All That Glitters Pt 1

 ...is gold in this case!

I have been doing this one slowly for a while since I decided to "refine" gold from some old broken electronics I was going to throw away (Compact Flash reader, etc.). Frankly, there was not much scrap and mostly only some pins were plated with gold, but it is good enough for an experiment. I am not trying to run a profitable gold reclamation enterprise. 

In this first post, I will just focus on getting the gold "foil" separated from the other electronics. Gold is typically plated onto some components such as pins and pads and fingers in connectors. These platings are very thin indeed. They exist only over the primary copper conductors so that oxidation will not interfere with the ability of a connector to make solid electrical connections over a long period of time. Yes, gold is a great conductor, but that has nothing to do with it. It is ideal for maintaining the ability to connect. 

Silver is an even better conductor, but tarnishes easily in the presence of sulfur as we read previously here. Copper forms blue-green oxides and hydroxides and so forth quite easily. Look at your pipes. These minerals do not have the same properties of conductance and malleability and ductility (yes, that is a word). They get brittle and they don't conduct electricity. The simple solution is to plate with a few atoms of gold, much like galvanizing steel with zinc.   

It does not matter what is inside wires and solder joints and underneath the gold as long as it is meets the basics needs of good-enough conductance for a decent price and environmental impact. If the outside of a wire or solder joint oxidize a bit, it really isn't terrible because the inside is still doing its job. The connector is the only place where two things made separately need to touch and conduct from the outside.

I am getting off topic, but sometimes corrosion on car battery terminals causes the vehicle to get an intermittent connection. In this case, you clean the terminals with baking soda and water, reconnect,  and you are good. But that is not practical for hundreds of microscopic connections inside a computer. 

I should mention briefly that the group 11 metals are all excellent conductors because of a quirk that fills their outermost d-shell completely with 10 electrons but leaves their outermost s-subshell only half full with one electron. That electron is freely given up, without any interference from the other 10 electrons in the d subshell, enabling many wonderful properties of these three prized metals. You might expect that the s subshell be filled and 9 electrons to inhabit the d subshell, but it doesn't. There are some theories on why this is not the case, but the best one is "because it just is."   

This topic will likely generate lots of posts, so I'll stop here for now and explain how I made gold flakes in green liquid in another post. Then we can probably continue on to refining the gold for purity (because we can!) and possibly melting it into a button. 

Thanks for reading,

Paul