A material processing apparatus comprising a plurality of interconnectable modules, each module comprising a frame and at least one material processing device, for example a hydraulic classifier, and at least one ancillary component, for example a hydrocyclone, carried by and located within the frame. The frame is shaped and dimensioned to define a peripheral boundary of the module, the material processing device(s) and ancillary component(s) being located within the peripheral boundary. When the apparatus is being stored or transported it can be disassembled into a plurality of modules that have components contained within the boundary defined by the frame, i.e. not projecting outside of the frame boundary. This facilitates storage and transport in shipping containers.