Aluminium casthouses are trying to raise the share of recycled metal in their furnaces without sacrificing melt quality, recovery rates or production efficiency. The difficulty is that the lightweight scrap, machining chips and other low-density fractions that come with that shift are awkward to introduce into conventional melting furnaces, which makes efficient scrap feeding and submergence central to recycling performance. Zmag America, Ltd. is promoting a family of permanent-magnet systems for molten-metal circulation, furnace stirring and scrap recovery as one answer to that combination of problems.
Light scrap, consistent melt
The challenge goes beyond preparing the scrap. Casthouses must hold temperature and chemical composition steady through the molten bath to produce specification-compliant aluminium, so circulation and stirring equipment has to support heat transfer and metal movement while limiting process interruptions and metal loss. Conventional mechanical pumps, although widely used, depend on immersed rotating components that can deteriorate through exposure to molten aluminium, dross accumulation and contact with refractory debris.
zPMC: a permanent magnetic circuit rather than an impeller
Zmag's background lies in the industrial application of magnets and magnetic circuits; its history traces back to magnetic engineering work and the commercialisation of eddy-current separation, used to recover non-ferrous metals from mixed material streams. The company later moved into molten-metal applications and developed its patented zPMC (Zmag Permanent Magnetic Circuit), the basis for equipment that stirs, circulates and submerges material in molten aluminium. Instead of a conventional electromagnetic stirring arrangement, zPMC uses a permanent magnetic circuit to generate the field that moves the metal. The company describes the resulting movement as a virtual impeller, since circulation is produced without conventional immersed mechanical impellers.
In an August 2025 interview with AL Circle, Eishin Takahashi, President of Zmag America, identified limited familiarity with the technology as one barrier to wider US adoption, noting that aluminium producers globally tend to be conservative and to favour equipment and processes they already know.
MagStir and MagPump
MagStir is a non-contact stirring system for aluminium melting and holding furnaces that uses the permanent magnetic circuit to move the bath and help homogenise temperature and alloy composition. Zmag offers configurations for furnaces of 15 to 200 metric tons, and the absence of an immersed mechanical stirring component is presented as an alternative for casthouses that want better melt circulation without adding moving parts to the molten-metal environment. New Zealand Aluminium Smelters installed the technology in a casting furnace and later extended it to further furnaces; a technical case study published in 2017 reported improvements in temperature control during furnace preparation. A MagStir unit was also fitted to a casthouse furnace at Rio Tinto-operated Boyne Smelters in Queensland, Australia, in 2019.
MagPump extends the same approach to molten-metal pumping and circulation. It is designed to fit a standard pump well without furnace modification and, unlike mechanical pumps, uses no physical impeller; Zmag markets it as a nearly hands-free option with no consumable parts and minimal downtime. At the TANDEM Division of US secondary producer TST Inc. in Fontana, California, a seven-week trial saw MagPump replace an existing mechanical pump in a production furnace. The findings described smooth operation and reduced disturbance of the molten-metal surface, and plant management reported that the system avoided the splashing seen with conventional pumping as the 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 alongside potential roles in gas injection and scrap submergence.
Typhoon and the Neuman installation
Typhoon targets scrap submergence and chip melting, drawing lightweight scrap and machining chips beneath the metal surface instead of letting them sit on top of the bath. Its magnetic circuit generates a vortex-like movement that pulls material into the melt, supporting heat exchange and recovery during remelting. At Neuman Aluminium's Marktl facility in Austria, the system was incorporated into a furnace modernisation intended to widen the plant's ability to process low-density post-consumer scrap, including lightweight fractions with a bulk density of about 375 kg/m³ that had been difficult to charge and melt conventionally. Neuman had targeted 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 operation, with low operator involvement and, according to the company, no negative impact on melt or finished-product quality. The published technical account puts power demand at 5-15 kW including the air-cooling blower, with capacity to submerge up to five metric tons per hour of machining chips and adjustable vortex intensity that can keep the bath moving when no scrap or alloying material is being charged.
A crowded equipment field
Several established suppliers compete in furnace stirring, molten-metal circulation and scrap submergence, though 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 it announced a further order from Arconic for a fifth stirrer at the producer's Hungarian casthouse, following earlier units at the same site. 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 remelting and complete casthouse equipment. Pyrotek covers electromagnetic pump systems and its LOTUSS (Low Turbulence Scrap Submergence) technology, in which a circulation pump and refractory well draw lightweight scrap under the surface, and its UK operations include EMP Technologies Ltd., which designs, sells and installs metal-melting and circulation systems using electromagnetic pumps. Rockwell Automation sits in the adjacent industrial automation segment rather than offering a like-for-like permanent-magnet stirrer, with furnace and ladle-shop control work that includes a modernisation project for Mozal Aluminium's casthouse.
For Zmag, the commercial question is whether casthouses shifting towards harder-to-process recycled feedstock will weigh the avoidance of immersed mechanical components heavily enough to change established purchasing habits.