Aluminium casthouses are under pressure to raise their use of recycled metal without sacrificing melt quality, recovery rates or production efficiency — a combination that places new demands on furnace circulation, pumping and scrap-charging equipment. Zmag America, Ltd., which develops magnetic systems for molten-metal circulation, furnace stirring and scrap recovery, is positioning its permanent-magnet technology as an alternative to immersed mechanical hardware.
The problem starts with feedstock. Lightweight scrap, machining chips and other low-density post-consumer material are difficult to introduce into conventional melting furnaces, so efficient feeding and submergence become essential to recycling performance. Holding a consistent temperature and chemical composition across the bath is equally critical for specification-compliant metal, which means circulation and stirring equipment must support heat transfer and metal movement while limiting process interruptions and metal loss. Conventional mechanical pumps depend on immersed rotating components that can deteriorate through contact with molten aluminium, dross accumulation and refractory debris.
From eddy-current separation to a virtual impeller
Zmag traces its roots 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) generates the field that moves the metal, producing circulation without a conventional immersed impeller — what the company describes as a virtual impeller. 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, offered in configurations for 15 to 200 metric tons of capacity. Its non-contact principle removes the immersed stirring component, making it an option for casthouses that want improved melt 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 technical case study published in 2017 reported improvements in temperature control during furnace preparation. Rio Tinto-operated Boyne Smelters in Queensland, Australia fitted a MagStir unit to a casthouse furnace in 2019.
MagPump extends the approach to pumping and circulation, fitting into a standard pump well without furnace modification. It has no physical impeller and is marketed as a nearly hands-free system with no consumable parts and minimal downtime. At the TANDEM Division of US secondary producer TST Inc. in Fontana, California, a seven-week trial saw MagPump replace an existing mechanical pump in a production furnace; the account describes 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 metal level fell during draining. The technology was also presented at the TMS 2023 Annual Meeting and Exhibition, where its use in side-well, multi-chamber furnaces was discussed alongside potential duties such as gas injection and scrap submergence.
Typhoon targets scrap submergence and chip melting, using a magnetic circuit to create vortex-like movement that draws light scrap and chips beneath the bath surface to support heat exchange and recovery. At Neuman Aluminium's Marktl facility in Austria, the system formed part of a furnace modernisation aimed at low-density post-consumer scrap, including fractions of roughly 375 kg/m³. Neuman set a target of one metric ton per hour while continuing to melt solid charge in the same furnace; in operation the unit processed almost twice the planned 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 says Typhoon operates 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 so metal keeps moving between charges.
A crowded supplier field
The segment includes established suppliers whose products are not all direct equivalents. ABB's AL-EMS electromagnetic stirring system has more than 430 installations, and in April 2026 the company announced a further Arconic order 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, while Pyrotek supplies electromagnetic pump systems and its LOTUSS low-turbulence scrap submergence technology, which relies on a circulation pump and refractory well. Rockwell Automation works in adjacent furnace and ladle-shop control and automation rather than permanent-magnet stirring.
Whether non-contact magnetic systems displace immersed hardware will depend largely on how quickly casthouses take on harder recycled feedstock — the condition under which avoiding conventional mechanical components in the melt becomes a more relevant consideration.