HCl/Cl Leach of Honeycombs and Beads PHOTOS

Here are some photos of the set-up I have been using to leach PGMs from catalytic converter honeycombs and beads.

kadriver

Each large container holds smaller pails containing honeycombs and beads that are leaching in diluted HCl and bleach.

By dilute HCl I mean 50% tap water and 50% HCl from lowes. HCl from Lowes is 31.45% concentration.

Using dilute HCl reduces the amount of acid used and reduces the amount of sodium carbonate that must be added before precipitating with zinc.

The bleach additions cause chlorine gas to form and this gas is what dissolves the PGMs from the cat honeycombs and beads.

I am always very careful working around these containers because the gas is deadly.

I accidentally got a whif one time and I had to sit down for a minute. It nearly dropped me to my knees!

This stuff is very dangerous - the large containers do a good job of containing the gas during leaching.

As long as this lids are on the big containers and tight, then I can not smell chlorine at all.

kadriver

Notice that the metal handles for these buckets have been removed.

If left on, the metal will begin to dissolve in the presence of the chlorine gas.

The dissolved metal could get into the PGM leach, so I removed them for that reason.

kadriver

Kadriver,

Looks like you are following the instructions given on my Fundamentals of Platinum and Palladium DVD. Have you come up with any improvements on the process?

Steve

Steve;

None except the one about using dilute HCl 50/50 tap water. But that has already been discussed.

The DVD was an excellent guide - I have watched it many times and still refer to it during these processes.

kadriver

I seem to recall beads weren't loaded with any Pd, you may have a very nice platinum-heavy solution there.

kadriver - my hat is off to you - you are doing an awesome job here on posting your process on pocessing PGMs from cats here.

I have been following your threads on this with great interest & have a couple questions.

(1) have you been tracking recovery per type of cat (examples - large GM - bread loaf - small standard Ford - after market - etc.)

(2) is there an advantage to using HCL/CL instead of AR for your leach

Kurt

kurt:

unfortunately, I have not tracked yields from the different types of cats or beads.

The beads seam to produce more leaches over the honeycombs.

Using HCl/Cl avoids the nitrates - that is the advantage for me.

Also, HCl/Cl leach is inexpensive - but takes more time.

kadriver

I've often wondered if you could use the Plattner Kiss process for this. I was thinking of taking a piece 3 in pvc pipe with removable caps with a pvc cut off valve on each end so you could drain from the bottom and bleed from the top. Fill that with material, wet the material with an hcl and water mix, then drain from the bottom. Save the run off for future washing. Then once the material is wet charge the holding chamber with cl gas by means of a chlorine generator allowing the gas to rise until the column is full. Close the top and bottom valve and allow it to do it's work. Once it has worked for awhile open the valves and pour the first solution through to wash the pgm out the bottom. Repeat the process again until the pgm's are leeched. Final wash would just be straight water. Seems like it would take less solution and your pgm's would be better concentrated. This is just theory of course!

Im new to this and cats have caught my attention. I just have a question, would it help to crush the honey combs? Im about to order the DVD and am waitng to review that before I start, I have about 6 cats to process, I had thought about crushing the honeycombs but wasnt sure.

It's been covered before - don't crush it.

In uncrushed honeycomb the PGMs are exposed to the acid with their maximum surface, if you crush them, all you do is exposed unplated surface to the acid, which is not only of no use, but will even increase the amount of solvant required.

Palladium said:

I've often wondered if you could use the Plattner Kiss process for this. I was thinking of taking a piece 3 in pvc pipe with removable caps with a pvc cut off valve on each end so you could drain from the bottom and bleed from the top. Fill that with material, wet the material with an hcl and water mix, then drain from the bottom. Save the run off for future washing. Then once the material is wet charge the holding chamber with cl gas by means of a chlorine generator allowing the gas to rise until the column is full. Close the top and bottom valve and allow it to do it's work. Once it has worked for awhile open the valves and pour the first solution through to wash the pgm out the bottom. Repeat the process again until the pgm's are leeched. Final wash would just be straight water. Seems like it would take less solution and your pgm's would be better concentrated. This is just theory of course!

Click to expand...

Palladium I too had a Similar thought. Material could be blocked with a band saw not crushed. you never said crushed to begin with. and Placed in a 4 inch Pvc sewer pipe reduced down to a 1 1/2 on the bottom before the pvc valve. The reducing coupling could drilled allowing you to get the gas closer to the center of the pipe. The only thing that keep me from trying it is I had serious questions on the cement holding up to the acid. but if you think about it isn't the cement actually welding the two pipes plastic pipes together. any ways it wouldn't be hard to place a quart or so in some 1 1/2 Pvc with ends to then pour it threw a filter and see there is lose material or leaking pipes after setting for a few months. Anyways can't believe you didn't get more brain storming on this one that you did. Great Thinking...

edit out an ideal about using a chemical pump in this setup. it seem like a good ideal at first. but if it leaked and sprayed it would be a disaster.

But I did have a idea similar to this where the pipe was on a seesaw slowing being rocked up and down kind of like one of those lava lamps you see on its side. Anyway hope I don't offend anyone. Just seemed like a circulation threw the material would be more affective.