# Smelting chloroauric acid from AR



## Vegasmelter1 (Feb 26, 2015)

Hi guys. Great forum here, learn something new every day  
Had a few questions/concerns about a smelting technique we employ here that 
Is more of a by-product of stone removal from scrap jewelry. We use a modified AR
Solution comprised of muriatic acid and SubZero to loosen the stones, then we boil off most of the water after filtering out all the stones and pieces of gold that weren't dissolved and then neutralize/dry the remaining solution with zinc powder. We then put everything in a crucible after it's dry, and melt it all together. Usually there is little to no weight loss of the gold by using this process, it's just very noxious. 
The biggest concern I have is the type of gasses released from smelting this type of material, as well as wondering if there might be a better way to do this type of stone removal. The biggest problem I have is the time window, as I cannot wait for AU to completely dissolve in AR so I can precipitate it. My time window is 24 hours. 
Any comments will help. Thank you in advance


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## 4metals (Feb 27, 2015)

Why can't you use classic aqua regia? In a 24 hour time frame it is totally possible. Many refiners put the work up in acid at the end of a work day and allow the reaction to proceed over night. In the morning the stones are separated and cleaned and the gold is dropped quickly from the acid solution. The gold you will produce will be as pure as .995 on the first pass and if you have a market for pure gold shot you can raise the purity to .9995+ with the equipment you have on hand to do the original process.

Your current process clearly produces a metal bar which you likely sell to your refiner. One thing you could do is filter the solution to separate the silver chlorides, which smoke badly when melted as a salt. Then use fine copper powder to drop your gold. The copper will be as effective as the zinc but only drop precious metals. This should get your purity up and the smoke and smell of the melt will be exponentially less.


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## Vegasmelter1 (Mar 2, 2015)

Thank you 4metals for your advice, I'll give that a shot and see if it makes a difference. I want to use classic AR but my working conditions are too cramped and under ventilated for nitric acid, something I have to deal with as my boss doesn't like to supply the proper equipment unless it's needed (as far as he's concerned). We do get results, which is all he cares about, I'm just concerned for the health and safety of my coworkers and I. 
Hopefully using your tips will work for me, it's just that I don't see using nitric acid being a viable method as of right now :|


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## 4metals (Mar 2, 2015)

If you are under ventilated for Nitric acid use then there is no doubt you are under ventilated for any acid use. Your employer is walking a slippery slope (as many do in this market) and even what you have described in your post is illegal for a business to do.


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## Vegasmelter1 (Mar 2, 2015)

I hear you 4metals, and I would rather not have to deal with these chemicals at all, if I can. I have to pay my bills regardless.. If you have any recommendations on air scrubbers or ducted ventilation hoods that are acid resistant, I would greatly appreciate it. Or even a website, as I am having trouble locating a supplier of what I need. 

Thank you,

Taylor


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## kurtak (Mar 3, 2015)

Vegasmelter1 said:


> I want to use classic AR but my working conditions are too cramped and under ventilated for nitric acid, something I have to deal with as my boss doesn't like to supply the proper equipment unless it's needed (as far as he's concerned). We do get results, which is all he cares about, I'm just concerned for the health and safety of my coworkers and I.



As a matter of my personal opinion - if I was working for a man as you describe - I would start looking for another job & when I found it I would walk out on this guy with out giving him notice & tell my coworkers to do the same --- he sounds like a self serving jerk & I would leave him hanging to do his own work in the conditions he expects you to work in --- I would most likely report him on my way out as well

Kurt


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## Palladium (Mar 3, 2015)

If your boss is that cheap he probably won't pay for it, but here is the link for some of the best equipment out there!

http://www.goldrefiningequipment.com/Index.html


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