| abstract |
A method for the removal, separation, and concentration of Rh, Ir, and/or Ru from a source solution which may contain larger concentrations of other ions including H + comprises bringing the source solution into contact with a compound comprising a polyalkylene-polyamine-containing ligand covalently bonded through an organic spacer silicon grouping to a solid inorganic support. The ligand portion(s) of the compound has affinity for complexed anionic species of Rh, Ir, and/or Ru thereby removing them from the source solution. The Rh and/or Ru are first selectively removed from the compound through contact with a much smaller volume of a first receiving solution which changes the Rh and/or Ru speciation to have no affinity for the ligand portion of the compound. The Ir is then removed from the compound through contact with a much smaller volume of a second receiving solution having a greater affinity for the Ir than the ligand portion of the compound or having a greater affinity for the ligand portion of the compound than the Ir species. The concentrated ions thus removed may be further separated and recovered by known methods. The process is useful in the recovery and refining of the valuable Rh and Ir from a variety of sources. The invention is also drawn to the particular highly stable branched polyalkylene-polyamine-containing ligands covalently bonded through a spacer grouping to a hydrophilic inorganic solid support material. |