Non-Chemical How can I make goldgranules from a gold-melt?

[Hungry Wolf]

Hello!
I am new to the forum....

How can I make goldgranules from a gold-melt?
What is the technic?

//Do I need only a sieve to put in the hot gold-melt and water (or is it a special NaCL-water etc.) to get nice goldgranules?//

Sincerely
Achim

 

[4metals]

Do you mean gold shot, the small round spheres of gold usually sold to jewelers for alloying purposes?

The gold beads are formed by pouring the molten flux free gold through a "shot box" into water.

The shot box is made from either a graphite mold with holes drilled on the bottom to act as a sieve. I prefer to use a #1 clay graphite un-glazed crucible with holes drilled on the bottom to act as a sieve. Either way the holes should be 1/8" diameter and fill the bottom of either the crucible or the mold.

The shot box has to be as hot as the melt so the gold doesn't cool off when it hits the shot box, I do this by placing the shot box in the crucible with the molten gold until it glows red. Since graphite starts to erode after heating the crucible shot box lasts longer.

You have to build a fixture to hold your shot box over the water tank. The hot shot box should be very close to the surface of the water so the water contacts the shot as it leaves the 1/8" holes. Not touching the water 1/4" to 1/2" above should do fine. This fixture has to be sturdy because you have to put in the shot box quickly while it is hot and you don't have time to be gentile.

Now you have to melt the gold, place the shot box in the melter to heat it up, quickly place the hot shot box into the fixture over the water tank which is full of cool water, and pour the molten gold through the shot box.

The tank, which should be metal so it doesn't melt (I prefer stainless) will have nice round shot on the bottom.

I have used this technique to shot as many as 600 ounces of fine gold into a 55 gallon water tank.

Some guys like to direct the flame of a torch on the molten metal in the shot box until it all passes through. I've never found this necessary. If the gold "freezes" in the shot box it is because you weren't quick enough or you didn't drill enough holes for the gold to run out of.

This is a technique which you have to perfect, your results will improve the more you do it. You will always have some small amount of metal frozen in the shot box which can be removed by either torch or mechanically when it cools, just save it for the next melt.

 

[4metals]

A technique I've also seen used for smaller melts involves drilling small 1/8" holes, 6 to 10 of them, at the top of the pour spout of a clay graphite unglazed crucible. Unglazed is important as the glaze gets hot and gums things up. The lip of the crucible acts like a shot box.

Drill the holes in a triangle pattern 3 or 4 across the top just below the lip, a few less just under them and less under them. Obviously this crucible will not have to be preheated because you're melting the gold in it. You have to carefully tip the crucible over a water tank, getting as close as you can, being careful to pour slowly enough that the gold goes out the holes and not over the lip. Any gold going over the lip is much larger so it has to be screened out.

This method works well for a few ounces up to a kilo of gold.

 

[Hungry Wolf]

Hello 4metals!

Thank you very much, for your answer!

What is the best (+minimum) heigt in cm for a filled water-container to get nice gold shots from one ounce of gold (experimental)?

Sincerely
Achim

 

[4metals]

You should be able to get away with a 2 1/2 gallon (10 liter) bucket. At least 12 inches (30.5 cm) deep.

An issue I can envision is the small quantity you plan to experiment with. The weight of the gold pushing the gold in front of it through the holes helps the process. With one ounce there's not a lot of weight to push. With a small quantity I would go with less holes so there is some backup behind the hole to push out the gold. The diameter of the hole acts like an orifice and the hole extrudes the molten metal to the desired bead size.

 

[Gold]

Very good post 4metals. :arrow:

 

[Hungry Wolf]

Hello 4metals and forum!

I heated the melt only to 1150°C!
Very fast was the viscosity too high (gold) to go to the holes of a clay-graphite crucible!
What is the optimum temperature for a gold-melt to make nice -gold shots-?
Do I need Na2B4O7 * X H20 (Borax) for the metal-melt?

Sincerely
Achim Sven Faforke

 

[4metals]

Do not use any flux when pouring shot, the hotter you can get the gold the better as it will cool before you can get it poured, I assume you are using the drilled crucible technique, you are not quite 100 degrees C over the mp of gold so it is probably not hot enough when you pour. What hole size did you use?

 

[Harold_V]

Hello 4metals and forum!

I heated the melt only to 1150°C!
Very fast was the viscosity too high (gold) to go to the holes of a clay-graphite crucible!
What is the optimum temperature for a gold-melt to make nice -gold shots-?
Do I need Na2B4O7 * X H20 (Borax) for the metal-melt?

Sincerely
Achim Sven Faforke

Achim,
I made gold shot on a regular basis, but I melted small volumes at any one time, even if I had a lot of gold to melt. My very largest single melt was right at 400 troy ounces, but all of it was melted just a few ounces at one time. It happens very fast when you have the right torch, which I did.

I used a melting dish when I made my shot. I drilled a 1/8" hole (3mm is nearly the same size), and kept the melting dish hot by playing a small Hoke torch near the orifice. This dish was mounted on a tripod, directly over my stainless steel container filled with water. My gold was melted in a different dish, then transferred to the one with the orifice.

While I fully agree with the use of a crucible for making shot, I don't think it's a good idea for small volumes. The mass of a small crucible will quickly chill the molten gold, giving no end to the problems you are experiencing. If you were melting large volumes, I would see this differently.

Flux: DO NOT USE FLUX. Coat both of the dishes with a film of borax, and nothing else. Otherwise you'll have flux and gold mixed, which can be troublesome. Should you find traces, it can be removed by boiling the shot in dilute sulfuric acid, but it's best to avoid having it included.

If the borax in either dish gets discolored, or if your gold shot comes out with an oxide coating, your gold is not well refined. The gold should be bright and shiny.

While I've posted this picture time and again, I want you to see the results of the method I used. It works, and very well.

Harold

 

[LeftyTheBandit]

While I've posted this picture time and again, I want you to see the results of the method I used. It works, and very well.

Harold

Every time I see this picture, I feel like pouring some milk into it and grabbing a spoon... It is one of the nicest pictures of gold I have ever seen. It motivates me!

 

[Hungry Wolf]

Hello 4metals!

In the clay-graphite-crucible are the holes 1/8!
Is 1300°C the optimum for the gold-melt (or higher)?

Hello Harold_V!

Could you make a photo from your -very good working technic- (gold shots)?

Sincerely
Achim

 

[4metals]

Achim

I rarely melted small lots usually shotting hundreds of ounces at a time in one pour. I can tell you that you cannot get it too hot and since I poured larger lots it always cooled down while pouring so we start as high as possible. The holes are always 1/8 inch.

 

[Harold_V]

Could you make a photo from your -very good working technic- (gold shots)?

Achim,
I'm sorry to say, I no longer refine. I sold my operation 15 years ago, so I no longer have any of the equipment. Therefore, I am unable to show anything except for pictures I have in my possession.

Harold

 

[Harold_V]

While I've posted this picture time and again, I want you to see the results of the method I used. It works, and very well.

Harold

Every time I see this picture, I feel like pouring some milk into it and grabbing a spoon... It is one of the nicest pictures of gold I have ever seen. It motivates me!

It strikes a note with me, too. I've taken an almost identical picture, which didn't turn out nearly as well.

It could very well be that the only thing I know less about than computers is photography, so I can't even tell you how I did what I did. I just know that I've seen a huge number of pictures of gold-----and rarely do they do justice to the product. I truly feel mine does.

Now if I could just duplicate the damned thing! :lol:

Harold

 

[qst42know]

The tail end of this video shows a big load of shot being poured.

http://in.reuters.com/news/video?videoId=112738&videoChannel=104




Spelling edit

 

[4metals]

Great video of shot being poured! They set up much higher above the water than we do but they are pouring huge quantities. They are also melting with induction heat so they can get hot enough for the gold not to freeze on pouring.

The pan you see in the end is not the tank the gold is poured into. The tank is much larger and deeper and the tray you see in the end is a collection tray that sits on the bottom. The shot box is pre-heated in a second furnace so it is hot when the gold is poured.

Excellent to see this being done!

 

[Hungry Wolf]

Hello Forum and 4metals!

Nice video!

My experimental gold shot is now much better (higher temperature)!

I think the distance between the clay cruible and water is not the optimum, but the gold-shot-result is nice too (photo):

Sincerely
Achim Sven Faforke

 

[Hungry Wolf]

Hello Forum and 4metals!

My experimental gold-shot is now optimised; additional I use a ceramic plate (heated) under the cruible!
Look at the nice result (photo)......

I`m happy!!!

Sincerely
Achim Sven Faforke

 

[Oz]

Your second photo shows a far more spherical result. Nice work!

I would enjoy seeing a photo or 2 of your setup that this was made with along with some additional details.

 

[4metals]

The shape looks good, the color however isn't so hot. If your gold isn't nice yellow like Harold's bowl of shot in this thread you have other issues. Hopefully it was just the camera settings.