Aluminium casthouses are being pulled in two directions at once: they must take in more post-consumer scrap, and they must hold melt quality, recovery rates and production efficiency where they are. The two demands collide in the furnace, where lightweight scrap, machining chips and other low-density fractions are difficult to charge into conventional melting equipment. Feeding and submerging such material efficiently has become a prerequisite for better recycling performance — and so has keeping temperature and chemical composition uniform across the bath.
That second requirement puts circulation and stirring equipment under scrutiny. Zmag America, Ltd. works in that niche, supplying magnetic engineering systems for molten-metal circulation, furnace stirring and scrap recovery. Its argument is that the immersed mechanical hardware long used for the job is the weak link.
Why immersed components wear
Conventional mechanical pumps are widely used, but they depend on rotating parts that sit in the melt. Molten aluminium, dross accumulation and contact with refractory debris all degrade those parts. The consequences reach beyond maintenance: interventions interrupt the process and metal is lost along the way. Equipment must therefore deliver heat transfer and metal movement while limiting disruption and losses — a balance that is hard to hold when the moving parts are inside the furnace.
Permanent magnets instead of electromagnetic stirring
Zmag's technological base is the industrial application of magnets and magnetic circuits. The company traces its history to magnetic engineering and to the commercialisation of eddy-current separation, a technique for recovering non-ferrous metals from mixed material streams. It later moved into molten-metal work and developed its patented zPMC (Zmag Permanent Magnetic Circuit) as the platform for equipment that stirs, circulates and submerges material in molten aluminium.
The distinction from conventional electromagnetic stirring matters. Rather than generating the moving field through a conventional electromagnetic arrangement, zPMC uses a permanent magnetic circuit to produce the field that drives the molten metal. Zmag describes the resulting movement as a "virtual impeller": circulation without an immersed mechanical impeller.
Adoption runs into familiarity rather than physics. In an August 2025 interview with AL Circle, Eishin Takahashi, president of Zmag America, named limited familiarity with the technology as a barrier in the United States, observing that aluminium producers globally "tend to be conservative and feel more comfortable with equipment and processes they are already familiar with."
MagStir: targeting furnace homogenisation
MagStir is a non-contact stirring system for aluminium melting and holding furnaces. It uses the permanent magnetic circuit to set the bath in motion and support homogenisation of temperature and alloy composition. Zmag offers configurations for furnaces of 15 to 200 metric tons; the absence of an immersed stirring component makes it an option for casthouses that want better melt circulation without adding moving parts to the molten-metal environment.
Installation history extends outside the United States. New Zealand Aluminium Smelters fitted the technology to a casting furnace and later extended it to further 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, added a MagStir unit to a casthouse furnace in 2019.
MagPump: circulation without an impeller
MagPump carries the approach into pumping and circulation. It is designed to drop into a standard pump well without furnace modification, and 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 most detailed public account comes from the TANDEM Division of US secondary producer TST Inc. in Fontana, California, where MagPump replaced an existing mechanical pump in a production furnace during a seven-week trial. Reported findings included 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. 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: pushing scrap under the surface
Typhoon tackles the feedstock problem directly through scrap submergence and chip melting. Instead of letting lightweight scrap and machining chips remain at the top of the bath, it introduces them below the surface; its magnetic circuit generates a vortex-like motion that draws material into the melt and supports heat exchange and recovery during remelting.
An installation at Neuman Aluminium's Marktl plant in Austria shows what that means in practice. Neuman added a Typhoon chip-submergence system as part of a furnace modernisation aimed at low-density post-consumer scrap, including lightweight fractions with a bulk density of roughly 375 kg/m³ that had been difficult to charge and melt conventionally. The results exceeded the initial target: Neuman had set out to process one metric ton per hour while continuing to melt solid charge in the same furnace, and the system handled almost twice the planned scrap quantity within the expected time without disrupting normal operations. Operator involvement was low, the company reported, and melt and finished-product quality were unaffected.
By the published technical account, Typhoon runs 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 molten-metal movement can be maintained even when no scrap or alloying material is being charged.
A crowded field, not all equivalents
Several established suppliers compete in furnace stirring, circulation and scrap submergence, though their products are not all direct substitutes for a permanent-magnet design. ABB supplies its AL-EMS electromagnetic stirring system for melting, holding and alloying furnaces, with more than 430 installations; in April 2026 it announced a further Arconic order for a fifth stirrer at Arconic'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 equipment and complete casthouse operations. Pyrotek covers a wider equipment range, including electromagnetic pump systems and its LOTUSS (Low Turbulence Scrap Submergence) technology; LOTUSS relies on a circulation pump and refractory well to submerge lightweight scrap, while Pyrotek's UK operations include EMP Technologies Ltd., which designs, sells and installs systems built around electromagnetic pumps. Rockwell Automation sits in the adjacent 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.
What the case record does and does not show
The evidence assembled so far is a set of plant trials and installations, reported largely by the supplier and by customers describing their own experience. It points to operational advantages — fewer immersed parts, less surface disturbance, higher scrap intake in at least one modernisation — but it does not establish performance against electromagnetic or mechanical systems under matched conditions, nor does it quantify maintenance savings over years of operation. Those gaps matter because purchasing decisions tend to be framed around reliability and total cost rather than principle.
The direction of travel is legible. As producers take on more difficult recycled feedstock, moving molten metal without immersing mechanical components in it becomes a more relevant consideration — and a more crowded set of suppliers will be making that case.