Hello, I’m currently trying to figure out why my solution (sample pic below) is a blue green cloudy color. The cat was a metal substrate cat from a 04 grand Cherokee. I figured while I was leeching it using the hcl - bleach method I’d try and leach the palladium out from some mlccs I collected as well. The solution has been sitting for about 24 hrs now and I think I may have added too much bleach. None the less I’m more so wondering why the solution is blue/green and why it hasn’t taken much of a red color that it would normally take
Why is it blue green? Pgm recovery from cat converter/mlccs.
- Thread starter Zemalo
- Start date
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The mlcc's will discolor.
The cat was it not ceramic honey comb?
EDIT: When I did cats I let them sit covered for a couple weeks, adding bleach every couple days.
The cat was it not ceramic honey comb?
EDIT: When I did cats I let them sit covered for a couple weeks, adding bleach every couple days.
Welcome to us.
You have started out in the wrong order here.
First of all dealing PGM salts are is very dangerous and toxic.
We never process mixed material like this, and how do you expect to dissolve values from a metal matrix without removing the base metals first?
Next The order of things is to study and then do, so now we will point you to some important study material:
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/
kurtak
Well-known member
Per the bold print (above quote) - because they make two different types of MLCCs
PM/MLCCs - the PM stands for Precious Metal/MLCCs --- the precious metals used in making this type MLCCs is silver & palladium
BM/MLCCs - the BM stands for Base Metal/MLCCs --- the base metals used in making this type MLCCs is copper & nickel
Dissolved copper = a blue solution
Dissolved nickel = a green solution
Dissolved copper/nickel = blue/green solution
So the MLCCs that you tried to leach were NOT PM/MLCCs but instead were BM/MLCCs
And for what it is worth leaching MLCCs is just about the worst way you can go about processing MLCCs
I have posted much about processing MLCCs which you can read about here ---------
https://goldrefiningforum.com/search/104938/?q=MLCCs&c[users]=kurtak&o=relevance
But - if you do leach MLCCs (the PM ones) HCl/bleach is the WRONG way to do it
That is because the HCl turns the silver in them to silver chloride which then gets lost in the ceramic mud (talked about in things I posted in above link)
Therefore IF (the VERY BIG IF) you are going to leach MLCCs (which as I say is NOT the best way to process) they NEED to be done with a nitric leaching & NOT a HCl leaching
The same is true with leaching CATs - it is just about the worst way to go about trying to recover the PMs from them & that is because you will only get "about" 70 - 80 % of the palladium --- "about" (plus/minus) 50 % of the platinum --- & VERY LITTLE of the rhodium
You can read more about that here ------------
https://goldrefiningforum.com/threads/large-volume-vs-small-volume-cat-processing.20573/
Bottom line - if you want to recover all of the PMs out of ceramics (MLCCs &/or CATs) you are far better served to smelt them
Can you recover PMs from ceramics with leaching ?
Yes --- BUT - you just can not & will not get all the PMs by way of leaching
Kurt
The interesting thing here is that he leached Metal Matrix Catalyst and MLCCs together in HCl/Bleach.
Besides the Toxicity of the PGMs the kinetics is as useless as it can be.
No it was a metal substrate. I made the mistake of taking a paddle bit and an impact driver to break it down to where I could get the substrate out. Ended up making a lot of powder that as I’ve read recently is not good.
I have refined some gold and silver. As well as read into hokes book. Tho I will admit I’m no expert. I have some experience but any advice yall give greatly appreciated. I simply didn’t know that the metal substrate was treated differently. In fact I didn’t know it existed until today. But I’m trying to roll with the punches as much as I can. I am well aware of the dangers of pgm salts and after I’m done with this project I probably won’t really mess with them again. At least until more experience is gained.
Your lack of gloves indicate you either didn't know/understand about the dangers or don't care.
So I'll say you have a lot of studies ahead of you.
HCl/Bleach may be used on ceramic substrate catalysts but absolutely not on metal substrate.
With metal substrate you need to dissolve ALL the base metals first, then you can go for the values.
And as mentioned MLCCs are best processed with smelting and then "only" the non magnetic ones.
I planned on letting it sit for a good while, adding small amounts of bleach once or twice a day and stirring to help agitate the powder
I do use glove actually. the container in the picture was completely sealed.
As I said in another reply I didn’t know that metal substrates existed until recently. I admit it was foolish of me to assume that
as I said before in a different reply I simply didn’t know prior to the addition of the acid and bleach that a) metal substrates existed and b) that they were treated differently. I would appreciate the passive aggressive responses to be minimized because I was simply asking for guidance not judgement
If handling anything that is suspected to have PGM salts in/on it one always use gloves.
There will always be contamination even on the outside of the containers, if they have not been washed after sealing.
PGM salts will build up and sensitize the body.
We have had members that has died by this!
You saw the metal matrix and just went on with the original plan even if you discovered that things was not as expected??
I really do not what to say to this!
What is your profession may I ask?
Maybe I can find another way to advice, if I know what you usually deal with.
