bhilton
Well-known member
Ah you are correct, I apologize, I thought you said smelt, but you sure didn’t!
Jewelers polish papers
- Thread starter bhilton
- Start date
Help Support Gold Refining Forum:
The original material lend it self well to smelting, but what you have in the beaker is ripe for a second refine and a melt.
The terms melt are often used interchangeably but it is not correct, one could call the process of fluxed cryolite melting a smelt and you wouldn't be wrong. But refined metals are melted as are alloys. Smelting is to remove certain deleterious components and catch it in the slag. Typically it is done by selective use of fluxes and bubbling oxygen or other gasses through molten metal.
I am working with a buyer in Missouri now who learned the hard way the difference. He wanted to set up a simple melt sample and ship gold buying operation. He originally called it smelting and I corrected him because it matters from a permitting aspect when done commercially. Well his lawyers submitted the paperwork for the building use to the planning board and sure enough called it smelting. And what do you know, application denied.
I had to go back to the board, hat in hand, and explain the mistake and explain in detail the process. Then I had to get an exception letter from the environmental folks in Missouri saying they would allow the process and direct ventilation without scrubbing or bag houses. Real pain to get them convinced we weren't going to pollute their town. All over the misuse of a word.
Their lawyer made a lot of money though!
I am working with a buyer in Missouri now who learned the hard way the difference. He wanted to set up a simple melt sample and ship gold buying operation. He originally called it smelting and I corrected him because it matters from a permitting aspect when done commercially. Well his lawyers submitted the paperwork for the building use to the planning board and sure enough called it smelting. And what do you know, application denied.
I had to go back to the board, hat in hand, and explain the mistake and explain in detail the process. Then I had to get an exception letter from the environmental folks in Missouri saying they would allow the process and direct ventilation without scrubbing or bag houses. Real pain to get them convinced we weren't going to pollute their town. All over the misuse of a word.
Their lawyer made a lot of money though!
I will add, much to my surprise, the Missouri Department of Natural Resources were quite helpful. They were informative and when presented with the proper information they worked quickly (for a government agency) and produced the letter we needed. After many years of doing this, I cannot say that about a lot of other states.
So if you use fluxes it still can be melting?
The reasoning for the fluxes is what defines what it is?
Generally if your process results in a homogeneous bar it is melting. Flux was originally used to help make the metal flow. In fact I believe the origin of the word meant to flow. Certain additives to flux can be made and still be considered melting. When melting the alloy in is very similar to the alloy you pour out.
Smelting works to oxidize base metals and catch them in the slag. Often there is a gaseous outpouring which is the reason for the greater environmental scrutiny.
I believe in some European countries the words are used interchangeably but I'd need verification of that from members across the pond. But in the refining context there is a big difference.
Yes we do not differentiate between melting and smelting.
As long as you bring something to a liquid phase, we use the same word and ours are "smelting"
It's funny how the same words mean different things in different countries. I had an Indian customer bring in a lot for chemical stone removal, the stones were red cape garnets, not too impressive looking but they were rings with stones. The Indians say this is here for melt. They meant chemical stone removal but they said melt. I was on vacation I think, anyway not there, and they gave the customer a receipt and filled out a melt ticket and melted the lot. Lawyers made money on that one too!
Words matter and when the same words mean 2 different things in different parts of the world, they matter even more!
Words matter and when the same words mean 2 different things in different parts of the world, they matter even more!
Yes I have noticed that a few of our members are referring to dissolving as melting.
Mainly in south west Asia
bhilton
Well-known member
4metals, to recap or summarize, I think you were saying to take my left over stuff and melt it? The stuff being the aluminum oxide sludge I couldn't filter very well (from the burnt sand paper) which probably contains silver in it, and maybe ~10% of the gold I couldn't get filtered through. Plus it should have trace amounts of copper for sure. Plus I would think there is stuff still in the cotton balls (more sludge) and filter paper (more sludge)...
My interpretation is to put all that into a melt dish and get my oxy/acetylene torch on it? Sprinkle or mix in cryolite powder to start? Or later when the material is molten?
My interpretation is to put all that into a melt dish and get my oxy/acetylene torch on it? Sprinkle or mix in cryolite powder to start? Or later when the material is molten?
The point of the Cryolite is to bring the melting temperature of the Alumina to a level one can melt it properly.
So I guess it need to be there from the beginning.
And all material including Cotton balls and Filters should be properly ashed first if I'm not mistaken.
bhilton
Well-known member
Thanks for highlighting the purpose of the Cryolite!
A torch will not get you to the temperature for cryolite to be effective. And it will smoke with a choking smell of the silver chloride releasing the chlorine. You could leach the silver chloride with ammonia and drop it as clean silver chloride to recover the Silver.
But let's be a little smart about this. The lot only yielded less than 2 grams of gold. you likely got about 90% of the gold so is processing this any further worth the exposure and chemicals? I think not!
But let's be a little smart about this. The lot only yielded less than 2 grams of gold. you likely got about 90% of the gold so is processing this any further worth the exposure and chemicals? I think not!
bhilton
Well-known member
I agree, I was only keeping the conversation going for theoretical purpose.
I will be getting lots more sandpaper from what I posted in my original picture, he has, for sure 4 or 5 times more than this one bagful he gave me.
I think I'll use the same quick method to attack the rest, maybe in 2 separate batches, because I honestly didn't mind juggling filters and funnels until I get 90% of it through. Let's say, if there are 5 more grams of gold I can get out of the rest of the unprocessed material he's giving me and I run it in 2 batches, each yielding 2.5 grams.
I'd be leaving behind arguably 10% of 2.5 (twice), so 0.5grams. At this stage, I would save all the sludge in a bucket with the stuff I've already run and maybe one day a few years from now after many more batches, I'll have enough to bother with the cryolite melting process...
There is a world of difference between digesting most of the gold entrapped in the alumina and recovering it from the acid and leaving behind 10% of the acid because it won't filter. You need to filter all of the solution because the gold that dissolved is equally distributed through all of that liquid.
What type of filtration are you using? Vacuum or gravity?
What type of filtration are you using? Vacuum or gravity?
bhilton
Well-known member
Just gravity, I learned in that first batch if i let the insolubles settle, I could easily filter 90% of the solution. The last chunk I diluted with water and mixed it into s slurry, then separated it 2 ways, used 2 funnels with cotton balls, then let gravity work at it, eventually poured them both into a coffee filter in a small plastic strainer over bowl, cotton balls too. Lastly I bundled up the coffee filter and squeezed all the solution out with my gloved hand, put more water into the that sludge ball, rung it out again, all into the bowl, and filtered the solution in the bowl easily through a cotton ball into my original beaker containing the first 90% of filtered solution.
Go ahead, laugh at me. It worked pretty good, I hope
you need one of these, speed funnels that use folded filter paper. no vacuum just gravity.
speed funnel
speed funnel
