Reactions of goethite and magnetite with sulfide solutions under CH4 and/or CO2 atmospheres were monitored in situ with Raman spectroscopy in the high-pressure capillary optical cells (HPOCs) at room temperature. Isolated systems were created in the enclosed HPOCsfor thestudy ofthemineral–solutioninteractions toprevent oxidationduring theexperiments.Weobserved thatiron (oxyhydr)oxidemineralswereinerttosulfidesolutionunderCH4 atmosphere,and thattheadditionofCO2 tothissystemtriggeredthe sulfidization reactions and produced iron monosulfide; mackinawite was identified in the solid phase immersed in the solution after six hours and pyrrhotite in the solid phase exposed to the vapor phase after 5 days. Mackinawite formed in the aqueous phase was metastable, and dissolved after about 10 days. The observed sulfidization of iron (oxyhydr)oxide minerals was through a replacement reaction rather than a dissolution–precipitation process.
Effects of CH4 and CO2 on the sulfidization of goethite and magnetite: an in situ Raman spectroscopic study in high-pressure capillary optical cells at room temperature / Wang, Menghan; Chou, I. Ming; Lu, Wanjun; DE VIVO, Benedetto. - In: EUROPEAN JOURNAL OF MINERALOGY. - ISSN 0935-1221. - 27:2(2015), pp. 193-201. [10.1127/ejm/2015/0027-2432]
Effects of CH4 and CO2 on the sulfidization of goethite and magnetite: an in situ Raman spectroscopic study in high-pressure capillary optical cells at room temperature
DE VIVO, BENEDETTO
2015
Abstract
Reactions of goethite and magnetite with sulfide solutions under CH4 and/or CO2 atmospheres were monitored in situ with Raman spectroscopy in the high-pressure capillary optical cells (HPOCs) at room temperature. Isolated systems were created in the enclosed HPOCsfor thestudy ofthemineral–solutioninteractions toprevent oxidationduring theexperiments.Weobserved thatiron (oxyhydr)oxidemineralswereinerttosulfidesolutionunderCH4 atmosphere,and thattheadditionofCO2 tothissystemtriggeredthe sulfidization reactions and produced iron monosulfide; mackinawite was identified in the solid phase immersed in the solution after six hours and pyrrhotite in the solid phase exposed to the vapor phase after 5 days. Mackinawite formed in the aqueous phase was metastable, and dissolved after about 10 days. The observed sulfidization of iron (oxyhydr)oxide minerals was through a replacement reaction rather than a dissolution–precipitation process.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.