Bioleaching of ores from Neuquén-Argentina using a percolation column

CHIACCHIARINI P.; LAVALLE L.; DONATI E.

OURO PRETO (BRASIL)

Congreso; VII Meeting of the Southern Hemisphere on Mineral Technology; 2007

The aim of this work was to evaluate the efficiency of the bioleaching of two zinc low grade minerals from Cerro Yeguas Vetas ore and Sofía mine, in the province of Neuquén, Argentina. Pure and mixed cultures of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans were used. Bioleaching experiments were carried out at 30°C in glass columns with the percolation of the medium through the minerals. The 9K medium without iron at initial pH 1.8 was used. The ore sample had a particle size between 10 and 16 mesh. Solubilized zinc was determined by atomic absorption spectrophotometry while bacterial populations in solution were evaluated using a Petroff-Hausser camera in a microscope with a contrast phase attachment. Metal recovery was significantly enhanced by inoculation. The highest extraction for both minerals was reached in the systems where mixed cultures were used.