I understand that after AR HCL will drop silver, then formic acid at 80degrees drops palladium?
NO - this is ABSOLUTELY WRONG !!!
I don't know where you are getting your info from but it most certainly is not from here on the forum because if you spent any real time studying this forum - &/or reading C.M. Hokes you would know that AR
does NOT dissolve silver but in fact creates silver chloride -
which will cause problems if you try to dissolve gold &/or PGMs that has silver in it with AR
Therefore - I "assume" you are getting your info from youtube ?
If that is the case - as I said yesterday -
STOP watching youtube !!!
Although there are some good youtube videos out there
(but VERY FEW) the vast majority of them are
FULL of incomplete info - actual
mis-information
& out right WRONG information
youtube has become a major problem for us here on the forum because youtube results in us then trying to have to fix the problems & the messes people come to us with after they have been watching youtube videos
Concerning the MLCCs - how do you even know if they even have any palladium in them ?
Not all MLCCs have Pd in them
There are 2 types of MLCCs
NME (Noble Metal Electrode) MLCCs - which are made with silver & palladium
BME (Base Metal Electrode) MLCCs - which are made with mostly copper & nickel (& they may - or not have
"some" silver in them -
but absolutely NO palladium)
Before 1998 - 2000 most MLCCs were made with NME (silver/palladium) AFTER 1998 - 2000 most MLCCs were made with BME (copper/nickel)
So if the circuit boards your MLCCs came from were made AFTER 2000 - there is likely absolutely NO palladium in them (MAYBE some silver) so - even if they have some silver - they are not worth processing because the cost of the acid to process them will cost MORE them the value of the silver you can recover from them
IF (the BIG IF) they happen to be NME - MLCCs (made BEFORE 2000) & you are going to leach them - you MUST use nitric acid
NOT AR - & even then leaching them is
NOT the best away to process them
Leaching MLCCs
is a very messy process with problems & you will NOT get all the Ag/Pd out of them by leaching
You are FAR better served to smelt MLCCs !!!
Kurt