Methods for the separation and/or purification of metals

A method for separating at least two metals from each other in a metal refining process, the method comprising:

• injecting a feed solution comprising the metals into a column or flow pipe comprising a monolithic solid body having a plurality of channels, wherein the monolithic solid body is a single, continuous, bonded, solid body comprising the plurality of channels through which the feed solution can flow;
• and
• flowing the feed solution through the plurality of channels in the monolithic solid body to separate the metals,
• wherein, the feed solution is mixed with an immiscible extractant liquid and the mixture of feed solution and immiscible extractant liquid is flowed through the plurality of channels in the monolithic solid body to separate the metals with at least one metal species extracting into the immiscible extractant liquid,
• wherein the feed solution is mixed with the immiscible extractant liquid using a distribution plate comprising a plurality of through-holes or nozzles through which the feed solution and/or extractant liquid are injected into a mixing chamber prior to the mixture of feed solution and immiscible extractant liquid flowing through the plurality of channels in the monolithic solid body,
• wherein each through-hole or nozzle in the distribution plate has a diameter of at least 1 mm and/or droplets produced by said through-holes or nozzles each have a diameter of at least 1 mm,
• wherein each of the channels in the monolithic solid body has a diameter of at least 1 mm,
• wherein the distribution plate and solid monolithic body are separate by a distance of at least 2 cm, and
• wherein a width of the monolithic body perpendicular to a flow direction is at least 0.5 m and a length of the monolithic body parallel to a flow direction is at least 0.5 m,
• wherein the metals include at least one platinum group metal, and
• wherein the monolithic solid body comprises one or more of:
• a methacrylate;
• a thioether functionalised methacrylate;
• a glycol;
• a hydrophilic acrylate;
• a polystyrene divinyl benzene;
• a cross linked co-polymer of glycol methacrylate and ethylene glycol dimethacrylate;
• a co-polymer of oligo ethylene glycol, glycidyl methacrylate and ethylene glycol di-methacrylate;
• a polystyrene divinyl benzene polymer with hydrophilic oligo glycols groups covalently attached thereto;
• a polyether ether ketone.