METHOD OF PYROMETALLURGICAL REFINING OF PLATINUM ALLOYS Russian patent published in 1998 - IPC

FIELD: metal refining. SUBSTANCE: invention may find use in refining of platinum alloys by vacuum electron-beam zone melting in crystallizer employing at least two electron beams. First, one of the beams is exposed on metal surface and maintained motionless until metal melts in its focal spot zone, after which the beam is displaced along extended water-cooled crystallizer and stops. Then, the second beam is switched on, directed onto initial position of the first beam and the two beams are simultaneously displaced in consecutive mode along crystallizer. Distance between the beams and velocity of their simultaneous motion are chosen from condition to provide temperature of metal between the two focal spots to range from platinum alloy liquidus and solidus points. When solid- liquid phase state is created and maintained in the inter-beam zone, precious component is recovered more completely via evaporation from melt, and impurities are isolated via recrystallization of alloy. EFFECT: increased degree of platinum recovery at low loss of basis material. 7 cl, 3 tbl