Why is it blue green? Pgm recovery from cat converter/mlccs.

[adam mizer]

I used zinc powder, works great. Second choice is thin zinc metal, but powder reacts like "now".
Got used to this zinc and how it reacts many years ago.
EDIT: You have to use it in additions as the reaction can be too much and foam over. It still took time and stirring but works well.
Copper is slow to dissolve. But I am thinking it will work. Slow.
EDIT: It is HCL Bleach. Don't know reaction of copper. But HCL needs bubbling air like AP solution.
The chlorine made from the bleach gets used up thats why you have to keep adding it. Also when heated even by the sun drives out the chlorine from the liquid.

 

[Yggdrasil]

Now would I be able to use copper instead of zinc powder to drop the pgms? Or would it be best to just stick to zinc

Zinc will drop most all metals while Copper will only drop precious metals and Mercury.
In this setting the Zinc will drop the ,metals from the Catalyst matrix as well.

 

[Zemalo]

Zinc will drop most all metals while Copper will only drop precious metals and Mercury.
In this setting the Zinc will drop the ,metals from the Catalyst matrix as well.

So in this case it would be more wise for me to use copper powder

 

[Yggdrasil]

So in this case it would be more wise for me to use copper powder

Yes.
Unless you are doing Cyanide leaching it is almost always better to use Copper powder. KEEP AWAY FROM ACIDS if Cyanide.
There is one drawback on Copper though and that is that proper stirring is vital so the PGMs don't plate out (passify) the Copper.
The use of fine powder will be beneficial, but still needs hard stirring.
With Zinc that is not that critical.
If you have a HCl based leach Aluminum may also be used.
Here it is important to not use too much and let it sit in the HCl as it sometimes gels up and becomes hard to filter.

 

[Zemalo]

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.

Found out my color problem was partially due to bad quality bleach. I switched up the brand and now the solution has a dark red orange color. I took a sample, filtered it and added some copper to get an idea of the upcoming process. The copper worked pretty well.

 

[orvi]

Found out my color problem was partially due to bad quality bleach. I switched up the brand and now the solution has a dark red orange color. I took a sample, filtered it and added some copper to get an idea of the upcoming process. The copper worked pretty well.

PGM chemistry is not fun and games when you really step into it

Some advice for the future:

1. Spend at least hour or two researching relevant forums and advice/articles/other literature/etc. before attempting ANY kind of chemistry which is new to you. Or ask here on the forum if this hour search won´t give any good results. Get familiar with dangers arising from it, look up not only substrates/chemicals used, but also all possible products of reaction. This can literally save your life. As professional organic chemist with relatively rich experience also with refining, I can say this routine is well worth it. And if it don´t save your health or life, it saves a lot of time.
It will be foolish to think that nobody ever tried the same procedure you attempted. Almost everything in simple aqueous inorganic chemistry was already done in the past (either by professionals and amateurs) and most of the times the information about it is on the internet.

2. Bleach is a commercial product. And as with all commercial products, the exact composition is proprietary. Many producers add additives into regular hypochlorite bleaches to cover the noxious odor or colourants, some even detergents. This can interfere with the reaction.

Also, my main concern will be if there was the hypochlorite itself. Bleach decompose over time by itself, and it can be well possible that your was already "dead". Always look to the manufacture date on the package and ensure it wasn´t stored for too long, espetially in summer months. Retailers have it placed on the shelf, or somewhere in the storage at the back of the supermarket, where it does not have AC in the summer - and whoopsie, you purchase "brand new" bottle claiming 5% potency, but in reality there is like 1-2 %. Happens a lot. Be aware of that.

3. Leaching out honeycomb from cats or leaching MLCCs is the worst procedure you can do to recover PGM´s from this ceramic type of matrix. There is one very lenghty thread where I, kurtak and many others tried to help to resolve the situation where one of our members started leaching several kilos of crushed MLCC´s in acid. It was very unplesant experience, mainly for him.

This is that thing about research - if you looked and thoroughly searched the forum, you will find this info in like 90% of the threads issuing "cats" or "MLCCs". But you will now know for the future

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As it is said "the damage was already done" But positive thing is - you cannot chemically destroy the very elements. If you don´t discard the solids or leachate, values are still there. Good thing is that you see red colour. Now you will need to stir it occasionally for some week or two and adding portions of bleach from time to time to assure high redox. Then proceed as sreetips in his video about wet cat leaching process.

 

[orvi]

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

I get the notion you have from some of us.
It is disputable if we should cautiously warn every newcomer thing by thing about what is toxic, what is a bad practice or what is unsafe and forbidden in general chemical practice. Or simply let the evolution sort it out.

We had there folks who poisoned themselves and nearly died after doing some refining in the backyard. And actually, one of our members, very knowledged and skilled man wrecked his health with PGM metal salts. My friend passed away after he poisoned himself in the lab. He had more than 15 years of experience.

We know these things and were through them. And then somebody show up here on the forum, clearly without proper chemistry background (I teached lab courses for several years, and I can clearly tell), trying to work with chemicals which claimed lives and health of many. We don´t want to feel responsible that we did not guide and warn him well enough. Of course, some guys just made their minds and do what they planned anyway... But we want to try discourage them first.

That is why our mods and members talked much more about what and why you shouldn´t do, as about actually resolving the situation Because resolving the situation will bring you back to those beakers with solutions and expose you to them more. Learning and executing basic safety protocols costs nearly nothing and prevent/or at least minimize possible damage

 

[4metals]

Or simply let the evolution sort it out.

This is a quote for the ages!!!!!