Aluminium casthouses are under pressure to raise their use of recycled metal without losing melt quality, recovery rates or production efficiency. Lightweight scrap fractions, machining chips and other low-density materials are hard to charge into conventional melting furnaces, so efficient feeding and submergence have become central to recycling performance. Consistent bath temperature and chemistry are equally critical, which places demands on circulation and stirring equipment to support heat transfer and metal movement while limiting interruptions and metal loss.
Conventional mechanical pumps rely on immersed rotating parts that can degrade through contact with molten aluminium, dross build-up and refractory debris. Zmag America, Ltd. works in this specialised corner of casthouse technology, developing magnetic systems for molten-metal circulation, furnace stirring and scrap recovery.
From eddy-current separation to molten metal
The company's background is in industrial magnets and magnetic circuits, including commercialisation of eddy-current separation used to recover non-ferrous metals from mixed streams. It 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 aluminium. Instead of a conventional electromagnetic stirring arrangement, the zPMC uses a permanent magnetic circuit to create the field that moves the metal. Zmag describes the resulting motion as a virtual impeller, since circulation is produced without immersed mechanical impellers.
Adoption has been slowed by familiarity rather than performance, according to Eishin Takahashi, President of Zmag America. In an August 2025 interview with AL Circle he said aluminium producers globally tend to be conservative and prefer equipment and processes they already know.
MagStir for furnace homogenisation
MagStir is a non-contact stirring system for melting and holding furnaces, using the permanent magnetic circuit to move the bath and homogenise temperature and alloy composition. Configurations cover furnaces from 15 to 200 metric tons. Because there is no immersed stirring component, casthouses can add circulation without putting further moving parts into the molten-metal environment. New Zealand Aluminium Smelters installed the system in a casting furnace and later extended it to other furnaces; a 2017 technical case study reported better temperature control during furnace preparation. Rio Tinto-operated Boyne Smelters in Queensland, Australia, fitted a MagStir unit to a casthouse furnace in 2019.
MagPump as a circulation alternative
MagPump applies the same approach to pumping and circulation and is designed to fit 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 in a production furnace. Zmag reports smooth operation and reduced disturbance of the molten-metal surface, and TST plant management 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 side-well, multi-chamber furnace applications were discussed alongside potential uses in gas injection and scrap submergence.
Typhoon targets low-density scrap
Typhoon addresses scrap submergence and chip melting by drawing light scrap and machining chips below the bath surface. Its magnetic circuit creates a vortex-like movement that pulls material into the melt, supporting heat exchange and recovery during remelting. At Neuman Aluminium's Marktl facility in Austria, a Typhoon chip-submergence system formed part of a furnace modernisation aimed at low-density post-consumer scrap, including fractions with a 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 system processed almost twice the planned quantity within the expected time without disrupting normal operations, with low operator involvement and no reported negative effect on melt or finished-product quality. Zmag states the unit runs 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.
A crowded equipment field
Other suppliers serve the same functions, though not always with equivalent technology. ABB's AL-EMS electromagnetic stirring system is used in melting, holding and alloying furnaces and has more than 430 installations; in April 2026 ABB announced a further Arconic order for a fifth stirrer at a Hungarian casthouse. Presezzi Extrusion Group's Melting Technology division offers the L.E.C. low-energy stirrer alongside remelting and casthouse equipment. Pyrotek supplies electromagnetic pump systems and its LOTUSS low-turbulence scrap submergence technology, which combines a circulation pump with a refractory well; its UK operations include EMP Technologies Ltd. Rockwell Automation works in adjacent industrial automation, including furnace and ladle-shop control systems, rather than permanent-magnet stirring hardware.
As producers take on more difficult recycled feedstock, managing molten-metal movement without immersed mechanical components is likely to remain a live consideration in casthouse equipment selection.