Methods for the separation and/or purification of metals

A method of separating at least two metals from each other in a metal refining process by injecting a feed solution 66 comprising the metals into a column or flow pipe 60 comprising a monolithic body 62 having a plurality of channels 64, and flowing the feed solution 66 through the channels 64 to separate the metals. The channels 64 have a diameter 1 mm or more and can be linear or formed from a network of pores. The monolithic body 62 can be made by additive layer manufacture or moulding using a polymer. Extracted metals can be platinum group metals or battery metals. Extraction can be by adsorption of at least one metal onto functionalised surfaces of the monolithic body, followed by elution of the metal with eluent concentration being reduced during elution. Alternatively, liquid-liquid extraction can be performed in the channels 64 where slug flow occurs between droplets of the two liquids 66 & 68. This is followed by settling in a vertical phase separator. Methods of fabricating a functionalised monolithic solid body comprising a plurality of channels for use in the metal separation method are also defined.