Aluminum casthouses are under pressure to raise their use of recycled metal without sacrificing melt quality, recovery rates or production efficiency. Lightweight scrap, machining chips and other low-density material are difficult to charge into conventional melting furnaces, which makes efficient scrap feeding and submergence central to recycling performance. Consistent temperature and chemical composition across the molten bath must also hold, so circulation and stirring equipment has to support heat transfer and metal movement while limiting process interruptions and metal loss. Conventional mechanical pumps, though widely used, depend on immersed rotating components that degrade through contact with molten aluminum, dross and refractory debris.
Zmag America, Ltd. works in that specialized segment, developing magnetic engineering solutions for molten metal circulation, furnace stirring and scrap recovery. Its background lies in industrial magnets and magnetic circuits, including commercialization of eddy-current separation for recovering non-ferrous metals from mixed streams. The company later moved into molten-metal applications and developed its patented zPMC (Zmag Permanent Magnetic Circuit) as the basis for equipment that stirs, circulates and submerges material in molten aluminum.
Permanent magnets instead of electromagnets
The approach differs from conventional electromagnetic stirring: zPMC uses a permanent magnetic circuit to generate the field that moves the molten metal rather than a conventional electromagnetic arrangement. Zmag describes the resulting movement as a virtual impeller, allowing circulation without immersed mechanical impellers. Adoption barriers remain. In an August 2025 interview with AL Circle, Eishin Takahashi, President of Zmag America, cited limited familiarity with the technology as an obstacle in the United States, noting that aluminum producers globally "tend to be conservative and feel more comfortable with equipment and processes they are already familiar with."
Three product lines
- MagStir is a non-contact stirring system for melting and holding furnaces that moves the bath to homogenize temperature and alloy composition. Zmag offers configurations for furnaces of 15 to 200 metric tons, and the non-contact principle removes the immersed mechanical stirring component. New Zealand Aluminium Smelters installed the technology in a casting furnace and later extended it to additional furnaces; a 2017 technical case study 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 approach to pumping and circulation, fitting 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. At the TANDEM Division of US secondary producer TST Inc. in Fontana, California, a seven-week trial replaced an existing mechanical pump; the company described smooth operation, reduced disturbance to the molten-metal surface and avoidance of the splashing seen with conventional pumping as furnace metal level fell during draining. The technology was presented at TMS 2023, where its use in side-well, multi-chamber furnaces was discussed along with potential for gas injection and scrap submergence.
- Typhoon targets scrap submergence and chip melting, drawing lightweight scrap and machining chips beneath the surface with a vortex-like movement that supports heat exchange and recovery. At Neuman Aluminium's Marktl facility in Austria, the system formed part of a furnace modernization aimed at low-density post-consumer scrap, including fractions with bulk density of about 375 kg/m³. Neuman set a target of one metric ton per hour while continuing to melt solid charge in the same furnace; the Typhoon processed almost twice the planned quantity within the expected time without disrupting normal operations, 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.
A crowded supplier landscape
Several established suppliers serve furnace stirring, circulation and scrap submergence, though not all are direct equivalents. ABB supplies its AL-EMS electromagnetic stirring system, reporting more than 430 installations, and in April 2026 announced an order from Arconic for a fifth stirrer at its Hungarian casthouse. Presezzi Extrusion Group offers the L.E.C. (Low Energy Consumption) Stirrer through its Melting Technology division. Pyrotek covers electromagnetic pump systems and LOTUSS low-turbulence scrap submergence, which uses a circulation pump and refractory well; its UK operations include EMP Technologies Ltd. Rockwell Automation sits in adjacent industrial automation with furnace and ladle-shop control systems, such as work for Mozal Aluminium's casthouse.
As producers take on more difficult recycled feedstock, managing molten-metal movement without conventional immersed mechanical parts may become a more relevant consideration for casthouses.