HI All,
I think I may have messed up and would greatly appreciate any input from anyone who may have done similar or can lead me in the right direction.
I processed 6 catalytic converters over 2 initial attempts ( using 2 x 5 litre buckets )and recovered some black powers after much filtering . I had used zinc shavings and could not get the powder to settle so had to try filter it out , which took ages, but I managed to recover some black powder . I kept the waste liquid ( which was still dark cloudy from suspended PGM's) and left in a 5 gallon bucket for a week or two. When i returned the liquid had settled nicely (better than expected ) but had regained an orange/red colour (indicating that PGMS are being re-dissolved into solution ). I siphoned off the liquid into another bucket and collected the black powder that had settled .
I have read many posts on this site over past year or so , and, remembered reading that the acids can be reused ( but now think that may have been referring to AP method not hcl/cl ). So since I had 10 liters of stock pot already, i decided to make a second pass on the first cats, using the stock pot liquid which i split between three 5 litre buckets, adding more HCL and CL to bring down Ph levels and to each i added 2 second pass honeycombs . I didn't get much colour change in the liquid and presumed I recovered most PGM on the first pass. So I added fresh catalytic converters to each leech and kept adding CL over a week or two.
The leech is not really looking like its absorbing the PGMs ( not getting any redder in colour ). Testing with stannous, shows a dark green colour on q-tip which I think indicates palladium, but when tested on spot plate looks almost blue / black , but no sign of any red tint for Pt. Litmus paper test shows ph 1 .
Now I have 3 theories on whats happening , i) That the pgm's are being dissolved but are dropping out immediately because there is zinc already in the solution.
ii) The acid is dead / almost dead and can only barley get the palladium into solution and not the Pt/Rh.
iii) Everything is perfect
If its(i) that the PGM are dropping immediately . I'm thinking i need to Filter out the liquid and keep the filtrate which will be carbon,and PGMs and maybe redissolve in fresh HCL/Cl and attempt again.
or
If its (ii) dead acid. I will need to try drop whatever palladium / PGM's that are in solution now and dispose of waste ( after settling , siphoning and stannous testing and neutralization ), and use new HCL/CL leech on these converters .
or
If its iii) everything is ok . happy days !
I have attached a few pics of the stannous test using a spot plate , and q-tips . The pic shows samples of the three leeches , I added stannous to the spot plate and q-tips for each bucket, and left the other leach samples without stannous to have comparison beside .
Sorry about the long post and thanks in advance for any input or advice.
Ken
I think I may have messed up and would greatly appreciate any input from anyone who may have done similar or can lead me in the right direction.
I processed 6 catalytic converters over 2 initial attempts ( using 2 x 5 litre buckets )and recovered some black powers after much filtering . I had used zinc shavings and could not get the powder to settle so had to try filter it out , which took ages, but I managed to recover some black powder . I kept the waste liquid ( which was still dark cloudy from suspended PGM's) and left in a 5 gallon bucket for a week or two. When i returned the liquid had settled nicely (better than expected ) but had regained an orange/red colour (indicating that PGMS are being re-dissolved into solution ). I siphoned off the liquid into another bucket and collected the black powder that had settled .
I have read many posts on this site over past year or so , and, remembered reading that the acids can be reused ( but now think that may have been referring to AP method not hcl/cl ). So since I had 10 liters of stock pot already, i decided to make a second pass on the first cats, using the stock pot liquid which i split between three 5 litre buckets, adding more HCL and CL to bring down Ph levels and to each i added 2 second pass honeycombs . I didn't get much colour change in the liquid and presumed I recovered most PGM on the first pass. So I added fresh catalytic converters to each leech and kept adding CL over a week or two.
The leech is not really looking like its absorbing the PGMs ( not getting any redder in colour ). Testing with stannous, shows a dark green colour on q-tip which I think indicates palladium, but when tested on spot plate looks almost blue / black , but no sign of any red tint for Pt. Litmus paper test shows ph 1 .
Now I have 3 theories on whats happening , i) That the pgm's are being dissolved but are dropping out immediately because there is zinc already in the solution.
ii) The acid is dead / almost dead and can only barley get the palladium into solution and not the Pt/Rh.
iii) Everything is perfect
If its(i) that the PGM are dropping immediately . I'm thinking i need to Filter out the liquid and keep the filtrate which will be carbon,and PGMs and maybe redissolve in fresh HCL/Cl and attempt again.
or
If its (ii) dead acid. I will need to try drop whatever palladium / PGM's that are in solution now and dispose of waste ( after settling , siphoning and stannous testing and neutralization ), and use new HCL/CL leech on these converters .
or
If its iii) everything is ok . happy days !
I have attached a few pics of the stannous test using a spot plate , and q-tips . The pic shows samples of the three leeches , I added stannous to the spot plate and q-tips for each bucket, and left the other leach samples without stannous to have comparison beside .
Sorry about the long post and thanks in advance for any input or advice.
Ken
