{"title":"Application of clean oxidation technology using H2O2 for simultaneous removal of sulfur and organic substances in the Bayer process","authors":"","doi":"10.1016/j.hydromet.2024.106367","DOIUrl":null,"url":null,"abstract":"<div><p>The harmful effects of sulfur and organic substances pose constraints on the green and sustainable development of the Bayer process for alumina production. This research aims to develop a method that utilizes H<sub>2</sub>O<sub>2</sub> to remove sulfur and organic substances during the digestion stage of bauxite, based on the mineralogical investigation of sulfur and organic substance. The extent of removal of S<sup>2−</sup> and total organic carbon reached 95.6% and 68.0%, respectively, under most suitable conditions of 12% H<sub>2</sub>O<sub>2</sub> dosage, temperature of 533 K, and duration of 80 min. Based on thermodynamic calculations, it is suggested that S<sup>2−</sup> is oxidized to SO<sub>4</sub><sup>2−</sup>. Additionally, the free radical reaction mechanism of organic substances in H<sub>2</sub>O<sub>2</sub> wet oxidation of Bayer liquor is proposed. The results confirm that this method does not introduce any impurities and does not have any impact on the digestion efficiency of alumina and the Bayer process.</p></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":null,"pages":null},"PeriodicalIF":4.8000,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Hydrometallurgy","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0304386X24001075","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"METALLURGY & METALLURGICAL ENGINEERING","Score":null,"Total":0}
引用次数: 0
Abstract
The harmful effects of sulfur and organic substances pose constraints on the green and sustainable development of the Bayer process for alumina production. This research aims to develop a method that utilizes H2O2 to remove sulfur and organic substances during the digestion stage of bauxite, based on the mineralogical investigation of sulfur and organic substance. The extent of removal of S2− and total organic carbon reached 95.6% and 68.0%, respectively, under most suitable conditions of 12% H2O2 dosage, temperature of 533 K, and duration of 80 min. Based on thermodynamic calculations, it is suggested that S2− is oxidized to SO42−. Additionally, the free radical reaction mechanism of organic substances in H2O2 wet oxidation of Bayer liquor is proposed. The results confirm that this method does not introduce any impurities and does not have any impact on the digestion efficiency of alumina and the Bayer process.
期刊介绍:
Hydrometallurgy aims to compile studies on novel processes, process design, chemistry, modelling, control, economics and interfaces between unit operations, and to provide a forum for discussions on case histories and operational difficulties.
Topics covered include: leaching of metal values by chemical reagents or bacterial action at ambient or elevated pressures and temperatures; separation of solids from leach liquors; removal of impurities and recovery of metal values by precipitation, ion exchange, solvent extraction, gaseous reduction, cementation, electro-winning and electro-refining; pre-treatment of ores by roasting or chemical treatments such as halogenation or reduction; recycling of reagents and treatment of effluents.