After the removal process it’s the time to have a journey of chemistry which includes several acid baths. After the first post.....
source
For removal process of gold from the metals of the processor, we have to use nitric acid. To remove the amount of metal mixed with gold, remove as much as possible. Before making gold aqua regain dissolving, we have to mixed nitric acid and water together. The ratio will be 2:1. That means if you put 2-liter water then you have to put 1 liter of nitric acid to mix the liquid.
Soak in liquid.
And when the liquid is ready then you can put the microprocessors and the connectors of the circuit board in it. Then cover it and leave it for two weeks. The measurement of liquid depends on the hardware from where you want to separate gold and materials.
After two weeks even you will find the gold-plated legs fall off and the watercolor turns to green. The time is not fixed. It can take less or more time. The watercolor will let you know it is OK or not.
You have no need to worry or upset to see the watercolor. Because nitric acid cannot dissolve gold. Many of those who are attached to it, you may see some of them skip this step to make gold aqua regain dissolving. But literally and practically if y broke or remove the gold plate by hands then there is a chance gold loss or it can contain too many other materials. Making gold aqua regain dissolving gold should have more than 60%. Gold precipitation with sodium metabisulfite will have and the gold 99.9%.
If you know a better way you can comment or suggest me. It will be a great help for all of us who are reading the post. Now you just have to clean it up before proceeding.
The post is rewrite and inspired from the post of source