The mining industry has seen several significant dam failures in recent years. Dam failures are associated with errors in design, implementation, operation, and monitoring (Azam, 2014, [2]). Dewatered stockpiling (dry stacking) is a safer alternative to tailings dams (Rico et al., 2008, [3]) for tailings disposal; however, this method has not yet been used in iron ore mines in Brazil, where geotechnical conditions and abundance of water are favorable for the use of tailings dams. This paper describes the results of the study that supported the implementation of an innovative dewatering plant for iron ore tailings in Pau Branco mine, Quadrilatero Ferrifero, Brazil, contributing to improve its sustainability (Gomes et al., 2015, [6]). Magnetic concentration rejects (>45μm) were feasibly dewatered through high-frequency screenings, and slimes (<45μm) were effectively filtered in a horizontal filter press, enabling dry stacking of tailings. A comparison with the current tailings dam structure is presented, demonstrating that Capital Expenditure (CAPEX) for the solution proposed here is significantly lower

Background: Molecular studies of Bacillus diversity in various environments have been reported. However, there have been few investigations concerning Bacillus in steel plant environments. In this study, genotypic and phenotypic diversity and phylogenetic relationships among 40 bacterial isolates recovered from steel plant waste were investigated using classical and molecular methods. Results: 16S rDNA partial sequencing assigned all the isolates to the Bacillus genus, with close genetic relatedness to the Bacillus subtilis and Bacillus cereus groups, and to the species Bacillus sphaericus. tDNA-intergenic spacer length polymorphisms and the 16S–23S intergenic transcribed spacer region failed to identify the isolates at the species level. Genomic diversity was investigated by molecular typing with rep (repetitive sequence) based PCR using the primer sets ERIC2 (enterobacterial repetitive intergenic consensus), (GTG)₅, and BOXAIR. Genotypic fingerprinting of the isolates reflected high intraspecies and interspecies diversity. Clustering of the isolates using ERIC-PCR fingerprinting was similar to that obtained from the 16S rRNA gene phylogenetic tree, indicating the potential of the former technique as a simple and useful tool for examining relationships among unknown Bacillus spp. Physiological, biochemical and heavy metal susceptibility profiles also indicated considerable phenotypic diversity. Among the heavy metal compounds tested Zn, Pb and Cu were least toxic to the bacterial isolates, whereas Ag inhibited all isolates at 0.001 mM. Conclusion: Isolates with identical 16S rRNA gene sequences had different genomic fingerprints and differed considerably in their physiological capabilities, so the high levels of phenotypic diversity found in this study are likely to have ecological relevance.