How to Melt Scrap Gold in a Crucible

Gold is a soft, easily worked metal that can be fashioned to any shape, but while you can reuse large pieces of gold by hammering them into the shape of your choice, you can recover smaller scrap pieces for use by casting the scrap pieces into ingots. To cast gold ingots requires that you heat the gold past its melting point before you pour it into molds. The process, using an acetylene torch, efficiently produces usable ingots without any loss of material, allowing you to put your scrap gold to new uses.

Things You'll Need

• Scrap gold
• Jewel's crucible
• Acetylene torch
• Leather welding gloves
• Crucible tongs
• Ingot mold

Instructions

1. Place the piece of scrap gold into the graphite jeweler's crucible and then place the crucible onto a heat-resistant surface. Gold melts at 1947 degrees Fahrenheit so make sure the heat resistant surface is located in a fireproof location. The crucible, ingot mold, and crucible tongs can be purchased online at a small tools supply store or from a machine and tool supply shop.

2. Connect the head of the acetylene torch to the hoses leading to the oxygen and acetylene tanks. Make sure the gas and air valves are shut off completely before making the connections. Put on the welding gloves and turn on the acetylene valve until the gas begins to flow, light the gas with your striker. The gas should make an orange-red flame. Turn the oxygen valve slowly adding oxygen to the mix until the flame turns blue and sits steady just on the tip of the torch.

3. Aim the flame at the gold resting in the jeweler's crucible and then trigger the torch. The flame should shorten slightly with the torch making a louder hissing noise as the flow of gas grows greater.

4. Move the flame over the gold until it reaches a completely liquid state.

5. Turn off the torch by shutting off the oxygen and then the acetylene. Lift the crucible with a pair of crucible tongs. Carefully pour the melted gold into a graphite ingot mold placed onto the heat-resistant surface. Place the crucible back on the surface.

6. Allow the gold to cool into a solid. The cooled gold can be removed from the mold and weighed on a scale capable of weighing in grams.

Tips & Warnings

• Wear UV protective safety goggles when using the acetylene torch to protect against the damaging glare.

• Wear protective clothing such as long pants and a long sleeved shirt.

References

• Nevada Outback Gems: Melting your Gold and Jewelry Scrap

Resources

• SPI Supplies