When In Doubt, Cement It Out _cementation_
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What type of plastic was it, and what did you have in it?
I would restate Snail's warning as "plastic containers are less prone to breakage than glass, but check them regularly as many of the solutions we use can cause them to become brittle over time".
Nitric, in particular, will cause many plastics, including HDPE, to become brittle.
Dave
Edited to correct error as pointed out by orvi in the next post.
I would restate Snail's warning as "plastic containers are less prone to breakage than glass, but check them regularly as many of the solutions we use can cause them to become brittle over time".
Nitric, in particular, will cause many plastics, including HDPE, to become brittle.
Dave
Edited to correct error as pointed out by orvi in the next post.
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I think you mean glass
Yes, it depends strongly on the type of plastic. Ordinary buckets are made of PP - problematic when cold, and also flexible just to some point. PP buckets are easy to break when smashed, or also it is easy to punch the hole through (eg when stirring with heavy rod) from the inside. Pick the buckets with thick wall, not these transparent thin ones. Good stuff is from old indoor wall paints or some pre-made plaster.
You can often found type of plastic on the bottom - either a number in that "recycling triangle" or stated in some other way.
PE buckets are much more durable and "bendable" - they do not break easily, even in the cold. They also withstand much more "chemistry", but nitric and even worse AR will slowly decay the plastic.
When dissolving and handling large volumes of eg waste solutions, I always stick to the classical PE canisters. From my experience, they are fine with nitric for quite a long time (50% nitric to be clear), but only at room temperature. Hot acids will make it brittle after few days.
Agreed. I use 1 gallon paint buckets, especially as secondary containers for a lot of acids. When we were rehabbing houses, I ended up with quite a few.
Here in the US, they are usually heavy polypropylene. I believe I have posted about them in the past.
Dave
I luckily acquired 3 heavy duty PE buckets for chemical shipping. Round, 25 L big and tall. If I was a refiner like folks in India, this type will be the best - for sedimentation of gold.
Martijn
Well-known member
They're actually pretty sturdy. I was waiting for the moment one bucket to fail or get brittle to make a picture of it, for this reply only. It didn't
This one was the iron pot for quite a few years. But I wanted to replace it before it got brittle anyway and so I smashed it on the edge of my bench to make the picture.Tried to break by pushing on the side and it was flexible as if it was new. Darn things.
It didn'tThis one was the iron pot for quite a few years. But I wanted to replace it before it got brittle anyway and so I smashed it on the edge of my bench to make the picture.
Tried to break by pushing on the side and it was flexible as if it was new. Darn things.
yellowfoil
Well-known member
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- Sep 14, 2014
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Depends what type of plastic it is made of. They make biodegradable plastics these days and used for buckets as well. Those will disintegrate very soon, specially outside, in the sun. Mostly made for food products, including new buckets supplied for hardware stores. I use buckets made for motor oils or some cleaning agent supplied for industry.They're actually pretty sturdy. I was waiting for the moment one bucket to fail or get brittle to make a picture of it, for this reply only.
This one was the iron pot for quite a few years. But I wanted to replace it before it got brittle anyway and so I smashed it on the edge of my bench to make the picture.
Daniel7878780
New member
Hello everyone, what steps after cementation, what should I do with cement, how do I recover?
Thanks for the response
Thanks for the response
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There are a few Isreali's here, but if you want an answer to your question, the chances increase many fold if you translate it to English.
Well, that depends on what kind of cement you are talking about, and how pure you want it.
Is it Gold, Silver or PGM's?
Silver on copper can if done correctly get up to 97% or more in purity if done correctly.
Many are happy with that. If not, electrolytic recovery is usually the next step regarding Silver.
The slimes from Gold/PGM's do usually need additional refining, by AR or other suitable method.
Recover?
As cement it is already recovered??
Is it Gold, Silver or PGM's?
Silver on copper can if done correctly get up to 97% or more in purity if done correctly.
Many are happy with that. If not, electrolytic recovery is usually the next step regarding Silver.
The slimes from Gold/PGM's do usually need additional refining, by AR or other suitable method.
Recover?
As cement it is already recovered??
Please leave the original content alone if you edit like this, it's better to see the progress of the thread.
Thanks
CO-WYO-Peter
Member
With regards to the need to agitate the solution with air to mix the solution to make contact with the copper; Will the addition of air cause the hcl to keep the precious metals in solution (AP leach ) and not cause cementation but actually just consume the copper ? I would like to understand this more.
NobleMetalsRecovery
Well-known member
I did not see the "book" that you mentioned.
If you are usung a phone to read, turn it sideways to read the signature lines.
The forum software does that
huggybear
Active member
Thanks for your detailed explanation, but there is one thing I still don't understand.
From what I have found online, copper is not soluble in HCl alone so if you are dealing with aqua regia which you have deNOX'd, there will be no cementation reaction if using copper.
That is correct, Copper do not dissolve in HCl.
But our goal by cementing is not to dissolve Copper.
What we do by cementing is to let the ions from precious metals change place with the Copper ions.
So the Chloride in the Gold Chloride happily grabs a Copper molecule from the Copper and forms Copper Chloride leaving the Gold behind as metal.
Or Palladium,Silver, Mercury and so on.
Ion exchange is what happens. A copper ion is traded for a PM ion. PM ion comes out of solution in exchange for an ion of copper going into solution. This is the simple explanation as I understand it.
Copper will not dissolve into HCl, but on exposure to oxygen it will. Copper in HCl, left with no sealed lid is enough exposure to allow the copper to dissolve, but very slowly. By adding a larger amount of oxygen, for example an air pump, will speed up the process. This is often why an air source is used for agitation when cementing PM’s.
Yggdrasil beat me to it.
Copper will not dissolve into HCl, but on exposure to oxygen it will. Copper in HCl, left with no sealed lid is enough exposure to allow the copper to dissolve, but very slowly. By adding a larger amount of oxygen, for example an air pump, will speed up the process. This is often why an air source is used for agitation when cementing PM’s.
Yggdrasil beat me to it.
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The reason for ion exchange with copper is AuCl4-, PdCl4=, are strong oxidizers. Air helps with stirring
