Warning! This video is intended for demonstration purposes only!
Trying to duplicate the shown procedures may result in serious injury or even death!
Gold recovery from 7900 light emitting diodes. LEDs.
After removing the LEDs from the boards, we incinerated them.
We washed the pins from the ashes with water.
We covered the pins with nitric acid and heated the pot.
After boiling for half an hour some foils started floating on top.
After saturation, we decanted the solution, and washed the semi-dissolved pins with water,
after which fresh acid was added.
When most of the pins dissolved, we moved them to a large beaker and covered them with
concentrated nitric acid.
We replaced the acid twice after saturation, before moving the foils to a coffee filter paper.
We covered the foils with borax and melted them into a button.
As the glass slag hardened before the button, we sprayed the molten metal with water to
remove it from the crucible.
The low melting point and the brittleness of the button indicated the presence of tin.
We collected all pieces of the button, placed them in a beaker and covered them with aqua regia.
We heated the beaker to speed up the dissolution process.
About 40 minutes later the button was completely dissolved.
We removed the excess nitric with sulphamic acid and diluted the solution with water.
Solution was filtered.
We added SMB to precipitate the gold.
To speed up the process, we heated the solution to boiling.
Once the solution cleared, we decanted the barren liquid, and washed the precipitate
with concentrated hydrochloric acid, and then with water.
We moved the gold precipitate to a melting dish and sprinkled some borax on top.
We melted the gold powder.
3.1g gold from 7900 light emitting diodes.
Thanks for watching!
Please, don't forget to like, comment and subscribe below!