The effects of Pb-Zn flotation reagents on the bioleaching process by mesophilic bacteria

A Comparative Study on the Effect of Flotation Reagents on Growth and Iron Oxidation Activities of Leptospirillum ferrooxidans and Acidithiobacillus ferrooxidans

“…Dehghan and Dianati (2015) reported the positive effect of potassium amylxanthate and potassium ethylxanthate on both A. ferrooxidans and L. ferrooxidans. The solubility of elemental sulfur as a passivation layer on the mineral surfaces was reported as a potential reason for such a positive effect [1].…”

“…Generally, flotation products (typically concentrates) are subjected to pyro-, hydro-, or biometallurgy process for the metal extraction. Although the presence of these residual surfactants on flotation products has no essential effect on the pyrometallurgical extractions [1], they may have Minerals 2017, 7, 2 2 of 13 significant impacts (positive or negative) on microbial activities involving in the biometallurgical metal extraction [2][3][4][5].…”

“…There are some investigations on the effect of flotation reagents in bioleaching technology that generally focused on their impacts over the metallurgical parameters (recovery and grade of products) [1,3,[6][7][8][9][10], however, the fundamental effects of these chemicals on bacterial activities are not yet widely studied. It was reported that the recovery and grade in a bioleaching process of flotation products (in the presence of remaining surfactants) could be highly affected by type of reagents (their chemical compositions and structures), concentration of reagents, and type of microorganisms (various metabolisms, cellular membranes, strains, etc.)…”

“…It was reported that the recovery and grade in a bioleaching process of flotation products (in the presence of remaining surfactants) could be highly affected by type of reagents (their chemical compositions and structures), concentration of reagents, and type of microorganisms (various metabolisms, cellular membranes, strains, etc.) [1,[3][4][5][6][7][8]. Among microorganisms, Acidithiobacillus ferrooxidans (A. ferrooxidans) was the first bacterium isolated from an acidic leaching environment for biomining, and it was used in many early bioleaching studies until Leptospirillum ferrooxidans (L. ferrooxidans) was found and it was reported that L. ferrooxidans can be the dominant iron-oxidizing bacteria in biomining processes [2,9,[11][12][13][14][15][16].…”

“…A systematic investigation on the effects of commercial surfactants on microbial activities can be a key to: (1) better understand the mechanisms of reactions and (2) efficiently select reagents when, in the downstream, flotation products are going to be processed by bioleaching for extraction of metals. In this study, to extensively realize possible interactions of industrial surfactants on biooxidation, the influence of various conventional reagents for flotation of sulfides (collectors: potassium amylxanthate (KAX), potassium isobutyl-xanthate (KIBX), sodium ethylxanthate (NaEX), potassium isopropylxanthate (KIPX), and dithiophosphate (Aero3477); and frothers: pine oil (PO) and methyl isobutyl carbinol (MIBC)) on L. ferrooxidans and A. ferrooxidans activities were compared by fundamental measurements (pH, oxidation-reduction potential (ORP), dissolved oxygen (DO 2 ), microorganisms counting method, and iron ion (Fe T (iron total), Fe 2+ , and Fe 3+ ) analyses.…”