kjavanb123
Well-known member
All,
Just wanted to start a threat regarding PCI slots. As I noticed in my batch they consisted 10.9% of the motherboard weight. So after depopulating 2 Chinese made motherboards ( colorful boards ). Here is the scope;
Motherboards combined weight = 1100 grams
PCI slots weight ( 10 pieces of them from 2 boards ) = 120.39 grams
Pins weight removed from 10 PCI slots = 31.57 grams
Therefore,
PCI slots weight percentage to the boards weight = 120.39 / 1100 x 100 = 10.94%
Also it took me 6 mins to remove the pins from each of the PCI slots. So time spent 1 hr.
Now, I have used the following methods on a trial batch and was wondering which one would be recommended on such a small scale amount of pins.
1. Hcl method, where pins are heated in muratic acid for 2 hrs, decant, rinse with water, then incinerate, follow by dilute nitric leach to remove the remaining base metals, filter, and proceed to HCL/Cl leach for gold and drop.
2. Dilute sulfuric acid method, where pins are put into a 1:10 sulfuric: water solution for few hrs to completely dissolves tin / leads, incinerate, follow by dilute nitric bath.
Tried the HCl method, and after incineration and dilute nitric bath still some white powder remained, using sulfuric method, all the tin were dissolved prior to incineration and further leaching.
Regards,
Kevin
Just wanted to start a threat regarding PCI slots. As I noticed in my batch they consisted 10.9% of the motherboard weight. So after depopulating 2 Chinese made motherboards ( colorful boards ). Here is the scope;
Motherboards combined weight = 1100 grams
PCI slots weight ( 10 pieces of them from 2 boards ) = 120.39 grams
Pins weight removed from 10 PCI slots = 31.57 grams
Therefore,
PCI slots weight percentage to the boards weight = 120.39 / 1100 x 100 = 10.94%
Also it took me 6 mins to remove the pins from each of the PCI slots. So time spent 1 hr.
Now, I have used the following methods on a trial batch and was wondering which one would be recommended on such a small scale amount of pins.
1. Hcl method, where pins are heated in muratic acid for 2 hrs, decant, rinse with water, then incinerate, follow by dilute nitric leach to remove the remaining base metals, filter, and proceed to HCL/Cl leach for gold and drop.
2. Dilute sulfuric acid method, where pins are put into a 1:10 sulfuric: water solution for few hrs to completely dissolves tin / leads, incinerate, follow by dilute nitric bath.
Tried the HCl method, and after incineration and dilute nitric bath still some white powder remained, using sulfuric method, all the tin were dissolved prior to incineration and further leaching.
Regards,
Kevin