Characterization of Accessory Minerals in the Birmingham Red Iron Ores and Eufaula Ferruginous Bauxite Deposits in Alabama

摘要

The character of phosphorous-bearing minerals in the Birmingham red iron ores and iron-bearing minerals in the Eufaula bauxite deposits in Alabama has been intensively studied by petrographic, ore microscopic, luminescent microscopic, scanning electron microscopic, electron microprobe, and X-ray diffraction techniques. Fifteen types of phosphorous-bearing mineral grains have been identified in Birmingham iron ores by the characteristic sizes, shapes, and distributions. Size measurements and modal and texture analyses have permitted an estimate of potential liberation of phosphorous from the iron ores by beneficiation to be 27% in areas of previous mining and 60% in areas of current iron reserves. Fine grinding, selective flocculation, and flotation may constitute the best beneficiation technique for future research. Hematite and goethite are the most important iron minerals in Eufaula ferruginous bauxites, but pyrite, marcasite, and siderite are important iron minerals in some varieties of ferruginous bauxite, and lepidocrocite and ilmenite occur locally in minor quantities.