Aluminium casthouses are under pressure to raise their use of recycled metal without giving up melt quality, recovery rates or production efficiency, a combination that places new demands on the equipment used to move, stir and charge molten aluminium.
Lightweight scrap, machining chips and other low-density materials are hard to introduce into conventional melting furnaces, which makes efficient feeding and submergence central to recycling performance. Keeping temperature and chemical composition consistent across the bath matters just as much, so circulation and stirring systems must support heat transfer and metal movement while limiting process interruptions and metal loss. Conventional mechanical pumps depend on immersed rotating components that degrade through contact with molten aluminium, dross accumulation and refractory debris.
From eddy-current separation to molten metal
Zmag America, Ltd. works in this specialised corner of casthouse technology, developing magnetic engineering solutions for molten-metal circulation, furnace stirring and scrap recovery. The company traces its origins to magnetic engineering and the commercialisation 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) underpins equipment that stirs, circulates and submerges material in molten aluminium.
The distinction from conventional electromagnetic stirring is central: zPMC uses a permanent magnetic circuit to generate the field that moves the metal, producing what the company calls a virtual impeller, or circulation without immersed mechanical impellers. In an August 2025 interview with AL Circle, Zmag America president Eishin Takahashi identified limited familiarity with the technology as a barrier to wider adoption in the United States, observing that aluminium producers globally tend to be conservative and more comfortable with equipment and processes they already know.
MagStir, MagPump and Typhoon
MagStir is a non-contact stirring system for melting and holding furnaces that uses the permanent magnetic circuit to homogenise temperature and alloy composition. Configurations cover furnaces of 15 to 200 metric tons. New Zealand Aluminium Smelters installed the system in 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. A MagStir unit was also fitted to a casthouse furnace at Rio Tinto-operated Boyne Smelters in Queensland, Australia, in 2019.
MagPump applies the same approach to pumping and circulation and fits a standard pump well without requiring furnace modification. It has no physical impeller and is marketed as a nearly hands-free option with no consumable parts and minimal downtime. At the TANDEM Division of US secondary producer TST Inc. in Fontana, California, a seven-week trial replaced an existing mechanical pump; the findings described smooth operation and reduced disturbance to the molten-metal surface, and plant management reported that the system avoided the splashing seen with conventional pumping as the furnace metal level fell during draining. Its use in side-well, multi-chamber furnaces was presented at the TMS 2023 Annual Meeting and Exhibition, alongside potential roles in gas injection and scrap submergence.
Typhoon targets scrap submergence and chip melting, drawing lightweight scrap and machining chips beneath the bath surface with a vortex-like movement generated by the magnetic circuit, which supports heat exchange and recovery during remelting. At Neuman Aluminium's Marktl facility in Austria, the system was added in a furnace modernisation aimed at low-density post-consumer scrap, including fractions with a bulk density of about 375 kg/m³ that had challenged conventional charging and melting. Against a target of one metric ton per hour while the furnace continued to melt solid charge, Typhoon processed almost twice the planned scrap quantity within the expected time, with low operator involvement and no reported negative impact on melt or finished-product quality. According to the published technical account, 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, with adjustable vortex intensity that can also keep the metal moving when no scrap or alloying material is being charged.
A crowded equipment field
Several established suppliers compete in furnace stirring, molten-metal circulation and scrap submergence, though not all offer direct equivalents to permanent-magnet equipment. ABB's AL-EMS electromagnetic stirring system has been deployed across more than 430 installations, and in April 2026 the company announced a further order from Arconic for a fifth stirrer at its Hungarian casthouse. Presezzi Extrusion Group's Melting Technology division offers the L.E.C. (Low Energy Consumption) Stirrer for melting and holding furnaces alongside remelting equipment. Pyrotek supplies electromagnetic pump systems and its LOTUSS low-turbulence scrap submergence technology, and its UK operations include EMP Technologies Ltd. Rockwell Automation sits in the adjacent industrial automation segment, supplying furnace and ladle-shop control systems, as in its modernisation work for Mozal Aluminium's casthouse.
As producers take on more difficult recycled feedstock, managing molten-metal movement without immersed mechanical components is likely to become a more relevant consideration, although adoption will still turn on familiarity and a proven operating record.