Weathering of Biotite inAcidithiobacillus ferrooxidansCultures

Bioleaching of waste material from the Salobo mine, Brazil: Recovery of refractory copper from Cu hosted in silicate minerals

“…ferrooxidans thereby maintains iron in the oxidised state. Although iron-oxidising bacteria will preferentially colonise Fe-sulphides (Edwards et al, 1999), recent studies demonstrate that populations of A. ferrooxidans can be sustained on a range of silicate minerals, including biotite (Dopson et al, 2009;Bhatti et al, 2011a), phlogopite (Bigham et al, 2001;Bhatti et al, 2011b), fayalite (Santelli et al, 2001;Welch and Banfield, 2002;Dopson et al, 2009), hornblende, augite and microcline (Dopson et al, 2009). These studies demonstrate that A. ferrooxidans is capable of utilizing ferrous iron released during acid neutralisation reactions of Fe-bearing silicates.…”

“…It is therefore possible that A. ferrooxidans are able to access Fe(II) and/or that magnetite functions as P sink which attracts bacteria. The bioleaching of biotite and phlogopite by A. ferrooxidans can lead to structural changes due to K + solubilisation from interlayers, which can precipitate with Fe(III) as K-jarosite (Bhatti et al, 2011a;Bhatti et al, 2011b;Dopson et al, 2009). No studies on chlorite have been completed to date.…”

Microbial activated mineral weathering and cementation as precursors to hardpan formation and heavy metal encapsulation in sulfidic tailings

“…created a localized acidic micro-environment on biotite surfaces, thereby enhancing biotite dissolution, since biotite dissolution rate varies by up to 1.5 orders of magnitude at a given acidic pH condition 34,35 . The weathering of biotite may release K + from the interlayer of crystal 36 , which may have coprecipitated with ferric iron and sulfate to form jarosite-like minerals. Jarosite formation is regulated by microbial activities when suitable cations such as K + , NH 4 + , or Na + are available at the pH range of 1.5-3.0 (Eq.…”

Bacterial influence on storage and mobilisation of metals in iron-rich mine tailings from the Salobo mine, Brazil

“…Their preferred environment for optimum activity is acidic and commonly involves oxidation of sulphide minerals (pH < 3; Amaro et al, 1991). Several studies (Bigham et al, 2001;Santelli et al, 2001;Welch and Banfield, 2002;Dopson et al, 2009;Bhatti et al, 2011a;Bhatti et al, 2011b;Henne et al, 2018) have shown that soluble Fe (II) from silicates can be used by A.…”