stannous chloride problems

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kroutonz

Active member
Joined
Nov 21, 2010
Messages
36
Hello, I've been reading up and have finally started an attempt to extract platinum/palladium from catalytic converters. So far my HCL-CL method has been sitting for about 1.5-2 weeks at 140-145 degrees f via a bucket heater.The starting amounts were 5 lbs of crushed/fine powder and about 1/2 of it is solid honeycomb material. I poured in 2 liters of 31% hcl into a 5 gallon bucket, and I've been pouring a couple capfulls of clorox bleech into the mixture every 2 days.

I was going to try and filter it today and found that the stannous chloride didn't react at all with the mixture. The hcl was a bright yellow color on a cue tip, but the stannous just seemed to kind of dilute it and make it less bright. Now I'm not sure if this is because of the way I made the stannous or as my friend thinks that theres no pgms in the solution. I took 30 or so ml of hcl (31%) and a couple small crystals est .5 to 1 gram of stannous chloride and mixed it up until it all seemed dissolved. I didn't heat this mixture at all. this was about 3-4 days before the extraction and was sitting in the garage in somewhat cold temperatures.

So I'm wondering if the stannous is bad, did i mess something up with the hcl-cl extraction or just have bad starting material(i would think there would be small amounts atleast)?
Also for raising the ph sodium bicarbonate should work instead of sodium carbonate right?
 
Test your stannous with a known sample of gold or PGM.

You can skip the soda ash if you don't have a lot of free acid, just go straight to the zinc turnings. Since making the DVD I've started using a more dilute HCl (15%) and found I use less zinc turnings and don't need to use soda ash any more.

If you have too much heat you won't get any chlorine to stay in the solution and the PGMs won't extract. I've had very good results at from 0C to 60C.

Steve
Steve
 
Few more things that maybe worth mentioning (that can also effect the test).

- You might have free chlorine ions that interfere with the test. (although not likely)
- Amount of dissolved PGM's is very small comparing the solution volume.

You may want to leach a few more batches with the same solution until you reach high dilution from the bleach additions, saves on the acids...
 
Well I went out there today, and made a new batch of stannous, and still the same problem. I don't have solution containing known pgm's to test it, but it isn't reacting at all. Can bleach go bad, like all the chlorine atoms getting destroyed from a couple days of cold weather? Not sure if I should just start over again with the same acid and try lower temperature on the bucket heater( although it should be fine according to steve), or try and see if the zinc does anything.
 
On the HCl-CL video on my website I show how to make a small test sampe from a single foil from an old card finger.

Do you have access to a junk pci or isa card from an old computer?


Do you have an old earring, link from a broken gold chain, or karat ring that you can shave a small sliver of gold off of to dissolve and test your stannous?


Steve
 
kroutonz said:
I'm gonna try a hard drive platter and see how the stannous works tomorrow.
Click to expand...


You should choose a better source of precious metals than a platter.

Try testing a sliver of something gold around your house.

Steve
 
Oh, alright I"ll scrape off something from a pci connector. It has to be dissolved for stannous to react right?
 
I went out there today and mixed up a fresh batch of stannous. I placed 2g of tin or so and dissolved it till it was mostly gone with a little bit of excess tin/antimony on the bottom. I used this to swab the solution and test it for pgms. I'm pretty sure I have platinum, just not sure if its enough to warrant a precipitation. The stannous took about 3-5 minutes or so to turn a light red/brown color but it definitley wasn't immediate or bright like I've seen.
I'm assuming its just majorly diluted from the chlorine bubbling out too quickly/ because of the gallon of muriatic diluting the few pgms.
DSCN0096.JPG
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I also tried to make a test solution out of a small pci connector from a card. I clipped it off and it seemed to be gold, but the AR wouldn't really dissolve it, and the stannous wasn't doing anything but maybe a verrrry light blue but that may have been my imagination. I probably diluted the AR with about 60% water 30% conc muriatic acid and 10% conc nitric. I also heated it up to around boiling but still no real quick reaction other than a green tint to the AR from the green motherboard looking piece probably. I'm not sure if I should of just used conc AR and no water.

But basically I just wanted you guys to take a look at the pictures and see if you think its diluted from there being alot of muriatic or if theres just few pgms in the mixture and I should try and leech the same cat material again.

Also thanks for all the help guys it's been a slow process but I think I'm figuring it all out (mostly).
 
I was cleaning up some purple stains in a dish pan with a small amount of AR and thought if I added water it would spread it around better. It quit working. Oz comfirmed that I should not have diluted AR with water. If you want more solution add more HCl.

FrugalEE
 
Dilute with water after the gold is dissolved. You might consider making several different strengths to get an idea of color Vs amount of gold.
 
To clarify this a bit further, there are times and circumstances that a dilute AR is best. Concentrated AR was best for what frugal was doing.

I tend to run reactions hard and concentrated so I seldom see a stannous test showing purple for gold or yellow for platinum. I am almost always seeing black for gold and orange for platinum. Although they “look” black and orange, they are just so concentrated they appear a different color. Much like with food coloring with the yellow looking orange and the blue looking black while still in concentrated form.

If you get a darker reaction like I do and are not used to it, you can easily check it by taking 1 drop of your concentrated solution to be tested, and add 10 drops (or more) of distilled water to dilute it. Then you will get the more muted colors when testing with your stannous chloride. It takes a bit of practice to become confident with stannous chloride testing. The number 1 mistake is testing solutions that still have oxidizers present. You will get a false negative for values in solution and end up throwing you’re values out.
 
Thanks Oz, I'll try that after this next attempt which hopefully yields enough pgm's to do that
I also realize now that my hcl cl will disolve pgms faster when it is colder so I'm scrapping the bucket heater for this process.

Hopefully in a couple weeks I'll have a ball of some metal lol.
 
Maybe it's just me but anytime i have dealt with cl be it hcl, ap, or acid clorox i have found that the cold is my favorite new best friend when it comes to keeping cl in solution. I loveeee my ap in the cold you just have to have more air. In some processes it might take a little longer but i find the results well worth waiting for. Cats are lazy like that. :p
 
Dang lazy cats, they just lay there and consume your Cl2 gas.

Kidding aside, you can have a far higher concentration of Cl2 gas in solution at a low temperature. However heat speeds up a Cl2 reaction with PGMs, as well as drives Cl2 out of your solution. You have to find the fine balance between the 2 depending on your goal. If you have time to wait, cold is your friend with chlorine gas as you are not wasting it in the name of speed.
 
A recent revelation I've had with the paradox of heating or not heating my HCl-Cl is the water content. Lately, I've tried diluting my HCl to 15% and it works better and consumes less zinc (when working with extracting cats) when recovering the values. I suppose this is because the extra water allows more chlorine to stay in the solution.

I started doing my cats this way in the last few months of the summer when I was running low on HCl one day. I found the entire process went much faster. Now I'm using a more dilute solution of HCl on my cats.

Steve
 
While I've not given the idea a go, it's entirely possible you can effect a recovery without the use of any HCl. Gold was routinely recovered by dissolution with chlorine, then rinsed out of the ore with water. That subject may be covered in Rose's The Metallurgy of Gold. If that's not the source, then I have no clue where I read about it.

Needless to say, if silver is involved, none is recovered.

Harold
 
Well gee Harold, that is plausible indeed. What was this I heard you say about not knowing “work around” methods of refining? I will need to give that some thought and maybe do a few tests.
 
Oz said:
Well gee Harold, that is plausible indeed. What was this I heard you say about not knowing “work around” methods of refining? I will need to give that some thought and maybe do a few tests.
Click to expand...
Not really a refining process, but one for extraction. If memory serves, they'd introduce the chlorine to a sealed chamber, where it was allowed to remain for a given period of time, then water was introduced to flush out the values. In a sense, a similar system to using cyanide, with pretty much the same hazards. Accidents had the potential to lead to death.

I gave thoughts to all of the strange processes that have been used in the past, including the Miller chlorine process----found them most interesting---but I stuck with conventional methods. My objective was to refine gold, not to do research. For me, it paid huge dividends in that it lead to a successful (unintended) business. Not sure that would have happened had I fancied myself a research scientist that never managed to master any of the processes.

Harold
 

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