...strial residues (tailings, sludges, slags and ashes) that contain sig¬nificant concentrations of both critical and economically important metals. The Euro¬pean Training Network for the Sustainable, zero-waste valorisation of critical-metal-containing industrial process residues (SOCRATES) targets ground-breaking metallurgical processes, incl. plasma-, bio-, solvo-, electro- and ionometallurgy, tha ...