Alloy yield

Alloy yield (recovery rate) is the ratio of metal recovered after smelting to the theoretical expected mass. A yield of 98% means that from 100 g of theoretical mass, only 98 g of fine metal is recovered. The remaining 2% is lost to oxides, splatter, and crucible waste.

Typical yields by metal: Fine gold (999‰) reaches 98% to 99.8% with a modern induction furnace. Jewellery gold alloys (750‰) show more losses (96% to 98%). Silver is more volatile and may show yields of 95% to 98%. Platinum, conversely, is nearly inert and easily reaches 99.5%.

To improve yield: use clean, non-porous crucibles, smelt under a reducing atmosphere, process slags and sludges (they often contain 20% to 50% precious metal), and regularly calibrate your loss rate with tested batches.