A mathematical model for the bacterial oxidation of a sulfide ore concentrate

Abstract

The effect of dilution rate and feed solids concentration on the bacterial leaching of a pyrite/arsenopyrite ore concentrate was studied. A mathematical model was developed for the process based on the steady-state data collected over the range of dilution rates (20 to 110 h) and feed solids concentrations (6 to 18% w/v) studied. A modified Monod model with inhibition by arsenic was used to model bacterial ferrous ion oxidation rates. The model assumes that (i) pyrite and arsenopyrite leaching occurs solely by the action of ferric iron produced from the bacterial oxidation of ferrous iron and (ii) bacterial growth rates are proportional to ferrous ion oxidation rate. The equilibrium among the various ionic species present in the leach solution that are likely to have a significant effect on the bioleach process were included in the model. (c) 1994 John Wiley & Sons, Inc.

Numerical simulation for electrochemical cultivation of iron oxidizing bacteria

“…In particular, Monod's dual limitation equation model has often been adopted when two limiting factors exist in a cultivation system (Bae and Rittmann, 1996;McClure and Sleep, 1996). Several simulation models for the growth of iron oxidizing bacteria have been constructed so far (Chang and Myerson, 1982;McClure and Sleep, 1996;Nagpal et al, 1994). The simulation model used in our report, however, included a factor for regeneration of Fe(II) by electrochemical reduction of Fe(III), which was the most likely growth-limiting factor in conventional cultivation of iron oxidizing bacteria.…”

A structured model for Thiobacillus ferrooxidans growth on ferrous iron

“…2. Data collected during a study of biooxidation of a pyrite/arsenopyrite ore concentrate (Nagpal, 1993;Nagpal et al, 1993Nagpal et al, , 1994) (referred to forthwith as the Dickenson data) from the Dickenson mine in Canada in continuous stirred tank reactors (CSTRs) with feed solids concentrations of 6, 12, and 18% w/v). Various steady-state operating conditions were characterized at ph 1.2-1.8, D-0.03-0.009, and T-35°C, with total iron of ∼5-25 g/L and total arsenic of ∼3-12 g/L.…”

Kinetic model of elemental sulfur oxidation by Thiobacillus thiooxidans in batch slurry reactors

“…A number of studies have been published on the kinetics of metal sul®de bioleaching in well-mixed batch reactors [1,9,10,19] and continuous-¯ow reactors [3,5,14,16]. Other studies have also been published more recently on the bio-oxidation of elemental sulfur particles in batch cultures [11,12].…”