Aluminium casthouses are being pushed in two directions at once: they must raise the share of recycled metal in their melts while holding melt quality, recovery rates and production efficiency steady. Much of the added feedstock arrives as lightweight scrap, machining chips and other low-density material that is awkward to charge into conventional melting furnaces, which turns controlled feeding and rapid submergence into a practical bottleneck rather than a secondary concern. The same operations also need consistent temperature and chemistry through the molten bath, so circulation and stirring equipment has to move metal and heat effectively without adding process interruptions or excessive metal loss.
Conventional mechanical pumps meet that duty with immersed rotating parts, which deteriorate through contact with molten aluminium, dross accumulation and refractory debris. Zmag America, Ltd. has built its casthouse business around avoiding that contact altogether. The company develops magnetic engineering solutions for molten-metal circulation, furnace stirring and scrap recovery, and traces its origins to industrial magnetics and the commercialisation of eddy-current separation for recovering non-ferrous metals from mixed material streams. That work led into molten-metal applications and to its patented zPMC (Zmag Permanent Magnetic Circuit), the platform behind equipment that stirs, circulates and submerges material in aluminium melts.
Permanent magnets instead of electromagnetic stirring
The distinction the company draws is between a conventional electromagnetic stirring arrangement and a permanent magnetic circuit that generates the field responsible for moving the metal. Zmag describes the resulting motion as a virtual impeller: circulation is produced without an immersed mechanical impeller. Its president, Eishin Takahashi, told AL Circle in August 2025 that limited familiarity with the approach was one barrier to wider adoption in the United States, observing that producers globally tend to be conservative and to favour equipment and processes they already know. That framing matters for how the performance claims below should be read: they rest on a small number of named installations and published technical accounts rather than on a broad installed base.
MagStir for melting and holding furnaces
MagStir is a non-contact stirring system for melting and holding furnaces that uses the permanent magnetic circuit to drive movement in the bath and homogenise temperature and alloy composition. Zmag offers configurations for furnaces with capacities from 15 to 200 metric tons. Because nothing is immersed, the system is positioned as a way for casthouses to improve melt circulation without introducing additional moving parts into the molten-metal environment.
Deployment evidence comes largely from outside the United States. New Zealand Aluminium Smelters installed the technology in a casting furnace and later extended its use to additional furnaces; a technical case study published in 2017 examined those installations and reported improvements in temperature control during furnace preparation. A MagStir unit was also fitted to a casthouse furnace at the Rio Tinto-operated Boyne Smelters in Queensland, Australia, in 2019.
MagPump and the TST trial
MagPump carries the same approach into pumping and circulation. It is designed to fit a standard pump well without requiring furnace modification and, unlike a mechanical pump, uses no physical impeller; Zmag markets it as a nearly hands-free alternative with no consumable parts and minimal downtime.
The most concrete account of its behaviour comes from a seven-week trial at the TANDEM Division of TST Inc., a secondary aluminium producer in Fontana, California, where MagPump replaced an existing mechanical pump in a production furnace. Reported findings included smooth running and reduced disturbance of the molten-metal surface, and plant management said the system avoided the splashing seen with conventional pumping as the metal level fell during draining. The concept was presented again at the TMS 2023 Annual Meeting and Exhibition, where side-well, multi-chamber furnace applications were discussed alongside potential uses in gas injection and scrap submergence.
Typhoon for low-density scrap and chips
Typhoon addresses a different problem: getting light scrap and machining chips beneath the bath surface instead of letting them remain at the top. Its magnetic circuit generates vortex-like motion that draws material into the melt, supporting heat exchange and recovery during remelting.
Neuman Aluminium's Marktl facility in Austria illustrates the application. The site incorporated a Typhoon chip-submergence system into a furnace modernisation aimed at low-density post-consumer scrap, including lightweight fractions with a bulk density of about 375 kg/m³ that had proved difficult to charge and melt conventionally. Neuman had set a target of one metric ton per hour while the same furnace continued to melt solid charge; 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, can submerge up to five metric tons per hour of machining chips, and allows vortex intensity to be adjusted so that metal keeps moving when scrap or alloying material is not being charged.
A crowded supplier field, not a like-for-like one
The market for furnace stirring, molten-metal circulation and scrap submergence includes established industrial suppliers, though their offerings are not all direct equivalents. ABB supplies its AL-EMS electromagnetic stirring system, with more than 430 installations reported, and in April 2026 announced a further Arconic order for a fifth stirrer at a Hungarian casthouse following earlier units at the same facility. 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 full casthouse equipment. Pyrotek spans a wider range of casthouse equipment, including electromagnetic pump systems and its LOTUSS low-turbulence scrap submergence technology, which pairs a circulation pump with a refractory well; its UK operations include EMP Technologies Ltd., involved in design, sale and installation of metal-melting and circulation systems. Rockwell Automation sits in adjacent industrial automation, supplying furnace and ladle-shop control systems, as in a modernisation project for Mozal Aluminium, rather than a permanent-magnet stirring product.
What shapes the outlook
The common thread is feedstock. If producers keep raising the share of awkward recycled material in their charges, the ability to keep metal moving and to bury light scrap without relying on immersed mechanical components becomes a more relevant selection criterion. Whether permanent-magnet circuits win share will depend less on the physics than on the usual industrial test: enough repeatable operating data at reference sites to persuade buyers who prefer proven equipment.