At the city of Brumadinho, state of Minas Gerais, Brazil, the rupture of the B1 tailings storage facility at the Córrego do Feijão Mine, which occurred on January 5, 2019, was one of the worst socio-environmental accidents of mining origin in recent times. Around 12 Mm3 of iron mining tailings were released along the Ferro e Carvão river and the main watercourse, the Paraopeba river.
Among the various challenges for social and environmental recovery from damages in consequence of the B1 dam break (which could take decades), is the management of the tailing’s deposits formed along the channel of Paraopeba River.
The Fe-tailings released from the B1 dam were predominantly made up of hematite [Fe2O3], with the occasional occurrence of the hematite predominance plus kaolinite [Al2Si2O5(OH)4)]. On the other hand, natural sediments not affected by tailings were predominantly composed of associations of kaolinite, quartz [SiO2] and quartz plus hematite [Fe2O3]. Furthermore, the group of Mn and Fe constitutes the chemical signature of the tailings.
In order to implement an approach that would either increase the efficiency of the resources allocated and the reclamation actions performance, the use of geochemical signatures of the released waste has been shown useful and practical due to the approach developed, which is robust enough to be used for different site, since supported by an adequate geochemical data set.
SRK Brazil Geoenvironmental team performed a profound review of the background studies developed by that time and the geochemical data set generated by the characterization program carried out as part of the reclamation work. As a result, based on this background information, and from whole rock analysis data, practical graphical tool was developed for identification and differentiation of the Fe-tailings and natural sediments in the environment allowing focused reclamation and management actions, which contributed significantly for the performance of the reclamation work. The tool developed by SRK Brazil is being used by Vale in its day-to-day tailings management.
