In a process for the reduction of a metalliferous ore or concentrate the ore or concentrate is first prepared into a particulate form. A reaction chamber (3, 103, 203, 301, 401, 503, 603, 702) is then charged with ore or concentrate, a reductant and an input gas. The reaction chamber (3, 103, 203, 301, 401, 503, 603, 702) is irradiated with electromagnetic radiation within a frequency range of 30 MHz to 300 GHz until a non-equilibrium plasma is initiated. The plasma is sustained and controlled with the radiation until the ore or concentrate is reduced to form reduction product.