# specific gravity sorter



## foamnone (Nov 3, 2013)

I found this unit on youtube as a seed sorter. Read up on something called a z-box and built this one to sort non-ferrous from plastic. The material is fed in the top left,airflow blows the lighter material into the box on the right leaving a heavier concentration of filtered material.(less plastic) My material size is 1 /16 and smaller. I want to shred boards to get a higher concentration of non-ferrous. What problems do you see


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## Pantherlikher (Nov 3, 2013)

Visualize a feather and a gold flake being dropped in there. Would they end up in the same spot or no?

Schredding a whole board will grind everything to the same size.
But would it seperate the feather from a flake?
How about a solder ball from a capaciter or piece of plastic same size and shape?

The air sluice idea is a possibility with the right material.
I just had a similar idea using a fan breeze for flatpacks for seperation of dust.

B.S.


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## foamnone (Nov 3, 2013)

B.S. 
yes, it can sort feathers from gold by weight. The air volume can change to allow 100% of the material to fall or 0% and is adjustable from 0-100. This machine sorts heavies from lights. It does not get only gold flakes(if it could, sign me up for two) I am trying to get a higher concentration of metal with less green board. This other sorter uses a 10hp CYCLONE. 4500cfm.I built this one for a 5 /16 size material.


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## Pantherlikher (Nov 4, 2013)

Nice...
Was just trying to picture how well it worked. 
So it would basically seperate different weights of same size.
Came be very usefully for say...Hmm... tons of boards with little labor intensive times.

B.S.


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## niteliteone (Nov 4, 2013)

Well since most of the gold flakes will be smaller and lighter than the green conformal coating on the boards, I see where you will be loosing any free gold knocked loose from the process. Not to mention all the silver and palladium powder from all the MLCC's.
:shock: :shock: POOF :!: :shock: :shock: it's all gone


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## Harold_V (Nov 4, 2013)

I'm inclined to agree that gravity isn't going to work well for this project. The issue is the extremely thin layer of gold, which, while heavy, has a tremendous amount of surface area relative to its density. It's going to be manipulated quite easily by the slightest of air movement. For lack of better description, it's going to behave much like a kite. 

Harold


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## g_axelsson (Nov 4, 2013)

This topic have drifted a bit, the gold isn't going to appear as flakes. The gold sits on different parts, as plating on fingers still attached to the board, as pieces of shredded pins, as bond wires embedded in shredded IC:s. So the density of the material containing the gold will be all over the scale from light to dense. The form of the particles will also affect how they move in the sorter. Larger particles will move as lighter but more dense particles.

My prediction is that it will be an utter failure. Gold will be with both fractions, the form of the particles will clog the channel unless a really high air speed is used and then the separation will fail.

Why not use magnetic separation if you want to remove ferrous material? Just remember that CPU pins are made of covar and are magnetic. Whatever method used, take samples after separation to see that the separation actually works. Test, not believe!

Göran


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## 9kuuby9 (Nov 4, 2013)

This might only work for gold nuggets, not gold foils or anything that is ground from electronics.


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## foamnone (Nov 4, 2013)

I read Hokes book and have spent many months reading on this forum. I did not have a thing to contribute till now. I like all the prcesses used to recover metal fro scrap. I posted this tool I made for another project to show some new ideas. I will use this sorter to class same weight materal to feed on my air table. I posted the air table in my other post. These machines class material. I read a lot of people cherry pick boards to get the most valuable parts. It is just information. The dust is not lost. It is just separated from heavier pieces. Kind of like sifting after ball mill but much faster


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