Need advice on motherboards

[Stowmaster]

Three years ago, I am refining the 20 motherboard. (3 pcs 7 socket, 2 pcs without socket (P-2), 15 pcs 370,462,478 socket). All parts are gold plated (socket, PCI, ISA, VGA, RAM, LPT, IDE-pins, no ceramic chipsets) were burned and dissolved in 56% technical nitric acid, ceramic chips not used.
No insoluble residue was melted without refining; bullion received 1.8 grams of the sample more than 6 carats, but less than 8 carats. It was sold as 6-carat gold.
The gold content verified in different places.
I was told that less than 0.1 grams of the motherboard is not the case, and that most of the gold I lost due to impurities in the acid or boards chloride.
Now I have collected 50 motherboards. I plan to recycle the following way:
1) The burning of organic matter.
2) dissolution in 30% sulfuric acid with a fresh air supply through the aquarium compressor.
3) Verify solutions are often not a magnet.
4) Refining the solution of iodine with potassium iodide (5% iodine, 2% potassium iodide, 45% alcohol, 50% water), followed by reduction of gold iodide. I am don’t can buy hydrochloric acid, therefore, with aqua regia variants do not see.
The economic aspect of the question does not interest me: acid free, a lot of iodine is not needed.

I would like to receive advice on errors and plans, as well as an opportunity to clarify the use of iodine.

 

[Marcel]

It takes me 10-15 minutes to completly strip a mobo with a hot air fan and a hot plate underneath.
First I remove all plastic housings of the slots etc. The reward, is a well seperated batch of material, which then can be processed the optimal way.
With the flat motherboard I will later use a grinder and grind the silver , tin and remaining metal on the surface.
I collect the tantal capacitors, coils with copper and chips and store them in a seperate box.

PCBs contain brom and other hazerous stuff that will be emitted if burned. Burning 50 mobos in the open here, would bring you in jail and maybe in hospital as well.
Take your time instead, remove all those pins and stuff and eventually sell them on ebay in small batches(!). You get more money and fun out of it that doing what you plan to do. Just my 2 cents....

 

[Stowmaster]

Thank you!
Since the success of the event is doubtful, try to revise the first five motherboards.