Aluminium casthouses are being asked to raise their use of recycled metal without giving up melt quality, recovery rates or production efficiency, a combination that puts pressure on how scrap is fed, submerged and circulated inside the furnace.
Lightweight scrap, machining chips and other low-density fractions are difficult to introduce into conventional melting furnaces, so efficient feeding and submergence become central to recycling performance. Holding consistent temperature and chemical composition across the molten bath is equally critical, and the equipment responsible for circulation and stirring must support heat transfer and metal movement while limiting process interruptions and metal loss.
Conventional mechanical pumps, although widely used, depend on immersed rotating components that deteriorate through contact with molten aluminium, dross accumulation and refractory debris. Zmag America, Ltd. works in this specialised corner of casthouse technology, developing magnetic engineering solutions for molten-metal circulation, furnace stirring and scrap recovery.
From eddy currents to molten metal
Zmag's technical base is the industrial application of magnets and magnetic circuits. The company traces its history 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, or Zmag Permanent Magnetic Circuit, is the platform for equipment that stirs, circulates and submerges material in molten aluminium.
The distinction from conventional electromagnetic stirring matters. Rather than an electromagnetic stirring arrangement, zPMC uses a permanent magnetic circuit to generate the field that moves the metal. Zmag describes the resulting movement as a virtual impeller, producing circulation without immersed mechanical impellers.
Familiarity, rather than physics, appears to be the main obstacle. In an August 2025 interview with AL Circle, Zmag America president Eishin Takahashi named limited familiarity with the technology as a barrier to wider US adoption, observing that aluminium producers around the world tend to be conservative and to prefer equipment and processes they already know.
MagStir, MagPump and Typhoon
MagStir is a non-contact stirring system for melting and holding furnaces, generating movement in the bath to homogenise temperature and alloy composition. Configurations cover furnaces of 15 to 200 metric tons, and because there is no immersed mechanical stirring component, casthouses can improve 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 reported better temperature control during furnace preparation. A unit was also fitted to a casthouse furnace at Rio Tinto-operated Boyne Smelters in Queensland in 2019.
MagPump applies the same approach to pumping and circulation. It fits a standard pump well without requiring furnace modification, uses 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 furnace used for aluminium production. The published findings described smooth operation and reduced disturbance to the molten-metal surface, and TST plant management reported that 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 addresses scrap submergence and chip melting. Its magnetic circuit creates a vortex-like movement that draws lightweight scrap and machining chips beneath the surface instead of letting them remain at the top of the bath, supporting heat exchange and recovery during remelting. At Neuman Aluminium's Marktl plant in Austria, a Typhoon chip-submergence system was folded into 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. Neuman had targeted one metric ton per hour while continuing to melt solid charge in the same furnace; the system processed almost twice the planned scrap quantity within the expected time without disrupting normal operations, with low operator involvement and no reported impact on melt or finished-product quality. Zmag cites consumption of 5–15 kW including the air-cooling blower, a submergence capacity of up to five metric tons of machining chips per hour, and adjustable vortex intensity that can keep the bath moving when no scrap or alloying material is being charged.
A crowded supplier field
Several established suppliers serve furnace stirring, molten-metal circulation and scrap submergence, although their products are not all direct equivalents. ABB's AL-EMS electromagnetic stirring system has been deployed across a substantial global base of more than 430 installations, and in April 2026 the company announced a further Arconic order for a fifth stirrer at a Hungarian casthouse. Presezzi Extrusion Group, through its Melting Technology division, offers the L.E.C., or Low Energy Consumption, Stirrer for melting and holding furnaces alongside remelting and casthouse equipment. Pyrotek supplies electromagnetic pump systems and LOTUSS, which pairs a circulation pump with a refractory well to submerge light scrap; its UK operations include EMP Technologies Ltd., which designs, sells and installs metal-melting and circulation systems built around electromagnetic pumps. Rockwell Automation sits in adjacent industrial automation, supplying furnace and ladle-shop control systems, as in its modernisation work for Mozal Aluminium, rather than a like-for-like permanent-magnet stirrer.
For casthouses moving toward harder-to-process recycled feedstock, the question is whether molten-metal movement can be managed without conventional immersed mechanical components. That is the case Zmag is making, and the operating record at a handful of smelters and secondary plants is what it will be judged on.