# HCL-CL leach method



## kjavanb123 (Apr 24, 2011)

I have been using AR on my cats, however I used to get a lot better result specially for Rh and Pt using HCL-Cl. in Steve's DVD he talks about putting in a bucket seal it and leave it there for few days, what is the ratio of HCL-Cl? I have purchases solid Cl used for cleaning pools. how about if i heat the HCL in a beaker, and use that plastic pump to circulate through the honeycomb, then add solid Cl to beaker in small increment? would that leach the PGMs out?

Thanks
Kev


----------



## Barren Realms 007 (Apr 24, 2011)

kjavanb123 said:


> I have been using AR on my cats, however I used to get a lot better result specially for Rh and Pt using HCL-Cl. in Steve's DVD he talks about putting in a bucket seal it and leave it there for few days, what is the ratio of HCL-Cl? I have purchases solid Cl used for cleaning pools. how about if i heat the HCL in a beaker, and use that plastic pump to circulate through the honeycomb, then add solid Cl to beaker in small increment? would that leach the PGMs out?
> 
> Thanks
> Kev



Steve has stated that he has had better results using a 15% diluted solution of HCL/CL. You can use the solid CL the way it is just add it in small amounts.


----------



## samuel-a (Apr 24, 2011)

kjavanb123 

Heat will actually serve the opposite purpose.
Gases solubility in solution increases as temperature drops, so, by heating the HCL, you may get a very active Cl generation, but it will not remain in the solution too long as it will gas off...

You'd be better off adding the Cl tablets at room temp'. i would even throw couple of ice cubes every now and then...
As 007 said, add slowly... 

I've seen you are quite a handy guy, you could always build your self a small electrolytic chlorine generator (brine) and bubble it through your solution (under the cat's) while the pump circulating the solution...


----------



## Barren Realms 007 (Apr 24, 2011)

samuel-a said:


> kjavanb123
> 
> Heat will actually serve the opposite purpose.
> Gases solubility in solution increases as temperature drops, so, by heating the HCL, you may get a very active Cl generation, but it will not remain in the solution too long as it will gas off...
> ...



You can take a stand alone pool chlorinator and make the same setup. Add water to the chlorinator and pump air thru it. Use granular chlorine not tablet form and don't mix them together


----------



## kjavanb123 (Apr 25, 2011)

i tested the hcl-cl method in room temp, on Pd metallic powder, and solution turned brown orange, but the metallic powder still not dissolved, yet solution tested positive for Pd. I heated it up a lil and metallic powder still undissolved after addition of solid Cl just color change to darker.

I tried the hcl-h202 at room temp and almost immidately the metallic powder got dissolved. I have yet to test the ability to dissolve Pt and Rh using hcl-h202 any ideas?

Thanks
Kev


----------



## samuel-a (Apr 25, 2011)

HCL+Cl is not as aggresive as HCL+H2O2 or AR, it will dissolve Pt/Pd with lots of stirring and repeated additions of Cl and takes more time to dissolve metals...
It work best for powders and foils that has large surface area, but still, it is a less superior method in sense of speed and amount of metals it can dissolve...


----------



## kjavanb123 (May 3, 2011)

ok i tried the HCL-H2O2 combination on Pd in room temp and worked faster than AR in room temp. I also did the same leach combination on Pt powder and it also works better at room temp, but to my surprise i leached the previously leached cats using hot concentrated sulfuric acid and got Rh in the solution. so lesson learned that a combination of HCL-H202 and hot concentrated sulfuric acid would extract all the PGMs from given cat. here are some pictures of sulfuric acid solution with Rh.


----------



## samuel-a (May 3, 2011)

kjavanb123 said:


> would extract all the PGMs from given cat.



That's a bit of an over statement, but yes, you probably did removed the majority of the PGM's from it.

Happy it worked out for ya.

Sam


----------



## Joeforbes (Jun 5, 2011)

I've been working on designing an enclosed circulating system that uses HCl-Cl. I'll post the "blue prints" (I'm no artist :lol: ) in a couple of days.

I, too, am wondering the amount of HCl-Cl to use per gram of expected PGM's though.


----------



## nalexandrov (Jun 12, 2011)

If you were to use HCl and bubble Cl through it you could never have too much Cl dissolved correct? If you were going this route what strength of HCl would be recommended?


----------



## samuel-a (Jun 12, 2011)

nalexandrov said:


> If you were to use HCl and bubble Cl through it you could never have too much Cl dissolved correct?



Not correct, even with this method you could have excess Cl2 dissolved in solution.

Excess Chlorine is not a problem while leaching, on the contrary to precipitation.
Eliminating Cl2 is very easy, let solution stand few days Cl2 will evaporate slowly, or just heat until no more Cl2 scent is felt.



nalexandrov said:


> If you were going this route what strength of HCl would be recommended?



10-15%


----------



## nalexandrov (Jun 13, 2011)

So for the main leaching process why not have a large container under a slight pressure to help keep the Cl in solution, maybe pump in a high concentration of bleach little by little to keep a perfect overpressure, a pressure gauge and vented blowout/bleed valve would be needed. Along with a method of agitation what do you guys think of this for the initial leach process? Then out-gas it out before cementing


----------



## samuel-a (Jun 13, 2011)

nalexandrov said:


> So for the main leaching process why not have a large container under a slight pressure to help keep the Cl in solution, maybe pump in a high concentration of bleach little by little to keep a perfect overpressure, a pressure gauge and vented blowout/bleed valve would be needed. Along with a method of agitation what do you guys think of this for the initial leach process? Then out-gas it out before cementing



I wouldn't advice anyone to pressurise gasses without the proper knowledge and equipment, especially Cl2 which co exist with its ustable and explosive dioxide brother.


----------



## nalexandrov (Jun 13, 2011)

I was thinking more about a few psi overpressure, when this dropped it would be a good indicator as to when to add bleach. This wouldn't be a hazard if you had a 5psi blowout valve and didnt add the bleach too fast. I don't recommend anyone doing it in a hobbyist environment this is more for someone with training, proper understanding and a safe environment.


----------



## Nijiman (Sep 20, 2013)

This my first time processing cats and wanted to experiment a little. After crushing and washing the substrate I put the substrate from 4 cats in a PVC fermentation barrel I had for making wine. I covered the material in a 60/40 solution of HCL/H2O2, addded a cup of Clorox, and put the airtight lid on with an airlock to allow the gasses to escape slowly. 3 X daily the barrel is agitated and every second day I add a cup of Clorox bleach. I've kept this at room temp (45 -50 F) and today marks the end of the second week, I will shortly test the solution for PGMs and post the results. Hopefully I havrny screwed this up or missed anything. If positive, Ill filter, anf boil off the excess CL, drop with zink and then process the solids in AR. Life is a learning process and I thank each of you for your input here, Ive learned a lot thanx to you and of course reading till my eyes felt like jelly.


----------



## lazersteve (Sep 20, 2013)

Sounds like you are on you way to success.

Keep us posted on your progress.

Steve


----------



## Magwitch80 (Aug 11, 2015)

Hello fellow refiners. I have been reading on the forum for almost a year and with all the available information I haven't needed to ask a question while I was working gold. I have been buying cats and DPF's and decided to test a 250 gram sample of the particulate filter. I have read leave honey comb whole and crush it to mesh 60. Well my question is how do you roast out hydrocarbons on the comb if its whole. I used a cutting torch and sparingly heated it. The sample has been sitting in a jar with HCL and I have added clorox to jar a few times in moderate incriminates. The solution is dark yellow like beer but its apparent that heating combs with torch got rid of none of the carbon inside filter and its all at bottom. If shaken solution turns black. Just filter or decant and that's the nature of the beast or can I get whole combs cleaner?

Didn't want to start new thread I hope this was the correct course of action.


----------

