# Copperas/ferris sulphate?



## austexjwlry (Jun 28, 2007)

Copperas - is an iron salt, in Hoke on pg. 64 she states one way to make is to dissolve iron in sulphuric, then crystallize out the salt that forms.

I put some small cast iron pieces in an old cast iron frying pan. Then covered with dilute sulphuric acid. It went to work right away. Started to stink real bad like rotten eggs, stunk up my whole shed!

All I managed to do was clean the old skillet really well, like new before I quit due to smell. I read somewhere to make away from light?

Does anyone know a proper way to make copperas?

Wayne


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## Harold_V (Jun 28, 2007)

Don't start with cast iron. Especially old cast iron. It is now melted with induction furnaces for the most part, but early iron was melted with a cupola that often used coke made with high sulfur coal. That is part of the source of the smell you described. 

Instead of selecting iron, use scrap steel. The carbon content will be much lower, and the sulfur content will, likewise, be lower. You should end up with a much cleaner product, assuming you're willing to go through the work involved. 

It's cheap enough to just buy copperas. It's used in fertilizer ----the only problem you'll find is that unless it's fairly green, it may not be as good as reagent grade material. Once it turns brown, it no longer precipitates gold. 

I used copperas when I first refined, but as my volumes increased, the added fluid became troublesome. I ended up using SO2 routinely. It's much easier to deal with, although it is somewhat difficult to buy. A large cylinder would last me about a year. 

Harold


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## austexjwlry (Jun 28, 2007)

Harold

I've paid too much on ebay a couple of times for almost worthless copperas, yellow instead of green, real clumpy. Bought it from a reseller, I didn't even try to return it. Buyer beware!

It's even more expensive from a local chemical supplier but it is good quality, doesn't seem worth the money. I've read you can buy products like Hy-yield brand copperas from garden supply, then add water, filter, then use. I bought some but haven't tried yet as its also yellow not greenish and doasn't seem fresh. I'm also afraid of adding too many unknowns to mix.

A supply of fresh, selective precipitant that I can make at home really appeals to me. I'll try to make again using your advice.

Thank you sir!

Wayne


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## lazersteve (Jun 28, 2007)

Wayne, 

Be sure to precipitate the gold powder a second time with a different precipitant to get your gold as pure as possible. Follow Harolds washing process between precipitations for the highest quality gold. Please take some photos for the forum. :wink: 

Good Luck,

Steve


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## Harold_V (Jun 29, 2007)

austexjwlry said:


> Harold
> 
> I've paid too much on ebay a couple of times for almost worthless copperas, yellow instead of green, real clumpy. Bought it from a reseller, I didn't even try to return it. Buyer beware!



Heh! The seller likely bought a small bag from a garden shop and resold it. That's the level of quality I found. When you buy reagent grade, it's real pretty and light green, with no traces of brown or yellow, but it's not cheap. 

I've used the garden variety iron sulfide and it works adequately, but I filtered it after it was dissolved in water to insure I didn't contaminate the gold. While there was indications of brown, there was also a lot of green. If you can find a bag, don't hesitate to give it a go. If it doesn't work for gold recovery, you can always add it to your lawn to green it up. It's usually not expensive----it's only expensive when it magically becomes related to gold refining. 

When you dissolve the stuff you use, I trust you add a few drops of HCL? You can see when you've added enough---the solution flashes light green and clear. 

Harold


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## AuMINIMayhem (Jun 30, 2007)

Harold or Steve.. I like using the "AR then Urea then SMB" method. Is there a reason for using the differing precipitants in AR? 

I guess what I'm asking is in what cases would I use Zinc powder, copperas, ferrous sulfate, oxalic acid, etc instead of SMB.. or would I use them in addition to SMB to recover gold that may not have dropped out?..

:? :?


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## Noxx (Jun 30, 2007)

It's only because one kind of precipitant may precipitate a contaminant. Using a other type of precipitant will not make the contaminant precipitate. I hope I've made it clear.

Unless you want very pure gold 99.999%+ you don't need to do this


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## Harold_V (Jun 30, 2007)

AuMINIMayhem said:


> Harold or Steve.. I like using the "AR then Urea then SMB" method. Is there a reason for using the differing precipitants in AR?



According to Hoke, there are instances where something may persist in following gold through the precipitation process when using any single reagent. By using more than one (not simultaneously, but upon a second refining), it's assumed that the substance may not be dragged down, or otherwise precipitated along with the gold. 



> I guess what I'm asking is in what cases would I use Zinc powder, copperas, ferrous sulfate, oxalic acid, etc instead of SMB.. or would I use them in addition to SMB to recover gold that may not have dropped out?..
> 
> :? :?



Gold, unlike the platinum group metals, will precipitate totally form solution if you have done your work properly. There should be no gold left behind, regardless of the precipitant of choice. If you're having that problem, you should look at your procedure and make any necessary changes so it isn't happening. 

Unless you're working with cyanide, I can't think of any instance when you'd use zinc for precipitating gold------for it precipitates virtually everything that may be in solution. Zinc can be used for recovery, but not for purification, in other words. As far as your choice in precipitants, pick your poison and go with it! I'm not convinced that any one is better than another-----although there may be small differences that play a role under given circumstances. 

SMB is nothing more than SO2, but in a solid form instead of a gas. My choice was to use SO2 in a cylinder. It is fast, easy, and very convenient the way I was set up. I had plumbed a line to my lab, so the bottle wasn't in the room with me. At the end of the line there was a hose barb and valve, located at the mouth of my fume hood. It took but seconds to apply the short length of vinyl hose to the barb, and attach the 3/8" glass tube I used for precipitation. It was all supported by a clamp that was fastened to the opening of the hood, so the setup was readily adjustable, and was completely out of the way when not in use, with the components stored in a drawer beneath the hood. 

I do not contend that my method is the best-----but it was the best for me. How you work, and the nature of your objective will dictate what is best for you. My endeavor was no longer a hobby---I had to work efficiently, for I was working many hours each day, and had to make every minute count in order to keep up with the work. 

So you'll know, ferrous sulfate and copperas are one and the same. Chemicals had strange names at one point in time (think sal ammoniac, which, if I'm not mistaken, is soda ash), then there was some attempt at organizing and standardizing chemical names. Why ferrous sulfate was called copperas is very strange-----for it is a salt of iron, not copper. It's been years since I last worried about these matters---- so I stand to be corrected if I recall it improperly. 

Harold


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## jimdoc (Jun 30, 2007)

Sal ammoniac is ammonium chloride, I just know that because I have platinum fever, probably worse than my gold fever.
Here is a link to a list;
http://chemistry.about.com/library/weekly/blcommon.htm

Here is another;
http://www.zompist.com/chemical.htm
Sal ammoniac from camel dung?????????


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## Harold_V (Jun 30, 2007)

Thanks, Jim. I stand corrected. Now to try to remember what I didn't before!  

As I said, it's been years, and time is taking a toll on this old dude.

Harold


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## jimdoc (Jun 30, 2007)

Harold,
I am only 43, and I know what you mean, especially with
stuff like that. It may win you some money on Jeapardy,
knowing the old alchemy names, but they aren't really used 
very often, and confuse a lot of people nowadays.
Jim


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## lazersteve (Jun 30, 2007)

jimdoc said:


> Sal ammoniac from camel dung??????



I can give you easy instructions on how to make sal ammoniac at home without playing with camels dung !!! :roll: :lol: 

Steve


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## AuMINIMayhem (Jul 1, 2007)

Sweet.. Thanks guys. Harold, thanks for the thourough response. I am definately nowhere near the league you are (were?) doing things so, yeah the SMB is best for my setup.. just making sure I wasn't missing out on something. 

Also, I forget who posed the question, but no, I'm not having a problem with gold being left in solution, so that's a good thing, I'm just wondering about what other stuff might be getting left behind such as silver, etc..

Does anyone have a list or order of how to precipitate the other metals out once you have done your gold? Let me set up the scenario and pick your respective brains..

I have just gotten my hands on a ton of old junk jewlery from a couple of yard sales and an estate sale.. some of it rather suspect (costume I presume due to lack of karat markings, but possibly plated?..)..

I melted it all down to hopefully inquart whatever gold was present by diluting it with whatever other metals were there.. being jewelry, I figure it's a relatively safe assumption that anything plated was either copper, silver, or something of that nature and some of the karated stuff (14k being the highest marking I've read) most likely contains similar metals..

I now have about 75g of "shot", a little larger shot this time. Last time I made the shot I made it very small and it was very hard to keep the reaction in AR under control because it kept wanting to boil over.. to the point that I put the beaker containing the AR in a crock pot of room temp water in case any spilled over.. the water in the crock pot, I later used to dilute the AR prior to the Urea and SMB steps..  

Now.. I know how to get the gold. However, if there are other metals, which I'm not sure there are, but let's assume for no other reason than to make an excersize out of this that there are PGM's and or silver present..

Do I go AR then Urea then SMB for the gold then take whats left and drop out the other metals or do I drop those first? and if so, how?.. (I've done the steel plate thing I saw Steve do in another forum to drop out the copper and stuff when I'm prepping for disposal so I know about that, I'm just worried I might be losing other valuables)..

Whew.. that was a lot of typing.. :? 

Thanks guys!
Derek


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## AuMINIMayhem (Jul 1, 2007)

Disregard that last post.. however if it did bring up any questions, I believe Harold gave a thorough explanation over on this thread http://goldrefiningforum.com/phpBB3/viewtopic.php?p=5696#5696

Thanks again.. 

Derek


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