Eletroflotação De Partículas Finas De Hematita Em Célula Modificada De Partridge Smith Usando Rhodococcus Opacus Como Biorreagente

Abstract

Eletroflotação de partículas finas de hematita em célula modificada de Partridge Smith usandoRhodococcus opacus como biorreagente This work aims to evaluate the electroflotation of hematite fine particles in a modified Partridge Smith cell using Rhodococcus opacus. A hematite sample with grade 96% was used in this study; additionally, three granulometric fractions were selected: -53+38; -38+20 and -20 micrometers. The variables studied were pH, reagent concentration and current density. Zeta potential measurements and analysis by infrared spectroscopy were carried out to assess the interaction before and after reagents interaction. In order to gain a better understanding of the bubble diameter influence in the process, measurements of the diameter of hydrogen and oxygen bubbles were done. The average bubble diameter (d 32 ) was found in the range of 40 to 60 micrometers for the hydrogen bubbles and of 50 to 70 micrometers for the oxygen bubbles. Finally, electrocoagulation assays the hematite with R. opacus and sodium oleate were carried out. The reduction in particle size favored the floatability of hematite; this fact can be related to the bubble size generated in the process and the ability of R. opacus to form floccules through the interaction of Van der Waals. On the other hand, the increase of reagent concentration (R. opacus and sodium oleate) favored the floatability of hematite. Suitable pH values for hematite flotation were found around 6 and 7 for R. opacus and sodium oleate, respectively. Maximum hematite floatability with R. opacus using hydrogen bubbles was around 80% and around 65% with oxygen bubbles. Sodium oleate presented a better performance reaching a maximum floatability of approximately 98% for hydrogen bubbles and around 90% for oxygen bubbles. The characteristics of the bacterial surface and the bubble size were determinant factors in the hematite floatability. Therefore, the electroflotation process using R. opacus as collector is a potential technology regarding environmental issues found with the synthetic reagents.