roasting process revealed that the heat generated by its combustion facilitates the roasting process of zinc leaching residue. The combustion product SO<sub>2</sub> can transform PbCO<sub>3</sub> in the leaching residue into PbSO<sub>4</sub>, and Fe<sub>2</sub>O<sub>3</sub> can convert ZnO, ZnS and ZnSO<sub>4</sub> into ZnFe<sub>2</sub>O<sub>4</sub>. PbFe<sub>6</sub>(SO<sub>4</sub>)<sub>4</sub>(OH)<sub>12</sub> transforms to PbSO<sub>4</sub>, Fe<sub>2</sub>O<sub>3</sub> and SO<sub>3</sub>. CdO generates CdFe<sub>8</sub>O<sub>16</sub>Zn<sub>3</sub> after roasting. As is immobilizated in the roasted residue in the form of FeAsO<sub>4</sub>. Magnetic separation was performed on the roasted residue to recover Fe, and the obtained concentrate had an Fe content of 54.20 %. The residue mass decreased by 25.73 % post-roasting, realizing “waste-treats-waste” through sulfur self-consumption and SO<sub>2</sub> fixation.</div></div>","PeriodicalId":9929,"journal":{"name":"Chemical Engineering and Processing - Process Intensification","volume":"216 ","pages":"Article 110391"},"PeriodicalIF":3.9000,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Chemical Engineering and Processing - Process Intensification","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0255270125002405","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ENERGY & FUELS","Score":null,"Total":0}
引用次数: 0
Abstract
In this paper, pyrite is innovatively used as sulfur source, and its combustion heat is used to achieve effective detoxification of zinc leaching residue. Realize the treatment of waste with waste. The effects of several factors on the immobilization of hazardous components like Zn, Pb, As, and Cd were systematically investigated. The results show that under the condition of a roasting temperature of 975 °C, roasting time of 2.5 h, sulfur content of 20 %, and air flow of 0.8 m3·h-1, the leaching concentrations of Zn, Pb, As, and Cd in the roasted residue were 15.9 mg·L-1, 0.1 mg·L-1, 1.72 mg·L-1, and 0.84 mg·L-1, respectively, all of which are below the limits of hazardous waste identification standard. Thermodynamic analysis of the pyrite roasting process revealed that the heat generated by its combustion facilitates the roasting process of zinc leaching residue. The combustion product SO2 can transform PbCO3 in the leaching residue into PbSO4, and Fe2O3 can convert ZnO, ZnS and ZnSO4 into ZnFe2O4. PbFe6(SO4)4(OH)12 transforms to PbSO4, Fe2O3 and SO3. CdO generates CdFe8O16Zn3 after roasting. As is immobilizated in the roasted residue in the form of FeAsO4. Magnetic separation was performed on the roasted residue to recover Fe, and the obtained concentrate had an Fe content of 54.20 %. The residue mass decreased by 25.73 % post-roasting, realizing “waste-treats-waste” through sulfur self-consumption and SO2 fixation.
期刊介绍:
Chemical Engineering and Processing: Process Intensification is intended for practicing researchers in industry and academia, working in the field of Process Engineering and related to the subject of Process Intensification.Articles published in the Journal demonstrate how novel discoveries, developments and theories in the field of Process Engineering and in particular Process Intensification may be used for analysis and design of innovative equipment and processing methods with substantially improved sustainability, efficiency and environmental performance.