Abstract:Address to the low dissolution efficiency and long refining cycle in the treatment of complex Pt-Ir Rh alloy, the process route and technical conditions for activating dissolution of complex platinum-iridium-rhodium alloys, TBP extraction and separation, cation exchange, and reduction preparation of rhodium powder were explored. The experimental results demonstrate that applying aluminum powder as activator, mass ratio of alloy to activator is 1︰9, reaction temperature is 1 300 ℃, reaction time is 3 h, the dissolution rate of platinum, iridium and rhodium in the activated alloy is more than 99%. By using TBP as extractant, the total concentration of platinum-iridium in the pre-extraction solution is controlled to be 15—20 g/L, and the potential is more than 1 100 mV, the efficient separation of platinum-iridium and rhodium can be achieved. The reduction method involving formic acid combined with polyvinylpyrrolidone enables the rapid preparation of rhodium powder with an average particle size of 1—3 μm and face-centered cubic crystal structure, which is same as the properties of rhodium powder extracted from primary mineral resources.