# Fumes from melting scrap?



## MiguelRosas (Dec 9, 2011)

FORUM!!!

I have privately messaged a few members, but am posing the question out to everyone that can help. 

I have a very large client that is 99.9% done with a small "smelting" side of his business. But the city will not give him the go ahead because they are concerned about health issues. He will be just buying scrap jewelry and melting it into 5 - 10 ounce dore bars. That's it. 

No acids, no chemicals, just induction melting and a pour into dore bars. He has all the proper vents, and scrubbers in place, but the city wants specifics on the fumes before and after they vented into the air.

In reading as many of the posts that I can, the randomness and different directions they go at times is making my "research" very entertaining, but time consuming. 

Do any of you have (or know any links) to literature, research, laws, etc. regarding the chemical breakdown of what the fumes consist of? And the toxicity levels of these fume? 

Any help would be greatly appreciated. 

Kindest regards,

Miguel Rosas


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## nickvc (Dec 9, 2011)

I can tell you from years of experience of melting live scrap that the worst fumes are from dried perfume soap and skin....the gold itself will not likely fume but the base metals can such as zinc or copper in the alloys if the melt is to hot but with scrubbing in place I can't for see a problem from that and in honesty I think the council are been a bit OTT.


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## MiguelRosas (Dec 9, 2011)

Nick - 

I completely agree. I have no idea what they are expecting to be released. We're really talking burned skin, oils, hair, dirt.... and maybe some zinc and copper.

The EPA has an exemption for small precious metal recovery- that are using hazardous chemical refining, so why does a city council care if a jeweler is just melting scrap with an induction burner or torch>?! 

But it's not my job to argue, I'm just trying to find out the answer to help please the city that this is safe.


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## Smack (Dec 9, 2011)

You've got city/village and or township to be delt with here and they can impose their personal opinions here and if there is a consensus on that opinion then it will be law until you prove otherwise. Local government can be a pain. Some thinks are better left unsaid.


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## MiguelRosas (Dec 9, 2011)

Smack - 

He is a very respected businessman in the town, and his reputation nationwide is very admirable - so if the "books" are saying, "We want proof and research".... then that is my duty to insure his business, and our relationship are sound. 

Que sirah sirah...


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## goldenchild (Dec 9, 2011)

I think this is one of those cases where you would cause yourself more trouble by asking than you would have if it was kept low key. I think when you ask then people get suspicious that there is something dangerous going on because you asked(hopefully that makes sense to someone). Since there are no chemicals involved I dont see melting scrap as a big deal. Wouldnt be much different than a camp fire. Are there ordanances about burning in your county?


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## 4metals (Dec 9, 2011)

Melting alloy and scrap gold is actually exempt from many EPA regulations. It is true that states can implement regulations stricter than the EPA but I have never seen a melt operation application denied and I've worked with many across the country. I've even gotten guys melting cadmium licensed by adding wet scrubbers and bag houses. 

All states require the applications be submitted by a PE (professional engineer) licensed in their state. Perhaps your client isn't following proper protocol and they are just blowing him off.


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## MiguelRosas (Dec 9, 2011)

4metals

I completely agree. It's ridiculous in my opinion, especially with the exemption information I provided them earlier in the week, however I'm sure we can all picture the little old man and the grouchy bitter lady that hate change or immediately reject anything they don't understand. 


But back to the point.... Does anyone know the average content of contamiments within the fumes? ( documented)


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## butcher (Dec 9, 2011)

I may be off topic of your direct question a bit, what is the regulation of the local jeweler making rings, maybe talk to him, and ask for his input in this matter.

As far as average contents in metals, I would believe that would depend on many factors (some lead mercury and other bad fumes) could be involved depending on the stock metals melted, and would be hard to come up with unless your stock was only one material with known composition. Then someone could have these fume chemically analyzed for what was released (assay your fumes?).

to me this would be like getting many different types of wood from around the world and knowing what the fumes contain, well we can generally say water, CO,CO2 and soot, but then again we could come up with many of the metals and other gases in combustion.


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## Westerngs (Dec 9, 2011)

For jewelry alloys, both gold and silver, probably just some zinc, maybe small amounts of other metals.

Easiest way to find out how much is by doing mass balance. Meaning, just melt some stuff (weigh and assay for 100% of constituents before and after), assume losses all went up in fumes. Ratio weight lost as fumes to assay percentages in starting material and present findings to city.


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## etack (Dec 10, 2011)

Some city schools, city art centers, or community collages offer jewelry making classes maybe they would know the answer if its a concern for his city. Assuming his city is large enough to have to have those amenities. Using government to answer its own questions :lol: 

Eric


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## nickvc (Dec 10, 2011)

Miguel my first place to try would be the manufacturer of the furnace or any other furnace to see if they have this sort of detail already covered failing that maybe a look at some of the large refiners and see if they have had the same sort of details requested. The other thought I had was as your client has scrubbers in place get a sample from the top of the stack on a melt with the scrubbers working to prove that no emissions will cause problems or health risks this will cost and will probably have to be done by the EPA as I think your agency is called.


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## qst42know (Dec 10, 2011)

I don't know if it will help much but here it is anyway. Some further digging through the OSHA regs may yield some useful information.

OSHA has some exposure limits for some metals likely found in jewelry alloys. There is a table of these limits on page 38 of this document.

http://www.osha.gov/Publications/OSHA3348-metal-scrap-recycling.pdf


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## MiguelRosas (Dec 10, 2011)

Thank you so much guys. 

In Texas we have difference regulations, and our part of town is semi-industrial, not residential so we have different guidelines than what my client's council is looking for. 

The OSHA article has a lot of great references that I am looking into. 

Thank you again.


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