Induction Oven for Melting Gold

I found two manufacturers but they are asking a ridiculus high price.

Commercial and Industrial grade induction furnaces are generally expensive. There is not really a market for small induction furnaces but there may be some manufacturers out there.

I am looking to buy a small induction oven to melt gold and silver.

That's rather relative (I am guessing this is for handicrafts). How much metal, how often do you need to melt the metal and what's your budget. What's the application?

In a pinch you CAN build your own, BUT some of the designs available on the internet are rather dangerous (like the microwave designs). Google "diy induction furnace" for more info.

How about the old fashioned way (smelting)

http://en.wikipedia.org/wiki/Gold_extraction#Gold_smelting

have you tried asking this manufacturer?

Try craigs list for ceramic kilns. there usualy a few used ones that can be had for cheap. I know ebay has some but because of the weight of the kiln shipping costs are prohibitive. You will need one that can achieve the melting point of gold.

oilcan13

My suggestion as follows. Take a graphite crucible (6 to 10 cm long & 2 to 3 cm wide) and using low voltage (one or two secondary turns) and high current step-down transformer (up to 100Amps) the crucible can be heated. Use variac (auto transformer) to control heat on primary side. You can melt up 30 grams. Such systems are used in Semiconductor wafer fabrication CVD (Chemical Vapour Deposition) equipment. This is the cheapest possible solution. www.hindhivac.com

Hi,

I have done a similar approach:

An Advanced Energy 400KHz 1KW generator, a copper coil of 11 turns made from 6mm tube, a pile of high voltage capacitors rated 1200V.

This was around a glass tube 20cm diameter. (Inside to be evacuated.)

Inside different tests for the 1 turn short-circuited secondary: Graphite, SS, Nickel.

Tuning the capacitors and the resistive matching of the generator to get to resonance was no problem. Orange hot crucibles inside showed good but nonuniform response.

Rising resistivity of material limited possible power and temperature.

Then at one promising experiment the current in the coil was above 100A and the soft solder to the capacitor bank became liquid and detached.

This caused a fast inductive shut down which caused a high voltage peak and the directional coupler failed - but not completely, only giving wrong indications of forward and reflected power.

This took me 4 weeks to detect and 4 more weeks to finally blow up most of the generator. Only the very big output stage is intact. (Anybody interested?)

After this experience I switched to resistive heaters.

RHABE

Don't remember all the details but used something very similar (glass tube, copper coil) to weld magnesium.

Thank you,

I also think now to switch to resistive heaters.

Thank you,

H. L.