Abstract: The invention relates to processing apparatus and methods and in particular, but not exclusively, to an apparatus that may be used to process a wide variety of feed materials by one or more of milling or grinding, mixing, blending, separation, drying and sterilisation. In a preferred embodiment there is provided a feed material processing apparatus (1) comprising: a chamber (2); at least one inlet (4) in flow communication to an upper region of the chamber (2); a rotor (3) located within the chamber (2) that is rotatable about a substantially vertical axis by a rotation drive (11), wherein the rotor (3) promotes a circulatory flow of feed material and/or gas within the chamber (2); at least one outlet (5) in flow communication from a lower region of the chamber (2). Preferably the apparatus (1) comprises at least one feature located laterally on the rotor (3) to promote the circulatory flow.