THE FORMATION AND TRANSITION OF THE METASTABLE MINERAL SCH WERTMANNITE IN ACID DRAINAGE FROM CAOL MINE

Schwertmannite was recognized as a Fe oxyhydroxy sulfate mineral and generally is formed in the acid mine drainage.In mining areas schwertmannite may play an important role in removing metals and metalloids from solutions due to its high specific surface area and metastable.This study identified the existence of schwertmannite in the acid drainage from coal mines in China by SEM/EDX and XRD.The simulating experiment of oxidation reaction was made on heterogeneous pyrite from coal seams.The result showed that in the reactant there was some schwertmannite and it is considered that the mineral was formed directly from solution and subsequently transformed into goethite.