At less than 650 degrees C, the oxidation of lead sulfide (PbS) with oxygen to produce lead sulfate (PbSO(4)) was found to have a very low activation energy of 10 kJ/mole, a reaction order with respect to oxygen of similar to 0.5, and one with respect to sulfur dioxide of 0, though the presence of sulfur dioxide was necessary to sustain the reaction. These kinetic parameters suggest that the rate-limiting step was initially oxygen adsorption, very quickly supplanted by slow intraparticle diffusion of sulfur and lead ions. (C) 2011 Elsevier Ltd. All rights reserved.