Williamjf77
Well-known member
- Joined
- Oct 30, 2018
- Messages
- 138
Hello I’m new here and I’ll start by saying thanks for the resources here.
I just (over the last few days) finished a process on 100 grams of sma connectors. I desoldered and cleaned then put them in AP solution. After a day or so i thought the gold got dissolved because they were all gray so stannous tested and was negative. Seems the left over solder got dissolved and plated on all the connectors. So I took one out and put it in a very dilute nitric acid and it cleaned right up to shiny gold plate and continued to dissolve base metals to a light blue solution so I put the rest in to nitric and heated over the course of a few days, decanting the spent nitric and re treating, the solution would go from blue when fresh nitric was added to green when reaction was over.
I believe the base metal was nickel, right?
Then I filtered and washed to keep the foils after all base metals were gone then put in HCl enough to cover all with a little headroom then added @(50% conc. HNO3) dropwise and heated until all dissolved.
Added few drops of Sulfuric and filtered out solids
Then SMB in water and I see gold precipitated but solution is cloudy brown from bottom up then clear green on top. I have gold powder at the bottom, is the brown color still gold that hasn’t settled yet it’s been a day , I haven’t been keeping it warm.
I tested solution and it is negative, can I just filter now or should I wait?
I just (over the last few days) finished a process on 100 grams of sma connectors. I desoldered and cleaned then put them in AP solution. After a day or so i thought the gold got dissolved because they were all gray so stannous tested and was negative. Seems the left over solder got dissolved and plated on all the connectors. So I took one out and put it in a very dilute nitric acid and it cleaned right up to shiny gold plate and continued to dissolve base metals to a light blue solution so I put the rest in to nitric and heated over the course of a few days, decanting the spent nitric and re treating, the solution would go from blue when fresh nitric was added to green when reaction was over.
I believe the base metal was nickel, right?
Then I filtered and washed to keep the foils after all base metals were gone then put in HCl enough to cover all with a little headroom then added @(50% conc. HNO3) dropwise and heated until all dissolved.
Added few drops of Sulfuric and filtered out solids
Then SMB in water and I see gold precipitated but solution is cloudy brown from bottom up then clear green on top. I have gold powder at the bottom, is the brown color still gold that hasn’t settled yet it’s been a day , I haven’t been keeping it warm.
I tested solution and it is negative, can I just filter now or should I wait?
