# HELP WITH COPPERAS AND ELECTROLYSIS DROPPING,PLEASE!!!.



## BIKAKA (Aug 17, 2019)

Hi every one!.
I w'd first thank you guys who have become members of this forum before us,your lovekind posts have always dragged my googles into this site and have never been disappointed of ur mutual helpful answers!.
I am of course new here and my interest is on 'how do i drop gold from gold chloride solution?"-and would like to get expirience from those ever tried electrolysis technique!.
I know that copperas drop gold but am not sure of the kinetic requirement of temperature,does it require HEATING the solution to get the reaction going to get done?!.
How much of the copperas is required to drop a gram of gold! and what are the risks of over using the copperas!
Waiting for your humble help,thanks!


----------



## butcher (Aug 17, 2019)

iron sulfate, ferrous sulfate, green vitriol, copperas, FeSO4, can be made with dilute 10% sulfuric acid and a source of fairly pure iron (not modern steels), I have several posts on how I make it.

How much to use? Well, I never calculated it, as the conditions of the solution will really determine this answer excess acid, temperature, how much base metals are involved...

Let us do some calculating to get a base estimate of how much it would take, for a gold chloride solution, not loaded with excess acids, not loaded with excess copper and other base metals...
we will use the formula of gold chloride (AuCl3) and our copperas (FeSO4) and on the other side of the equation ---> we get gold (Au) precipitating as metal, and leaving in solution salts of ferric sulfate (Fe(SO4)3) and ferric chloride (FeCl3)...


AuCl3(aq) +3 FeSO4 (aq) --> Au(s) + 2Fe(SO4)3(aq) + FeCl3(aq)

Balancing the equation we see it will take 3 moles of copperas for every mole of gold in solution.
One mole of gold is 196.96 grams, so for 196 grams of gold in solution it should take about 3 moles of Copperas,

One mole of copperas is 151.9 grams, here we need 3 moles of ferrous sulfate, 3 X 151.9 = 455.7 grams.

So from this, we see that we will need about 456 grams of green vitriol (copperas) to precipitate one mole of gold (197 grams) of gold. from solution. 
Looks like in this case, it would take about 2.3 grams of iron sulfate to precipitate one gram of gold.

Now if the solution contains excess acids, or base metals the amount needed to complete the reaction may differ...
Not much risk of overusing copperas it is soluble, and normally will not precipitate copper, although it can convert CuCl2 into CuCl changing a green solution to brownish.


Copperas is good where PGMs are in solution, and for testing.

Heat is not needed to precipitate the gold or to get the reaction moving forward...

Copperas is a great testing tool to check for gold in solution.
In a spot test it is also useful to test for the gold while precipitating it out of solution, then moving our gold-barren solution to another well of the spot plate we can then test for PGM metals, without the interference of gold affecting the test... 

I am confused about what you are asking about electrolysis in this case?

You can use different keywords, like gold chloride and copperas in the search box to find more on the subject.
http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=48&t=14026

https://goldrefiningforum.com/phpBB3/viewtopic.php?t=14029

https://goldrefiningforum.com/phpBB3/viewtopic.php?f=48&t=12801&p=129008&hilit=Reducing+agents+that+list#p129008

http://www.goldrefiningforum.com/phpBB3/viewtopic.php?f=49&t=6026&p=87562#p87562


----------



## anachronism (Aug 17, 2019)

Great post and informative as usual Sir.

That given in reality it takes as much Ferrous Sulphate as is needed to drop your gold. Stoichiometric weights and masses of precipitants are mostly irrelevant in the real world. Too many other factors mess with the calculations and all you really want and need to do its recover your gold. 

Another thing. Copperas is low grade dehydrated Ferrous Sulphate. Don't mix the two up. Buy the real thing and you'll experience a world of difference.


----------



## Shark (Aug 17, 2019)

As a side note. Hi-Yield has discontinued their copperas type plant food (or what ever they call that aspect of it). They have changed the sulfur (sulphur?) content and possibly other content and now call it Iron Sulfate. I have not tried the new stuff and have no idea yet if that will affect it's use. 

Also for Jon, I am still trying to get around to picking up some ascorbic acid to try out, your take on it has peaked my interest in it lately. To many things to try and not enough hours in the day.....


----------



## FrugalRefiner (Aug 17, 2019)

Copperas is simply an antiquated name for ferrous sulfate (sulphate). It was given that name because of the green color, typical of copper based solutions. It had nothing to do with copper, but the name has persisted for centuries.

Similarly, I recently bought a bag of "nitrate of soda" at my local Ace Hardware store. It's just an old name for sodium nitrate.

Both copperas and nitrate of soda are sold in the US as fertilizers. As such, they aren't highly refined chemicals, but, they are suitable for spreading on your lawn or garden. They also work in refining.

Sometimes, purer grades of chemicals are available at similar or better prices. Sometimes, it's more economical to make your own from readily available products. Sometimes not. It all depends on your individual circumstances. We try to provide information on all possible solutions.

Dave


----------



## BIKAKA (Aug 19, 2019)

Thanks to you guys,all of you #Butcher,#Frugalrefiner,#anacronism etc.
Your deep into mind answers and contributions have become so helpful to me after all.
I work as a local miner in Tanzania(East Africa) and has been working hard online looking for a means to get the cyanide-mercury free method that would replace the uses of cyanide and mercury among the local mining population here around.
Amalgamation is stil the most dominant practice and the awareness to the use of cyanide alternative lixiviants is almost neiglible among local miners(who actually believe the use of mercury is the one and only means to get gold from its ores).
My vision is to establish a green based mining project that would put its efforts on not only reducing but eradicating the use of mercury by providing the folk miners with alternative more economic,healthy and enviromental benign


----------



## anachronism (Aug 19, 2019)

FrugalRefiner said:


> Copperas is simply an antiquated name for ferrous sulfate (sulphate). It was given that name because of the green color, typical of copper based solutions. It had nothing to do with copper, but the name has persisted for centuries.



Maybe so Dave. Ask both Kurt and Goran what they saw when they were at my place using pure green Ferrous Sulphate straight out of the bag. Kurt mentioned that it was utterly different to what he was used to using over there in the US and Goran indicated the same. 

You can shovel it into a solution as crystals and it drops the gold a treat. 

Jon


----------



## g_axelsson (Aug 19, 2019)

Well, I have never bought any copperas so I can't say it is different from other brands. It was a perfect pale greenish blue, quite like the copperas I did for myself with left over sulfuric from my sulfuric cell. Except that some of my crystals were larger.



I think Dave's explanation is quite good.

Left over time copperas is oxidizing and turns brown from the iron oxides. I guess (from what I've read on the forum) that it is often sold as fertilizer as it still works in agriculture even when it is oxidized.

I don't think you will find dehydrated iron sulfate in any garden store. You need to find a specialized chemical dealer, and added to water it would turn into heptahydrate, just as the copperas you had in your bag, Jon.

Butcher, you need to add 7 water to your equation as copperas most often come in the heptahydrate form... about 120 AU more. That will almost double the weight you need to precipitate the gold.

... or according to Nick, take a hand full of the green stuff to get the yellow stuff out. Add another hand full if needed until it tests negative for gold.*
That large bag of ferrous sulfate or copperas worked like a charm. I've been wondering about the "When the process is done the solution turns black."... it's probably a result from CuCl2 being reduced back into CuCl, which is really dark in water solution.

* Nick didn't use the word "stuff" but I can't repeat it here. :mrgreen: 

Göran


----------



## FrugalRefiner (Aug 19, 2019)

anachronism said:


> Maybe so Dave. Ask both Kurt and Goran what they saw when they were at my place using pure green Ferrous Sulphate straight out of the bag. Kurt mentioned that it was utterly different to what he was used to using over there in the US and Goran indicated the same.


Yes, I should have mentioned, as has been discussed many time on the forum, that if the copperas is fresh, it will be green in color, but that it will deteriorate over time, turning brown, and will no longer be useful in refining.

Dave


----------



## anachronism (Aug 20, 2019)

FrugalRefiner said:


> anachronism said:
> 
> 
> > Maybe so Dave. Ask both Kurt and Goran what they saw when they were at my place using pure green Ferrous Sulphate straight out of the bag. Kurt mentioned that it was utterly different to what he was used to using over there in the US and Goran indicated the same.
> ...



It depends on your definition of time Dave. Also the point I was making was not about it being fresh, it was about it being the heptahydrate. Kurt was adamant that this is not the way it is presented as Copperas over there. This is the difference.


----------



## kurtak (Aug 20, 2019)

anachronism said:


> FrugalRefiner said:
> 
> 
> > anachronism said:
> ...



Jon 

To clarify - it's not a matter of the copperas here in the U.S. being different then the copperas over there in England --- it's a question of the supplier - the supplier I got mine from was just a few miles down the road from where I lived - they were a farm supply company & so provide BULK copperas to the farmers for fertilizer & was therefor in a dry form & therefore also oxidized

Being close & handy this was not a problem for me because I would just first dissolve the copperas in some water & then add "a bit" (takes very little) HCl which would clean it up

I am sure I could have looked for it in a hydrated form rather then a dehydrated form - it just never really dawned on me (until seeing you use the hydrated) because the dehydrated was only like 3 miles down the road from where I lived & still worked fine for dropping my gold - I just had to put it through the extra step of cleaning it up before using it to dropping my gold

Kurt


----------



## anachronism (Aug 20, 2019)

I hear you Kurt. 

To be frank I'd always had the impression that the dehydrated version was the version that was always talked about here. That's lead to my confusion as to why so much prep work needs to be done. I once used the "dry" version and frankly I didn't care for it too much. Certainly not when compared to the heptahydrate. 

It's probably way more readily available in this form now than it was ten years ago.


----------



## Shark (Aug 20, 2019)

I have always used mine the same as Kurt. Primarily because that is how Hoke explained it in her book, (and following that method I didn't need to ask questions of the forum). I think she must have used the "dry" version as well. I keep my fertilizer type copperas in self sealing vacuum type canisters. I press all the air out of the bag and seal them in a canister. I have had a partial bag for three years now and it still has the dull greenish color that they had when I opened the bag. I used some last week and they worked as well as they always have. I still want to try the heptahydrate version some time not so much to see if they work better but for the experience and to learn untried methods. The more we know, the easier to over come unexpected problems.


----------



## butcher (Aug 20, 2019)

I have always made my own copperas, what the garden centers sold was oxidized mostly beyond use for what we do.


----------



## Shark (Aug 20, 2019)

I would also like to make some but right now I am pressed for space. I am hoping for a larger building by spring, or sooner. Making the things we use is very interesting and has the potential to teach us much more than just following directions.


----------



## FrugalRefiner (Aug 20, 2019)

Shark said:


> I still want to try the heptahydrate version some time not so much to see if they work better but for the experience and to learn untried methods.


For the record, the copperas distributed by Hi-Yield as fertilizer (now sold as iron sulfate) is ferrous sulfate heptahydrate. If you Google "copperas" and follow the link to Ace Hardware (who sells it in my neck of the woods), you'll find a link to the product safety data sheet. It starts life as iron sulfate heptahydrate.

It's not really a definition of time, but the conditions under which it is stored. Oxygen is the great destroyer, but temperature, humidity, pH, etc. also play a part. As the fresh product "ages", it decompose into a combination of ferric sulfate and ferric oxide/hydroxide. The resulting combination takes on a yellow-brown color.

Dave


----------



## Shark (Aug 20, 2019)

Our temperatures can get pretty hot, but humidity here kills a lot things. Humidity is why I started using the vacuum canisters in first place. I originally stored dried salted shrimp in them for fish bait when visiting the Florida coast. It worked pretty well so I bought some to store a few chemicals in. I found a used vacuum type food sealer that I use on some chemicals that I use very seldom or are fairly expensive as well. It works better on the dry chemicals. I just fold the original package where the label can be easily read and seal the whole thing in a new, clear bag. I still write the contents on the new bag as well, it makes me feel better. 

And we should know by now that anything used for chemicals should be kept separate from anything concerning food or drink. 

Thanks Dave, I am looking for that MSDS next.


----------



## anachronism (Aug 20, 2019)

FrugalRefiner said:


> Shark said:
> 
> 
> > I still want to try the heptahydrate version some time not so much to see if they work better but for the experience and to learn untried methods.
> ...



The message is apparently getting misconstrued. I am referring to hydrated Ferrous Sulphate crystals. Damp, fluffy, wet, "with water," non dessicated. Supplied in opaque bags that keep it fresh even in sunlight for long periods of time until you open in which case a sealed opaque tub is a great idea. As opposed to dried out and dehydrated, in transparent bags or otherwise. 

We can debate semantics all day but the presentation of the product in the two forms makes a difference to how the process is followed in practise.


----------



## nickvc (Aug 20, 2019)

As I have been cited here I feel I should make a comment, I’m a great believer in precipitates are cheap while gold is expensive, why use an inferior product when an alternative is available and so much better, when using ferrous that is green you don’t need to add more liquid to use it, as I said to Göran throw it in stir and look, the color definitely changes once the gold drops but I always check with stannous just to be sure. If you can source decent ferrous you will never ever go back to the nasty version, it’s so easy to use and has few complications.
I must admit I tend to work on fairly high concentrations of gold in solution so the throw it in and check works fine but if you are looking for a few grams then perhaps a little discretion might be required in its use.


----------



## FrugalRefiner (Aug 20, 2019)

Without a doubt, experience plays a large part. Nick has great experience, so he can throw it in based on his experience. When members provide "guidelines" based on "stoichiometry", they're trying to help those who don't have that experience. I think we've all read posts from folks who've dissolved, _maybe_, a gram or two of gold, then dumped in a pound of SMB or copperas. That's where the "guidelines" can be helpful. They're not meant to be used as exact quantities, but as helpful hints as to the amount of precipitant that might be needed.

Dave


----------



## Shark (Aug 20, 2019)

nickvc said:


> As I have been cited here I feel I should make a comment, I’m a great believer in precipitates are cheap while gold is expensive, why use an inferior product when an alternative is available and so much better, when using ferrous that is green you don’t need to add more liquid to use it, as I said to Göran throw it in stir and look, the color definitely changes once the gold drops but I always check with stannous just to be sure. If you can source decent ferrous you will never ever go back to the nasty version, it’s so easy to use and has few complications.
> I must admit I tend to work on fairly high concentrations of gold in solution so the throw it in and check works fine but if you are looking for a few grams then perhaps a little discretion might be required in its use.



Mine almost always turns dark once the gold is out of the solution. Even when working with just a few grams. I had become to think that the dark color was directly related to the change of the metallic gold in some way. (And once again, that is something beyond my understanding.) It is one of the reasons that I like using it as much as it seems to drop cleaner from a dirty solution. These days my solutions aren't quite as dirty as when I started but sometimes they are still pretty bad. Sometime back I posted a picture after a drop and Göran made a comment about the color and ask had I used copperas that got me to watching more closely. I also noticed when using copperas that I get more gold colored flakes with the drop than I normally see with SMB. This lead me to think that the drop pulled less base contaminants down also, as a confirmation of the things I had read across the forum on their use. With all that said, it would be nice to just drop some in without the hydrochloric and other steps involved with the copperas I have been using.

This has been a great and helpful conversation on the subject, thanks to everyone involved.


----------



## Shark (Aug 20, 2019)

anachronism said:


> The message is apparently getting misconstrued. I am referring to hydrated Ferrous Sulphate crystals. Damp, fluffy, wet, "with water," non dessicated. Supplied in opaque bags that keep it fresh even in sunlight for long periods of time until you open in which case a sealed opaque tub is a great idea. As opposed to dried out and dehydrated, in transparent bags or otherwise.
> 
> We can debate semantics all day but the presentation of the product in the two forms makes a difference to how the process is followed in practise.




I hate to keep coming back to this but here goes..............I knew Jon was talking about actually a wet form of Copperas from the pictures he had posted and/or refereed to in various post, but....I had assumed they were stored in dilute sulfuric acid as mentioned a few times on the forum. I think butcher has referred to that method in the past for storing some of his homemade copperas. I had never realized that Jon meant they were shipped/stored in water. For some reason that just makes me more curious about trying them now.


----------



## BSGMiner (Aug 20, 2019)

With all the mentions of *copper chloride* and *iron sulfate*, which is the more preferred/useful byproduct, and why? Thanks.


----------



## butcher (Aug 20, 2019)

With all the mentions of copper chloride and iron sulfate, which is the more preferred/useful byproduct, and why? Thanks.

For me, it depends there are so many uses for either of these, you can make other chemicals, Use them in recovery and refining...
It would be like asking me, which tool was the best in my toolbox.


----------



## BSGMiner (Aug 20, 2019)

butcher said:


> For me, it depends there are so many uses for either of these, you can make other chemicals, Use them in recovery and refining...
> It would be like asking me, which tool was the best in my toolbox.


Good point. I like the regenerative nature of copper chloride that you've discussed before, and ending up with some iron sulfate to precipitate gold someday will come in handy, so it looks like a win-win with both, I suppose. (I'm specifically referring to the byproducts from the saltwater cell for de-plating silverware, adding HCl & H2O2 to dissolve the base meals, and then the sulfuric-iron method of converting the silver chloride)


----------



## butcher (Aug 21, 2019)

My opinion is worrying about the byproduct here, is not worth the product of silver.


The Ferrous sulfate I make to precipitate gold is not a byproduct, It is easy and cheap to make, And I want my ferrous sulfate pure and fresh...

2AgCl + H2SO4 + Fe --> Ag + FeSO4 + 2HCl

You would have a solution of ferric chloride mixed with hydrochloric acid, you could distill off the HCl as gas, and make a tiny bit of copperas crystals but it would not be worth the effort...

As far as copper chloride, well I generate way too much, which is still useful just in working with the cupric chloride etching process.


----------



## anachronism (Aug 21, 2019)

FrugalRefiner said:


> Without a doubt, experience plays a large part. Nick has great experience, so he can throw it in based on his experience. When members provide "guidelines" based on "stoichiometry", they're trying to help those who don't have that experience. I think we've all read posts from folks who've dissolved, _maybe_, a gram or two of gold, then dumped in a pound of SMB or copperas. That's where the "guidelines" can be helpful. They're not meant to be used as exact quantities, but as helpful hints as to the amount of precipitant that might be needed.
> 
> Dave



You make me laugh Dave. I have to laugh otherwise I'd cry.


----------



## BSGMiner (Aug 21, 2019)

butcher said:


> ...2AgCl + H2SO4 + Fe --> Ag + FeSO4 + 2HCl
> 
> You would have a solution of ferric [stt]chloride[/stt] [sulfate?] mixed with hydrochloric acid, you could distill off the HCl as gas, and make a tiny bit of copperas crystals but it would not be worth the effort...


Thanks for giving the balanced equation to help understand better what Hoke was talking about with the Sulfuric-Iron process. Somehow, I was unaware that it would result in 2HCl. I think you meant to say Ferric Sulfate, though, right? Anyway, I'll definitely re-read that section in Hoke's book in a new light now.

Also, do I understand correctly that you just use common steel nails for the Sulfuric-Iron method?


----------



## snail (Aug 21, 2019)

I've used bolts and rebar before. I was concerned because the solution was black, but a pass through a coffee filter gave me a clear green solution that crystallized beautifully.
It worked with no issues. 
It's my favorite precipitant for the first drop from dirty solutions, no foul odor!


----------



## butcher (Aug 21, 2019)

BSGMiner said:


> butcher said:
> 
> 
> > ...2AgCl + H2SO4 + Fe --> Ag + FeSO4 + 2HCl
> ...



No, I did not mean to say you would be left with a solution of ferric sulfate, I was talking about the 
solution would also contain ferric chloride, ferrous chloride, as well as HCl along with your copperas...


----------



## BSGMiner (Aug 21, 2019)

butcher said:


> No, I did not mean to say you would be left with a solution of ferric sulfate, I was talking about the
> solution would also contain ferric chloride, ferrous chloride, as well as HCl along with your copperas...


Ahh, so the H2SO4 + Fe is strong enough to cause the Cl from the AgCl to react with the Fe to create FeCl since Iron is higher than Silver in the reactivity series. Somehow, I lost the fact about FeCl along the way once I got it in my head about HCl being made too.

I suppose since there won't be a perfectly balanced amount of Fe and Cl to only make FeCl, so excess Cl will result in HCl as well.

If that's right, then I think I got it now.


----------



## butcher (Aug 21, 2019)

We can have several different reactions going on in a solution, depending on conditions, elemental iron reacting not only with the sulfuric acid but also the hydrochloric acid in solution, we could even have some copper ions in solution.

Basically, in the solution we have a bowl full of acids and metals as well as the salts of the metals and the salts of the acids reacting with each other, external conditions can also come to play in these reactions ions from the metals and the acids reacting with each other.

In reality, you would not have copperas in solution, but we do have a soup of ions positive metal anions and negative cations which react with each other and the insoluble metals or salts within this soup bowl.
Ag, Fe, Cu, and other positive metal ions depending on the purity of silver chloride, the iron, and the acids used...
We also have the negative ions of the acids Cloirides, sulfates...


We do not have ferrous sulfate in this soup, but we do have positive Fe ions (Cations)and negative Cl- And SO4-(Anions) which we could make ferrous sulfate from this soup bowl of ions.
Yes we could evaporate the solution, removing the water, breaking down the more volatile acids with the heat of evaporation and removing the free HCl gas, and crystalizing out the Ferrous sulfate from the more soluble ionic salts in solution, with this we can also convert the iron chloride salts into iron sulfate salts as long as there was some free H2SO4, Chloride salts will give up their positive metal ions to the sulfuric acid to form metal sulfate salts, when evaporated down and concentrated under a strong heat, as the more volatile chloride ions are driven from solution, or still soluble in solution, for a higher purity we could recrystallize the product to remove drag down and contamination of the crystals...


Edit to correct my mistake, I had the positive metal ions (the Cations), and the non-metal ions (Anions) names backward.


----------



## g_axelsson (Aug 22, 2019)

Shark said:


> I hate to keep coming back to this but here goes..............I knew Jon was talking about actually a wet form of Copperas from the pictures he had posted and/or refereed to in various post, but....I had assumed they were stored in dilute sulfuric acid as mentioned a few times on the forum. I think butcher has referred to that method in the past for storing some of his homemade copperas. I had never realized that Jon meant they were shipped/stored in water. For some reason that just makes me more curious about trying them now.


It's more like damp sand. Here is the best picture I have of the bag of copperas. Obviously not stored in water. My guess is that it is a 20 - 25 kg bag.




Göran


----------



## Shark (Aug 22, 2019)

I was convinced to try and make some of my own. They are just starting to form crystals. I should know more later on how they turn out. The green copperas seem to be termed as FeS04 7H2O. It seems other grades(?) have fewer H2O molecules(?). The different H2O figures can also change the color outcome it seems. 


If nothing else I have some chemistry to work, again..


----------



## g_axelsson (Aug 23, 2019)

My bulk copperas turned out like this,




The dark color is probably from carbon contamination from the iron used. I dissolved it in enough water and filtered it off and store it as a solution in a chemical bottle. Very easy to pour off what I need. I just need to keep it apart from a bottle with silver nitrate slightly contaminated with copper, it looks almost the same.  




I don't use it often, I prefer SMB most of the time, so the solution I made up over two years ago is still sitting in it's bottle and looks like I made it yesterday. Keep it sealed from oxygen and it will not degrade. 

Göran


----------



## butcher (Aug 23, 2019)

The crystals do look to be a much darker green, you could recrystallize them easily.
The redissolved crystals / filtered solution looks better.


----------



## Shark (Aug 23, 2019)

My first try at making copperas and somethings seems off. The first half seems to have came down as whitish crystals and very fine. The second part seems to be a nice pale green and looks right, or what I picture in my mind as "looks right".

I used 300 Ml distilled water, 44 grams #0000 Steel wool and 50 Ml of 93% sulfuric acid. Everything dissolved fine, using some low heat. I left it on a medium heat until the crystals started to form, then lowered it a small bit more. Keeping just enough heat to see an occasional puff of steam until the crystals started to get thick, then I turned the heat off.

Any idea why the first part came out whitish?
Will it affect the performance of them as a precipitant?


----------



## butcher (Aug 23, 2019)

The ferrous sulfate looks good and will work good, you should not have problems using it, the crystals will be fairly pure, it is easy to recrystallize it for higher purity.

I cannot think of an answer why some crystals are more clear or white.


----------



## FrugalRefiner (Aug 23, 2019)

Shark said:


> My first try at making copperas and somethings seems off. The first half seems to have came down as whitish crystals and very fine. The second part seems to be a nice pale green and looks right, or what I picture in my mind as "looks right".


A couple of possibilities.

Ferrous sulfate can exist in a variety of different states as far as the "water of crystallization". As mentioned earlier in this thread, the most common is the heptahydrate: FeSO4·7H2O, i.e., seven molecules of water attached to each molecule of FeSO4. You could have other forms. FeSO4·4H2O is white, and relatively common in nature.

You mentioned that you have fine crystals at the top, which would have formed when the solution was more dilute. Consider that, like gold precipitated from solution, which is brown, your fine crystals may just refract light differently than the large crystals that formed later from a more concentrated solution, so their color could appear different.

Based on your starting material, it should all be fine.

Dave


----------



## Shark (Aug 23, 2019)

Thanks guys, I have enjoyed doing this more than I expected. I can order this stuff from Amazon for about $15 a pound or so. I just wanted the experience as much as anything. For the money, just buying it is not expensive at all. A pound will drop a lot of gold from solution. Since I had everything on hand the experience was very interesting and time well spent, just not a necessity. If I was out of precipitants and need something fairly quick this isn't difficult or real time consuming. It is another tool in the box that may be needed one day, and I am fairly sure I can do it again.

Now I just need some gold in solution to see how they work first hand,


----------



## BSGMiner (Aug 24, 2019)

Congrats on the successful experiment. Thanks for sharing. This and looking up some NurdRage vids of similar experiments makes me want to try someday.


----------



## butcher (Aug 24, 2019)

Copperas is as useful, if not more useful than sodium metabisulfite, or other sulfite reducing agents as reagents ( or tools in my box) in my opinion.

Copperas will not reduce copper ions in the solution as the sulfites reagents can.
As in refining the second time (for higher purity) using a different reducing agent the second refining.
Reducing gold from a solution containing PGMs.
For testing gold for gold.
For precipitating gold in a test (removing the gold) so we can test for the PGM metals in solution...
Easy to make, good storage life (when made and stored properly.

Gold chloride reduction with ferrous sulfate:
HAuCl4 + 3FeSO4 --> Au + Fe2(SO4)3 + FeCl3 + HCl

aqua regia overuse of acids:
3HCl + 3HNO3 + 3FeSO4 --> Fe2(SO4)3 + 3NO2 + FeCl3 + 3H2O


----------



## Shark (Sep 20, 2019)

My copperas have been sitting for a while now in open air and I have seen some changes. The white colored parts turned dark quicker and took on a dirty grey look. The green colored ones still look good and have kept their green color well. I am in the middle of redissolving them and will recrystallize them as well. If they look good after this second process I will be trying them on some gold. Now I need to get the gold in solution....


----------



## FrugalRefiner (Sep 20, 2019)

Once you have crystals you're happy with, store them in an air tight container and add a few drops of dilute sulfuric to help preserve them.

Dave


----------

