PGM Converting Process with Staged Slagging

A process for converting platinum group metal (PGM) collector alloy, comprising the steps of:

• (I) melting an initial charge of a collector alloy in a pot of a converter to form an alloy pool to start a converter cycle;
• (II) introducing a converter feed into the pot with the alloy pool;
• (III) injecting oxygen-containing gas into the alloy pool to convert iron to iron oxide and enrich PGM in the alloy pool, wherein the introduction of the converter feed and the injection of the oxygen containing gas are at least partially concurrent;
• (IV) allowing a slag comprising the iron oxide to collect in a low-density layer above the alloy pool;
• (V) terminating steps (II) and (III) and tapping the low-density layer to recover the slag from the converter;
• (VI) repeating a sequence of steps (II), (III), (IV), and (V) a plurality of times, including one or more non-final sequences and a final sequence, wherein step (V) in each sequence follows steps (III) and (IV);
• (VII) prior to the tapping of the low-density layer in step (V) of each non-final sequence, allowing alloy entrained in the low-density layer to substantially settle into the alloy pool following termination of the oxygen-containing gas injection;
• (VIII) promptly commencing the tapping of the low-density layer following termination of the oxygen-containing gas injection in step (V) in the final sequence wherein solidification of the alloy pool in the pot is avoided;
• and
• (IX) at an end of the converter cycle, tapping the alloy pool to recover the PGM-enriched alloy wherein solidification of the alloy pool in the pot is avoided.