The adsorption of precious metals and base metals on a quaternary ammoniumgroup ion exchange resin

Adsorption tests were conducted with a quaternary ammonium group ion exchan ge resin to determine the equilibrium adsorption of precious- and base meta ls. The resin used is a macroreticular polystyrene type 1 strong base anion exchange resin. The adsorption was determined for synthetic single metal s olutions as well as for multi-component solutions. The effect of the Cl- co ncentration on the equilibrium adsorption was determined for three differen t HCl concentrations, i.e. 6, 8 and 10%. The effect of chloride strength in the solution was also determined for mixed and base metal solutions. Pure metals, i.e. platinum, palladium and gold, were dissolved in aqua-regia and diluted to 2000 ppm (as metal) in 4M HCI. Ruthenium, rhodium and iridium w ere dissolved fr om pure salts in HCl. A 2000 ppm base-metal solution was p repared by dissolving all the required components, including precious metal s, to match an in-plant industrial base-metals solution composition. For ea ch precious metal the equilibrium adsorption was determined for typically t wo solution concentrations. Data points were established by varying the amo unt of resin added to the solution. The equilibrium concentrations were det ermined by TCP analysis after 24 hours exposure using the bottle-roll techn ique. (C) 2000 Published by Elsevier Science Ltd All rights reserved.