Hello folks.
I keep running into the same issue over and over again and for some reason i keep getting the white residue and absolutely demolish my gold recovery (despire clearly seeing gold and testing gold). I documented everything this time and taken pictures
1. I have incinerated 10 CPU pinned chips, and 100 grams of IC chips. And 3 BGAs
2. Grind with mortar and pestle
3. Reburn
4. Wash with hot water until no more carbon
5.2x boiling HCL bath
6. Wash with water 9x
7. 2x nitric acid bath
8. Wash 9x hot water until clear
9 Poorman aqua regia with 125 ml hcl, 28g sodium nitrate, 68 ml water (tap)
10. Tested gold (positive) spread out between 5 hrs apart
11. At 80c added pinches of Sulfamic acid until no reaction (3 pinches)
12. Waited 5 hours
13. Filter solution
14. Tested gold (color became lighter but still positive
15. Added stump out to 50ml tap water and mix in to AR.
15. Waited 7 hours and i get this cloudy non brown color. What is going on here. Why am i not able to get any return. Im so perplexed.
I keep running into the same issue over and over again and for some reason i keep getting the white residue and absolutely demolish my gold recovery (despire clearly seeing gold and testing gold). I documented everything this time and taken pictures
1. I have incinerated 10 CPU pinned chips, and 100 grams of IC chips. And 3 BGAs
2. Grind with mortar and pestle
3. Reburn
4. Wash with hot water until no more carbon
5.2x boiling HCL bath
6. Wash with water 9x
7. 2x nitric acid bath
8. Wash 9x hot water until clear
9 Poorman aqua regia with 125 ml hcl, 28g sodium nitrate, 68 ml water (tap)
10. Tested gold (positive) spread out between 5 hrs apart
11. At 80c added pinches of Sulfamic acid until no reaction (3 pinches)
12. Waited 5 hours
13. Filter solution
14. Tested gold (color became lighter but still positive
15. Added stump out to 50ml tap water and mix in to AR.
15. Waited 7 hours and i get this cloudy non brown color. What is going on here. Why am i not able to get any return. Im so perplexed.