STRUCTURAL AND MORPHOLOGICAL-STUDIES OF IRON SULFIDE

Treatment of high surface area feroxyhyte (delta'-FeOOH) with hydrogen sulfide, at room temperature, yielded mackinawite (FeS) and amorphous sulfur. On exposure to air, the sulfided material underwent an exothe rmic reaction during which crystalline sulfur and an amorphous hydrate d iron oxide species were formed. On leaving this material in air for a period of days crystalline goethite (alpha-FeOOH) was formed. These chemical and structural changes were accompanied by alterations in the morphologies of the materials, all of which occurred at, or close to, room temperature. These differences are important for two reasons. Fi rst, they are of relevance to the sulfiding of metal oxides and second ly they involve high-melting-point ionic lattices undergoing complete reorganisation at close to ambient temperature.