# improvised steel crucible



## yonderfishin (May 20, 2012)

Hypothetical situation , say you tried to do some smelting using a steel can for a crucible. What would happen ? Would gold just stick to the steel ? In a situation where you werent so concerned about contamination from other metals , would steel work if you didnt have a clay , silica , or graphite melting crucible?


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## Smack (May 20, 2012)

Not melting would be the best advice, save up and wait until you have the proper tools. You could melt on a fire brick, just grind a slight depression in it.


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## butcher (May 20, 2012)

http://www.goldrecovery.us/


Melting dish’s are very cheap @ $ 3.75, or a cupel @ $1.25 are also cheap, your gold is valuable surely you can afford 5 dollars for the proper tool to melt gold in.

If not a lump of charcoal, or wood, or even a fire brick, I have tried these and other things, but nothing works half as good a cheap melting dish, if melting with steel the gold would mix with the other metal.

My suggestion just buy the dish, you will be much happier, it will work much better than fooling around.


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## yonderfishin (May 20, 2012)

If I had a local source for crucibles or dishes Id go ahead and swing by and pick some up but I cant seem to find anyone who sells them in my immediate area ( Findlay/Toledo OH.) so apparently my only option is to order some. But Id actually rather find a way to melt/smelt a decent amount of the pyrite and concentrates I have first and get an idea of whether its really worth putting the time , money , and effort into ordering them....if at all possible , thats why I am entertaining the idea of something improvised. Ive already melted a few small pieces of the pyrite type ore I have in a charcoal briquette with a torch and was amazed that there was actually visible gold in the slag. But that was such a small sample I dont know if I have a bunch of pyrite with an unusually high amount of gold in it , or I was just lucky and had one or two pieces in the bunch that happened to be like that. The only way to be sure is to melt a larger sample and see if more of it equals more gold. That much wont fit into charcoal unfortunately. I know a steel can is not reccomended but it does have a higher melting temp. than what I am trying to melt , I just dont know what negative effects that may have on the process or the outcome. The idea came to me that if i could find some sort of a small one piece steel container with a concave bottom I might get away with it atleast once but I dont know exactly why steel is not a good choice , and I dont want to totally ruin the sample by trying it that way. I dont know if any of this makes sense or not but atleast it should explain my reasoning.

Thanks for the help.


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## depperl001 (May 20, 2012)

yonderfishin said:


> If I had a local source for crucibles or dishes Id go ahead and swing by and pick some up but I cant seem to find anyone who sells them in my immediate area ( Findlay/Toledo OH.) so apparently my only option is to order some. But Id actually rather find a way to melt/smelt a decent amount of the pyrite and concentrates I have first and get an idea of whether its really worth putting the time , money , and effort into ordering them....if at all possible , thats why I am entertaining the idea of something improvised. Ive already melted a few small pieces of the pyrite type ore I have in a charcoal briquette with a torch and was amazed that there was actually visible gold in the slag. But that was such a small sample I dont know if I have a bunch of pyrite with an unusually high amount of gold in it , or I was just lucky and had one or two pieces in the bunch that happened to be like that. The only way to be sure is to melt a larger sample and see if more of it equals more gold. That much wont fit into charcoal unfortunately. I know a steel can is not reccomended but it does have a higher melting temp. than what I am trying to melt , I just dont know what negative effects that may have on the process or the outcome. The idea came to me that if i could find some sort of a small one piece steel container with a concave bottom I might get away with it atleast once but I dont know exactly why steel is not a good choice , and I dont want to totally ruin the sample by trying it that way. I dont know if any of this makes sense or not but atleast it should explain my reasoning.
> 
> Thanks for the help.



I belief that carbon black, soot, on the steel would stop the gold from sticking to steel. If I am wrong I am sure that there are sufficient members here to shoot me down.

Regards,

Josef Vavryn


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## butcher (May 20, 2012)

If you are smelting or pyrite it would be best to go ahead and make a furnace, the burner and buy crucibles, if you can drill holes in pipe you can make the propane burner, the furnace can be made from an old propane tank welding not absolutely necessary but better if you can, a second hand regulator and some hose for the burner, a little refractory and some flux and your in business, a cone mold can be made from a drilled and ground out cast iron pipe fitting plug. Or some other scrap piece of cast iron, I think I remember Harold saying something about using angle iron to make an improvised cone mold.

A torch and a dish would not work well for smelting, you cannot get the temperature up (even with a rose bud tip), and keep it up for the process to combine the gold in the melt, the flux and gases are hard on your torch, a torch would also use a lot of expensive fuel to heat the atmosphere (a wood stove is better for that if you have a source of wood and do not mind working for your heat).


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## yonderfishin (May 21, 2012)

butcher said:


> If you are smelting or pyrite it would be best to go ahead and make a furnace, the burner and buy crucibles, if you can drill holes in pipe you can make the propane burner, the furnace can be made from an old propane tank welding not absolutely necessary but better if you can, a second hand regulator and some hose for the burner, a little refractory and some flux and your in business, a cone mold can be made from a drilled and ground out cast iron pipe fitting plug. Or some other scrap piece of cast iron, I think I remember Harold saying something about using angle iron to make an improvised cone mold.
> 
> A torch and a dish would not work well for smelting, you cannot get the temperature up (even with a rose bud tip), and keep it up for the process to combine the gold in the melt, the flux and gases are hard on your torch, a torch would also use a lot of expensive fuel to heat the atmosphere (a wood stove is better for that if you have a source of wood and do not mind working for your heat).




Thanks for the idea of the cast iron pipe fitting plug , that should work. I just finished making a charcoal fueled furnace and I should be about ready in that regard. I dont have the ability to weld or do much cutting. I have been thinking about heating a metal muffin pan and forming it into a cone shape for a cone mold , or getting a thin cast iron pan red hot and pounding the right shaped depression in it with a hammer , I should be able to come up with something for a mold to use atleast for now. I just have to keep my expenses low for now since there isnt enough gold to make any money doing this. Its just for the love of tinkering with the stuff , and it dont hurt that coming up with ways to make my own tools has been half of the fun. It started with gold panning and building my own equipment , now it has branched into metal working and chemistry. Coming up with ways to make my own stuff has been both a heck of a lot of fun and mindnumbingly frustrating at the same time.


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## NoIdea (May 21, 2012)

yonderfishin said:


> Hypothetical situation , say you tried to do some smelting using a steel can for a crucible. What would happen ? Would gold just stick to the steel ? In a situation where you werent so concerned about contamination from other metals , would steel work if you didnt have a clay , silica , or graphite melting crucible?



Hey yonderfishin, not sure if your exact question was actually answered, well here it goes.

I have sort of tried this and this is what happened: The tin can heated up very quickly enabling the metal to be melted, melt, though it looked like ... um, don’t swear, um, terrible, that's it, it looked terrible. :lol: So I added a flux, borax and very fine, acid washed, silica sand(chromatography grade), this worked a treat, except it allowed alloying of the melt with the can, this in turn cause a hole to develop and my metal poured into a nice oddly shaped bar/nugget at the botton of the furnace(back yard bonfire). The can still contained PM’s.

Now, this was not gold, but an allow containing high-ish amount of it. How pure gold would react under these conditions, I can’t say. I have a funny feeling you might end up doing the same if trying pure or high quality melt.

Hope that helps

Deano


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## yonderfishin (May 21, 2012)

Yeah I dont want that to happen. And though all the answers on here are good , that one solved the "what would happen" part. I am glad I asked before trying. I just need to find some melting crucibles. Probably gonna have to order some since my search results arent bringing anything up locally. thanks


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## ForTheLoveOfAu (Sep 8, 2022)

Still curious as to the actual results of using a stainless steel crucible for gold recovery so I am going to just do it and will respond with the results. I have been a member on here for sometime, lurking in the shadows. I've read "The Holy Bible" always refered to on here and I appreciate most advice given.

That being said, I also understand not feeding trolls. Some on here may consider me one. I don't care. Im here for professional opinions and analysis and tried and true way to learn something, GIVING IT A FREAKIN SHOT. 

I feel the strong need to point out not only this gentleman's very humble responses. Your a true tinkerer like myself. Hell like I believe most everybody here. One thing consistently bothers me and not for the intent behind not directly answering questions with a viable answer to protect those not wise or experienced enough, so as maybe one day they will have lived long enough to become wise and experienced enough. It's just frustrating to see someone genuinely seeking knowledge and it be sidetracked or obscured by the unauthentic when the authentic basis of THE ENTIRE PREMISES OF WHAT ALL OF US DO WAS BUILT UPON THE PRINCIPLE OF ELIMINATING THEORY BY WAY OF JUST DOING IT. 

I am going to attempt to use a repurposed stainless steel cylinder to melt gold and my findings will be reported once documented in my own journal. Thank you all for your kindness and wise exercise of helping others avoid costly time or monetary waste. In the same contention, I've wasted more time reading the same rhetorical " don't do that, not because it won't work but because I simply will not condone a lesser solution" that I'm wondering how many of you remember what it's like, if at all have been, in my current situation where I can not even afford a $1.35 ceramic dish due to my unconventional and ultra-extra-ordinary less-than-ideal circumstances. I am not attempting to complain but a more foddered regard to the actual questions would be relieving and possible shorter winded to the entire forums goal if possibly considered


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## Shark (Sep 8, 2022)

Plain and simple, and has been answered several times across the forum, as well as a few pictures that used to be around a few years ago. Melting gold in a stainless steel crucible will cause the gold to bond with the stainless steel. Even a potato would be better than melting it in steel.


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## snoman701 (Sep 8, 2022)

At high temperature gold will form an alloy with the stainless steel, dissolving it until it causes a hole crucible. Not recommended. 

That's what an alloy is, one metal being soluble in another metal or alloy.


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## 4metals (Sep 8, 2022)

ForTheLoveOfAu said:


> till curious as to the actual results of using a stainless steel crucible for gold recovery so I am going to just do it and will respond with the results. I have been a member on here for sometime, lurking in the shadows. I've read "The Holy Bible" always refered to on here and I appreciate most advice given.
> 
> That being said, I also understand not feeding trolls. Some on here may consider me one. I don't care. Im here for professional opinions and analysis and tried and true way to learn something, GIVING IT A FREAKIN SHOT.
> 
> ...


I've quoted your entire post, posted on the day you joined this forum, because something tells me you may not be here for long. You have been warned that the molten gold will alloy with the stainless crucible given ample contact time. That alone should make you wary. 

But until I feel different, I will remember your name ForTheLoveofAu and remember that I likely am not wise or experienced enough to benefit your level of expertise in this field. So I'll save my time and effort and let someone else answer you. 

I'd normally say welcome to the forum but I'm not inclined to be welcoming you, given your first post.


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## goldshark (Sep 8, 2022)

your initial post stated melting in a steel crucible, so we will address steel. and cast iron, and not stainless steel. 2 very different alloys. In my opinion ( which are like as--oleas, and everybody has one, and generally they do stink), we will address the chemical reactions. Since steel can be alloyed from a variety of recipes, including Moly, high or low Carbon, and a variety of other additives, maybe we will stick to say cast Iron for now. So a cast Iron vessel has Fe and Carbon predominately. Melting point around 1,200 degrees C., steel ( mild ) around 1,400 C , adequate to do a fire assay, if you don't go bat--it crazy on the temperature. So plausible for a crucible, if you have the proper tools to hold a plastic material while pouring. The next thing to consider is the reaction between what you are cooking, basic, acid, heavily pyritic ore, etc.. If you are cooking a pyritic ore in cast Iron or steel, depending on the constituents of the sample, may dictate how much consumption of the Iron crucible walls may be consumed. The same holds true for an Alumina/Silica crucible but based on flux PH. So some knowledge of the chemistry involved is necessary to keep from making a mess of the furnace, or your feet. An interesting subject. In a nut shell, yes it can be used , if you know what you are doing. Since historically ceramics are considerably cheaper, and more user friendly, they have taken a front seat to using an Iron vessel.
The only advantages I can see in using an iron vessel is; 1, the only thing available ( poor people make poor decisions ),2. No need to add additional FeO to a pyritic ore, as the crucible will pull The Sulphur from the melt, but leave a hole in the weakest point consumed by the Sulphur, depending on wall thickness. 3. a plethora of heavy walled Vessels you are trying to use up.
A lot of options, knowledge is king.


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## GoIdman (Sep 8, 2022)

yonderfishin said:


> If I had a local source for crucibles or dishes Id go ahead and swing by and pick some up but I cant seem to find anyone who sells them in my immediate area ( Findlay/Toledo OH.) so apparently my only option is to order some. But Id actually rather find a way to melt/smelt a decent amount of the pyrite and concentrates I have first and get an idea of whether its really worth putting the time , money , and effort into ordering them....if at all possible , thats why I am entertaining the idea of something improvised. Ive already melted a few small pieces of the pyrite type ore I have in a charcoal briquette with a torch and was amazed that there was actually visible gold in the slag. But that was such a small sample I dont know if I have a bunch of pyrite with an unusually high amount of gold in it , or I was just lucky and had one or two pieces in the bunch that happened to be like that. The only way to be sure is to melt a larger sample and see if more of it equals more gold. That much wont fit into charcoal unfortunately. I know a steel can is not reccomended but it does have a higher melting temp. than what I am trying to melt , I just dont know what negative effects that may have on the process or the outcome. The idea came to me that if i could find some sort of a small one piece steel container with a concave bottom I might get away with it atleast once but I dont know exactly why steel is not a good choice , and I dont want to totally ruin the sample by trying it that way. I dont know if any of this makes sense or not but atleast it should explain my reasoning.
> 
> Thanks for the help.


Hi mate,

The easiest way to get a proper crucible is to hunt for dental lab technicians supply shop. I believe you will have one in your area as well since they supply dental clinics with everything they need. Just take a trip , you`ll find a large quantity of things very useful in recovery and refining.

Try to find the type of crucible from the picture attached. This stuff is very cheap (at least here), its about 4-5 $ at max and is a proper melting crucible.

I call it slippers crucible.. 

Be safe

Pete


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## goldshark (Sep 9, 2022)

GoIdman said:


> Hi mate,
> 
> The easiest way to get a proper crucible is to hunt for dental lab technicians supply shop. I believe you will have one in your area as well since they supply dental clinics with everything they need. Just take a trip , you`ll find a large quantity of things very useful in recovery and refining.
> 
> ...


A very good source for melting Au/or alloys. The original post/thread, was about using a steel can for SMELTING. It is always funny to see the responses from various people, throwing out some tangent, sort of related to the original question asked. Like stating "don't use a stainless steel can", without answering the original simple statement. And don't mean to be critical of Goldman, but how much material can you smelt, in that size container/ slipper? There is a huge difference between smelting, and melting metals. Thanks for listening to my rant. Lets try to be more analytical about a question, and maybe reread the question, before answering.


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## FrugalRefiner (Sep 10, 2022)

goldshark, you are right that the OP was asking about smelting in a steel can. That conversation ended in 2012.

But then, ForTheLoveOfAu revived the thread a couple of days ago and said "I am going to attempt to use a repurposed stainless steel cylinder to melt gold". I believe that is what everyone has been responding to.

Dave


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## campbellj46 (Sep 10, 2022)

I make crucibles out of cement and use use 2 stainless steel bowls as molds. 1 60 lb sack of mortar will make 20-30 crucibles, depending on how big they are. mix the cement to the consistency of sand on a beach to build a sand castle. put it in a stainless steel bowl, let it set up about 10-15 minutes as long as it's not quick dry. push the other stainless steel bowl down on top of the cement until it's as thick as you want, usually about 1 inch. Give it a little twist, pull off the stainless steel bowl and let it dry. once it's dry, heat (slowly) for about 30 minutes to completely dry the cement crucible. once cured (dried) add borax and glaze just like a ceramic crucible. cement crucibles are also good for cupelling, they absorb a lot of impurities... down side? they don't last long, maybe 3, 4 maybe 5 firings. upside, they're cheap to make. A 60 lb bag of mortar mix costs $7-$8

it's 3 ingredients, sand, mortar and water. 1 lb sand, 1/2 lb mortar mix add water to the consistency you need. spray stainless steel bowls with Pam cooking spray. put cement mixture in 1 bowl, use other bowl to press down and shape mold. Do not let it dry in the bowl. Do not use the quickcrete or bagged concrete mixes unless you sift out all of the rocks.

I have used steel as a crucible. it DOES work. 3 main problems. Gold and silver LOVES steel, it attracts to it like a magnet when it's molten. molten gold will adhere like glue to bare steel. as long as you keep it flowing, it's not a problem. second, you can get contamination if you don't control your heat. Steel melts at 2400F... gold, 1900F...500F is difference is VERY easy to misjudge using a torch. It can be done, but you have to control the heat. That's to melt it, to get it flowing to pour, it's going to be closer to the 2400F melting temp of the steel, so not much room for error with hot (soft) steel and molten gold.


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## goldshark (Sep 11, 2022)

FrugalRefiner said:


> goldshark, you are right that the OP was asking about smelting in a steel can. That conversation ended in 2012.
> 
> But then, ForTheLoveOfAu revived the thread a couple of days ago and said "I am going to attempt to use a repurposed stainless steel cylinder to melt gold". I believe that is what everyone has been responding to.
> 
> Dave


Sorry, I didn't see the whole expanded post about the stainless, until you pointed it out, thanks.


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## GoIdman (Sep 11, 2022)

goldshark said:


> A very good source for melting Au/or alloys. The original post/thread, was about using a steel can for SMELTING. It is always funny to see the responses from various people, throwing out some tangent, sort of related to the original question asked. Like stating "don't use a stainless steel can", without answering the original simple statement. And don't mean to be critical of Goldman, but how much material can you smelt, in that size container/ slipper? There is a huge difference between smelting, and melting metals. Thanks for listening to my rant. Lets try to be more analytical about a question, and maybe reread the question, before answering.


You are absolutely right, i think i messed up the quotes when answering....indeed my reply is useless regarding the smelting process and the crucibles i was talking about...my mistake....


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## kurtak (Sep 11, 2022)

Can you melt gold in an iron, carbon steel or stainless steel crucible

Simple answer = yes --- because the melt point of gold is lower then the melt point of iron/steel/SS - so as long as you don't bring the melt temp up more then a few degrees over the melt point of the gold - yes it will work

The risk is (or at least one risk is) getting to hot & melting the iron/steel/SS along with the gold

so yes - *you can get away with it - BUT !!!*

With that said - *I would NEVER* melt gold in anything other then an actual "melting dish" or crucible

Why ?

Because gold alloys with iron (as well as other metals of course)

For gold to alloy with iron - *you do NOT* need to get the iron up to its melt point

Why ?

Because "lower" melt point metals - once molten - becomes *a* *solvent* for "higher" melt point metals

In other words - though the iron - as a whole may not be hot enough to melt - the molten gold - that is on the surface of the iron - is going to dissolve iron at the contact point of the molten gold & the iron

*That dissolved iron is going to then alloy with the gold* - your gold is now contaminated with iron

In other words - the molten gold (acting as a solvent) "lowers" the melting point of the iron (where the gold is in contact with the iron) allowing the iron to alloy with gold (though the iron - as a whole - is not hot enough to melt)

Therefore I would NEVER "melt" gold in anything other then actual melting dishes/crucibles

For what it is worth - silver does NOT alloy with iron (though it may act as a solvent for iron)

Therefore - because iron will not alloy with silver - any dissolved iron will phase out to the surface & can be removed with HCl

So you can use iron to melt silver in without concern of iron alloy/contamination

Kurt


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## kurtak (Sep 11, 2022)

Like wise - smelting - is going to cause iron to alloy with gold

It's just not as much of a concern as when melting

That is because you are likely going to put your smelted dore (alloy) through a refining process anyway

Kurt


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