| CPC C22B 9/10 (2013.01) [C21C 5/36 (2013.01); C21C 5/44 (2013.01); C21C 5/4606 (2013.01); C21C 5/466 (2013.01); C22B 1/005 (2013.01); C22B 7/009 (2013.01); C22B 7/04 (2013.01); C22B 9/05 (2013.01); C22B 9/106 (2013.01); C22B 9/16 (2013.01); C22B 11/026 (2013.01); C22B 11/048 (2013.01); C22C 1/02 (2013.01)] | 54 Claims |

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1. A process for converting platinum group metal (PGM) collector alloy, comprising the steps of:
(a) introducing a converter feed into a pot of a converter holding a molten alloy pool, wherein the converter feed comprises:
(i) 100 parts by weight of a collector alloy comprising no less than 0.5 wt % PGM, no less than 40 wt % iron, and no less than 0.5 wt % nickel, based on the total weight of the collector alloy; and
(ii) if an added flux material comprises 10 wt % or more of silica and 10 wt % or more of calcium oxide, magnesium oxide, or a combination of calcium oxide and magnesium oxide, by weight of the added flux material, less than 20 parts by weight of the added flux material per 100 parts by weight of the collector alloy;
(b) injecting oxygen-containing gas into the alloy pool to convert iron and one or more other oxidizable elements from the collector alloy to corresponding oxides and enrich PGM in the alloy pool;
(c) allowing a slag comprising the iron oxide to collect in a low-density layer above the alloy pool;
(d) tapping the low-density layer to recover the slag from the converter; and
(e) tapping the alloy pool to recover the PGM-enriched alloy; and
wherein the oxygen-containing gas injection in step (b) is continued until the alloy pool comprises no more than about 10 wt % iron.
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