# Gold isn't dropping



## teriobost (Jan 17, 2022)

Hello everyone. I am having trouble getting my gold to settle. I started with 30 pounds of Military connectors. I used hydrochloric acid distilled water and a very small amount of hydrogen peroxide to separate gold foils. Dissolved gold in aqua regia, boiled everything down to a syrup to ensure all nitric was boiled off. Rehydrated with hydrochloric and began dropping SMB and adding distilled water as needed to continue diluting solution until the solution turned black. Continued to drop SMB until I got a negative stanus test (way more SMB than I thought it would take). It has been 3 days and the gold seems to be just very finely suspended in solution and won't settle to the bottom. 
I took a 1 liter sample and boiled it down to 500 ml because I thought I may have added too much water. But the sample seems to be acting the same as the main solution. 
Has anyone had this kind of problem before? Any advice?


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## FrugalRefiner (Jan 17, 2022)

First, you don't want to boil your solutions to reduce their volume. You want to evaporate them. When you boil, you will lose some of your gold. Evaporation is slower, because it's done at less than boiling temperatures, but it keeps all your gold in your vessel.

I'm moving your post to the Help Needed section since you're asking for help.

In this section you will find another thread dealing with a similar problem; Gold taking a long time to settle after third wash cycle with water.

Dave


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## teriobost (Jan 17, 2022)

Gold doesn't evaporate from boiling if there is already a percipitating agent, that has been proven multiple time. Thanks for the feedback.


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## FrugalRefiner (Jan 17, 2022)

teriobost said:


> Hello everyone. I am having trouble getting my gold to settle. I started with 30 pounds of Military connectors. I used hydrochloric acid distilled water and a very small amount of hydrogen peroxide to separate gold foils. Dissolved gold in aqua regia, boiled everything down to a syrup to ensure all nitric was boiled off.





> Gold doesn't evaporate from boiling if there is already a percipitating agent, that has been proven multiple time. Thanks for the feedback.


I didn't say gold evaporated. But when you "boil" a liquid, all those bubbles pop at the surface. When they pop, they send some very tiny droplets flying into the air. You can demonstrate this to yourself. Dissolve some salt in some water in a pot. Put it on your stove and bring it to a boil. Let it boil for a while. When you're done, check the surface of your stove around your pot. That residue you feel and/or see is salt that has been carried out of your pot by those tiny droplets of water as the bubbles burst at the surface.

But hey, it's your gold.

Dave


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## teriobost (Jan 17, 2022)

Why would you assume I don't have a watch glass in a tall enough beaker to not have this issue. I'm running a 30 pound batch this is obviously not my first time. I've only done this for 2 years but that's not even a mistake I make on my first one gram batch. Also your feedback hasn't helped answer any part of my question so please only respond if it is productive and not presumptive.


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## teriobost (Jan 17, 2022)

Also to be clear there are several reasons I didn't post this under the previous topic and the big one is that in the thread you somehow moved this to ( I guess you are admin) is about an issue on a 3rd refining. Now, again, I have only been doing this for two years but even I know that there are different types of issues that can happen on the first refining vs. the 3rd. Also your condescending tone in the comments from start to finish probably isn't inline with what this site is about, at least not the what I thought it was about. Lastly, I posted this to get advice from people that have more knowledge than me that run batches this size on a regular basis. This is only my second batch this size and first time I have had an issue where gold is suspended in solution. Again thanks for the feedback.


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## Yggdrasil (Jan 17, 2022)

First:
You have been given some good advice regarding the process.
(Why evaporate in a tall beaker??
Evaporation should be done in a lowest possible dish, and hot not boiling, preferably with a gentle breeze across it.)

Second:
Open posts on this site is for everybody that reads it, and as such has to be formatted to benefit all readers. Even noobs.

Then to the question at hand.
It would be beneficial if you give more detailed information, step by step on what you did, colours and such, since this can explain this unexpected behaviour.

Regards Per-Ove


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## FrugalRefiner (Jan 17, 2022)

teriobost said:


> Why would you assume I don't have a watch glass in a tall enough beaker to not have this issue.


Because you said you "Dissolved gold in aqua regia, boiled everything down to a syrup to ensure all nitric was boiled off." If you did that in a tall beaker with a watch glass it must have taken a very long time, as most of the vapors produced would have condensed on the watch glass and dripped back into the beaker over and over again. It would have been faster to evaporate it at a lower temperature in a short form beaker without the watch glass.

Dave


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## FrugalRefiner (Jan 17, 2022)

teriobost said:


> Also to be clear there are several reasons I didn't post this under the previous topic and the big one is that in the thread you somehow moved this to ( I guess you are admin) is about an issue on a 3rd refining.


I did not move your post into another topic. I only moved it to the Help Needed section of the forum since you were asking for help. I felt you might get better responses in this section.


teriobost said:


> Also your condescending tone in the comments from start to finish probably isn't inline with what this site is about, at least not the what I thought it was about.


I apologize if you felt my tone was condescending. I tried to help by pointing you to a thread where another member also had problems getting his gold to settle. I won't bother you again.

Dave


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## teriobost (Feb 3, 2022)

I got it fixed. I seriously don't know how or why you think it takes a long time to boil off AR. The only way it takes a long time is if there's an huge excess of nitric acid, which if you have any experience at all and understand economics then you use as little as possible. A half assed apology doesn't do anything when you still act like g-d's gift to gold. You could just simply admit that you made a lot of presumptive statements but apparently that's too hard. Good luck with your refining.


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## Quiklearner (Feb 3, 2022)

So angry....


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## Yggdrasil (Feb 3, 2022)

Todays world seem to be like this...


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## AMS-Pro (Feb 3, 2022)

Lord, Oi. A scaled up process, well researched maybe, but not well enough considering that result of the process. A very acceptable answer/ solution to said problem that was well written was provided. A response to that solution filled with misunderstanding of what was actually said, and filled with the need to be right about something not even being discussed more than an appreciation for solving the initial problem. I'm sure that I'm safe to assume that the solution provided was read too fast, which leads me to believe that information used to scale up the original process was probably read too fast as well. Which explains why the problem even happened. If we were to reference the technical scaling up of process with a trade like the experts of NASA, there's a reason while there are thousand of steps heavily scrutinized, and the reason why progress is halted until they can replicate the problem to understand what went wrong and prevent it in the future. In conclusion, I feel that the original poster being more inclined to argue about a misunderstanding, and to be right about something not even pertaining to the topic at hand rather then carefully read the very sound information provided, is most certainly a disaster waiting to happen in what is most definitely a dangerous process. I hope that the original poster takes the time to reread what had transpired, and pay better attention to what is actually happening so as not to become an example of what not to do for others. It's incredibly alarming to me how some individuals are ready to jump to being hostile and argumentative or more concerned about being right with such a dangerous process. This is the exact mindset that leads to too many people getting seriously injured or worse in most trades with some element of danger. I have personally had to have discussions and occasionally let people go that have had this kind of mindset and wouldn't change. I have seen people lose their lives in the industrial trades because of people like this. It is a shame, and is very much disrespectful to those that have already been seriously injured, or have lost their lives to be the example of how not to do things. Any information that was provided to the original poster was done with positive intent to how the process should correctly be commenced that is proven and most certainly safer, it is why it is considered the classic process. I've worded this post as well as I feel I could've at the moment considering I've been reading these few post now for hours in complete disbelief of what transpired. For someone only doing the process for a couple years now, the original poster sure has grown a pair and an ego to come out swinging with that kind of animosity. Professionally, he could be the richest person in the world and I the poorest, and I still wouldn't do business with him out of fear for my well being and his/hers. Absolutely ridiculous. There's no place in the professional world for people willing to display that level of ignorance and disrespect towards others that responded so quick to be helpful and concerned. I hope the original poster takes this with a grain of salt, and strives to better handle the transaction of information in the future. This forum seems to me to be the best source of correct information small scale and large. There are many experienced, bright, and properly educated minds to pick about such a dangerous process. It is not wise by any means, nor necessary to show such hostility, to those that have many more posts, are clearly well known, and definitely more informed with the knowledge they have. Original poster is likely to be frowned upon, and avoided by the more experienced, if that's how they will continue to handle themselves in conversation and morally. Please make the choice to read the information you obtain more slowly and thoroughly before reacting. This type of activity is too dangerous not to. Any information or criticism you receive by most, is out of concern for your well being, and that you are able to do the process right with success and your life intact. Although I don't believe I would ever do business with the original poster professionally, I do bid them good luck and god speed on their endeavors, and that they become as successful as they can be on their journey.

Okay, rant over, time for more coffee.


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## Yggdrasil (Feb 3, 2022)

Thanks, wise words mate.


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## Martijn (Feb 4, 2022)

The op cearly missed the link to another post where the solution to his problem is given. (By me)
Reading the info given in the very clear and polite relpy from dave in stead of feeling corrected because he has soooo much experience.
Corrections are sometimes given because new members also read this and may get misinformed. 

Anyway... very wise words, AMS-pro!


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## orvi (Feb 4, 2022)

teriobost said:


> I got it fixed. I seriously don't know how or why you think it takes a long time to boil off AR. The only way it takes a long time is if there's an huge excess of nitric acid, which if you have any experience at all and understand economics then you use as little as possible. A half assed apology doesn't do anything when you still act like g-d's gift to gold. You could just simply admit that you made a lot of presumptive statements but apparently that's too hard. Good luck with your refining.


If you boil down with watchglass on top, it would be painfully slow in the tall beaker. AR is majority water, and water has very high heat of evaporation. That´s it. That´s why denoxing agents are cleverly used to obviate the lengthy boil-down of acid solutions. Energy and time consuming. Could be done, certainly work, but slow.

From 30 pounds of military grade connectors, there should be very nice pile of foils. Meaning lots of gold. I don´t know how would be possible to obtain semi-colloidal suspension of more than ounce of gold in the beaker, without some stabilising agents or organics involved. Very strange. Nothing settled to the bottom of the beaker after some hours ? Why diluting the AR gold solution when dropping the gold ? Usually, more you dilute the solution, finer the precipitate would be. If it will be unseparable, first thing would be to redissolve back to the solution and opt for another precipitant like ascorbic acid. Or cementing out on copper - this do not produce colloids as far as I know  

I would like to hear how you fixed this and collected the gold, as it might be interesting case-investigation for others


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## AMS-Pro (Feb 4, 2022)

orvi said:


> If you boil down with watchglass on top, it would be painfully slow in the tall beaker. AR is majority water, and water has very high heat of evaporation. That´s it. That´s why denoxing agents are cleverly used to obviate the lengthy boil-down of acid solutions. Energy and time consuming. Could be done, certainly work, but slow.
> 
> From 30 pounds of military grade connectors, there should be very nice pile of foils. Meaning lots of gold. I don´t know how would be possible to obtain semi-colloidal suspension of more than ounce of gold in the beaker, without some stabilising agents or organics involved. Very strange. Nothing settled to the bottom of the beaker after some hours ? Why diluting the AR gold solution when dropping the gold ? Usually, more you dilute the solution, finer the precipitate would be. If it will be unseparable, first thing would be to redissolve back to the solution and opt for another precipitant like ascorbic acid. Or cementing out on copper - this do not produce colloids as far as I know
> 
> I would like to hear how you fixed this and collected the gold, as it might be interesting case-investigation for others


I have to say, this was a beautiful transition back to the questions of chemicals and process. I wonder if his fix was maybe dissolving the gold back into the Aqua regia, then precipitating with Ferrous Chloride maybe? An interesting case investigation indeed.


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## Dougplogan (Feb 4, 2022)

What is the purpose of boiling solution down to a syrup? I get boiling off excess nitric but boiling down to syrup seems off to me. Just genuinely curious about that one. I don't have alot of experience but of the solutions I have done I've never heated to an actual boiling and a few hrs at near boiling has almost always worked. Of the times I have still actually had a small amount of nitric at that point urea or sulfamic acid quickly fixed it without adding very much volume at all. And I never really dilute solution much with water. I always thought more diluted ment finer gold when dropping? Again I've only done a few batches and just now passing the ounce mark on my stores gold. Almost all from ram. Fingers and bga chips off the ram and the ice chips with legs and the glass chips on the ram.


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## Yggdrasil (Feb 4, 2022)

That is how they did it in the past, and it was recommended in Hoke's book.
By evaporating to syrup, you drive off "all" the water capable of holding the nitric. Effectively driving the NOx out of solution. By adding HCl you create a minute amount of AR if there are still nitric available. And it will give off a bit of brown fumes. If so, you will have to repeat it.

Today it is much simpler to use Sulfamic acid.

Or use Harolds method.
Add a small weighed gold button.
It will spend the excess nitric.
If the gold is yours, that's it.
If you refine for others, weigh the button after and deduct the gold added to solution.


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## galenrog (Feb 4, 2022)

I understand why evaporation is good in some situations. Boiling is almost a bad idea, even though it is found in Hoke. Adding a gold button is number two on preferred methods, in my opinion. Sulfamic acid is easy and always works, and is currently the best method. Urea belongs in the garden. It does neutralize nitric acid, but it does not eliminate it. Other opinions may differ.

Time for more coffee.


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## orvi (Feb 5, 2022)

Dougplogan said:


> What is the purpose of boiling solution down to a syrup? I get boiling off excess nitric but boiling down to syrup seems off to me. Just genuinely curious about that one. I don't have alot of experience but of the solutions I have done I've never heated to an actual boiling and a few hrs at near boiling has almost always worked. Of the times I have still actually had a small amount of nitric at that point urea or sulfamic acid quickly fixed it without adding very much volume at all. And I never really dilute solution much with water. I always thought more diluted ment finer gold when dropping? Again I've only done a few batches and just now passing the ounce mark on my stores gold. Almost all from ram. Fingers and bga chips off the ram and the ice chips with legs and the glass chips on the ram.


When you combine nitric and hydrochloric acid, they react together, forming nitrosyl chloride and chlorine:

HNO3 + 3 HCl ---> NOCl + Cl2 + 2 H2O

This is why the fumes comming out of the AR dissolution have golden-yellow colour, contrary to plain nitric on silver, where mainly NO2 is produced and fumes are brown.

It take some time for this reaction to happen. Unreacted nitric acid is very hard to drive off with evaporation, but these decomposition products are gaseous/volatile, so by boiling you accomplish two things:
1. higher temperature = faster decomposition
2. higher temperature = easier driving off gases

Chlorine and NOCl are fairly water soluble, so getting rid of them is slow, and you need to physically remove water as vapor to carry them away.
As you concentrate the solution, content of chlorides and salts rises, and the boiling point also rises = harder for the nitric and its decomposition products to readsorb when once evaporated. And easier to escape from the vessel. That´s why evaporating nearly to syrup is good, but unfortunately lengthy and messy practice.

EDIT: and I forgotten one very important thing. Many metals, not only PGMs, form nitroso-complexes. These complexes hold NOx, easily said. And these could be quite stable. To decompose them, you need to heat up the solution to quite a high temperature to destabilize them and force them to liberate NO molecules, and change them with chloride ligands. This is why boil down to syrup is very helpful - if you denox this way. 
You rise the temperature, so disrupting complex´s equilibrium and liberating the ligands (NO) which could then interchange for chlorides more easily.

Huge ammounts of NOCl, chlorine and HCl are evaporated, ruining your fume-hood fan extraordinarily quickly  and of course, anything around the fume exhaust. 
As galenrog said, sulfamic acid always works (you need to heat the solution to get nitric reacting, not only NOCl - this work at ambient temps also), and the cost is not high. Partial boildown of the solution sometimes cannot accomplish full denoxxing, even that you cannot see NOx vapors in covered beaker.


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## AMS-Pro (Feb 5, 2022)

orvi said:


> When you combine nitric and hydrochloric acid, they react together, forming nitrosyl chloride and chlorine:
> 
> HNO3 + 3 HCl ---> NOCl + Cl2 + 2 H2O
> 
> ...


Well, I guess here's my question then - If original poster had already evaporated or "boiled" everything to a syrup what part of this process could've have allowed the gold particulates to just "suspend in the solution"? That's why i was wondering, if he had maybe dissolved the gold back into the Aqua regia, and then used Ferrous Chloride to precipitate the gold (like he was going after the platinum), it would have allowed it to settle instead of suspend for whatever reason it did in his original syrup. I'm aware that using Ferrous chloride or Iron(II) chloride would contaminate the gold, but he would've at least been able to recover it, and refine the impurities out of it from that stage with a different process, and get past whatever his initial problem may have been. Without knowing what the cause was, that didn't allow the gold to settle in his syrup, could this route have been a viable solution for him to be able to recover the gold, as it is a simple/common precipitant, when nothing else seemed to work for the original poster?


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## orvi (Feb 5, 2022)

AMS-Pro said:


> Well, I guess here's my question then - If original poster had already evaporated or "boiled" everything to a syrup what part of this process could've have allowed the gold particulates to just "suspend in the solution"? That's why i was wondering, if he had maybe dissolved the gold back into the Aqua regia, and then used Ferrous Chloride to precipitate the gold (like he was going after the platinum), it would have allowed it to settle instead of suspend for whatever reason it did in his original syrup. I'm aware that using Ferrous chloride or Iron(II) chloride would contaminate the gold, but he would've at least been able to recover it, and refine the impurities out of it from that stage with a different process, and get past whatever his initial problem may have been? Without knowing what the cause was, that didn't allow the gold to settle in his syrup, could this route have been a viable solution for him to be able to recover the gold, as it is a simple/common precipitant, when nothing else seemed to work for the original poster?


Very small, non settling particles occur mainly on two occasions. First is that there is very very little gold, and it just dont clump together and stay suspended in the liquid for very very long time. 
Second is that the solution was not clear, eg there was some precipitate, opalescence/milkiness, or worse - some kind of dissolved polymeric substance which could form micelles in the liquid, or blocking the particles of gold to agglomerate. Notorious for this are things like tin hydrated oxides or metastannic acid fine dispersions.
Doing silver contacts, there would always be solder containing tin. Nitric will create metastannic acid, and if this is not filtered clean, attempted precipitation on copper would create rather fine particles of silver, which do not clump together or grow bigger (sadly, my personal experience also).

If your material contained some polymers which could be attacked by acids, or resins... They could be liquified to the some extent, and stay in solution in the form of short-length segments. And acting similarly as cotton soaked in water  blocking effective diffusion in the liquid.
And when effective diffusion is blocked... Many nucleation sites are available = greater number of individual growing particles = logically they will be smaller in size, because there is limited gold in solution. And voila, semi-colloidal suspension is born 

There is simply that many factors that could be significant, you can experience this even if you think everything was done right. Golden rule is: dirtier and lower-grade the material is, probability of difficulties arising from the process also rise  mainly with pulling the gold out of the complicated matrix and getting it precipitated in some workable form.


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## FrugalRefiner (Feb 5, 2022)

AMS-Pro said:


> That's why i was wondering, if he had maybe dissolved the gold back into the Aqua regia, and then used Ferrous Chloride to precipitate the gold (like he was going after the platinum), it would have allowed it to settle instead of suspend for whatever reason it did in his original syrup. I'm aware that using Ferrous chloride or Iron(II) chloride would contaminate the gold, but he would've at least been able to recover it, and refine the impurities out of it from that stage with a different process, and get past whatever his initial problem may have been. Without knowing what the cause was, that didn't allow the gold to settle in his syrup, could this route have been a viable solution for him to be able to recover the gold, as it is a simple/common precipitant, when nothing else seemed to work for the original poster?


AMS, do you mean ferrous chloride, or ferrous sulfate?

I'm very familiar with ferrous sulfate (copperas) being used to reduce gold from an AR solution, but I've not heard about using ferrous chloride.

Dave


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## AMS-Pro (Feb 5, 2022)

FrugalRefiner said:


> AMS, do you mean ferrous chloride, or ferrous sulfate?
> 
> I'm very familiar with ferrous sulfate (copperas) being used to reduce gold from an AR solution, but I've not heard about using ferrous chloride.
> 
> Dave


Hello Dave, how are you enjoying this Ohio weather?
As far as specifics go, I believe both chemical classifications ( yours, and mine ) could be used, or are technically right with how we're referencing their use in this post.


eagle2 said:


> The FERROUS ion that moves to FERRIC. It becomes more oxidized as it picks up Cl from the Gold Trichloride. An excess of Ferrous or any precipitant is usually a good idea. A drawback with Ferrous is it co-precips with Gold as Ferric Hydoxide and has to be washed out.
> 
> Ferrrous Chloride is FeCl2 or Ferrous Sulfate (Copperas) is FeSO4. This does the work of precipitation. Ferric ion (FeCl3) is the oxidized result and is now useless and in the way.



Edit* I am using the above as reference to answer your question. 

FeCl2 replacement reaction
And this referenced post, that the quote came from, in its entirety is an interesting, short read.


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## AMS-Pro (Feb 5, 2022)

orvi said:


> Very small, non settling particles occur mainly on two occasions. First is that there is very very little gold, and it just dont clump together and stay suspended in the liquid for very very long time.
> Second is that the solution was not clear, eg there was some precipitate, opalescence/milkiness, or worse - some kind of dissolved polymeric substance which could form micelles in the liquid, or blocking the particles of gold to agglomerate. Notorious for this are things like tin hydrated oxides or metastannic acid fine dispersions.
> Doing silver contacts, there would always be solder containing tin. Nitric will create metastannic acid, and if this is not filtered clean, attempted precipitation on copper would create rather fine particles of silver, which do not clump together or grow bigger (sadly, my personal experience also).
> 
> ...


I'm content with your explanation of how the gold particles could suspend in his syrup. Ironically, your explanation is eerily similar to a concern I have with running material that I have access to, and a lot of (gaylords full). My solution to it is more of a eco-goldex, electrolytic based process I'm currently working on/developing, that however is for a different post, at a different time. Thank you for your response.


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## Junior2021 (Feb 16, 2022)

FrugalRefiner said:


> Porque você disse que "Dissolveu ouro em água régia, ferveu tudo a um xarope para garantir que todo o nítrico fosse evaporado". Se você fez isso em um béquer alto com um vidro de relógio, deve ter levado muito tempo, pois a maioria dos vapores produzidos se condensaria no vidro de relógio e pingaria de volta no béquer repetidamente. Teria sido mais rápido evaporá-lo a uma temperatura mais baixa em um béquer curto sem o vidro


Em
Sou grata por estar sempre aprendendo com você. obrigado


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## Junior2021 (Feb 16, 2022)

FrugalRefiner said:


> Primeiro, você não quer ferver suas soluções para reduzir seu volume. Você quer evaporá-los. Quando você ferver, você perderá um pouco do seu ouro. A evaporação é mais lenta, porque é feita a temperaturas inferiores às de ebulição, mas mantém todo o seu ouro no recipiente.
> 
> Estou movendo sua postagem para a seção Ajuda necessária, pois você está pedindo ajuda.
> 
> ...


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