Hammer Mill vs Granulator

I think you need to establish exactly what you want to do with the PC boards to decide what you need to use to grind them up. Are you going to "grind" the boards and all the electronic "stuff" on the boards into a powder so you can separate the metals by washing, with the heavies settling out? Kinda like panning gold?

Or are you just breaking the stuff down so you can get a chemical process going on all the metals in the mix? Which might mean quite a bit coarser grind? (and less costly grinder)

There will be a tradeoff here, as the finer the material is ground, the quicker the chemical reactions will take place. But the cost of finer grinding may start to interfere with the economics of the process.

Also, you probably are looking for the higher value metals from the mix, such as gold, silver, etc, that is found in small amounts in e-scrap. It can outweigh the copper in value.



I am doing a bit of blue sky talking here, as I have not done either type of process but understand some of the physics behind them.

If you are looking to do the chemical recovery work, you need to pop over to the "gold refining forum" to ask some questions. But be warned: they are a crusty bunch over there and don't take the sillier newbie questions very well!! I'm sure there are lots of people over there who have done or are doing exactly what you describe.

We have a few people who refine e-scrap who visit this site from time to time...maybe they will chime in.

Good luck,
Jon.

Originally Posted by sawmilleng

I think you need to establish exactly what you want to do with the PC boards to decide what you need to use to grind them up. Are you going to "grind" the boards and all the electronic "stuff" on the boards into a powder so you can separate the metals by washing, with the heavies settling out? Kinda like panning gold?

Or are you just breaking the stuff down so you can get a chemical process going on all the metals in the mix? Which might mean quite a bit coarser grind? (and less costly grinder)

There will be a tradeoff here, as the finer the material is ground, the quicker the chemical reactions will take place. But the cost of finer grinding may start to interfere with the economics of the process.

Also, you probably are looking for the higher value metals from the mix, such as gold, silver, etc, that is found in small amounts in e-scrap. It can outweigh the copper in value.

I am doing a bit of blue sky talking here, as I have not done either type of process but understand some of the physics behind them.

If you are looking to do the chemical recovery work, you need to pop over to the "gold refining forum" to ask some questions. But be warned: they are a crusty bunch over there and don't take the sillier newbie questions very well!! I'm sure there are lots of people over there who have done or are doing exactly what you describe.

We have a few people who refine e-scrap who visit this site from time to time...maybe they will chime in.

Good luck,
Jon.

I am looking to get them as fine as possible and use water methods.

Now i am planning to remove all the chips from the board first, then incinerate those and run them with a water process so i would just be grinding up the bare PCB for the copper the gold and such should be in all the chips.

Another food for thought, do you know how well the fiberglass of the pcb bonds to the copper? In the video posted below they use a granulator to chop up copper wire, and then separate the shield from the copper based on a shaker table due to the weight difference. This works because the copper has no bond with the shield and when it gets to the shaker table it is 2 pieces. If the fiberglass bonds to the copper, it wont be 2 different pieces and be unable for the table to separate The higher the bond with the fiberglass the smaller finer the pcb needs to be ground to get them to separate.

Thanks for the responses guys
Mike