Oxidation of finely ground ore minerals by means of upward currents of air, blown through a reaction vessel with sufficient force to cause the bed of material to become fluid. Reaction between mineral and air is maintained at a desired exothermic level by control of oxygen entry, by admission of cooling water, or by added fuel. Fluidized beds are used in the mineral industry for a number of concentrates, including copper, lead, zinc, and carbonaceous gold ores.