Urea question

[Yggdrasil]

WOW - some really awesome reading this morning - or as the moto of this forum says - "Gold Refiners Helping One Another"

Don't really have time to reply to all that has been said this morning - but likely will when more time allows


I have been "trying" to teach the value of cementation for years now - I first learned it's true "value" from 4metals back in 2014 in this thread -------

https://goldrefiningforum.com/threads/fuzz-button-interconnects-need-some-advice.22203/#p232030

And I have been using it ever since

That does NOT mean it is the only method I use


I agree

You probably wouldn't want mine then ether

Kurt

As you also replied to me.
I have used cementing as a part of the stock pot pre waste treatment.
But it never occurred to me that it can be used as in process step or actively as a part of the processing.

Partly due to two things.
1. I for the most part process PCB in AP for recovery in which cementing would not be appropriate.
2. When ever I use Nitric, volumes and processing do not lend itself to have a favorable need for these processes.
Now I know they are there and can use it if needed.

My processing has been strictly low volume through put.

Edit to add:
I have read this thread before, but in light of the new information and understanding I guess I need to revisit it

 

[Ahmed Fouda]

Hi everybody i hope you are all well
A friend of mine brought to me some rocks and he says that they hold gold . I am biggenner but i had a try. I crushed it to fine powder , then washed it with water then wahed with HCl which had a kind of vigorous reaction with a lot of bubbles then washed it again with water then I added AR but when i test with stannous chloride the deep yellow colour of AR becomes colourless . And i can't precipetat any thing with smb
could any one till me what does that mean.
My friend says that an expert t him that this stone holds gold.

 

[Yggdrasil]

Hi everybody i hope you are all well
A friend of mine brought to me some rocks and he says that they hold gold . I am biggenner but i had a try. I crushed it to fine powder , then washed it with water then wahed with HCl which had a kind of vigorous reaction with a lot of bubbles then washed it again with water then I added AR but when i test with stannous chloride the deep yellow colour of AR becomes colourless . And i can't precipetat any thing with smb
could any one till me what does that mean.
My friend says that an expert t him that this stone holds gold.

Welcome.
Why do you post this in this thread?
That means you have no Gold in solution or too much Nitric or it is still in the material.

Anyway you NEVER add acids to rocks you know nothing about, unless you have a death wish.
STOP WHAT YOU ARE DOING.
Set your stuff away and study what I give you here.
When you think you know what to do you come back and present your plan and we can say if it is good or not.

We ask our new members to do 3 things.
1. Read C.M. Hokes book on refining jewelers scrap, it gives an easy introduction to the most important chemistry regarding refining.
It is free here on the forum: https://goldrefiningforum.com/phpBB3/viewtopic.php?f=54&t=19798
2. Then read the safety section of the forum: https://goldrefiningforum.com/forums/safety.47/
3. And then read about "Dealing with waste" in the forum: https://goldrefiningforum.com/threads/dealing-with-waste.10539/

Suggested reading:
https://goldrefiningforum.com/forums/the-library.101/
https://goldrefiningforum.com/threads/when-in-doubt-cement-it-out.30236/
https://goldrefiningforum.com/threa...le-read-this-before-you-post-about-ore.33333/


Forum rules is here.
https://goldrefiningforum.com/threads/gold-refining-forum-rules.31182/

 

[minero74]

This thread has so far been quite informative.
I like it, so keep it coming.
It might end up as Library material

Excellent Idea
this thread share so much knowledge
that must be write down.
the benefit for new member and members is amazing.
thank guys for sharing years of knowledge
now I understood many thing.
like cementation
I was cementing silver with copper
even when i put in lot of pipe of copper in 5 gallon bucket.
after i think all silver cement out.
i decant the liquid to another bucket
i add HCL to the liquid,next morning I found out there was silver chloride at the bottom of the bucket.
i was having no idea how that was happen
because I put a fish pump that agitate the liquid and all the liquid touch the copper pipe.

 

[orvi]

This thread has so far been quite informative.
I like it, so keep it coming.
It might end up as Library material

I was placed into situation when over the course of two months, I scaled up from several hundred grams to dozen kg of material per batch. You can have all theoretical background possible, but dozen kg of metal represent around 50L of solution minimum. That changes things from foundation.

All things change on this scale, everything took longer, simple filtration take not several minutes but hour and more... You need to optimize all of the steps to be as economical and rational as possible. And also you will have to (for sake of your own safety) incorporate pumping of liquids instead of just pouring from barrels.

That is how my processing route was born. Every step was re-thought, optimized and evaluated afterwards to see if I made better protocol/save reagents/save time. That is when all of the thinking methods from the college kicks in - and you look into every step as chem PhD. In the end, time emerged as most valuable variable, so my prefered route was optimized to save as much time as possible.

That explains excess of nitric used, cementation as bulk modus operandi (as hot cementation of gold is quite fast). I slowly become friend with 120L barrel and AR. As I learned how to use it wisely, protect myself and turn profit with what I was doing.

It is long gone, but I feel that knowledge that I accumulated should live somewhere to be useful for others.

I plan to release something bigger in upcoming time, but we will see if it pass review of the more knowledged ones here As a scientist and active researcher, I want everything confirmed, read and clarified

 

[Ahmed Fouda]

Welcome.
Why do you post this in this thread?
That means you have no Gold in solution or too much Nitric or it is still in the material.

Anyway you NEVER add acids to rocks you know nothing about, unless you have a death wish.
STOP WHAT YOU ARE DOING.
Set your stuff away and study what I give you here.
When you think you know what to do you come back and present your plan and we can say if it is good or not.

We ask our new members to do 3 things.
1. Read C.M. Hokes book on refining jewelers scrap, it gives an easy introduction to the most important chemistry regarding refining.
It is free here on the forum: https://goldrefiningforum.com/phpBB3/viewtopic.php?f=54&t=19798
2. Then read the safety section of the forum: https://goldrefiningforum.com/forums/safety.47/
3. And then read about "Dealing with waste" in the forum: https://goldrefiningforum.com/threads/dealing-with-waste.10539/

Suggested reading:
https://goldrefiningforum.com/forums/the-library.101/
https://goldrefiningforum.com/threads/when-in-doubt-cement-it-out.30236/
https://goldrefiningforum.com/threa...le-read-this-before-you-post-about-ore.33333/


Forum rules is here.
https://goldrefiningforum.com/threads/gold-refining-forum-rules.31182/

Thank you sir for your advice.
And for your valuable sharing

 

[kurtak]

I was cementing silver with copper
even when i put in lot of pipe of copper in 5 gallon bucket.
after i think all silver cement out.
i decant the liquid to another bucket
i add HCL to the liquid,next morning I found out there was silver chloride at the bottom of the bucket.
i was having no idea how that was happen
because I put a fish pump that agitate the liquid and all the liquid touch the copper pipe.

Per the bold print - Because you did not get complete cementation of the all the silver from the silver nitrate

This is likely due to silver nitrate being "trapped" in the silver cement when the cement silver settles in the bottom of the bucket as the silver cements out of the silver nitrate

The silver cement that settles in the bottom of the bucket MUST be stirred up from time to time in order to bring the silver nitrate up & out of the silver cement that is settled in the bottom of the bucket so that the silver nitrate that is trapped in the silver cement can make contact with the copper

because I put a fish pump that agitate the liquid and all the liquid touch the copper pipe.

Though a fish tank air bubbler will keep "some" of the silver cement that is settling in the bucket stirred up it will not keep all of the silver cement that is settling in the bucket stirred up

The bubbler will only stir up some of the silver cement near to the end of the bubbler hose that is bubbling air out the end of the bubbler hose

So - silver that is settling further away from the end of the bubbler hose is still settling in the bucket & trapping silver nitrate in the silver cement as the silver cements out

So - from time to time you still have to "physically" give the silver cement a "good" stirring to bring the silver nitrate that is being trapped in the settling silver cement up & out of that silver cement so that the (trapped) silver nitrate can make contact with the copper

I have always used piece of 1/2 inch or 3/4 inch plastic pipe to do this "physical" stirring with - & you want to do this physical stirring very good - from time to time

As you near the end of the cementing process - where you "think" most of the silver has cemented out you want to start testing to see if in fact all the silver has actually finished cementing out

You want to do this by allowing the cement silver to settle after each time you stir it - then take a small sample of the solution & add a couple drops of HCl - if silver chloride forms the cementing process is not complete & you need to continue the process - which includes more stirring

IMO - when cementing silver you do not need the bubbler - you are better served to just physically stirring the silver cement up from time to time

As a side note; - what is the source of your silver ?

I ask because if there was any lead in your original silver source when you added the HCl you may (or not) have precipitated lead chloride instead of silver chloride

There is a way to test for the difference between silver chloride & lead chloride but that is a whole other post

Kurt

 

[minero74]

Per the bold print - Because you did not get complete cementation of the all the silver from the silver nitrate

This is likely due to silver nitrate being "trapped" in the silver cement when the cement silver settles in the bottom of the bucket as the silver cements out of the silver nitrate

The silver cement that settles in the bottom of the bucket MUST be stirred up from time to time in order to bring the silver nitrate up & out of the silver cement that is settled in the bottom of the bucket so that the silver nitrate that is trapped in the silver cement can make contact with the copper


Though a fish tank air bubbler will keep "some" of the silver cement that is settling in the bucket stirred up it will not keep all of the silver cement that is settling in the bucket stirred up

The bubbler will only stir up some of the silver cement near to the end of the bubbler hose that is bubbling air out the end of the bubbler hose

So - silver that is settling further away from the end of the bubbler hose is still settling in the bucket & trapping silver nitrate in the silver cement as the silver cements out

So - from time to time you still have to "physically" give the silver cement a "good" stirring to bring the silver nitrate that is being trapped in the settling silver cement up & out of that silver cement so that the (trapped) silver nitrate can make contact with the copper

I have always used piece of 1/2 inch or 3/4 inch plastic pipe to do this "physical" stirring with - & you want to do this physical stirring very good - from time to time

As you near the end of the cementing process - where you "think" most of the silver has cemented out you want to start testing to see if in fact all the silver has actually finished cementing out

You want to do this by allowing the cement silver to settle after each time you stir it - then take a small sample of the solution & add a couple drops of HCl - if silver chloride forms the cementing process is not complete & you need to continue the process - which includes more stirring

IMO - when cementing silver you do not need the bubbler - you are better served to just physically stirring the silver cement up from time to time

As a side note; - what is the source of your silver ?

I ask because if there was any lead in your original silver source when you added the HCl you may (or not) have precipitated lead chloride instead of silver chloride

There is a way to test for the difference between silver chloride & lead chloride but that is a whole other post

Kurt

Excellent
Thank you very much for the explanation.

Now I see why I still precipitating silver chloride from the solution.

I washed the silver chloride with Hot water few time,to get rid of any lead chloride.

but the silver chloride not dissolved.
I keep it for the next lye and sugar process.

the source of the silver were some old silver bars.
It was smelting from silver ore,but Not from galena.
then cupellation ,so the lead evaporate/adsorbed , the result silver
was grained ,then dissolved in HN03.

then i put the solution into a 5 gallons bucket .

when I get certain volume of the solution
I add lot of copper pipes for cementation

I could use salt,but I want to see how I was doing with cementing of volume of silver nitrate solution.

for obvious reason I restrain myself for writing down the entire process.
Edited.