Aluminium casthouses are being asked to raise their use of recycled metal without losing melt quality, recovery or throughput, and that pressure is drawing attention to how molten metal is moved inside furnaces. Zmag America, Ltd., which works in a specialised segment of casthouse technology, is positioning a family of permanent-magnet systems — MagStir for furnace stirring, MagPump for circulation and Typhoon for scrap submergence — as alternatives to equipment that relies on components immersed in the melt.
The operating problem is twofold. Lightweight scrap, machining chips and other low-density fractions are difficult to feed into conventional melting furnaces, so efficient charging and submergence become decisive for recycling performance. At the same time, temperature and chemical composition must remain consistent across the bath to hit specification, which places demands on circulation and heat transfer while keeping process interruptions and metal loss low. Mechanical pumps, although widely used, depend on immersed rotating parts that deteriorate through contact with molten aluminium, dross accumulation and refractory debris.
From eddy-current separation to molten metal
Zmag's background is in the industrial application of magnets and magnetic circuits, including commercialisation of eddy-current separation for recovering non-ferrous metals from mixed material streams. The company later expanded into molten-metal applications and developed its patented zPMC (Zmag Permanent Magnetic Circuit), the platform behind equipment that stirs, circulates and submerges material in aluminium. Rather than using a conventional electromagnetic stirring arrangement, zPMC employs a permanent magnetic circuit to generate the field that drives metal movement — an effect the company describes as a virtual impeller, because circulation is produced without immersed mechanical impellers.
Adoption has been slowed by familiarity rather than performance, according to Eishin Takahashi, president of Zmag America, who told AL Circle in an August 2025 interview that producers globally tend to be conservative and feel 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, offered in configurations for furnaces of 15 to 200 metric tons, and is intended to homogenise temperature and alloy composition without adding moving parts to the molten-metal environment. New Zealand Aluminium Smelters installed it in a casting furnace and later extended its use to additional furnaces; a technical case study published in 2017 reported improved temperature control during furnace preparation. Rio Tinto-operated Boyne Smelters in Queensland fitted a MagStir unit to a casthouse furnace in 2019.
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; the company reported smooth running, reduced disturbance of the metal surface and avoidance of the splashing seen with conventional pumping as the furnace level fell during draining. The technology was also presented at TMS 2023, where its use in side-well, multi-chamber furnaces and possible roles in gas injection and scrap submergence were discussed.
Typhoon addresses the scrap-feeding bottleneck, drawing light scrap and machining chips beneath the surface with a vortex generated by its magnetic circuit to support heat exchange and recovery during remelting. At Neuman Aluminium's Marktl facility in Austria, the chip-submergence system was added during a furnace modernisation to handle low-density post-consumer fractions of roughly 375 kg/m³. Neuman had targeted one metric ton per hour while continuing to melt solid charge in the same furnace; in operation the unit processed almost twice the planned scrap quantity within the expected time without disrupting normal melting, with low operator involvement and, according to the company, no negative impact on melt or finished-product quality. Zmag cites consumption of 5–15 kW including the air-cooling blower, submergence of up to five metric tons per hour of machining chips, and adjustable vortex intensity so metal keeps moving when no scrap or alloying material is being charged.
A crowded supplier field
Competing offerings are not all direct equivalents. ABB's AL-EMS electromagnetic stirring system has more than 430 installations worldwide, 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 supplies the L.E.C. (Low Energy Consumption) stirrer for melting and holding furnaces alongside remelting and complete casthouse equipment. Pyrotek covers electromagnetic pump systems and its LOTUSS low-turbulence scrap submergence technology, and its UK operations include EMP Technologies Ltd., which designs, sells and installs metal-melting and circulation systems using electromagnetic pumps. Rockwell Automation sits in the adjacent automation segment, supplying furnace and ladle-shop control systems such as those provided for Mozal Aluminium's casthouse modernisation.
Zmag's argument is that as producers take on more challenging recycled feedstock, the ability to manage molten-metal movement without immersed mechanical components becomes a more relevant consideration — a claim the performance of its own installations will continue to test.