Ir recycling step 5

This is a note of contention as to whether or not this step is necessary. Professor Heller suggested that the black Ir/ash was good enough to carry on, while I thought this step would yield better results. As such, I'll do some of the batch both ways and see if the result is the same.

I've used a glassblowing torch in order mix some O2 in with the natural gas. This increases the temperature of the flame considerably, enough so that the bottom of the crucible glows like a light bulb. After a fews tens of minutes of heating, the black Ir/ash has melted into a glowing red lava-like goo. There were two separate layers evident, what I can only guess is metalic iridium made up the glowing red material in the bottom of the crucible, covered by a clearish liquid layer which I'm guessing is molten salts. This step gave off some pretty intense radiant heat, making me wonder if the fire extinguishers in the top of the hood would be triggered, happily this did not occur.


Several attempts were made to get this process to work correctly. I was successful once, shown in the picture, but subsequent attempts led to the crucibles breaking due to thermal shock and uneven heating. I tried to remedy this by using a Meker burner on full blast for hours, but the temperatures achieved was not enough to convert the ash to salts and the (presumably) iridium oxides to metallic iridium. I tried to spread the flame of the glass blowing torch out by loosely affixing the Meker burner grating to the top of the torch, but the O2 content was too high in the cavity in between, leading to a lot of backfiring and me almost crapping my pants. Clearly, a safe, more controlled heating method is needed, either by furnace or adapting the current setup to prevent thermal shock to the crucible and promote even heating. More on this soon....