Aluminium casthouses are under pressure to increase their use of recycled metal without compromising melt quality, recovery rates or production efficiency. As producers add more post-consumer recycled aluminium, lightweight scrap, machining chips and other low-density materials are becoming more important as feedstock. These materials are difficult to introduce into conventional melting furnaces, so efficient scrap feeding and submergence are central to improving recycling performance.
The difficulty is not limited to scrap preparation. Temperature and chemical composition must remain consistent throughout the molten bath to produce specification-compliant aluminium. Circulation and stirring equipment therefore has to support heat transfer and metal movement while limiting process interruptions and excessive metal loss.
Conventional mechanical pumps are widely used, but they rely on immersed rotating components. Those components can deteriorate through exposure to molten aluminium, dross accumulation and contact with refractory debris.
A permanent-magnet alternative
Zmag America, Ltd. works in this specialised part of casthouse technology, developing magnetic systems for molten-metal circulation, furnace stirring and scrap recovery. Its technical roots are in industrial magnets and magnetic circuits, including the commercialisation of eddy-current separation for recovering non-ferrous metals from mixed material streams. The company later moved into molten-metal applications and developed its patented zPMC permanent magnetic circuit as the basis for equipment that stirs, circulates and submerges material in molten aluminium.
The difference from conventional electromagnetic stirring is central to Zmag's approach. Instead of a conventional electromagnetic stirring arrangement, zPMC uses a permanent magnetic circuit to generate the field that moves the molten metal. Zmag describes the resulting movement as a virtual impeller, because circulation is generated without conventional immersed mechanical impellers.
Adoption is not only a technical question. In an August 2025 interview with AL Circle, Zmag America president Eishin Takahashi identified limited familiarity with the technology as a barrier in the United States. He observed that aluminium producers globally tend to be conservative and more comfortable with equipment and processes they already know.
MagStir: stirring without an immersed impeller
MagStir is a non-contact stirring system for aluminium melting and holding furnaces. It uses the permanent magnetic circuit to create movement in the molten bath and support homogenisation of temperature and alloy composition. Zmag offers configurations for furnaces from 15 to 200 metric tons. Because the system has no immersed mechanical stirring component, it is an alternative for casthouses that want better melt circulation without adding moving parts to the molten-metal environment.
Its application history extends beyond the United States. New Zealand Aluminium Smelters installed MagStir in a casting furnace and later extended its use to additional furnaces. A technical case study published in 2017 examined those installations and reported improvements in temperature control during furnace preparation. Rio Tinto-operated Boyne Smelters in Queensland, Australia, also installed a MagStir unit in a casthouse furnace in 2019.
MagPump and the TST trial
MagPump applies the same magnetic-engineering approach to molten-metal pumping and circulation. It is designed to fit a standard pump well without furnace modification. Unlike a conventional mechanical pump, it has no physical impeller. Zmag markets it as a nearly hands-free option with no consumable parts and minimal downtime.
The system was examined at the TANDEM Division of US secondary aluminium producer TST Inc. in Fontana, California. During a seven-week trial, MagPump replaced an existing mechanical pump in a production furnace. The reported findings described smooth operation and reduced disturbance to the molten-metal surface. TST plant management also reported that the system avoided the splashing seen with conventional pumping arrangements as the furnace metal level fell during draining.
The technology was presented at the TMS 2023 Annual Meeting and Exhibition, where its use in side-well, multi-chamber furnaces was discussed. The presentation covered its primary circulation role and potential for other operations, including gas injection and scrap submergence.
Typhoon: submerging light scrap and chips
Typhoon focuses on scrap submergence and chip melting. The system is designed to introduce lightweight aluminium scrap and machining chips beneath the molten-metal surface instead of leaving them at the top of the bath. Its magnetic circuit generates a vortex-like movement that draws material into the melt and supports heat exchange and recovery during remelting.
A recent installation at Neuman Aluminium's Marktl facility in Austria shows the intended application. Neuman added a Typhoon chip-submergence system to a furnace modernisation project to expand its ability to process low-density post-consumer scrap. The targeted material included light fractions with a bulk density of about 375 kg/m³, which had been difficult to charge and melt in conventional furnaces.
Reported operating results exceeded the initial expectations. Neuman had set a target of processing one metric ton per hour while continuing to melt solid charge in the same furnace. During operation, the Typhoon system processed almost twice the planned scrap quantity within the expected time without disrupting normal furnace operations. Neuman also reported low operator involvement and no negative impact on melt or finished-product quality.
According to the published technical account, Typhoon operates at 5-15 kW, including its air-cooling blower, and can submerge up to five metric tons per hour of machining chips. Its vortex intensity can be adjusted to suit operating requirements, so the system can maintain molten-metal movement when scrap or alloying material is not being charged.
A competitive field with different technical routes
The market for aluminium furnace stirring, molten-metal circulation and scrap-submergence equipment includes established suppliers, but their products are not all direct equivalents of Zmag's permanent-magnet approach. ABB supplies its AL-EMS electromagnetic stirring system for melting, holding and alloying furnaces and reports more than 430 installations. In April 2026, ABB announced a further order from Arconic for a fifth stirrer at its Hungarian casthouse, following earlier installations at the same facility.
Presezzi Extrusion Group, through its Melting Technology division and North American presence, offers the L.E.C. Low Energy Consumption Stirrer for melting and holding furnaces, alongside equipment for aluminium remelting and complete casthouse operations. Pyrotek has a broader casthouse equipment portfolio, including electromagnetic pump systems and LOTUSS low-turbulence scrap submergence. Its EMP systems use electromagnetic forces to circulate molten aluminium and support metal transfer and scrap charging, while LOTUSS uses a circulation pump and refractory well to submerge lightweight scrap. Pyrotek's UK operations include EMP Technologies Ltd., which designs, sells and installs metal-melting and circulation systems incorporating electromagnetic pumps.
Rockwell Automation operates in the adjacent industrial automation segment rather than offering a like-for-like permanent-magnet stirring product. Its aluminium-sector work includes furnace and ladle-shop control systems, as shown by a modernisation project for Mozal Aluminium's casthouse operations.
What the cases show
The evidence assembled by Zmag and its customers points to three narrower claims: non-contact stirring can support temperature homogenisation; magnetic pumping can avoid some surface disturbance and splashing associated with mechanical pumps; and magnetic vortex submergence can draw low-density scrap into the melt at higher-than-planned rates in a specific installation. These are application reports and company descriptions, not independent comparisons across all furnaces or feedstock mixes.
The wider constraint is adoption. Casthouses handling more challenging recycled feedstock need reliable molten-metal movement, but they also tend to favour familiar equipment and proven processes. Permanent-magnet systems offer an alternative to immersed mechanical components; how quickly they are taken up will depend on site-specific validation, operating experience and competition from established electromagnetic and mechanical routes.