Efficiently Drying Gold Powder

[Bertho]

I have been following instructions on how to dry precipitated gold powder and it takes along time since humidity re-condenses on the sides of the beaker.

A simple solution: I wrapped the beaker sides with a folded paper towel held in place with two rubber bands to keep the beaker sides hot and avoid the condensation problem. See the picture.
Bertho

 

[anachronism]

As your gold dries on the hotplate, the only condensation coming is from the gold itself rising upwards. If you let it carry on with the heat on it then the condensation on the beaker walls deals with itself. I use that as an indicator that the gold is completely dry. Ive not had the need to wrap things around the beaker- and I think you just need to leave it longer assuming your hotplate is warm enough.

Hope that helps

Jon

 

[g_axelsson]

Nice tip for speeding up drying the gold in a beaker. The same trick would work if you are evaporating AR to get the nitric out.
You could also use a piece of aluminum foil covering the beaker and the edge of the hotplate (common trick among chemists doing distillation). That way the heat from the hotplate would travel up between the beaker and the foil, heating the sides too.

I have a set of evaporation dishes, basically a beaker twice as wide as high. I use them all the time for various things, especially when I want to evaporate something off like removing nitric acid.
You can see them in this thread. http://goldrefiningforum.com/phpBB3/viewtopic.php?f=37&t=26647

For drying my (well washed) gold I usually just put a beaker in an oven set at 110 C, it will heat the whole beaker as well as the gold. Wouldn't recommend it if you have acid residues left, in that case a beaker on a hotplate in a fume hood is the way to go.

Göran

 

[Lou]

We use a heat lamp

 

[g_axelsson]

I think it was Chris (GSP) that recommended an incandescent light bulb over a vacuum filter.

Göran

 

[anachronism]

Like the ones you use for piggies. Awwwww cuteness.

 

[IdahoMole]

As your gold dries on the hotplate, the only condensation coming is from the gold itself rising upwards. If you let it carry on with the heat on it then the condensation on the beaker walls deals with itself. I use that as an indicator that the gold is completely dry.

Jon

When the beaker walls do become dry as Jon describes, I will take a watch glass and put it on the beaker as a double check. If there is any moisture left in the gold it will condense the watch glass pretty quickly.