Tellurium Extraction from the Unique Independent Tellurium Ores in China by Bioleaching

Abstract

This study was designed to investigate tellurium bioleaching from the unique independent low-grade tellurium ores containing tetradymite, joseite, pyrite, chalcopyrite, silica, and a minor amount of dolomite, which is the first discovered scattered element deposit in the world. For the bioleaching, the tellurium extractions from the low-grade ores by with and without the adapted bacteria of acidophilic Thiobacillus ferrooxidans were examined. The effects of pH, pulp density, and temperature for bioleaching were studied systematically. After 20 days of bioleaching at 30°C, an 80 % of the tellurium was extracted in laboratory study. Leaching kinetics indicated that diffusion through the product layer was the rate controlling process during tellurium bioleaching, and the relative activation energies during tellurium bioleaching stage was calculated to be 34.75 kJ/mol.