Twitch
Floated fragmentiser aluminium — the aluminium fraction lifted out of Zorba by sink-float separation, and the grade that connects shredders to secondary smelters.
AlISRI Floated Fragmentizer Aluminium
- Float-separated shredded aluminium
- Typical Al metallics 90-98%
- Cast/wrought ratio by agreement
- Max free zinc, copper and magnesium limits
Typical outlets:
- Secondary alloy production
- ADC12 / 380 alloys
- Remelt ingot
- Deox
What Twitch is
Twitch is floated fragmentiser aluminium: shredded aluminium recovered from Zorba by sink-float media separation, carrying the ISRI designation of the same name.
Zorba comes off a fragmentiser as a mixed non-ferrous concentrate — aluminium together with copper, brass, zinc and stainless. Passing it through a heavy-media plant floats the aluminium off and sinks the heavier metals. What floats is Twitch.
The result is typically ninety per cent or better aluminium metallics, in a mixture of cast and wrought pieces. It is a processed product rather than a collected one, which is why it trades on measured analysis rather than visual grading.
Metallics and the cast-to-wrought ratio
Two numbers govern the value of a Twitch shipment: the metallics percentage, and the ratio of cast to wrought aluminium within it.
Metallics is the proportion that is actually aluminium metal rather than residual plastic, rubber, glass or entrained heavies. Typical shipments run between ninety and ninety-eight per cent.
The cast-to-wrought ratio matters because the two behave differently on remelt. A cast-heavy Twitch suits secondary foundry alloys such as ADC12 and 380; a wrought-heavy one is more useful as a diluent. Free zinc, copper and magnesium are limited by agreement, because each shifts the chemistry of the resulting alloy.
How a shipment is assessed
Twitch is bought on analysis. A representative sample is taken and the metallics and alloy split established before a firm price is agreed, and the basis of that assessment is set out in writing before material moves.
This is normal for a processed grade and protects both sides: the seller is paid for what the material contains rather than what it resembles, and the buyer is not pricing an unknown.
Where it goes
Twitch feeds secondary alloy production — remelt ingot, ADC12 and 380-series alloys, and deoxidation aluminium for steelmaking.
Because it arrives already liberated and sized, it melts predictably and with less handling than mixed collected scrap, which is precisely what secondary smelters pay for.
Every grade we trade in this metal is listed on the Aluminium page. If you have material to sell, see how to sell non-ferrous scrap metal.
Common questions
Twitch, explained
What is the difference between Zorba and Twitch?
Zorba is the mixed non-ferrous concentrate that comes off a fragmentiser, containing aluminium along with copper, brass, zinc and stainless. Twitch is the aluminium fraction after that mixture has been through sink-float separation. Twitch is a processed product; Zorba is the feed it is made from.
What metallics content is normal for Twitch?
Typically between ninety and ninety-eight per cent aluminium metallics. The balance is residual non-metallics and entrained heavier metals. The figure is established by sampling rather than estimated.
Why does the cast-to-wrought ratio affect the price?
Cast and wrought aluminium suit different outlets. A cast-heavy shipment goes to foundry alloys such as ADC12; a wrought-heavy one is more valuable as a diluent in secondary alloy production. The ratio therefore changes who will buy it and at what level.
Is Twitch bought on sight or on analysis?
On analysis. A representative sample determines the metallics and alloy split, and the basis is agreed in writing before the shipment moves.
Do you buy Zorba as well as Twitch?
Yes. Both are traded, together with the other fragmentiser grades. Zorba has its own page setting out how it is assessed.
Trading Twitch?
Send the grade, quantity, photographs and location, and we will provide a firm quotation.
or email info@mohmet.co.uk