The invention relates to a method for increasing the concentration of platinum group metals in urban waste material. The method comprises obtaining particles of urban waste material; screening the particles of urban waste material by size,—selecting particles of urban waste material that lie within a defined size range; and processing the selected particles using at least one physical or chemical technique whereby to increase the concentration of platinum group metals to at least 5 ppm. The invention also relates to an apparatus for increasing the concentration of platinum group metals in particulate urban waste material. The apparatus comprises: a drying unit (4), a particle size screening unit (5); and one or more processing units for effecting platinum group metal concentration of the particulate urban waste material by physical and/or chemical techniques, in particular a magnetic separation unit (7) and a froth flotation cell (9).