Best options for this ash

[Alondro]

Isn't the best way for recovering the PM's from ic chips ash is the lead bath?
Copper as a collector metal will consume a lot of nitric acid unless we use copper electrolysis cell, but lead bath can collect all PM's from the ash "literally All PM's" since the ash fully washed in the lead bath and with some NaOH any epoxy cover gold particles will be melted, lead bath with steel pot will help to reduce the used lead, for example we can wash 5 kg of ic chips ash with only 1-2 kilos of lead till it evaporated, also we can wash the ic chips with lead bath without milling or incinerate them but in this case we will get a lot of smoke, I think the only con of using lead bath is the toxic of it, isn't it?

Well, yes, that's the point of using a copper electrolysis cell. It's very easy to set up and run. The equipment is very cheap and reusable. And instead of using huge volumes of acid, it uses much lower volumes of less corrosive salts, while also crystalizing out the copper on the cathode. It can process a HUGE amount of metal with far less waste.