Most common question when someone wants to recycle gold from electronic parts is ‘How many grams can I get from X kilos of PC boards?’. Well it depends of few things. First thing is what exactly do you weigh as a raw material? Inside one board gold persist on certain parts only. Which means if you weigh all board then you should know that percentage of gold in the total weight persist in a small amount, not even a 0.001% of gold. On the other hand if you separate pins with gold spots on them your calculation will go a lot more in your benefit.
Lets say that a precise separated pins from PC board can contain about 0.4% or maybe in best case scenario even 0.6% of gold. These numbers comes from our experiences and they are usually correct.
Now for those who think that there is no money in this lets take a small and simple calculation for gold as an example.
1 kilo contains 1000 grams, and we say there is about 0.5% gold in one kilo. This means that from one kilo we can separate exactly 5 grams of gold. Keep in mind that with Aqua Regia we can get 24 karat of gold purity. Now, for example in time when we wrote this article gold value reached 53.46$ per one gram. This means that you can get about 260$ from one kilo of good separated raw materials from old PC boards.
Other things that can have an impact are based on producing process so there are no rules. You must learn how to extract gold in the most valuable way with minimal waste.