# nitric solution too thick for filtration....



## hfywc (Aug 25, 2010)

hi again.

quick question. 

i dissolved 1 pound of pins in a concentrated nitric acid...almost all of the base metal are completely dissolved. i would like to start the filtration process but afraid that the solution is too thick to pass through the filter...is it okay if i add water to the solution to make it thinner? would i still be able to recover the silver after adding if there are any? 

thanks,
alan


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## Oz (Aug 25, 2010)

You would have to describe “too thick” better, but it sounds like you have tin in your nitric.


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## hfywc (Aug 25, 2010)

i didn't measure nor put some water in the nitric acid i used to dissolved the pins...what i am saying is that i probably didn't use enough nitric acid. now the solution is saturated with the base metal more than it could contain -- this is what i meant with "thick". 

also, any problem with tin being present in the solution?


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## Oz (Aug 25, 2010)

By concentrated nitric acid do you mean 70%? If so it should have been diluted by half before adding pins, but it will still help some now due to the solubility of the base metals. 

It does not take much tin in nitric before it becomes a non-filterable gelatinous mess.

Did you use heat when digesting your pins?


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## Higashi (Aug 27, 2010)

hfywc said:


> i didn't measure nor put some water in the nitric acid i used to dissolved the pins...what i am saying is that i probably didn't use enough nitric acid. now the solution is saturated with the base metal more than it could contain -- this is what i meant with "thick".
> 
> also, any problem with tin being present in the solution?




maybe there's not enough HNO3, maybe there's not enough H20.

the problem that i see is that you might not have enough water to dissolve the nitrates that formed from the reaction between nitric acid and the base metals.

a concentrated nitric acid is about 70% nitric acid and 30% water. 

ie., each Kg of 70% nitric acid contain only 300ml of water.

based on that you can calculate the maximum each base metal nitrates maximum that could be contained in your solution. make some probability chart.

1 kg of HNO3 70% has enough NO3- ions to react with certain amount of copper to form copper nitrates, but not enough H20 to dissolve all of them. Do some calculations and see for your self. 

My datas in my spreadsheet but this comp dont have Excell, I'm too lazy/sleepy to check and calculate the specific figures again (it's 5AM here now)...




now if you have tin in it, that's another extra problem.




adding more water doesn't make it "more acid nitric", it's just more water and more dillute solution of nitric acid.


my 2 cents.


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## hfywc (Aug 28, 2010)

hi.

most of the base metals are already dissolved, if it's safe to still add water then i will go ahead and do so. however would i still be able to recover the dissolved silver after adding water? 

thanks.

alan


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## goldsilverpro (Aug 28, 2010)

Just add an equal amount of water as you have acid. Hot water would be best. The water won't affect the silver recovery.


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## hfywc (Sep 1, 2010)

great, just the answer i am looking for..thanks gsp. alan


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## fyatim (Apr 20, 2017)

I m trying to recover some gold field pieces. I use diluted nitric acid 68% to dissolve the base materials.
Here is the picture of what I end with: a red/brown thick mud hard to filter.
Can you help me identified this material?


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## fyatim (Apr 20, 2017)




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## nickvc (Apr 20, 2017)

Can you describe better or post a picture of what exactly you dissolved as until then we can only guess.


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## Palladium (Apr 20, 2017)

If i had to guess iron! The green of the nitric tell me and the rust to go along with it!
Add more nitric and heat until completion. I think what you will find out is the items are plated and not filled and they are on a cheap iron magnetic base. Yield will be low!


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## Palladium (Apr 20, 2017)

Don't dilute it or the worse it will get! Let everything settle and siphon the clear liquid off the top. Once it's concentrated again add nitric and proceed.


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## modtheworld44 (Apr 20, 2017)

Follow Palladium"s instructions,Iron falls out of nitric when it is diluted.



modtheworld44


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## justinhcase (Apr 20, 2017)

I always use hydrochloric acid with iron and iron oxide.
Fe2O3 + 6HCL -> 2FeCl3 + 3H2O
as you say settle and take off the liquor,but then may be wash and settle again.
Then try a hydrochloric leach?
Try a sample each way before you make a decision.


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## fyatim (Apr 20, 2017)

Here is a picture of what has been treated as Goold field.


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## fyatim (Apr 20, 2017)

For the rest, I will follow Palladium"s instructions and will let you know what happens.


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## Topher_osAUrus (Apr 20, 2017)

justinhcase said:


> I always use hydrochloric acid with iron and iron oxide.
> Fe2O3 + 6HCL -> 2FeCl3 + 3H2O
> as you say settle and take off the liquor,but then may be wash and settle again.
> Then try a hydrochloric leach?
> Try a sample each way before you make a decision.



That could end up dissolving the gold, unless he incinerates between the nitric leach/rinse and the hcl leach. If there is enough iron (or very little hcl) it would precipitate the gold back out via cementation, but since he is already doing a nitric leach, continuing it would be the quickest. 

Though, I have had pretty good luck with using a dilute sulfuric leach after the initial nitric run. After the iron is gone, assuming more base metal exists, I do another nitric bath before going to ar, just to be certain all the base metal junk is eliminated.


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## Palladium (Apr 20, 2017)

The chain marked 24k was probably the culprit and iron.


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## justinhcase (Apr 21, 2017)

Topher_osAUrus said:


> justinhcase said:
> 
> 
> > I always use hydrochloric acid with iron and iron oxide.
> ...


I do not think there is much chance of getting any gold into solution while there is so much base metals present. Though you may put it into solution and instantly cement it as fine deposition.
As you will have to rely on settling instead of filtering that should not be too much of an issue.
You can see the remains of a ring poking out.
The sediment should wash off the remaining metal so you can see what is left.
Fine particle should be settled out.
if the nitric leach has produced such an adverse reaction ,stop and test all alternatives before you try and make a decision.
He has the gunk so only he can test which rout is best.


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## nickvc (Apr 21, 2017)

Looking at what you are working with its quite possible that some was simply plated and maybe some karat items, if it's plated that could well be your problem as they plate a myriad of alloys.
I would be tempted to filter your solution and the powder and any solids off, rinse well several times put them back into a beaker and try some dilute sulphuric with gentle heat, if that fails to remove the powder then rinse off the sulphuric and try some HCl, if that was all you started with then unless there was some karat material you are not looking at a lot of gold but be sure to test your solutions before safe disposal.


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## g_axelsson (Apr 21, 2017)

justinhcase said:


> Topher_osAUrus said:
> 
> 
> > justinhcase said:
> ...


I can't see any base metals left. Rust isn't base metal, it's a compound and would not cement any gold from a solution.

I haven't worked with gold filled yet but many times with tricky sediments...

If this was gold filled, wouldn't the karat gold be sitting on the bottom as small flakes and pieces? If so, the red silt could be washed away before it settle and with a couple of washes most of it could be separated from undissolved base metal and gold pieces. The silt and any fine gold particles can then be processed away from the major part of the gold.
It is better to have as little gold in with the problem material as possible.

Göran


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## justinhcase (Apr 21, 2017)

g_axelsson said:


> justinhcase said:
> 
> 
> > Topher_osAUrus said:
> ...


Bottom picture of a beaker. you can see a ring or some other curved bit of metal sticking out.
Let us see if there are any undigested metals .


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## Topher_osAUrus (Apr 21, 2017)

Goldfilled doesnt always end up in solid foils, only if you're lucky.  
Rarely though, since it is usually heavily worn in some spots. So there will be foils, but there will be tons of little flakes too.
So just dumping it off, is dumping off a good bit of your gold.


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## g_axelsson (Apr 21, 2017)

Little flakes should sink quite fast too. I have separated gold plate from stannous sludge at times.

I just suggested to split the lot in a easy and a hard part, not dumping it off... unless the hard part doesn't contain enough gold to warrant the extra work and chemical expenses.

Göran


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## Topher_osAUrus (Apr 21, 2017)

True that. The flakes do usually sink fast, but there are always those odd bits that dont. ..Or the pieces of clasp that have air pockets in them so they float forever. 

I think I would try to take a small sample of the red motor oil looking nitric, and add just a couple mL of sulfuric. See if it gets all the oxidized iron to go into solution and clear up a bit. That way he can see whats really going on.

I know I would definitely try to fish that "24k" chain out of the mix, so it can't keep causing issues.


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## fyatim (Apr 22, 2017)

Palladium said:


> If i had to guess iron! The green of the nitric tell me and the rust to go along with it!
> Add more nitric and heat until completion. I think what you will find out is the items are plated and not filled and they are on a cheap iron magnetic base. Yield will be low!



Following Palladium's suggestion and valuable remark from modtheworld44 "Iron falls out of nitric when it is diluted", I proceeded as follows:
- Left the beaker containing the staff to settle and evaporate on mid heat for about 24H.
- Then, added about 200ml nitric acid while the beaker is on heat. Acid added in small quantities during about 24H.
I end up with some gold foils and some dark powder in the solution without any trace of the red sludge shown in the photos. I attach a new photo of the resulting solution.
Possible conclusions:
- My GF contains Iron (I bleive in the pieces marked 24K and 10k balls)
- After processing with normally diluted nitric acid and heat, No red sludge was observed.
- Only after adding quantity of water and ice cubes to cool down before filtering, the Red sludge appears as shown in the picture.
I will continue processing the batch:
- Filtering and rinsing with water
- Rinsing with hcl
- Treatment with AR


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## g_axelsson (Apr 22, 2017)

fyatim said:


> - Only after adding quantity of water and ice cubes to cool down before filtering, the Red sludge appears as shown in the picture.


This is a leading question, I want you to think and motivate why you cool down and dilute the solution before filtering. What are you trying to accomplice and what are the results of your actions?



fyatim said:


> I will continue processing the batch:
> - Filtering and rinsing with water
> - Rinsing with hcl
> - Treatment with AR


What is going to happen at step "-Rinsing with hcl"?
I would advise you to think about it for a while and not do it.

Göran


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## nickvc (Apr 22, 2017)

g_axelsson said:


> fyatim said:
> 
> 
> > - Only after adding quantity of water and ice cubes to cool down before filtering, the Red sludge appears as shown in the picture.
> ...




This could be a case of a little knowledge been a dangerous thing....
Take Gorans advice and step back and read some more about what you are trying to achieve.


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## fyatim (Apr 22, 2017)

nickvc said:


> g_axelsson said:
> 
> 
> > fyatim said:
> ...



Thank you for your advice, but please try to be more direct. I do not see what is your issues!!
I added water to cool the solution and facilitate the filtering process. Now, I learned that this will precipitate any Iron present in the nitric acid solution. What else?
After washing with water the content of my filter, I plan to wash with HCl to clean any residuals, what is again the issue?
Please, explain your point of view or direct me to a specific reading. Do not just say " step back and read some more about what you are trying to achieve". I m a beginner, I know, and you are experts. Tha's why I m a member of this forum... To get direct advice and help when possible.


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## nickvc (Apr 22, 2017)

fyatim said:


> nickvc said:
> 
> 
> > g_axelsson said:
> ...



I accept you are new and english probably isn't your first language but you need to read Hoke and some of the threads here on the forum to gain a basic understanding in what you want to achieve, not wanting to be rude but you will make a very large mess that can take a lot more understanding to recover from, I cannot sugar coat my reply as the study and reading are essential if you want to be successful not just in this but in any future processing, we can't make you understand the reactions and processes without some basic knowledge from you.


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## modtheworld44 (Apr 22, 2017)

fyatim said:


> nickvc said:
> 
> 
> > g_axelsson said:
> ...




If this was my materials,this is what I would do.

I would filter(without the use of water) then go straight to AR.
I would add small milliliter additions of nitric until everything was dissolved.
I would de-nox and then refilter and then drop the gold out with SMB.
Then wash powders in boiling distilled water and then simmering HCL.
Then see if the powders had a color change and do this until I see color change.
Then I would melt the powders into a nice shiny button.
Thanks in advance.



modtheworld44


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## fyatim (Apr 22, 2017)

Following on my case (of Red sludge in nitric acid solution), here is a picture of the result after washing the filtered foils with distilled water and treatment with AR. The other picture is the positive test with stannous chloride.
Please note that I skipped the HCl washing step to avoid the risk of having nitric acid particles not cleaned after water washing (this was the point of nickvc and goran I think).
Also, notice the very small amount of gold as predicted by Palladium;


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## fyatim (Apr 22, 2017)

modtheworld44 said:


> If this was my materials,this is what I would do.
> 
> I would filter(without the use of water) then go straight to AR.
> I would add small milliliter additions of nitric until everything was dissolved.
> ...


You are right. I have filtered the materials without water, but after the filtering is done, I start adding water into the filter. The solution down the filter was re-contaminated with the re-precipitation of iron, but the filtered materials in the filter were clear.
I did not add any nitric acid in the filter, but I could have done that to be sure (you are right);
What do you mean by de-nox? I do not know this term...
For the gold precipitation and melting, I will do it later with other batches as this one is very small...

I would like to thank all of you for your interest and support.
The return in gold is nothing, but the return in knowledge was very important for me during those few days.


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## FrugalRefiner (Apr 22, 2017)

fyatim said:


> What do you mean by de-nox? I do not know this term...


See A Glossary of Common Terms.

Dave


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## g_axelsson (Apr 22, 2017)

By finding out why washing the filter in HCl you learned it and will remember it next time.
If I had told you why you would have forgotten about it in a few days.

The forum helps those that show they put some effort in doing the research themselves.

Göran


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## fyatim (Apr 24, 2017)

FrugalRefiner said:


> fyatim said:
> 
> 
> > What do you mean by de-nox? I do not know this term...
> ...


Thank you, Dave, for this valuable glossary.
Regards


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## fyatim (Apr 24, 2017)

g_axelsson said:


> By finding out why washing the filter in HCl you learned it and will remember it next time.
> If I had told you why you would have forgotten about it in a few days.
> 
> The forum helps those that show they put some effort in doing the research themselves.
> ...


Yes, you are absolute right Goran. But, you know, when we are under pressure of the situation and looking to understand what is happening it becomes frustrating to hear general advice instead of specific action.
Please be assured that my first experience with the forum is very rich and I will stay in contact with you for my next fun experiences.
regards


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## Topher_osAUrus (Apr 24, 2017)

So the forum is only good to come to when you are in the thick of it? -no pun intended on your first nitric run...


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## FrugalRefiner (Apr 24, 2017)

Topher_osAUrus said:


> So the forum is only good to come to when you are in the thick of it? -no pun intended on your first nitric run...


I didn't take his comment that way. I understood him to be saying that he was under the gun on this batch, so he didn't have as much time to search out the answer in this case. I could be wrong, but I always try to give everyone the benefit of the doubt.

Dave


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## nickvc (Apr 24, 2017)

I think a little slack is always allowable for any member who's first language isn't English, translations are rarely as you think or say.


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## Topher_osAUrus (Apr 24, 2017)

FrugalRefiner said:


> I didn't take his comment that way..
> Dave



You are probably right.
Hope so anyways, if not, he doesn't know what he is missing!


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## g_axelsson (Apr 24, 2017)

As a non native English speaker I interpreted it as he was a bit frustrated by getting a lecture instead of a straight answer, but still grateful in the end and will continue to study. I can be wrong thou...  

Göran


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## Geo (Apr 24, 2017)

It is best to filter saturated solutions hot. When the solution cools, salts are formed. These salts clog the filter and make filtering harder. If you must cool the solution, let everything settle completely and draw the clear solution off of the solids first. That will speed up the process even if you have to wait for everything to settle.


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## fyatim (Apr 25, 2017)

Topher_osAUrus said:


> So the forum is only good to come to when you are in the thick of it? -no pun intended on your first nitric run...


Topher,
Dave, nickvc and Goran interpreted correctly my reaction and answer. 
I do not see what was wrong in my message, but please do not take it negatively.
Thanks


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## fyatim (Apr 25, 2017)

Geo said:


> It is best to filter saturated solutions hot. When the solution cools, salts are formed. These salts clog the filter and make filtering harder. If you must cool the solution, let everything settle completely and draw the clear solution off of the solids first. That will speed up the process even if you have to wait for everything to settle.


I understand. Thank you, Geo.


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## justinhcase (Apr 25, 2017)

Filtering is one of the most frustrating processes some times.
A fresh filter paper will not always stop all particles,some times I find I have to run a little sediment through to reduce the pore size before a paper becomes truly effective.
This is not too much trouble as all you do is empty your buncher flask once yous see a clear flow and keep going.
But then the life of the paper is limited because the same action will soon render it water tight. 
I have been looking for a buchner funnel with a top and a tube so you can better control what part of the liquor you take off.
if you could leave the beaker still and "Vacuum" up the fluid as you would do with a Vacuum cleaner that would save some farting around and disturbing sediment .


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## Topher_osAUrus (Apr 25, 2017)

Forgive my misinterpretation fyatim. Happy to hear I was wrong.  

Justin, that would be a pretty handy thing to have, wouldn't it?
Would make life much easier than using a suction bulb or pipette, and having that then go through the filter. I'll have to do some searching now, as that surely has to be an available piece of lab gear.


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## nickvc (Apr 25, 2017)

Justin the one suggestion I can give you is to move your filter below the level of the beaker and simply symphony your clearer solution off and into your filter or if the solution is still fuming syphon into another vessel and pour it into the filter.


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## justinhcase (Apr 25, 2017)

Topher_osAUrus said:


> Justin, that would be a pretty handy thing to have, wouldn't it?
> Would make life much easier than using a suction bulb or pipette, and having that then go through the filter. I'll have to do some searching now, as that surely has to be an available piece of lab gear.


Yes it would be handy ,emptying a 20L flask with a Pipette is a bit of a pain.
Been there Dun That. :lol:
Thanks Nick,I do let settle and use siphoning for larger batches just use a wash bottle to fill the tube.
But this is a little bit fiddly for the 2000ml to 5000ml batches, having an on demand vacuum system would save a bit of time.
A bit run off my feet so every second counts.lucky if I get the time for one good run a week.
Just got off an extra night shift,have a client booked in first thing this after noon.
sleep or filter


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## Topher_osAUrus (Apr 25, 2017)

For big batches of a litre or more, I use a big suction bulb.
I believe in a previous life, it was meant to be a "booger sucker" for newborns. It can get a good bit of solution in each squeeze. 
I can take a picture for you tomorrow if youd like.

Surprisingly, both of mine have lasted well over a year and are still holding up strong. ...thank goodness, because I don't want to have another child, just to get the complimentary booger sucker from the hospital so I can use it in my shop.  

...I'm sure they sell similar ones at the store though.
Also, a nice auto siphon device, is available at a local beer brew store, they had them as small as a 10-12" and as large as 5 foot long, or so.
I like using them, as they dont add the extra water to start the siphon. The two I have, have held up for quite a while as well.


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## justinhcase (Apr 25, 2017)

Topher_osAUrus said:


> For big batches of a litre or more, I use a big suction bulb.
> I believe in a previous life, it was meant to be a "booger sucker" for newborns. It can get a good bit of solution in each squeeze.
> I can take a picture for you tomorrow if youd like.
> 
> ...


Yes I also have some large lab pipettes with various valves so you can get up to 200ml.
I find they tend to loos the odd drip of fluid so I only use them very carefully :roll: .


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## Topher_osAUrus (Apr 25, 2017)

Yeah, that is one of the downfalls of the pipette/suction bulb that I have encountered too. Especially if the solution is hot and the bulb is cold, then all hell can break loose!

But, for the random drip, I just use a watchglass or small beaker underneath the tip when im goin back and forth. When its all said and done, I rinse that out, and use that diluted solution to begin rinsing out the filter of the more pregnant liquor. Then continue with the water rinsing.

It's all about the little tips and tricks to go along with the correct processes, isn't it?


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## upcyclist (Apr 25, 2017)

For siphoning, when maintaining purity is not of the essence (like draining waste liquors), I just keep some narrow flexible tubing in a mason jar full of distilled water. Pick up one end of the tubing and pinch it, then pull the rest out. Now you have a primed siphon tube. I can also drain some of that water in the jar to flush the tubing when I'm done.

Of course, a quick flush doesn't get all the solution off the inside of the tubing, much less the outside. When the distilled water doesn't look so distilled anymore (cloudy or colored), it can can always join the waste stream.


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## justinhcase (Apr 25, 2017)

Topher_osAUrus said:


> Especially if the solution is hot and the bulb is cold, then all hell can break loose!



I do not like filtering hot solutions.
They wreck other wise hardened filter papers,Over fume,and hold other wise insoluble compounds in solution.
I alleyway's leave to cool,If they are too thick to filter readily I just go back to gravity filtering and leave them in a very big funnel for a day or two.adding H2O when every they look depleted..most soluble compounds work there way through.


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## anachronism (Apr 25, 2017)

justinhcase said:


> Topher_osAUrus said:
> 
> 
> > Especially if the solution is hot and the bulb is cold, then all hell can break loose!
> ...



Filtering hot solutions is fine if you have the right kit to do it and haven't loaded the solutions with H2SO4 using Sulphamic acid. That's one of the things eats the filters. This post has nothing to do with the fact that I dislike you Justin it's merely an opinion based upon the fact that I disagree with you. Do feel free to come back with an articulate reply. Or not as may be the case.


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## Topher_osAUrus (Apr 25, 2017)

Well, here is my two cents worth (afterall, what can you really get with a couple pennies nowadays?)  

Sometimes it is better to filter hot, sometimes it is better to filter cold. If I don't have any AgCl in the mix, then I have no quarrels with running it through the filter while its hot. I haven't had much trouble with any paper getting chewed up, but more times than not, when I am filtering while hot I have a charmin plug underneath the filter paper, so it moderately supports some of the fluid and keeps it from blowing straight through. I see the benefit in both, and do both. 

The hot stuff, seems to filter much quicker and also seems to have the majority of the junk settle on the bottom of the beaker faster too, so not as much of it gets caught in the filter. The cold stuff, doesn't fume you out of the building, and isn't a bear to handle. Also, I need not mention silver chloride won't be mucking up the precipitation. (..wait, that IS mentioning it, isn't it..  :roll: )

Although, I have started to take the stance as some others on the board, that the first time gold is in solution, it's a recovery, even if it is from some perfectly run inquarted gold. I just choose to think of it as recovery and the minute amount of contaminants that come through, will be alleviated with the washes or the next solution of the gold.

note to the mods/admin, can we get a heart emoji? :mrgreen: :twisted:


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## 4metals (Apr 25, 2017)

Sulfamic is a great trick but not one that you should feel warrants overuse of nitric acid. Paper and sulfuric acid don't get along well, and paper with hot sulfuric is even worse. 

And I always prefer to filter cold. In fact one of the things I tell clients to acquire from auction sites is a commercial ice maker. Helps the acid to get cold fast and assures any silver is out of the aqua regia because it's cold and the solubility is at its lowest.

Members of this forum tend to know their scrap pretty well, so an argument saying there is no silver may be valid. Commercially, often they do not know whether or not to expect silver so i prefer to err on the side of assuming it all has silver. 

Plus a hot solution fumes while you are pouring and working with it. Cool to cold solutions are rather tame. Considering how many members idea of a hood is the back yard with a slight wind, solutions that aren't fumey are a plus.


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## Geo (Apr 26, 2017)

For the beginner or the less prepared, I agree on filtering cold. The only stipulation is allowing time for everything to settle. Often times, filtering is unnecessary. I allow everything to settle and draw the clear solution from the top down. The last little bit of solution and any solids gets washed into a smaller beaker and allowed to settle again. By the time I am washing it into a 50ml beaker, there's no gold left and only wash water.
This may not be an option if you are working with someone else's material and have to finish it quickly. A good vacuum filter rig is fairly cheap on Ebay and comes with a cheap hand pump. I bought a 100ml vacuum flask kit with two 70ml porcelain buchner funnels for $29 and free shipping.


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## justinhcase (Apr 26, 2017)

4metals said:


> Sulfamic is a great trick but not one that you should feel warrants overuse of nitric acid. Paper and sulfuric acid don't get along well, and paper with hot sulfuric is even worse.
> 
> And I always prefer to filter cold. In fact one of the things I tell clients to acquire from auction sites is a commercial ice maker. Helps the acid to get cold fast and assures any silver is out of the aqua regia because it's cold and the solubility is at its lowest.
> 
> ...


As karat gold is my main stock that must be why I never need to filter hot.
I have looked at other material but karat pays where as the rest is only for experimental purposes at the quantity's I can get.
The karat gold makes my silver economical so I just about only run inquartation's


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## g_axelsson (Apr 26, 2017)

Filtering a hot or a cold solution isn't something that should be done never or always. It is something that should be decided of circumstances.

If I have gold foils from fingers and other scrap dissolved in copper chloride, i.e. metallic gold with dissolved crap, then cooling the solution only makes it harder to filter and lower the solubility of the metals.
As seen in this thread a gold filled digestion would probably have filtered just fine before ice cubes were added. Cooled it became a mess.

If I have gold chloride in solution and I want to get rid of silver chloride then dilution and cooling the solution before filtration is a perfect way to accomplish that.

This is why it's advantageous to understand what is happening when we mix different solutions, dissolve metals or dilute liquids.
I actually recommend looking at some youtube videos on organic chemistry. The way they crash out products by varying the solubility or mix different solvents is fascinating. Some techniques are really good, re-crystallization for example can produce very pure chemicals. As an experiment I tried making copperas and re-crystallize the first part that came out when evaporating the water.
How about these crystals, apparently I super saturated the solution as this grew just in a few hours. :mrgreen: 



Göran


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## Topher_osAUrus (Apr 26, 2017)

g_axelsson said:


> I tried making copperas and re-crystallize the first part that came out when evaporating the water.
> How about these crystals, apparently I super saturated the solution as this grew just in a few hours. :mrgreen:
> Copperas-1.jpg
> 
> Göran



Looks good to me!
Love the way copperas crystals layer upon themselves and make a sort of step-up, plateau.
Science is beautiful


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## 4metals (Apr 26, 2017)

Most commercial refiners do not inquart for karat, just a direct dissolve, so cold filtration through a tight paper (requiring good vacuum) is very important.


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