alvaschein said:9kuuby9 said:Can you tell us exactly what steps you took in processing the MLCC's ?
that would really help in finding the cause.
The steps:
1. weighed batch of 50 g assorted MLCC's (dimensions +/- 0.8 x 0.8 x 2.0 mm)
2. put batch in beaker and added 320 ml HCl (that means 250 ml as 5 times the batch's weight plus 70 ml to compensate the difference of my 25% HCl to 32% HCl as described in the process)
3. let it boil for about 4-5 hours
4. let it settle over night
5. solution was divided into 3 sections (top down): purple solution (2" thick), grey sludge (0.5"-0.75" thick), metallic traces (visible only from the bottom view)
6. poured off only the purple solution, kept sludge and metals
7. added diluted aqua regia
8. let it boil for 3-4 hours
9. let it cool and settle over night
10. the solution was divided into two sections (top down): clear orange solution (2.5" thick), white(?) sludge (0.5" thick)
11. filtered solution
12. tested remainder for Ag --> negative --> to the waste
13. tested solution for Pd --> positive
14. added Zn to solution for cementing Pd
These were all the steps I took, ending up with this mysterious grey sludge...
Roy
How much time needed for socking MLCCs in HCl to remove tin ?Washing in hydrochloric acid to remove the tin. Prolonged treatment could dissolve the ceramics too, freeing the internal metal electrodes.
Wash in water and then crush the ceramics to access the internal metal.
Dissolve silver, nickel and palladium with nitric acid.
Thanksg_axelsson said:Just add acid and watch the reaction until it is finished. There is no fixed time, there are so many factors affecting the speed of a reaction. Heat, concentration, agitation, material, volumes.... who could tell.
Göran
saadat68 said:Thanksg_axelsson said:Just add acid and watch the reaction until it is finished. There is no fixed time, there are so many factors affecting the speed of a reaction. Heat, concentration, agitation, material, volumes.... who could tell.
Göran
So one or two hours is enough.
Not several days
Right?
__________________
How much time and temperature needed for incineration to rid of HCl ?
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