Ore flotation residue has been tested for the recovery of titanium in two different systems (agitated vessel and percolated fixed-bed column). For each of these systems, titanium extraction did not exceed 1 % of the metal available. Biomass removed from ore residue adsorbed a small part of the titanium with sorption capacities below 20-30 mg g-1, but the best part of this biomass was sequestered on the ore residue. Oxygen and carbon dioxide concentrations were monitored, and changes in concentration correlated with bacteria and fungal development.