A plasma arc reactor and process for producing a powder from a solid feed material, for example aluminium, is provided. The reactor comprises: (a) a first electrode (5), (b) a second electrode (10) which is adapted to be spaced apart from the first electrode by a distance sufficient to achieve a plasma arc therebetween, (c) means for introducing a plasma gas into the space between the first and second electrodes, (d) means for generating a plasma arc in the space between the first and second electrodes, wherein the first electrode has a channel (7) running therethrough, an outlet of the channel exiting into the space between the first and second electrodes, and wherein means are provided for feeding solid material (20) through the channel to exit therefrom via the outlet into the space between the first and second electrodes.