Surface and Interface Analysis · 2020 · 12 citations · 17 references
Natural SciencesChemistryEarth SciencesElemental AnalysisGeochemistryInorganic ChemistryIron OxidesMineral GeochemistryMineral Surface ChemistryMineral WeatheringRedox ProcessesWeathering GeochemistryChemical CharacteristicsCoal GeochemistryCoal Mineral MatterMercury GeochemistrySecondary Ion Mass SpectrometryThermal StabilityTime-of-flight Secondary Ion Mass SpectrometryWeathering Reaction Mechanisms
Pyrite is considered to be the major carrier of mercury in coal. Here, the chemical characteristics of two natural pyrite samples of different weathering degrees were characterized by time‐of‐flight secondary ion mass spectrometry (TOF‐SIMS). Thermal stability of Hg was also analyzed via temperature programmed desorption experiment (TPD). Characteristic ions such as S − , Fe + , FeS − , and FeS 2 − were detected on the surface of fresh pyrite. The release temperature of Hg ranged between 180°C and 300°C, and the characteristic peak of black HgS was recorded. In addition, abundant Fe 2 O 3 − , FeSO − , SO 4 − , and HSO 4 − were detected on the surface of weathered pyrite, and the release temperature of Hg therein was mainly distributed at 260°C to 380°C and 520°C to 600°C, corresponding to the characteristic peaks of red HgS and HgSO 4 , respectively. The results show that pyrite is acidified during weathering and that Hg forms in pyrite are transformed from the original state (HgS) to HgSO 4 .
17
Analysis of mercury species present during coal combustion by thermal desorption
M. Antonia López-Antón, Yang Yuan, Ron Perry et al. · Fuel · 2009 · 212 citations · Full text