Kinetics of the Cupric Catalyzed Oxidation of Fe^IIby Oxygen at High Temperature and High Pressure

Causes of inhibition of bioleaching by Cu are also thermodynamic

“…With no Cu 2+ present, not even 5% conversion was achieved (results not shown). Kinetic models found in the literature suggest an order of reaction between 1.84 and 2.7 for Fe 2+ — the most frequent value being 2 — and between 0 and 0.5 for Cu 2+ . In this regard, the results shown in Fig.…”

“…Owing to this mechanism, bioleaching applications happen in atmospheric conditions, and no reagents are consumed in the process. These facts, derived mainly from the microbial activity in Fe 2+ bio‐oxidation, place bioleaching at an advantage when compared with high pressure leaching technologies, which require far greater pressures and temperatures in order to regenerate the leaching agent …”

“…The consulted literature only mentions the negative effect of Cu 2+ on microbial activity and overlooks the simultaneous — and synergic — effect Cu 2+ has as a chemical catalyst on Fe 2+ oxidation …”

“…These facts, derived mainly from the microbial activity in Fe 2+ bio-oxidation, place bioleaching at an advantage when compared with high pressure leaching technologies, which require far greater pressures and temperatures in order to regenerate the leaching agent. 14 Among biohydrometallurgical technologies based on bioleaching, the most widely used for producing Cu are those known as heap bioleaching and dump bioleaching. 2,3,5,6 Conceptually, these technologies consist in wetting -with a leaching solution -mineral particles piled into heaps or dumps that act as a packed bed, the process of metal extraction being catalysed by cells adhered to the mineral surface.…”

“…The consulted literature only mentions the negative effect of Cu 2+ on microbial activity and overlooks the simultaneousand synergic -effect Cu 2+ has as a chemical catalyst on Fe 2+ oxidation. 14 Thus, the available information about the influence of Cu 2+ on bioleaching, which is necessary for the design of plants for the treatment of Cu ores, is very limited. This paper shows the results obtained from studying the effect of Cu 2+ on Fe 2+ bio-oxidation, with the novelty of experiments wileyonlinelibrary.com/jctb being conducted in continuous operation of a packed bed bioreactor with immobilised cells.…”