Converting process with partial pre-oxidation of PGM collector alloy

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

• (I) partially pre-oxidizing a raw collector alloy comprising no less than 0.5 wt % PGM, no less than 40 wt % iron, no less than 0.5 wt % nickel, no more than 3 wt % sulfur, and no more than 3 wt % copper, based on the total weight of the collector alloy;
• (II) introducing an initial charge into a pot of a converter, wherein the initial charge comprises:
• (i) at least 20 parts by weight of the partially pre-oxidized collector alloy product of step (I);
• and
• (ii) up to 80 parts by weight of the raw collector alloy, wherein the sum of the parts by weight of the raw collector alloy and the partially pre-oxidized collector alloy product of step (I) equals 100;
• (III) melting the initial charge to form an alloy pool in the pot;
• (IV) introducing a converter feed into the alloy pool, wherein the converter feed comprises the raw collector alloy, the partially pre-oxidized collector alloy product of step (i), or a combination thereof;
• (V) 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;
• (VI) allowing a slag comprising the iron oxide to collect in a low-density layer above the alloy pool;
• (VII) tapping the low-density layer to recover the slag from the converter;
• and
• (VIII) tapping the alloy pool to recover the PGM-enriched alloy.