"The process is quite versatile, and the several feed materials tested produced high recovery efficiencies for gold
(95%), palladium (94%), copper (99%) and nickel
(94%). Platinum is generally the most refractory of the pay metals, but even Pt can usually be recovered at 80 to
95% efficiency under optimum conditions. "
http://www.met.sgs.com/min_sgs_426_australia_pgm_ore_processing_a4.pdf