Creating pure silver shot

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nd77

New member
Joined
Dec 8, 2011
Messages
3
I would like to take 100 ounce pure silver bars and turn them into pure silver grade pellets (silver shot). How can this be accomplished and is the process cost effective?
Thanks,
Nick
 
My terminology may not be correct but that is what I wish to do. I want to eliminate the shipping & refinery and do it ourselves. Similar to sending a 100 ounce bar to the refiner and having them send me 100 ounces of silver shot.
 
I don't understand why you would not simply buy the silver shot.

Assuming you would do the relatively simple work of locating the cheapest source; If you were to buy 100 oz bars, there will be an associated premium, at least $1 per ounce, (only $1 per ounce if you're lucky) If you now physically carry or ship (both of which cost $$) that bar to a refiner who is in the business of supplying bars and shot, the best you're likely to do is a straight across exchange, your bar for his shot. Now you can ship the shot back to you. More $$. Unless I miss my guess, buying the shot directly from said refiner avoids (1) the premium associated with the buy of the 100 oz bar and (2) freight to the refiner on the bar.

The only thing I can think of is that you think your refiner will take your exact (assayed and branded) silver bar and make silver shot out of it and thus you will have Englehard or Johnson-Matthey shot. While you may be secure in that knowledge, I doubt the refiner would actually do that, and you wouldn't be able to convince anyone else of that UNLESS you have some sort of factory-sealed bag of J-M shot that comes with its own assay, and if that's what you want or think you will end up with, why not just buy that item (if it's available) in the first place?
 
Dr. Poe to the rescue: Melt one half to two thirds your crucible's capacity in silver. Spray Pam on both sides of a iron, steel or stainless steel sieve. Indent the sieve to concave downward. Wear goggles or a face shield. Wear hot gloves, use crucible tongs. Bring the melt to easy flow (975C) Take the crucible out and sit it on a brick, grab it by the side and pour slowly through the sieve into a barrel filled half way with cold water.
To keep the crucible from sticking to bricks, thickly shake talcum powder on the supporting brick.
Do I need to go into more detail?
Dr. Poe
 
[youtube] http://www.youtube.com/watch?v=e-WJZpxAqvI [/youtube]

But why not just sell the bar and buy shot from anywhere. Skip alot of work.
 
I hate to disagree Doc but one should never pour molten metal into a metal sieve. You will contaminate the silver and end up with a mess. You want to pour into a heated shot box made of graphite or a crucible.

A series of holes in a #1 clay graphite crucible, unglazed, will work for shotting upwards of 500 ounces at a time.

These pictures were from gold shotting but the procedure is the same. The silver in the bottom photo was made this way.

gold shot tank and crucible holder.JPG

melting gold and preheating shot crucible.JPG

preheated crucible ready for shotting.JPG

pouring gold into shot crucible.JPG

silver shot.JPG

molten gold pouring out of shot crucible.JPG
 
Dr. Poe said:
Dr. Poe to the rescue: Melt one half to two thirds your crucible's capacity in silver. Spray Pam on both sides of a iron, steel or stainless steel sieve. Indent the sieve to concave downward. Wear goggles or a face shield. Wear hot gloves, use crucible tongs. Bring the melt to easy flow (975C) Take the crucible out and sit it on a brick, grab it by the side and pour slowly through the sieve into a barrel filled half way with cold water.
To keep the crucible from sticking to bricks, thickly shake talcum powder on the supporting brick.
Do I need to go into more detail?
Dr. Poe
Shudder!

Absolutely not a good idea!

I don't think I'd try that unless I had no regard for the losses and contamination that would result.

It's dead easy to pour shot. One pours molten gold/silver to a crucible or dish that has 1/8" holes drilled randomly. The resulting shot falls a short distance to cold water. Moving water is suggested, so a stream of vapors doesn't develop, permitting molten metal to hit the bottom.

It is NEVER a good idea to introduce molten metals of any description to other metals unless that is your mission. Molten metals are strong solvents of other metals, to say nothing of the grief that one experiences when the molten metal chooses to solder to the sieve being used.

Harold

edit:
I see I should have read further before responding. It has already been addressed.
 
Had it not been for the Pam (non-stick spray oil) you would be right. But you are not right and obviously have never tried it this way. No biggie, I like the shot crucible of yours better anyway, I just didn't know that it existed. Did you make it yourself from a crucible and a hand drill and drill bit? The pictures didn't show the bottom holes. Also the beads of yours were much smaller than mine. So yes, I think I'll switch to your way. As to the advise from the others to just buy the shot: Some times one needs to inquart electrum to separate silver from gold. So this newbie needs to know, to practice so to be ready.
Would you tell me the size of the drill bit where you made the holes? How many holes total in the bottom of the crucible?
See, even old veterans like myself can learn from this forum. Thanks
Dr. Poe 8)
 
I think Pam is great at the temperature you're frying eggs but at the melting point of non ferrous metals, I think it will be useless. If you don't totally fuse the openings in the sieve with the metal you're pouring you will melt away portions of the sieve and alloy same into your shotted metal.

I'm not saying I haven't tried shotting by bouncing off a sheet of metal submerged in the water of the tank but those results were less than desirable. I think most refiners have tried to shot off of metal and learned the hard way.

I like to use 1/8" holes drilled into the bottom of the crucible, there are probably 20 holes in a drilled crucible. Agitating the water beneath the shot helps unless the water is very cold. The setup in the photo's is at a shop that has an ice-maker so they add about 10 gallons of ice to the cold tap water when they are setting up and pour when its mostly melted. Just an aside to the mixing of the water and metal contacting the molten shot, I have seen stainless steel propellers that have contacted the metal being poured (totally submerged) come out with globs of metal fused to the blade.

On the day the pour I photographed was made they were pouring gold, the photo of the gold shot is below.

gold shot.JPG
 
My screen was about 14 inches above the cold water. It never stuck, never clogged, and always worked. The metals never made shot as fine as yours. The real education here is that a hot graphite crucible with holes in the bottom trumps a steel, oil coated sieve. Very old tech just poured a slow stream of metal into water, like in Hoke's book. My method trumped that and your method trumps mine. I've never seen such beautiful gold shot. I hope that you keep upgrading me in better methods at least in the physical side of refining.Dr. Poe :p
 
That is a very nice rig fourmetals. Is the flux pouring off ever an issue? I do have to say that silver shot is no where near as pretty as gold shot. How big is the market for shot? Gold or silver.
 
Never use flux when pouring shot! Refined metal only in a dedicated crucible. The market for shot is mixed but when making either silver or gold bars of exact weight, shot is always used. It is weighed out and either melted in a clean crucible and poured into a mold with controlled cooling or it is heated and cooled under an oxygen free atmosphere to cool into a nice blemish free bar.
 
Most manufacturing jewelers buy pure gold in shot form. That way, they can simply weigh out exactly the amount they need to make up karat alloys.

One place I worked was making silver shot in 1000-2000 oz batches. They used a fairly large gas fired standard crucible furnace elevated on a platform. There was a hole in the bottom of the furnace and the crucible was luted into the hole. Holes were drilled in the bottom of the crucible. I'm thinking that the holes were drilled with a #56 bit but they could have been a little larger, maybe a #53 or #54.

The stainless catch tank, about 50 gallons, on wheels, was moved into position under the furnace. There was about a 300 gal reservoir that continually provided cool water to the catch tank. The water was pumped into the bottom on the catch tank, at an angle, and there was an overflow near the top where the hot water returned to the reservoir. A large stainless small-holed colander, suspended by heavy wires, was placed near the bottom of the catch tank to catch the shot and make it easier to remove.

For making tiny karat gold shot for dissolving purposes, I once carved about a 3"-4" hardwood prop, drilled a hole in the middle, mounted it with nuts and washers on a length of threaded rod, and chucked in in a drill. I put the prop several inches deep in the water in a stainless container and poured the molten gold directly into the rotating prop. It wasn't as small as atomization would be, but it was the smallest I've ever seen from pouring into water.
 
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