Physical and chemical analysis of elemental sulfur formation during galena surface oxidation
The surface oxidation of sulfide minerals, such as galena (PbS), in aqueous solutions is of critical importance in a number of applications. A comprehensive understanding of the formation of oxidation species at the galena surface is still lacking. Much controversy over the nature of these oxidation...
| Veröffentlicht in: | Langmuir : the ACS journal of surfaces and colloids. - 1992. - 27(2011), 7 vom: 05. Apr., Seite 4190-201 |
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| Weitere Verfasser: | , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2011
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| Zugriff auf das übergeordnete Werk: | Langmuir : the ACS journal of surfaces and colloids |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Sulfides lead sulfide 2425D15SYM Lead 2P299V784P Sulfur 70FD1KFU70 |
| Zusammenfassung: | The surface oxidation of sulfide minerals, such as galena (PbS), in aqueous solutions is of critical importance in a number of applications. A comprehensive understanding of the formation of oxidation species at the galena surface is still lacking. Much controversy over the nature of these oxidation products exists. A number of oxidation pathways have been proposed, and experimental evidence for the formation of elemental sulfur, metal polysulfides, and metal-deficient lead sulfides in acidic conditions has been shown and argued. This paper provides further insight into the electrochemical behavior of galena at pH 4.5. Utilizing a novel experimental system that combines in situ electrochemical control and AC mode atomic force microscopy (AFM) surface imaging, the formation and growth of nanoscopic domains on the galena surface are detected and examined at anodic potentials. AFM phase images indicate that these domains have different material properties to the underlying galena. Continued oxidation results in nanoscopic pitting and the formation of microscopic surface domains, which are confirmed to be elemental sulfur by Raman spectroscopy. Further clarification of the presence of elemental sulfur is provided by Cryo-XPS. Polysulfide and metal-deficient sulfide could not be detected within this system |
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| Beschreibung: | Date Completed 13.07.2011 Date Revised 21.11.2013 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1520-5827 |
| DOI: | 10.1021/la104755a |