Aluminium casthouses are being pushed in two directions at once: they must take in more post-consumer scrap, and they must do so without losing melt quality, recovery rates or throughput. Lightweight fractions, machining chips and other low-density material are the hardest to feed into a conventional melting furnace, which makes scrap feeding and submergence a bottleneck rather than an afterthought. Zmag America, Ltd. is positioning a family of permanent-magnet devices — MagStir, MagPump and Typhoon — against that constraint, arguing that molten-metal movement can be produced without putting rotating hardware into the bath.
The melt-side problem goes beyond scrap preparation. Temperature and chemical composition have to stay consistent through the bath for the cast product to meet specification, so circulation and stirring equipment must deliver heat transfer and metal movement while keeping process interruptions and metal loss in check. Conventional mechanical pumps, widely used across the industry, depend on immersed rotating components that deteriorate through contact with molten aluminium, dross build-up and refractory debris.
A magnetic circuit instead of an impeller
Zmag's starting point is the industrial use of magnets and magnetic circuits rather than metallurgical machinery. The company traces its origins to magnetic engineering and to the commercialisation of eddy-current separation, a technique for recovering non-ferrous metals from mixed material streams, before extending into molten-metal applications. Its patented zPMC (Zmag Permanent Magnetic Circuit) is the platform for equipment that stirs, circulates and submerges material in molten aluminium.
The distinction the company draws is between permanent-magnet systems and conventional electromagnetic stirring. Rather than an electromagnetic stirring arrangement, zPMC uses a permanent magnetic circuit to generate the field that drives the molten metal. Zmag describes the resulting motion as a virtual impeller, because circulation is produced without relying on an immersed mechanical impeller.
That is a claim about hardware architecture rather than a verified head-to-head performance comparison. What the company does set out is where the equipment has been installed and what operators reported.
MagStir: stirring without contact
MagStir is Zmag's non-contact stirring system for aluminium melting and holding furnaces. The permanent magnetic circuit moves the bath to homogenise temperature and alloy composition. Configurations cover furnaces from 15 to 200 metric tons, and because no stirring element is immersed, a casthouse 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 improvements in temperature control during furnace preparation. Rio Tinto-operated Boyne Smelters in Queensland, Australia, had a MagStir unit fitted to a casthouse furnace in 2019.
MagPump and the trial at TST
MagPump applies the same approach to pumping and circulation, and is designed to fit a standard pump well without furnace modification. It has no physical impeller and is marketed as a nearly hands-free option with no consumable parts and minimal downtime.
US secondary producer TST Inc. examined it at its TANDEM Division in Fontana, California, in a seven-week trial in which MagPump replaced an existing mechanical pump in a furnace used for aluminium production. The reported findings were smooth operation and reduced disturbance of the molten-metal surface; plant management also said the system avoided the splashing seen with conventional pumping as the metal level fell during draining. At the TMS 2023 Annual Meeting and Exhibition, its use in side-well, multi-chamber furnaces was presented, together with potential additional duties such as gas injection and scrap submergence alongside its primary circulation role.
Typhoon: attacking low-density scrap
Typhoon addresses the feed end, submerging lightweight scrap and machining chips beneath the molten-metal surface instead of letting them remain on top of the bath. The magnetic circuit generates a vortex-like movement that draws material into the melt, supporting heat exchange and recovery during remelting.
The most detailed example comes from Neuman Aluminium's Marktl facility in Austria, where a Typhoon chip-submergence system was folded into a furnace modernisation aimed at expanding the plant's ability to process low-density post-consumer scrap. The targeted material included lightweight fractions with a bulk density of roughly 375 kg/m³, a stream that had proved awkward for conventional furnace charging and melting. Neuman set a goal of one metric ton per hour while the same furnace continued to melt solid charge; in operation the system handled almost twice the planned scrap quantity within the expected time without disrupting normal furnace operations. The company 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. Vortex intensity is adjustable, so the unit can maintain molten-metal movement even when no scrap or alloying material is being charged.
A crowded field of near-equivalents
Zmag is not operating in an empty segment, but the competing offerings are not all direct equivalents. ABB supplies its AL-EMS electromagnetic stirring system for aluminium melting, holding and alloying furnaces, with more than 430 installations reported worldwide; in April 2026 it announced a further order from Arconic for a fifth stirrer at the company'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 aluminium remelting equipment and complete casthouse operations. Pyrotek spans a wider range of casthouse equipment, including electromagnetic pump systems and LOTUSS (Low Turbulence Scrap Submergence): the EMP systems use electromagnetic forces to circulate molten aluminium and support metal transfer and scrap charging, while LOTUSS combines a circulation pump with a refractory well to submerge lightweight scrap. Pyrotek's UK operations include EMP Technologies Ltd., which designs, sells and installs metal-melting and circulation systems built around electromagnetic pumps. Rockwell Automation sits in the adjacent industrial automation segment rather than offering a like-for-like permanent-magnet stirrer; its casthouse work includes furnace and ladle-shop control systems, as in a modernisation project for Mozal Aluminium.
Familiarity as the brake
The barrier Zmag has flagged is familiarity rather than capability. In an August 2025 interview with AL Circle, Zmag America president Eishin Takahashi named limited familiarity with the technology as one obstacle to wider uptake in the United States, observing that producers globally tend to be conservative and more comfortable with equipment and processes they already know.
That makes the commercial question one of risk tolerance as much as metallurgy. The case for permanent-magnet circulation rests on taking immersed mechanical components — the parts most exposed to molten metal, dross and refractory debris — out of the bath, and the installations described give that argument a track record to point to. Whether it carries further will depend on how those units perform as casthouses raise the share of difficult recycled feedstock. As producers seek to incorporate more challenging scrap, managing molten-metal movement without conventional immersed hardware is likely to become a more relevant consideration.