Aluminum casthouses are under pressure to use more post-consumer 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, so efficient scrap feeding and submergence are becoming more important. The challenge also extends to keeping temperature and chemical composition consistent throughout the molten bath, which requires circulation and stirring that support heat transfer and metal movement while limiting interruptions and metal loss. Conventional mechanical pumps rely on immersed rotating components that can deteriorate through exposure to molten aluminum, dross and refractory debris.
Zmag America, Ltd. works in this specialized part of aluminum casthouse technology, developing magnetic systems for molten-metal circulation, furnace stirring and scrap recovery. Its foundation 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 streams, before expanding into molten-metal applications. Its patented zPMC permanent magnetic circuit underpins equipment that stirs, circulates and submerges material in molten aluminum. Rather than a conventional electromagnetic stirring arrangement, the system uses a permanent magnetic circuit to generate the field that moves the metal. Zmag describes the resulting movement as a virtual impeller, because circulation is generated without conventional immersed mechanical impellers.
A non-contact approach to stirring and pumping
MagStir is Zmag's non-contact stirring system for aluminum melting and holding furnaces. It uses the permanent magnetic circuit to create movement in the bath and support homogenization of temperature and alloy composition. Configurations are available for furnaces from 15 to 200 metric tons. Because it has no immersed mechanical stirring component, it offers casthouses a way to 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 2017 technical case study examined those installations and reported improvements in temperature control during furnace preparation. A MagStir unit was also fitted to a casthouse furnace at Rio Tinto-operated Boyne Smelters in Queensland, Australia, in 2019.
MagPump extends the magnetic approach to molten-metal pumping and circulation. It is designed to fit a standard pump well without furnace modification and, unlike conventional mechanical pumps, uses no physical impeller. Zmag markets it as a nearly hands-free option with no consumable parts and minimal downtime. At the TANDEM Division of US secondary aluminum 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 to the molten-metal surface. TST plant management also reported that the system avoided the splashing seen with conventional pumping as the furnace 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, along with potential applications in gas injection and scrap submergence.
Typhoon targets difficult recycled feedstock
Zmag's Typhoon system focuses on scrap submergence and chip melting. It is designed to introduce lightweight aluminum scrap and machining chips beneath the molten-metal surface instead of leaving them at the top of the bath. Its magnetic circuit generates a vortex-like movement that draws material into the melt, supporting heat exchange and recovery during remelting. At Neuman Aluminium's Marktl facility in Austria, a Typhoon chip-submergence system was incorporated into a furnace modernization project intended to expand processing of low-density post-consumer scrap. The targeted material included lightweight fractions with a bulk density of about 375 kg/m³, which had been difficult to charge and melt in conventional equipment. Neuman set a target of processing one metric ton per hour while continuing to melt solid charge in the same furnace. During operation, the Typhoon system processed almost twice the planned scrap quantity within the expected time without disrupting normal furnace operations, and the company reported low operator involvement and no negative impact on melt or finished-product quality. 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, according to the technical account. Its vortex intensity can be adjusted to suit operating requirements and maintain metal movement when scrap or alloying material is not being charged.
A competitive field with non-identical alternatives
The market for aluminum furnace stirring, molten-metal circulation and scrap-submergence equipment includes several established suppliers, but not all of their products are direct equivalents to Zmag's permanent-magnet approach. ABB supplies its AL-EMS electromagnetic stirring system for melting, holding and alloying furnaces and reports more than 430 installations. In April 2026, ABB announced a further order from Arconic for a fifth stirrer at its Hungarian casthouse, following earlier installations 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 equipment for aluminum remelting and complete casthouse operations. Pyrotek has a broader casthouse equipment portfolio, including electromagnetic pump systems and its LOTUSS low-turbulence scrap submergence technology. Its EMP systems use electromagnetic forces to circulate molten aluminum and support metal transfer and scrap charging, while LOTUSS uses a circulation pump and refractory well to submerge lightweight scrap. Pyrotek's UK operations include EMP Technologies Ltd., which designs, sells and installs metal-melting and circulation systems incorporating electromagnetic pumps. Rockwell Automation operates in the adjacent industrial automation segment rather than offering a like-for-like permanent-magnet stirring product; its aluminum-sector work includes furnace and ladle-shop control systems, as shown by a modernization project for Mozal Aluminium's casthouse.
What determines adoption
The strategic question is whether permanent-magnet systems can win acceptance as casthouses add more challenging recycled feedstock. Zmag's case rests on eliminating immersed impellers, reducing disturbance at the metal surface and enabling scrap submergence without adding moving parts to the bath. Those features matter most where lightweight scrap, chip melting, surface splashing or pump maintenance are constraints. Adoption, however, will depend on more than the principle of non-contact operation. Casthouses must weigh familiarity, integration with existing furnace designs, uptime, metal loss and consistent quality. In an August 2025 interview with AL Circle, Zmag America President Eishin Takahashi identified limited familiarity with the technology as a barrier in the United States and observed that aluminum producers globally tend to be conservative and more comfortable with equipment and processes they already know. The available cases show gradual adoption at specific furnaces rather than wholesale replacement. They also remain site-specific and do not establish like-for-like performance across furnace types. Competing electromagnetic and mechanical systems have longer installation records, and Zmag's claims are largely tied to company descriptions, a technical case study and customer trial accounts. The technology may be most relevant as a targeted tool for circulation, homogenization and scrap submergence, not as a substitute for scrap preparation or furnace control. As recycled feedstock becomes more difficult, that targeted role could become more valuable, but repeatable performance data and broader operating experience will decide how far it travels.