NO !!! - this will ABSOLUTELY NOT WORK !!!
Because the plastics (epoxy & other plastics) on/in the boards MUST first be burned off (incinerated) in order for the flux to "slag off" the ash/carbon created in the FIRST step of the process - which is incineration of the boards (which is actually the second step - because the "very first" step is shedding the boards - then incineration)
NO !!! - you are NOT understanding what orvi is telling you - you are only hearing the "part" you want to hear
In other words - the very first thing orvi said in his first post was -----------
In other words - NO - you can NOT just put circuit boards in a furnace with flux & expect a separation of all the plastic from the metal
In fact - what will happen - if you try that - is that the flux will melt together with all the plastic & that molten flux/plastic will simply "incase" the metals in the molten flux/plastic
In other words - the metal will be "tied up" in a matrix along with the flux/plastic - instead of getting an actual separation of plastic from the metal
The plastic MUST first be burned (incinerated) in order to turn the plastic to carbon/ash
The system - that orvi described - is NOT a simple furnace that the BIG BOYS just throw there circuit boards into along with some flux
It is a continuous feed system that automatically feeds the material into the beginning of the process & it continues to feed that material through "different stages" of the process until it comes out the other end as metal separated from the other junk on/in the starting circuit boards (the junk being the plastics, ceramics, fiberglass & "some" of the metals like aluminum, iron etc. etc.)
And this is how that system works -------
The very first thing they do is dump about 20 tons of CBs at a time into a VERY large shredder
As the "shredded" CBs come out of the shredder - a "screw" (kind of like a conveyer belt - but a screw in a tube) feeds the shredded CBs into an "incineration chamber" that burns up all the plastic
In other words - the screw feeds the shredded CBs in one end of this incineration chamber - then once all the plastics are burned up - a screw removes the material from this burn chamber (which is now carbon/ash mixed with the metals in the CBs) as the screw moves the incinerated material from the burn chamber to the actual furnace part of the system flux is added to that incinerated material
In other words - as the screw moves the incinerated fraction of the shredded boards from the burn chamber - to the furnace - flux is added - & the screw acts as a mixer to mix the flux with the ash/carbon/fiberglass/ceramics/metal (this is known as the "smelt load") the screw then feeds this smelt load into the actual furnace - where when the 'smelt load" becomes molten the flux is allowed to "slag off" the carbon/ash/fiberglass/ceramics as well as "some" of the more reactive metals (like aluminum iron etc. etc.)
The molten smelt load is then poured to molds where the molten metal settles to the bottom of the mold with the molten slag on top - once it all cools/solidifies the slag is then knocked off the separated metal
This separation only happens because the plastics FIRST went through an incineration process/stage to burn them to carbon/ash - BEFORE going to the smelt furnace stage/part of the process
Bottom line - if you don't first shred - then incinerate - then smelt --- you will end up with a BIG MESS
The BIG BOYS just have a continuous feed system - that puts the CBs though those "different" stages of the process
They DON'T just put the CBs - mixed with flux into the furnace - & that is because it DOES NOT work - & it WILL NOT work for you ether !!!!
Kurt
Yeah, I am aware of the multiple stages, I just wanted to simplify it to be understandable. Also aware of some design features, like recuperation of heat from combustion to pre-heat the air which is blown to the bottom etc.
This is the process which I could not imagine doing somewhere in the backyard or anywhere near people in DIY setup...
I have done some experiments with two step sequential process, just with several kilos of PCBs... And I stumbled across so many issues with it, that I straightly abandoned that idea long ago. In order to be profitable, scale of the operation will need to be huge, and I simply do not have resources and premises which will allow such venture.
My refining partner always wanted to build such system, semi-industrial scale, working with few hundred kg´s of PCBs a day. As engineer in the field, he calculated all the theoretical parameters, size of rotary pyrolysis/incineration furnance, approximate neccessary power and natgas input to onset the burning, air blowers and feeds, gas heat exchanger to pre-heat air from incineration heat to aid smelting, fluxing parameters, he had done several experiments regarding fluxing of the incinerated PCBs, designed the shaft furnance, lining, dimensions, emergency afterburner, scrubber... Experiments with oxidative cleaning of the melted mixed metal alloy, scorifying, electrolysis tub, electrode shapes, casting molds, rectifiers... Everything.
It was his dream, so I learned a lot from him regarding this toppic. Such a shame he will never pursue his dreams...