Centrifuge

This might sound stoopid, but following on a previous topic about breaking down clay, has anybody tried using centrifugal force to separate gold from other heavies, particularly black sand? After all, gold is the heaviest of the material that we find and theoretically it should be able to be separated in a centrifuge. I understand that conventional centrifuges generally only handle small quantities, but what if one were to create two containers that would handle several cup fulls each and place them in a spin drier opposite to each other and let er rip?

Is anybody game enough to possibly incur the wrath of the washer woman to try it out?

I've got a big one I scavenged, nuvva day project!

To do that sort of thing you need to use what is called a cyclone. In the mining industry we used them quite often on certain ores. They are probably too large to be of any real use for a miner. The blue bucket thingies are based on a similar principle.

Araluen

Anolphart said:

This might sound stoopid, but following on a previous topic about breaking down clay, has anybody tried using centrifugal force to separate gold from other heavies, particularly black sand? After all, gold is the heaviest of the material that we find and theoretically it should be able to be separated in a centrifuge. I understand that conventional centrifuges generally only handle small quantities, but what if one were to create two containers that would handle several cup fulls each and place them in a spin drier opposite to each other and let er rip?

Is anybody game enough to possibly incur the wrath of the washer woman to try it out?

Click to expand...

I reckon those old twin tub washers would be ideal for what your proposing, the spin dry side anyway.

Hey Simmo, is that a spiral continuous groove or a series of different sized tiered rings? is the bowl perforated? with fine holes. Do you want to sell it???

Its differant rings. Not perforated. It spins, and the material is fed in the top, gold goes to the bottom or caught in the riffles, and lighter stuff goes over the side.
When you are finished, you pull the plug out of the bottom and wash the gold into a pan. Nah I dont wanna sell it!!!
I'll try to find a video.
[video=480,360]https://www.youtube.com/watch?v=DGTJ2jDIoS0[/video]

Simmo said:

Its differant rings. Not perforated. It spins, and the material is fed in the top, gold goes to the bottom or caught in the riffles, and lighter stuff goes over the side.
When you are finished, you pull the plug out of the bottom and wash the gold into a pan. Nah I dont wanna sell it!!!
I'll try to find a video.
[video=480,360]https://www.youtube.com/watch?v=DGTJ2jDIoS0[/video]

Click to expand...

Simmo I'm interested in this type of separator. I visited a neighbour a few days ago and he has a big funnel style of device that is smooth on the inside and lies on its side while spinning. It's quite unusual and since thinking about it I'm going back for another look. It's way too big for my use, about a metre across the top of the cone but I'm sure the same principal can be used on a smaller scale.

Absolutely mate, if you scour around YT you can find some home built and smaller versions.
Mine too would be just under a meter across and the bowl probably 600mm^3

[video=480,360]https://youtu.be/Egik4BPfVX8[/video]
Knudson bowl.

[video=480,360]https://youtu.be/5mLCf9DEisA[/video]
amalgam bowl

[video=480,360]https://youtu.be/9kx_7Gv6jlk[/video]
retorting

That Knudsen is identical to mine.

Hey thanks guys, I found that really interesting.

Now if I can extract the amalgam from my teeth ...

Nicely done. Love your safety shoes

HH

Love the retort. Have never seen that design before.
Love its Simplicity.

if you look closely the knudsen and knelson bowls are different

One has tiny holes in each riffle and water flows into the grooves from outside to keep the fines stirred up , the gold stays in the groove and gets washed down after the bowl has stopped spinning , the other one is just grooves.

They are also made out of a tough rubber , any made from steel would be either very old models or home made.

Has anyone attempted to do the rear feed of water on the centrifuge cone on a DIY build ?

Per instructions here https://www.911metallurgist.com/blog/gold-centrifuge

"Water injected tangentially was a major breakthrough as it helps to keep the material moving within the unit. Most people have done same panning and will agree that if you just gently roll a pan and tip it far enough to wash some of the material over the edge, you will in effect create the same performance as a stream on alluvial gravels. You will create a surface enrichment but you will not move the heavies to the bottom of the pan. If you are to move the heavies to the bottom of the pan, you are going to have to move that pan violently enough to make all of the material move within or in relation to the pan. By doing so, you cause material shifting and as it shifts, the heavier particles will go to the bottom. This is the same effect we strive for in the concentrator. We dont want the material to ever attain the some speed as the cone because if it does, it will be stagnant, so by injecting the water in the reverse direction to rotation, we help to keep the material in a constant fluid motion thereby allowing any particle that is heavier than what is in the rings to inject in and displace something that is lighter.

In creating tangential injection, we got a fringe benefit we never even thought about. Whom you shut the machine down to drop out the concentrate, you simply turn on the back pressure water and it immediately blows everything off the rings and you only need to hose out the bottom ring. This cuts cleanup time from thirty minutes to five minutes."

Anolphart said:

This might sound stoopid, but following on a previous topic about breaking down clay, has anybody tried using centrifugal force to separate gold from other heavies, particularly black sand? After all, gold is the heaviest of the material that we find and theoretically it should be able to be separated in a centrifuge. I understand that conventional centrifuges generally only handle small quantities, but what if one were to create two containers that would handle several cup fulls each and place them in a spin drier opposite to each other and let er rip?

Is anybody game enough to possibly incur the wrath of the washer woman to try it out?

Click to expand...

I know a bit about them...what do you want to know?

Clay is the biggest problem when recovering gold...doesn't matter if your a single operator or BHP...clay is a prick.

Centrifuge recovery can be anything from 3tph up to 100 cubic meters an hour per unit.