Aluminium casthouses are under pressure to raise their use of recycled metal without sacrificing melt quality, recovery rates or production efficiency. Lightweight scrap, machining chips and other low-density materials are difficult to introduce into conventional melting furnaces, which makes efficient feeding and submergence of scrap central to recycling performance. Consistent temperature and chemical composition across the molten bath are equally critical, so circulation and stirring equipment must support heat transfer and metal movement while limiting interruptions and metal loss. Conventional mechanical pumps rely on immersed rotating parts that can degrade through contact with molten aluminium, dross and refractory debris.
Zmag America, Ltd. works in this specialised corner of casthouse technology, developing magnetic systems for molten-metal circulation, furnace stirring and scrap recovery.
From eddy-current separation to molten metal
The company's foundation is the industrial application of magnets and magnetic circuits. Its history traces back to magnetic engineering and the commercialisation of eddy-current separation, used to recover non-ferrous metals from mixed streams, before it moved into molten-metal applications. Its patented zPMC (Zmag Permanent Magnetic Circuit) underpins equipment that stirs, circulates and submerges material in molten aluminium. Unlike conventional electromagnetic stirring, the zPMC design uses a permanent magnetic circuit to generate the field that moves the metal. Zmag describes the resulting movement as a virtual impeller, since circulation is achieved without immersed mechanical impellers.
Adoption barriers remain. In an August 2025 interview with AL Circle, Eishin Takahashi, president of Zmag America, identified limited familiarity with the technology as an obstacle in the United States, noting that aluminium producers globally tend to be conservative and prefer equipment and processes they already know.
MagStir targets furnace homogenisation
MagStir is a non-contact stirring system for melting and holding furnaces. It uses the permanent magnetic circuit to move the bath and homogenise temperature and alloy composition, and is offered in configurations for furnaces of 15 to 200 metric tons. Because there is no immersed mechanical stirring component, casthouses can improve 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 additional furnaces; a technical case study published in 2017 reported improvements in temperature control during furnace preparation. Rio Tinto-operated Boyne Smelters in Queensland, Australia, fitted a MagStir unit to a casthouse furnace in 2019.
MagPump offers an alternative to mechanical circulation
MagPump applies the same approach to pumping and circulation. It fits a standard pump well without furnace modification, uses no physical impeller and is marketed 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 replaced 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 also presented at the TMS 2023 Annual Meeting and Exhibition, where its use in side-well, multi-chamber furnaces was discussed, along with potential roles in gas injection and scrap submergence.
Typhoon addresses difficult scrap
Typhoon is aimed at scrap submergence and chip melting, drawing lightweight scrap and machining chips beneath the bath surface instead of letting them float. Its magnetic circuit creates a vortex-like movement that pulls material into the melt, supporting heat exchange and recovery. At Neuman Aluminium's Marktl facility in Austria, the system was included in a furnace modernisation intended to expand processing of low-density post-consumer scrap, including lightweight fractions with a bulk density of about 375 kg/m³. Neuman set a target of one metric ton per hour while continuing to melt solid charge in the same furnace; in operation the Typhoon processed almost twice the planned scrap quantity within the expected time without disrupting normal operations, with low operator involvement and no reported negative impact on melt or finished-product quality. According to the published technical account, the system operates at 5-15 kW including its air-cooling blower and can submerge up to five metric tons per hour of machining chips, with adjustable vortex intensity that keeps metal moving when no scrap or alloy is being charged.
A competitive technology landscape
Several established suppliers serve furnace stirring, circulation and scrap submergence, though not all offer direct equivalents to permanent-magnet equipment. ABB supplies its AL-EMS electromagnetic stirring system and reports more than 430 installations; in April 2026 it announced a further order from Arconic for a fifth stirrer at the company's Hungarian casthouse. Presezzi Extrusion Group, through its Melting Technology division, offers the L.E.C. (Low Energy Consumption) Stirrer for melting and holding furnaces alongside remelting and casthouse equipment. Pyrotek's range includes electromagnetic pump systems and its LOTUSS low-turbulence scrap submergence technology, which uses a circulation pump and refractory well, and its UK operations include EMP Technologies Ltd. Rockwell Automation sits in the adjacent automation segment, supplying furnace and ladle-shop control systems, as in its modernisation work for Mozal Aluminium's casthouse.
For producers taking on harder recycled feedstock, the ability to manage molten-metal movement without immersed mechanical components may become a more relevant consideration.