The sulfite leaching of an Italian Mn ore has been carried out to determine the feasibility of extracting Mn by percolation leaching. Aqueous SO sub 2 has been found to be an effective leachant for Mn dissolution owing to fast dissolution kinetics and low temperatures. Bench-scale experimental results have established the best conditions for the leaching operation in terms of SO sub 2 concentration, pH, solution flow rate, ore particle size and time. 11 ref.--AA