Resumo

ARROYAVE G., DIANA; MARQUEZ G, MARCO; GALLEGO S., DARIO  e  PACHECO, GAMALIEL. EVALUATION AND MINERALOGICAL CHARACTERIZATION OF BIOOXIDATION PROCESS IN A CONTINUOS STIRRED TANK REACTOR. Dyna rev.fac.nac.minas [online]. 2010, vol.77, n.164, pp. 18-28. ISSN 0012-7353.

The bioxidation of refractory gold mineral of the “El Zancudo” mine (Titiribi-Antioquia) was carried out in a continuous stirred tank reactor using an acidofile microorganisms compatible with Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans. The reactor was operated initially in batch to achieve the ferric iron maximum concentration in solution, before beginning the continuos process. The mineralogical characterization was performed to samples gathered in batch, transitory and steady state in continuous using Scanning Electron Microscopy (SEM) and X-Ray Diffraction (DRX). The mineralogical characterization showed an advanced oxidation of the pyrite and arsenopyrite in batch and partial in continuous operation. Additionally, it was found the formation of silicates, jarosite and brushita. The results indicate that the system reached the steady-state after 8 days of operation in continuous, achieving a ferric iron concentration in solution of 8.3 g/l corresponding to a gold and silver extraction percentage of 78 and 80%, respectively.

Palavras-chave : Biooxidation; Acidithiobacillus; reactor; Cyaniding; SEM; DRX.