Pyrometallurgy: Roasting, Smelting, Refining & Electrowinning

Pyrometallurgy: Roasting, Smelting, Refining & Electrowinning 2017-03-23T09:55:18+00:00
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Aluminum Dust for Billet Brushes (8 replies)

Alan Carter
1 year ago
Alan Carter 1 year ago

With regards to the disposal of billet brushes' aluminum dust, what is the best way to dispose the aluminum dust produced from billet brushes in extrusion lines? Is remelting in melting furnaces safe?

I am aware that the dust is highly explosive and the recovery will be negative. It is only a question of disposing the dust.

JohnnyD
1 year ago
JohnnyD 1 year ago

DO NOT try to recycle aluminum fines in a melting furnace. If you ignore the fact that fine Al dusts (below 200 mesh) are explosive, the recovery you would get is minimal, and most likely negative, meaning it will oxidize and take some of your valuable metal with it!  I would suggest you get hold of the publications department of the American Aluminum Association and procure of both of their publications on Al dust safety.

Helena Russell
1 year ago
Helena Russell 1 year ago

Dust will explode & oxidise. I have melted in Indcution furnace by briquetting powder/ dust. You can compress in a press or better if required better stregth to chare you can mix some alumium flakes / granules to have binding to handle to charge into the furnace. Melting was safe & healthy recovery too.

Since the volume to area ratio is very less it would immediately oxidise reducing recovery. Better alternatives are bailing these fines or melting them in an induction furnace.

John Koenig
1 year ago
John Koenig 1 year ago

The fines are likely to be with moisture , so first ensure it to be completely dry by storing near furnace or the below procedure. Fines are either to be melted in crucible furnace or induction furnace by indirect heat. Use coverall flux to avoid burning. Use low heat and charge powder in metal pool in little quantities at a time. Operators normally make a hole in a sheet, kept over the crucible and keep powder over it and charge manually little by little thru hole.

JohnnyD
1 year ago
JohnnyD 1 year ago

As you can see there are more warnings and detailed procedures needed to recover Al fines safely. You will need to evaluate if your operation can meet these strict requirements to be safe.

Have you considered selling the material to others who can use it? For example the steel industry buys tons of Al as De-Ox.

John Koenig
1 year ago
John Koenig 1 year ago

Could be sale to a Chemical company, who produce Aluminum compounds.

Maybe you can remelt with heavy-metal and can sale it chemical industries.

Also did think to briquette the dust. Chinese machines for this purpose are good. Remelting these briquettes is a better option.

Tony Verdeschi
1 year ago
Tony Verdeschi 1 year ago

There are many applications as such. No need of spending resources over it.

But if you must consider that -200 mesh means 74 micron aluminium fins will be contact with atmospheric air at hot condition, its an explosive range. At cold condition it will be pass the vibrating screen for separation of above 200 mesh and below 200 mesh aluminium fins.
Above 200 mesh fins- will be used for deox granular for steel industry / raw material for ferro alloy 'mfg / sparkler industry.
Below 200 mesh fins - convert in to briquettes and melt with the help of small PMS furnace.

David Kano
1 year ago
David Kano 1 year ago

Al chips can be briquetted but can Al dust? Does brushing produce Al dust in enough quantity to think of disposal or recovery? Would that dust be in enough quantity to have an explosion hazard in an extrusion plant's atmosphere that would be too big volume to be filled by Al dust I suppose.

JohnnyD
1 year ago
JohnnyD 1 year ago

David, you pose an interesting point. The quantity of dust generated by rolling mill or extrusion brushes are quite low on a weight/time scale basis. Well below the expected Minimum Explosive Concentration (MEC) for Al.
The real-world issue though is dust accumulation. If the material is not vacuum ducted away as it is being generated, then it is quite easy to accumulate enough material to, in fact, reach the MEC if an upset condition (like an operator inappropriately uses an air hose) happens. There would be no need to fill up a whole room with dust, just the area around the brushes. At a pressure rise rate of close to 20K psi/sec that could be very dangerous.

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