Help with Precipitation.

[SureShot72]

Well I had precipitated .25 troy from AR soulution. Once the brown cloud had fallen. My AR was still yellow gold in color. I drained off bulk of liquid to caim my prize at the bottom. I then tried to precipitate some more. Nothing. So I thought maybe I had too much nitric. I steamed it down to half the amount. Solution had turned dark yellow almost redish. Then added a little water and split the solution into two glass jars. The first a room temp, I tried SMB again. Nothing. It just turns the yellow to a light yellow with a tint of greenish blue, but still mostly yellow. Then I let it sit a few days and it went back to a darker yellow. The second jar I cooled for 5 hours on ice with salt added. I still had the same reaction. Is their too much SMB in solution now? My stannus test turns black as it did before I dropped the .25 from the first precipitation.
Is it possible for the AR "which is now very dilute and had much urea and SMB added" to be yellow with no gold? Maybe my stannus solution is old and not working.
I tried a few searches for "will not precipitate", and "precipitation problem" among other things, I still have no idea what may be going on.
I don't mind if the gold is all out, but all that I have seen and read points to the solution turning clear when the gold is out.

Thank you all.

 

[nickvc]

You can still have metals in the solution after precipitation as you are only using a precipitant for gold and the quality of your starting product determines what you have. If you feel you have values left add some copper sheet and see if anything cements out, if it does you can test what exactly you have.

 

[Harold_V]

From your description, it is my opinion that you have iron in solution.

When using stannous chloride, it is advisable to have a gold standard solution at your disposal, so you can verify it works. It takes only a grain or two of gold to prepare enough solution to last a long time, so there's no excuse for not having some at your disposal. Best of all, even those couple grains can be recovered by processing the tested materials, or by sending the test to the stock pot.

There are tests for iron in solution. If you'll explore Hoke, you'll discover what chemical reagent is required. The presence of iron results in an almost blood red reaction when you perform a test and there's iron present.

Can you see the value in testing?

Harold

 

[samuel-a]

I agree with Harold.
Learning to test solution is as important as learning how to make them.

It sounds like you have a solution of base metals that may (or maynot) fools you into thinking it's gold, i think most of us been there at some point at the begining.
Grab a sample from your liquides and heat it for cuple of minutes to rid of SO2. Then dilute it 3-4 times over with water and test again.
Gold, even at very low presence will give faint purple stain.

Also worth a shot and good to have around anyway, testing with DMG for presence of Pd (depends on you source material).
We have a member here, Patnor1011 who sell DMG test solution at very reasonably price.

 

[jasondean88888]

From your description, it is my opinion that you have iron in solution.

When using stannous chloride, it is advisable to have a gold standard solution at your disposal, so you can verify it works. It takes only a grain or two of gold to prepare enough solution to last a long time, so there's no excuse for not having some at your disposal. Best of all, even those couple grains can be recovered by processing the tested materials, or by sending the test to the stock pot.

There are tests for iron in solution. If you'll explore Hoke, you'll discover what chemical reagent is required. The presence of iron results in an almost blood red reaction when you perform a test and there's iron present.

Can you see the value in testing?

Harold

I'm only a couple weeks into the process of educating myself, but I simply can't believe the number of people who do this without testing. It seems so basic. And it seems pretty self evident that it saves WAY more than it costs, plus you never have to lose any gold doing it. As has been mentioned, you can just add the tested sample back into the current or future batches. One thing I'm curious about, can someone explain what exactly is happening when using stannous cloride? If you have a solution that is free from copper ect and has gold, is the black color change the gold precipitating out or is it the tin or a mix of the two? I'm guessing it's the gold being forced out by the tin...

 

[Harold_V]

I'm only a couple weeks into the process of educating myself, but I simply can't believe the number of people who do this without testing. It seems so basic. And it seems pretty self evident that it saves WAY more than it costs, plus you never have to lose any gold doing it.

I have a policy---one whereby if a reader isn't using stannous chloride, I have no interest in trying to help. If they can overlook what is so obvious, they likely will never enjoy success in ways that those that pay attention and do things properly do. Being a moron comes with a price-----part of which is not gleaning help from those that may have it to offer.

As has been mentioned, you can just add the tested sample back into the current or future batches.

That's not recommended, but there's nothing wrong with sending the samples to the stock pot, where any values will be recovered. Returning test samples can create problems, thanks to the presence of tin, which is best kept out of the refining circuit.

can someone explain what exactly is happening when using stannous cloride?

Stannous chloride reacts with gold chloride to form colloidal particles of gold, thus the purple color.

Harold

 

[jasondean88888]

I'm only a couple weeks into the process of educating myself, but I simply can't believe the number of people who do this without testing. It seems so basic. And it seems pretty self evident that it saves WAY more than it costs, plus you never have to lose any gold doing it.

I have a policy---one whereby if a reader isn't using stannous chloride, I have no interest in trying to help. If they can overlook what is so obvious, they likely will never enjoy success in ways that those that pay attention and do things properly do. Being a moron comes with a price-----part of which is not gleaning help from those that may have it to offer.

As has been mentioned, you can just add the tested sample back into the current or future batches.

That's not recommended, but there's nothing wrong with sending the samples to the stock pot, where any values will be recovered. Returning test samples can create problems, thanks to the presence of tin, which is best kept out of the refining circuit.

can someone explain what exactly is happening when using stannous cloride?

Stannous chloride reacts with gold chloride to form colloidal particles of gold, thus the purple color.

Harold

col·loid (kloid)
n.
1. Chemistry
a. A system in which finely divided particles, which are approximately 10 to 10,000 angstroms in size, are dispersed within a continuous medium in a manner that prevents them from being filtered easily or settled rapidly.
b. The particulate matter so dispersed.

I put the definition up there because I didn't know that word and figured others didn't either. So working with this definition Harold, you're saying that Stannous Cloride precipitates super small particals of gold? I'm guessing that the tin takes the place of the gold in solution? If all of that is right, doesn't that mean that stannous could be used as a precipitant? Since I'm sure thats not the case (or else everyone would be doing it), I'm trying to figure out what information I'm missing that fills in the missing puzzle pieces for me. Or is it simply that the stannous will precipitate EVERYTHING in solution leaving you with gold...but everything else too? I'm thinking that last bit is the right answer. This is normally how I learn. If I'm allowed to turn things over and backwards and figure out the answer on my own (with help in the form of someone letting me bounce words off them) then it's not something I was taught, but something I reasoned out for myself, which sticks with me soooo much better. Still, please let me know if I'm off base or if theres some truth to what I said. Thanks for the clear, plain, and thorough explanation.

 

[Harold_V]

So working with this definition Harold, you're saying that Stannous Cloride precipitates super small particals of gold?

Correct.

I'm guessing that the tin takes the place of the gold in solution? If all of that is right, doesn't that mean that stannous could be used as a precipitant? Since I'm sure thats not the case (or else everyone would be doing it), I'm trying to figure out what information I'm missing that fills in the missing puzzle pieces for me.

Key here is the fact that the particles are so small they can't be filtered. It's also important that when you precipitate any of the precious metals that they can be selectively precipitated. Because stannous chloride reacts with all of them, that is not the case, plus the fact that it precipitates colloids makes it far less than desirable. There are other precipitants that work far better, and don't create any issues.

Or is it simply that the stannous will precipitate EVERYTHING in solution leaving you with gold...but everything else too?

Yeah, this one-----plus the inherent problems of tin being involved in solutions. It has a way of making filtration difficult, if not impossible. There's nothing to be gained by its use, aside from testing, where it is essential.

Harold

 

[jasondean88888]

So working with this definition Harold, you're saying that Stannous Cloride precipitates super small particals of gold?

Correct.

I'm guessing that the tin takes the place of the gold in solution? If all of that is right, doesn't that mean that stannous could be used as a precipitant? Since I'm sure thats not the case (or else everyone would be doing it), I'm trying to figure out what information I'm missing that fills in the missing puzzle pieces for me.

Key here is the fact that the particles are so small they can't be filtered. It's also important that when you precipitate any of the precious metals that they can be selectively precipitated. Because stannous chloride reacts with all of them, that is not the case, plus the fact that it precipitates colloids makes it far less than desirable. There are other precipitants that work far better, and don't create any issues.

Or is it simply that the stannous will precipitate EVERYTHING in solution leaving you with gold...but everything else too?

Yeah, this one-----plus the inherent problems of tin being involved in solutions. It has a way of making filtration difficult, if not impossible. There's nothing to be gained by its use, aside from testing, where it is essential.

Harold

YAY! I'm so digging the learning curve on this stuff! Thanks again for your reply! Now I have to think on what to do with the solutions I have created. (Dont tell me yet!) I ran a few experiments I knew had a 99% chance of failure, but I tend to learn far more from failing and being forced to figure out why rather than just having the answer handed to me...which is why I occassionally run experiments I know will fail even after I know the right way.

 

[rewalston]

Jason

Your experimental solutions and tested solutions can be placed in a 5 gallon plastic bucket (assuming your volume isn't too great). As time goes on you'll move to a bigger bucket or barrel. This container is referred to as the "Stock Pot". This is where all of your waste solutions go to after you've done your recovery, washes, etc. Because your stock pot will have a multitude of different metals in there, gold, copper, silver, tin, lead, maybe even some platinum or palladium. When it gets full you can drop all of the metals in the solution for recovery and then treating the resulting liquor for safe disposal. Check out the following link and it will explain everything.

Dealing with wastes

I hope it helps you out.

Rusty

 

[Harold_V]

What Rusty said, but with this caveat. Sending *all* solutions to the stock pot is not wise. Sending solutions that bear traces of values should be the objective, so you don't end up endlessly recycling solutions, raising the cost of extracting traces of values. In other words, use stannous chloride and other tests to determine if a solution contains precious metals. If it does not, treat it as waste material instead. You'll be happy you did when the time comes to recover the faint traces of values you gather in the stock pot.

Harold

 

[jasondean88888]

So working with this definition Harold, you're saying that Stannous Cloride precipitates super small particals of gold?

Correct.

I'm guessing that the tin takes the place of the gold in solution? If all of that is right, doesn't that mean that stannous could be used as a precipitant? Since I'm sure thats not the case (or else everyone would be doing it), I'm trying to figure out what information I'm missing that fills in the missing puzzle pieces for me.

Key here is the fact that the particles are so small they can't be filtered. It's also important that when you precipitate any of the precious metals that they can be selectively precipitated. Because stannous chloride reacts with all of them, that is not the case, plus the fact that it precipitates colloids makes it far less than desirable. There are other precipitants that work far better, and don't create any issues.

Or is it simply that the stannous will precipitate EVERYTHING in solution leaving you with gold...but everything else too?

Yeah, this one-----plus the inherent problems of tin being involved in solutions. It has a way of making filtration difficult, if not impossible. There's nothing to be gained by its use, aside from testing, where it is essential.

Harold

Was hoping for some insight:
I have essentially recreated the steps in Lasersteves AP video as closely as I could. I only used a pound of some really beautiful gold fingers instead of 600grams like he did. They were all fully covered on both sides. Everystep has gone textbook. I had about 3grams of foils and was very careful during disolving. I added very small amounts of clorox when disolving, stirred, and only added another tablespoon or so if there were still undisolved foils. Once it was all disolved, I filtered through 3 pre wetted filters to seperate out the solder mask. I then let it set for about 12 hours to allow the clorox to evaporate. I poured off about an ounce and added a small about of smb to test and see if everything was ok. It took a couple minutes, but it eventually turned clear, and then VERY slightly muddy. Just enough that I could tell there was gold precipitating out. I then let it set for another 12 hours just to be sure. After adding a very small amount of smb as a time (I'm up to about 1.5 TBS) I've got SOME gold but it isn't anywhere near what I expected. I would say it's about 2 to 3 pinches worth.

Is this normal? It seems like it should have had a yield of (percentage wise) much more. Do I need to add more smb maybe? I'm hesitant to as that was something I did wrong in my first batch. I'm waiting for it to settle right now and will run another test with stannous. (Last test was positive so I added a bit more smb) But I'm getting to a point with the smb that Im really worried I'm going to far. Thanks in advance for the insight/help.

 

[Geo]

keep in mind that gold is very very heavy compared to other material of the same volume.it doesn't take much gold to amount to 3 grams. after everything in the solution settled, did you test to see if any gold remained in solution? one problem you may face is trying to precipitate a metal you know is in solution and cant seem to get it to drop out of solution.you may have had free chlorine left even after 12 hours. next time gently warm the solution until it starts to steam and keep it at this temperature for 5-10 minutes. the heat will insure you have driven off any excess chlorine.also, have you ever heard the saying a watched pot never boils? put the needed amount of precipitant in the solution (3 grams of gold = 6 grams of SMB) and leave it alone.if in the morning by the afternoon everything that is going to precipitate should have dropped. make a habit out of testing solutions even after the drop to insure all gold has been precipitated.

 

[dtectr]

So working with this definition Harold, you're saying that Stannous Cloride precipitates super small particals of gold?

Correct.

I'm guessing that the tin takes the place of the gold in solution? If all of that is right, doesn't that mean that stannous could be used as a precipitant? Since I'm sure thats not the case (or else everyone would be doing it), I'm trying to figure out what information I'm missing that fills in the missing puzzle pieces for me.

Key here is the fact that the particles are so small they can't be filtered. It's also important that when you precipitate any of the precious metals that they can be selectively precipitated. Because stannous chloride reacts with all of them, that is not the case, plus the fact that it precipitates colloids makes it far less than desirable. There are other precipitants that work far better, and don't create any issues.

Or is it simply that the stannous will precipitate EVERYTHING in solution leaving you with gold...but everything else too?

Yeah, this one-----plus the inherent problems of tin being involved in solutions. It has a way of making filtration difficult, if not impossible. There's nothing to be gained by its use, aside from testing, where it is essential.

Harold

Was hoping for some insight:
I have essentially recreated the steps in Lasersteves AP video as closely as I could. I only used a pound of some really beautiful gold fingers instead of 600grams like he did. They were all fully covered on both sides. Everystep has gone textbook. I had about 3grams of foils and was very careful during disolving. I added very small amounts of clorox when disolving, stirred, and only added another tablespoon or so if there were still undisolved foils. Once it was all disolved, I filtered through 3 pre wetted filters to seperate out the solder mask. I then let it set for about 12 hours to allow the clorox to evaporate. I poured off about an ounce and added a small about of smb to test and see if everything was ok. It took a couple minutes, but it eventually turned clear, and then VERY slightly muddy. Just enough that I could tell there was gold precipitating out. I then let it set for another 12 hours just to be sure. After adding a very small amount of smb as a time (I'm up to about 1.5 TBS) I've got SOME gold but it isn't anywhere near what I expected. I would say it's about 2 to 3 pinches worth.

Is this normal? It seems like it should have had a yield of (percentage wise) much more. Do I need to add more smb maybe? I'm hesitant to as that was something I did wrong in my first batch. I'm waiting for it to settle right now and will run another test with stannous. (Last test was positive so I added a bit more smb) But I'm getting to a point with the smb that Im really worried I'm going to far. Thanks in advance for the insight/help.

Are you talking about your 1 ounce test batch representative of the whole batch? If you do your math, 1 pound (about 454g.) vs. lazersteve's 600g (1.3 lb.) numbers should be right. Don't try this experiment alot, though.

When I was a sheetrock contractor, everyone hated taping closets, because a closet, no matter how small, has EXACTLY the same number of corners, angles, and drops (top, vertical & horizontal corners) as a large room, & actually took almost as long, with a lot less progress made.

It takes exactly the same number of steps to process a fraction of a batch as it does to do the whole one, and the results are often times less satisfying.

 

[jasondean88888]

So working with this definition Harold, you're saying that Stannous Cloride precipitates super small particals of gold?

Correct.

I'm guessing that the tin takes the place of the gold in solution? If all of that is right, doesn't that mean that stannous could be used as a precipitant? Since I'm sure thats not the case (or else everyone would be doing it), I'm trying to figure out what information I'm missing that fills in the missing puzzle pieces for me.

Key here is the fact that the particles are so small they can't be filtered. It's also important that when you precipitate any of the precious metals that they can be selectively precipitated. Because stannous chloride reacts with all of them, that is not the case, plus the fact that it precipitates colloids makes it far less than desirable. There are other precipitants that work far better, and don't create any issues.

Or is it simply that the stannous will precipitate EVERYTHING in solution leaving you with gold...but everything else too?

Yeah, this one-----plus the inherent problems of tin being involved in solutions. It has a way of making filtration difficult, if not impossible. There's nothing to be gained by its use, aside from testing, where it is essential.

Harold

Was hoping for some insight:
I have essentially recreated the steps in Lasersteves AP video as closely as I could. I only used a pound of some really beautiful gold fingers instead of 600grams like he did. They were all fully covered on both sides. Everystep has gone textbook. I had about 3grams of foils and was very careful during disolving. I added very small amounts of clorox when disolving, stirred, and only added another tablespoon or so if there were still undisolved foils. Once it was all disolved, I filtered through 3 pre wetted filters to seperate out the solder mask. I then let it set for about 12 hours to allow the clorox to evaporate. I poured off about an ounce and added a small about of smb to test and see if everything was ok. It took a couple minutes, but it eventually turned clear, and then VERY slightly muddy. Just enough that I could tell there was gold precipitating out. I then let it set for another 12 hours just to be sure. After adding a very small amount of smb as a time (I'm up to about 1.5 TBS) I've got SOME gold but it isn't anywhere near what I expected. I would say it's about 2 to 3 pinches worth.

Is this normal? It seems like it should have had a yield of (percentage wise) much more. Do I need to add more smb maybe? I'm hesitant to as that was something I did wrong in my first batch. I'm waiting for it to settle right now and will run another test with stannous. (Last test was positive so I added a bit more smb) But I'm getting to a point with the smb that Im really worried I'm going to far. Thanks in advance for the insight/help.

Are you talking about your 1 ounce test batch representative of the whole batch? If you do your math, 1 pound (about 454g.) vs. lazersteve's 600g (1.3 lb.) numbers should be right. Don't try this experiment alot, though.

When I was a sheetrock contractor, everyone hated taping closets, because a closet, no matter how small, has EXACTLY the same number of corners, angles, and drops (top, vertical & horizontal corners) as a large room, & actually took almost as long, with a lot less progress made.

It takes exactly the same number of steps to process a fraction of a batch as it does to do the whole one, and the results are often times less satisfying.

I didn't make a one ounce test batch. I poured off an ounce of the overall batch to test for precipitation to see if the clorox had evaporated yet. When I saw that gold precipitated out of the one ounce, I felt comfortable proceeding with the full batch. The few pinches I'm talking about is for the total batch.

 

[Geo]

you can actually add too much smb and the SO2 sort of floats the particles of gold and it seems like it never settles. the liquid stays clowdy and wont clear up. try heating your solution,either way you should see some sort of change.if you added too much smb then the heat will drive off the SO2 gas and let any precipitate settle and if its still got free chlorine the heat will make it gas off and you will get a positive with a stannous test. if you have free chlorine in your solution you will get a negative test result even if gold is there.