Extraction of REEs from Blast Furnace Slag by Gluconobacter oxydans

Granulated blast furnace slag (GGBFS) is a potential resource of rare earth elements (REEs), and due to the complex mineralogy, extraction by conventional hydrometallurgical process makes it an acid-consuming method. Bioleaching thus investigated using chemo-organotrophic bacterium Gluconobacter oxydans (DSMZ 46616) for REE from GGBFS containing 157 ppm Ce, 90 La, 71 Nd 40 Er, hosted in Ca-Al-Si matrix. The gluconic acid generation G. was assessed its role GGBFS. With 5% (w/v) mixture non-adapted GGBFS-adapted culture, maximum solubilization 67% 88% observed after 12 days incubation, respectively. total amount excreted bacteria increased with leaching duration, which contributed rise metal extraction. Scanning electron microscope-energy dispersive analysis (SEM-EDAX) solid residue showed bacterial cells corrosion pits, thereby assisting solubilization.