Aluminum casthouses are being asked to run more post-consumer recycled metal through furnaces originally configured for denser charge. Lightweight scrap fractions, machining chips and other low-density material are difficult to introduce into conventional melting furnaces, so efficient scrap feeding and submergence have become central to recovery rates and melt quality. The constraint does not stop at charging: temperature and chemical composition must stay consistent throughout the bath, which puts the burden on circulation and stirring equipment to move metal and transfer heat without interrupting the process or losing excessive metal.
Conventional mechanical pumps remain the default for that duty, but they depend on immersed rotating components that deteriorate through contact with molten aluminum, dross accumulation and refractory debris. Zmag America, Ltd. works in the narrower segment of magnetic engineering for molten-metal circulation, furnace stirring and scrap recovery, and argues that the wear mechanism itself can be designed out.
From eddy-current separation to a virtual impeller
Zmag's technical base is the industrial application of magnets and magnetic circuits. The company traces its history to magnetic engineering and the commercialization of eddy-current separation, used to recover non-ferrous metals from mixed material streams, before extending into molten-metal applications. Its patented zPMC (Zmag Permanent Magnetic Circuit) generates the field that moves molten aluminum, producing circulation the company describes as a virtual impeller — movement without an immersed mechanical impeller. The distinction from conventional electromagnetic stirring lies in the source of the field: a permanent magnetic circuit rather than an electromagnetic arrangement.
Adoption has been slower than the technical case might suggest. Eishin Takahashi, president of Zmag America, told AL Circle in August 2025 that limited familiarity with the approach was one barrier in the United States, observing that aluminum producers globally tend to be conservative and to feel more comfortable with equipment and processes they already know.
MagStir: homogenization without immersed parts
MagStir applies the circuit to non-contact stirring in aluminum melting and holding furnaces, supporting homogenization of temperature and alloy composition. Zmag offers configurations for furnaces with capacities from 15 to 200 metric tons. Because nothing is immersed, casthouses can add circulation without introducing further moving parts into the molten-metal environment.
Installation history outside the United States includes New Zealand Aluminium Smelters, which fitted the technology to a casting furnace and later extended it to additional furnaces; a technical case study published in 2017 examined those installations and reported improved temperature control during furnace preparation. Rio Tinto-operated Boyne Smelters in Queensland, Australia, added a MagStir unit to a casthouse furnace in 2019.
MagPump: a fit-in-the-well alternative
MagPump extends the same principle to pumping and circulation, designed to fit a standard pump well without furnace modification. It has no physical impeller and is marketed as a nearly hands-free unit with no consumable parts and minimal downtime.
The most concrete evidence comes from a seven-week trial at the TANDEM Division of TST Inc., a secondary aluminum producer in Fontana, California, where MagPump replaced an existing mechanical pump in a furnace used for aluminum production. Reported findings describe smooth operation and reduced disturbance to the molten-metal surface; plant management also reported that the system avoided the splashing experienced with conventional pumping arrangements as the furnace metal level fell during draining. At the TMS 2023 Annual Meeting and Exhibition, the technology was presented in the context of side-well, multi-chamber furnaces, with potential extensions into gas injection and scrap submergence alongside its primary circulation role.
Typhoon: pulling light scrap beneath the surface
The third product, Typhoon, targets scrap submergence and chip melting. Rather than letting lightweight scrap and machining chips remain at the top of the bath, its magnetic circuit generates a vortex-like movement that draws the material into the melt, supporting heat exchange and recovery during remelting.
Neuman Aluminium's Marktl facility in Austria illustrates the application. As part of a furnace modernization intended to widen its intake of low-density post-consumer scrap, Neuman incorporated a Typhoon chip-submergence system to handle lightweight fractions with a bulk density of roughly 375 kg/m³ — material that had presented challenges for conventional furnace charging and melting. Neuman set a target of one metric ton per hour while the same furnace continued to melt solid charge materials; in operation the system processed almost twice the planned scrap quantity within the expected time without disrupting normal furnace operations. The company 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, with vortex intensity adjustable to operating requirements — including maintaining molten-metal movement when no scrap or alloying material is being charged.
A crowded but not equivalent supplier field
Furnace stirring, molten-metal circulation and scrap submergence have established suppliers, though their offerings are not all direct equivalents to permanent-magnet technology. ABB supplies its AL-EMS electromagnetic stirring system for melting, holding and alloying furnaces, with more than 430 installations reported; in April 2026 it announced a further Arconic order for a fifth stirrer at a Hungarian casthouse, following earlier units at the same facility. Presezzi Extrusion Group's Melting Technology division offers the L.E.C. (Low Energy Consumption) Stirrer for melting and holding furnaces alongside remelting equipment and complete casthouse operations. Pyrotek spans a wider equipment range, including electromagnetic pump systems and LOTUSS (Low Turbulence Scrap Submergence), which pairs a circulation pump with a refractory well to submerge lightweight scrap; its UK operations include EMP Technologies Ltd., involved in design, sale and installation of metal-melting and circulation systems built around electromagnetic pumps. Rockwell Automation sits in the adjacent automation segment rather than supplying a like-for-like permanent-magnet stirrer, with furnace and ladle-shop control work that includes a modernization project for Mozal Aluminium's casthouse.
What the record supports, and what it does not
The available evidence is a set of vendor and customer accounts rather than independent comparative trials. Reported improvements in temperature control, surface stability and submergence throughput establish feasibility at named plants; they do not demonstrate a general performance advantage over electromagnetic or mechanical systems. Zmag's claim of no consumable parts and minimal downtime is likewise a design argument: the absence of immersed rotating components is verifiable in principle, while its commercial effect remains unproven.
The strategic logic, however, is straightforward. As producers widen the range of recycled feedstock they accept, the ability to move molten metal and submerge difficult scrap without immersed mechanical components becomes a more relevant consideration. Whether that consideration converts into orders depends on the same factor Takahashi identified: familiarity. In an industry that prefers proven equipment, the binding constraint on permanent-magnet technology is less the physics than the reference list.