Platinum melting: technical challenges
Working at high temperatures (1768°C) and specific equipment needed.
At a glanceMelting platinum in a jewelry workshop is a challenging metallurgical operation. Melting at 1,768 °C, platinum tolerates zero contamination. Contact with carbon ruins the metal permanently. This guide outlines necessary precautions.
The Lethal Carbon Hazard
Molten platinum must NEVER contact carbon, graphite, or carburizing flames!
At high temperatures, platinum dissolves carbon to form brittle platinum carbide ($PtC$), shattering ingots like glass upon rolling.
Requirements:
- No graphite crucibles: Use fused silica (quartz) or stabilized zirconia ($ZrO_2$).
- No standard torches: Use oxy-hydrogen ($H_2$ + $O_2$) torches or induction furnaces.
- No borax: Borax burns into molten platinum, creating insoluble glass slag inclusions.
Workshop Setup for Platinum Melting
| Equipment | Specification | Metallurgical Reason |
|---|---|---|
| Heat Source | Oxy-Hydrogen Torch | Carbon-free flame reaching 2,800 °C |
| Crucible | Fused Silica / Zirconia | Heat-resistant past 2,000 °C |
| Ingot Mold | Polished steel or water-cooled copper | Prevents thermal fusion during pour |
| Eye Protection | Dark Shade DIN 6 to 8 | Molten platinum emits blinding white radiance |
Frequently Asked Questions (FAQ): Platinum Melting
Why doesn't platinum need flux like gold?
Pure platinum and Pt/Ru alloys do not oxidize in open air at high temperatures, eliminating the need to dissolve surface oxides.
How fast does cast platinum solidify?
Within 2 seconds, due to the massive temperature gradient with the ambient room.
Buy Investment Gold in Switzerland (VAT-Exempt)
Buy and store physical gold in secure Zurich or Geneva vaults at direct live LBMA spot rates.
Melt loss calculator
Melt Loss (Merma)
Typical losses: Gold 0.5–1.5% · Silver 1–3% · Platinum 0.8–2%