Influencia del tiempo de residencia sobre la solubilización de un mineral aurífero refractario del distrito minero Portovelo en un sistema continúo de biooxidación en reactores de tanque agitado a escala laboratorio

Abstract

Abstract: The biooxidation of sulfide minerals using native microorganisms aims to take advantage of Ecuador's natural resources in a sustainable way. Therefore, the objective of this study was to determine the optimal parameters in the biooxidation process that allow obtaining the best solubilization of the mineral. The batch system tests were carried out by varying the height of the rotor; once optimized, the continuous system tests began by modifying the residence time. In both systems, the following were kept constant: stirring speed (400rpm), air flow (3vvm), temperature (30°C), pH (1.8), particle size (-200 mesh) and pulp density (15% w/ v). In both cases, the concentration of Fe2+, total Fe, sulfates, plant protein, total protein and microbial count were determined. The results showed that in the batch system at 3.5cm rotor height, a Qp Fe3+ of 1.49 g/Lday, Qp SO42- of 1.88 g/Lday and a gold recovery of 60% were obtained. While for the continuous system (tr=6 days) a Qp Fe3+ of 6.64 g/Lday, Qp SO42- of 6.89 g/Lday and a gold recovery of 17% were obtained.