Magnetic Separation of Material

Its part of what is called the 8-d 8 Disciplines method of problemsolving,

Who?

What?

When?

WHere?

Why?- (usually this is what we're trying to figure out)

How?

How many?

One you accumulate the answers to these- the problem is at least identified and usually 95% solved.

Milo

Thanks.

Hi Milo,

I got the 5H-2W but what's 8-d-8?

Who: As long as it's not "Guest" with a bad attitude.

What: If the poster does know "what" he/she wants help with it's a lost cause.

Why: Because it's fun to figure out someone elses problem(s).

When: ASAP!

Where: On CR4.

How: Seems to me like this is what everyone is really trying to figure out.

How many: >0

John

Excellent response MILO -- at least you have a name -- I am so tired of GUESTS who criticize others who identify themselves and step up to the plate, even if it is criticism.

I agree with you, but all have the right to respond in the manner they choose - if they are outside the forum rules then they may be eliminated from participation.

Respectfully

IETECH

dear arun54

if you use 10 meter long convear belt for seperation and use maltipale stage for seperation you can seperate almost 99 % magnetic material just find out if any one making poweder for plastoferriet in your region am seperating almost 50 micron particale

regards

Arun,

I think the centrifuge slurry idea is very practical and has a great chance of working.

Another option might be heat. The materials you mentioned have a fair distribution of melting points. It might be difficult given the particle size, but you theoretically could heat the powder on a fine mesh and get the stuff you want as it melts and passes through the mesh. Because of the small particles and how fine a mesh would have to be, you would probably need to force the liquid through via centrifuge, or some other method. Could be neat, but possibly not practical.

You might try vibration in combination with your magnetic system. Using high frequency (100's kHz-GHz?), low amplitude vibration may keep the non-magnetic particles from adhering well. You can either vibrate the magnet after picking up the particles, or vibrate the surface the mixed powder is on while the magnet is passed over with sufficient gap to only pick up particles that have been bounced off of the surface.

Very interesting problem; make sure to post the solution that works.

Here's one thing you might want to take a look at if weight figures into this at all. For years people that paned for gold were looking for a better way to get the job done. Several years ago, a company came out with a device that helped a lot. Essentially, it's a shallow, round drum about three feet wide. The center of the drum is lined with rubber and spirals in toward the hub (consult Kris about cycloids ). The hub sits almost straight up - meaning if you stand in front of it, you're looking into the drum (hope that's clear). Anyway, the drum is slowly turned by an electric motor and a low pressure stream of water gently flushes the hub. Next, gravel from a riverbed is dropped into the bottom of the hub. The gravel tumbles and is washed. Heavier particles tend not to be flushed out as easily as lighter debris, and tends to stick to the rubber lining by friction. The heavier stuff eventually tumbles up the spiral to reach the hub. 99.999% of the stuff that makes it to the hub is bits of gold of various shapes and sizes. Not much else gets to the hub. And, at the hub, the gold is easily extracted without having to do all that backbreaking panning.

Just wondering if something like this would work for your problem - If not the solution, at least possibly part of the process.

Or you could pass a slurry over a fleece. Having got the golden fleece , you just torch the organic crap out of the way. Moss on a river bank can do the job , but conservationist may want to shoot you.

Maybe some kind of dirt cheap natural filter could work. "Many a true word spoken in jest " they say. (who is the proverbial 'they' anyhow ?)

Cousin Floyd and me. Hadn't you guessed?!

Air-Lingus ?

Arun,

As I understand it the waste particles are powdery and their size is about 100 microns. This was stated in your initial post. In another post you said:

"The materials in question are ores, ore concentrates and metallic wastes. They contain Iron, Nickel, Cobalt, copper, Manganese, Aluminium in varied proportions along with acid insoluble material like silica, silicates etc. Particle size distribution varies drastically but could be classified. We are basically talking about particles of around 300 micron to 100 micron size."

This is a bit confusing. Are the 300-100 microns size particles all waste (the "powdery" stuff). If so, which materials and what sizes are the "Magnetic Material" particles which you want to salvage?

I think I have a good, practical, answer for you, depending on what your answer to the above might be.

I took that to mean that all particles are 100-300 microns, wanted and unwanted.

Another possibility that comes to mind, that I think some others were getting at, is use of air to filter out lighter particles. If you let the powder fall in a fine wall, like a waterfall, a cross-flow of air will push the light stuff further than the heavy stuff, and give you some separation. However, I doubt it would work well with particles that small, and I doubt you would get total separation.

Funny! In the 21st century we're talking about the same technology for winnowing grain.

You could try chemical means. I'm a mechanical guy, so I can't give you details that will work.

But, I'm thinking you do something based on the fact that metal + acid = metal salt + hydrogen. Add sulfuric acid to the slurry, and you'll get iron sulphate (along with metal salts for the other things you mentioned). I seem to remember from chemistry that you could then cause the the desired metal salt to precipitate out of the solution by adding something that will drop the solubility or by changing temperature, etc.

I'd be that if you used the right acid to get the right metal salts, there are well proven methods for pulling the desired salt out of the solution, then getting back to the pure metal. Find a ChemE!

Butcher,

I am surprised a "mechanical guy" is proposing a chemical solution (no pun intended)! Hey, we've got to protect our phony-baloney jobs! Those Chem-E's already make too much money as it is!

Seriously, though, if there is a significant weight/size difference in the particles, a cyclonic filter might just do the trick. These are available through companies that deal with coolant handling for metal-working machine tools. They are used to separate metal chips from soluble oil / water coolant solutions to recycle the expensive chemicals and salvage metal chips for waste or recycling, depending on the metals involved and their relative value. These systems use the same vortex effect you see used in some of the newer vacuum cleaners (particularly, no pun intend, the Dyson machines), however the medium is water instead of air.

In Arun's process the "clean" water can be recycled to help further wash the heavier particles, after the fine powdery trash has been removed via disposable paper filter media (like filtering your coffee grounds).

If this stuff is in fact ore, I think Butcher's idea is a good one. A lot of metal ores are treated this way to separate the metal and non-metal stuff. Just keep in mind, however, that this is usually a very eco-unfriendly process and typically creates a great deal of really nasty pollution.

Dunno.

Arun 54,

Are you dealing with a small (i.e., "bench") scale issue of separation, or a larger/production scale issue?

I recall back in my College days, that in one of my geology courses (possibly Geochemistry), we used a device known as a "Franz isodynamic magnetic separator" to separate the magnetic from non-magnetic fraction of both sediment, and crushed rock samples.

As I recall, this was a fairly small bench-top device, but used a LOT of power, and caused all sorts of funkiness to occur in equipment located in other Department Labs both adjacent, and on the floor below. Talk about EMF!

(But that was back in the 70's)

there is the one wich i want which uses a permanent magnet can not know the distance between magnet and the cover