Hai I am new to this forum and currently I am doing some refining gold from electronic scrap mostly are PCBs from mobile phones. This forum is very helpful for me as when something goes wrong I will look for the solution here.
So I managed to get the gold dust which I am not sure if it is the right dust as the color are brownish after I put the SMB into Aqua Regia solution. However there are things that I am not sure if I am doing it right and confused with the usage of Urea to eliminate the excess nitrate. Some people say in this forum to use Urea but some are not as Urea is very dangerous when mixing with Nitric Acid. I got scared and find another way to get rid of this nitrate such as evaporation and addition of water. But it does not work as when I put a lot of SMB into the solution the brownish fume came out and it does not precipitate the gold. So I tried to put Urea and SMB again and it worked. yes it did precipitate the gold.
So my question is if the using Urea is correct way? is it safe? since some says it could be explosive
Appreciate if some can answer my question.
Thanks
So I managed to get the gold dust which I am not sure if it is the right dust as the color are brownish after I put the SMB into Aqua Regia solution. However there are things that I am not sure if I am doing it right and confused with the usage of Urea to eliminate the excess nitrate. Some people say in this forum to use Urea but some are not as Urea is very dangerous when mixing with Nitric Acid. I got scared and find another way to get rid of this nitrate such as evaporation and addition of water. But it does not work as when I put a lot of SMB into the solution the brownish fume came out and it does not precipitate the gold. So I tried to put Urea and SMB again and it worked. yes it did precipitate the gold.
So my question is if the using Urea is correct way? is it safe? since some says it could be explosive
Appreciate if some can answer my question.
Thanks