I am new to refining gold and other precious metals. I am trying to learn all I can about the chemistry of extracting the metals before I attempt to give it a go. God, I wished I payed more attention in Chemistry class when I was in school Anyhow, to my questions... Can gold be extracted from gold ore slag? If so, is it worth the time and is the process any diffrent from extracting gold from a circut board? Also, on a circut board... I see several small capasitors and diodes. Is there any precious metal in them or should I discard them? And finally...I have been told that after stripping the board I should soak the whole board in Nitric Acid because there is silver in all the solder.