Platinum Recovery

[10fingers]

I'm trying to recover the platinum from an automotive catalytic convertor. I took out the innards and crushed it up and am now dissolving the substrate with the platinum on it in aqua regia. This should convert the platinum to chloroplatinic acid. I think when this solution is filtered and dried it will leave platinum chloride. I'm not exactly sure how to get the chloride out and leave pure metallic platinum. I think it can be done by intense heat but I want to make sure since there may only be a very small amout of platinum and I don't want to lose any of it.

[shooter3]

10. This link tells how to recover gold. I've tried it and it works. It's easy enough to try on platinum. Gold and platinum have some things in common. This process may be one of them. Good luck.

<a href="http://www.tomashworth.com/aqua_regia_clean.shtml" target="_blank">www.tomashworth.com/aqua_regia_clean.shtml</a>

<small>[ March 15, 2003, 11:01 PM: Message edited by: megalomania ]</small>

[VX]

Shooter, that link doesn't work.

10fingers, apparently their is about 5 grams of platinum per catalytic converter, from <a href="http://www.planetark.org/dailynewsstory.cfm/newsid/19807/story.htm" target="_blank">here</a> (not a direct quote but it does say that 10grams of Platinum is twice what is used in a standard cat.)

How do you plan to separate the Platinum from the Palladium and Rhodium?

[10fingers]

That's good to know. 5 gms is not a lot but it's currently worth $24.00 per gram.
I don't really care about the getting the rhodium out of it, for what I'm going to use it for it may be beneficial.

[shooter3]

The other way too it is;

Do a google on "Tom Ashworth's prospectors cache".

Open the first hit, titled "Tom ashworth's prospectors cache.

Under "site contents" click on "how to do it".

Next click on "Using aqua-regia to clean gold".

[megalomania]

The link works, but the format is wrong. It is supposed to end with "shtml" not "shml" I have fixed it.

There may be a few pages at the Organic Synthesis website, and maybe even at the Hive, for making platinum catalyst material. Platinum metal from solutions are depositied on inert substrates this way. You may also wish to consider electroplating (electrolysis) to get the metal.

[rikkitikkitavi]

Platinum chloride decomposes into platinum and chlorine upon heating.
However, the platinum is extremely porous, which makes it an excellent catalyst due to the large surface.

/rickard

[Mr Cool]

I get the impression that you're using it for a catalyst ("I don't really care about the getting the rhodium out of it, for what I'm going to use it for it may be beneficial"), in which case soak a platinum chloride solution onto mineral wool and heat it in a gas flame. This will produce very porous platinum, coated onto many thin fibres = huge surface area. Using activated charcoal instead of mineral wool will also work, but note that the charcoal needs to be quite pure carbon, no sulphur etc.

[10fingers]

OK, thanks a lot you guys. I'll let you know if it works.
Also, I just found some info on the Rhodium site on how to make platinum and palladium catalysts, very informative.

[10fingers]

Just an update in case anyone wants to try this. I did get the platinum out. It was about 4 grams.
Before I embarked on this process I tried to use the catalyst as it was out of the convertor. For some reason it would not work for anything. I can only guess that since the catalytic convertor was out of an old car that somehow the platinum had become deactivated.
Another thing, I've made aqua regia several times using 1 part 70% HNO3 to 3 parts 31% HCL. This time I didn't have any 70% HNO3 on hand so I distilled a batch which was probably 90% to 95%. When I mixed this with the HCL it started to bubble vigorously giving off a lot of chlorine gas, I was doing this in the kitchen and the whole place filled up with chlorine. I was trying to open windows and get a fan going to air it out and in the process I breathed in quite a lot of chlorine, it's bad shit, it's been three days and I'm still coughing up phlegm. So, the moral of this story is if you're going to make aqua regia, I wouldn't use HNO3 that's over 70%.
An example of how strong chlorine is, my wife had left some jewelry on the kitchen counter, the gas ate the plating right off some of it. Also, there was a 10K gold ring which become so brittle that it shattered when she picked it up. I've never heard of metal doing something like this after being exposed to chlorine, very strange.
Anyway, my wife has been bitching at me nonstop over this little fiasco and banned me from using chemcials in the house.
But I don't care, I got my 4 grams of platinum.

[Mr Cool]

I didn't think just chlorine would attack a metal like that, maybe you had some nasty NOCl etc floating about. Or maybe I'm wrong about chlorine.
I think your wife has a point, filling the kitchen with war gases is never a popular act!!
But like you said, you got the platinum so it was worth it :D .

[10fingers]

Yea, some women don't seem to appreciate a guys misadventures in chemistry.

[Anthony]

"But dear, I only wanted to make you a ring out of it!" <img border="0" title="" alt="[Wink]" src="wink.gif" />

Unfortunately, it turned out to be of unsuitable quality/purity to make a ring and you had to just sell it and buy chems with the money :)

[CommonScientist]

Go to a junkyard and get as many catyltic converters a you can, fill up the back of your 4x4 or somthing, get the platium out of them , melt t in a crucible. Then pour it on a peice of metal that you want to coat it with. You could use those platinum coted rods for anodes in a chlorate cell.

What is with me ad chlorate cells, im addicted to them, chorate cell his, chlorate cell that, eye yai yai.

[rikkitikkitavi]

unfortunately, finding catalytic converters at the junkyard might be difficult.

it is the second thing removed (air bag charge the first) since all converters are recycled, due to the high cost of Pt. But you can probably negotiate with the
owner over buying one, since they hardly cost more than the Pt-price, most likely far less, due to the cost of recycling Pt

/rickard

[megalomania]

I am sure platinum recovery is not that easy. First of all the market for used catalytic converters is around 50% according to some research I have read. The market being scrap hunters who snatch up catalytic converters to recover the platinum. If you are in a larger city, forget about it, scrap hunters will have picked the car lots clean.

The used converters are quite choked with carbon, and metal you get will be contaminated. Also just heating the catalyst is difficut because it is a thin layer of metal over a honeycombed matrix. This will have to be pulverized and shredded, and that will contaminate the metal.

Industrially they grind the things by the thousands and load them into electric furnaces. That won't help much on a small scale. Your nest bet is to dissolve the metal in acid (aqua regia I believe) and precipitate the metal from chloroplatinic acid or some such platinum compound.

[Dave the Rave]

10, I´ve been wondering, did you have some plan about your platinum ? May I ask what you will do with it ?

[Marvin]

Common, I think that might be a shade more difficult than you imply, and that has to be the worst method Ive ever heard of for making chlorate anodes. Pt melting point is.... difficult to get to, about 1700C or so. Arc welder would probably do it for small amounts. Better would be to electroplate the Pt from the chloride complex directly onto a very clean carrier cathode. Should make a decent anode for chlorates.

Very interesting problem with high concentration aqua regia. Something else that isnt in the textbooks and should be.