Aluminium casthouses are under pressure to use more post-consumer scrap without sacrificing melt quality, recovery rates or production efficiency. Lightweight scrap, machining chips and other low-density fractions are difficult to charge into conventional melting furnaces, while immersed mechanical pumps and impellers must contend with molten aluminium, dross accumulation and refractory debris. Zmag America is advancing permanent-magnet engineering as a non-contact alternative for three closely related duties: furnace stirring, molten-metal circulation and scrap submergence.
Why non-contact movement matters
Zmag's technical foundation is the industrial application of magnets and magnetic circuits. Its history includes eddy-current separation, used to recover non-ferrous metals from mixed streams, before the company moved into molten-metal applications. Its patented zPMC permanent magnetic circuit is the basis for equipment that stirs, circulates and submerges material in molten aluminium. The company contrasts this with conventional electromagnetic stirring: instead of relying on an electromagnetic arrangement, its system uses a permanent magnetic circuit to generate the field that moves the metal. Zmag describes the resulting movement as a virtual impeller, because circulation can be produced without an immersed mechanical impeller.
The operational logic is straightforward. Removing immersed rotating parts can reduce exposure to aggressive molten metal, dross and refractory debris. That does not prove lower maintenance or better economics across a casthouse, and no fleet-wide comparative data on downtime, metal loss or energy use is presented. It does explain why non-contact movement is being presented as a practical option as charge mixes become more difficult. In an August 2025 interview, Eishin Takahashi, president of Zmag America, identified limited familiarity as a barrier in the United States and said aluminium producers tend to be conservative, preferring equipment and processes they already know.
Three products, three operating duties
MagStir is a non-contact stirring system for melting and holding furnaces. It uses the permanent magnetic circuit to create movement in the bath and support homogenization of temperature and alloy composition. Zmag offers configurations for furnaces from 15 to 200 metric tons. Because there is no immersed mechanical stirring component, the system is aimed at casthouses that want better 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 2017 technical case study reported improvements in temperature control during furnace preparation, and a MagStir unit was fitted to a Rio Tinto-operated Boyne Smelters casthouse furnace in Queensland in 2019.
MagPump extends the same approach to pumping and circulation. It is designed to fit a standard pump well without furnace modification and, unlike a conventional mechanical pump, has no physical impeller. Zmag markets it as a nearly hands-free option with no consumable parts and minimal downtime. At the TANDEM Division of TST Inc., a secondary aluminium producer in Fontana, California, MagPump replaced an existing mechanical pump during a seven-week trial. The reported findings described smooth operation and less disturbance of the molten-metal surface. TST plant management also reported that the system avoided the splashing seen with conventional pumping as the furnace metal level fell during draining. The technology was presented at TMS 2023 in connection with side-well, multi-chamber furnaces, with potential also cited for gas injection and scrap submergence.
Typhoon addresses scrap submergence and chip melting. It is designed to introduce lightweight aluminium scrap and machining chips below the surface instead of letting them remain at the top of the bath. Its magnetic circuit generates a vortex-like movement that draws material into the melt, supporting heat exchange and recovery during remelting. At Neuman Aluminium's Marktl facility in Austria, a Typhoon chip-submergence system was included in a furnace modernization intended to expand processing of low-density post-consumer scrap. The targeted material included lightweight fractions with a bulk density of about 375 kg/m³, which had been difficult to charge and melt conventionally.
Neuman set a target of processing one metric ton per hour while continuing to melt solid charge in the same furnace. During operation, the Typhoon system processed almost twice the planned scrap quantity within the expected time without disrupting normal furnace operations, according to the published account. The company also reported low operator involvement and no negative impact on melt or finished-product quality. 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. Its vortex intensity can be adjusted to suit operating requirements and to maintain molten-metal movement when scrap or alloying material is not being charged.
A competitive field with different technical routes
The market for furnace stirring, circulation and scrap submergence is not empty. ABB supplies its AL-EMS electromagnetic stirring system for melting, holding and alloying furnaces and reports more than 430 installations. In April 2026 it announced a further order from Arconic for a fifth stirrer at a Hungarian casthouse. Presezzi Extrusion Group offers the L.E.C. low-energy-consumption stirrer through its Melting Technology division. Pyrotek has electromagnetic pump systems and LOTUSS low-turbulence scrap submergence technology, while its UK operations include EMP Technologies. Rockwell Automation sits in the adjacent industrial-automation segment, including furnace and ladle-shop control systems such as work for Mozal Aluminium.
These offerings are not all direct equivalents. Zmag's differentiation rests on a permanent magnetic circuit rather than a conventional electromagnetic stirring arrangement, and on product designs intended to avoid immersed impellers. The competitive question is therefore not simply whether magnetic movement works, but whether a given configuration fits a furnace, charge mix and operating routine better than established mechanical or electromagnetic equipment. Installed base, service familiarity and operator confidence matter, especially in a sector that Takahashi describes as conservative.
What adoption will depend on
For casthouses, the practical test is plant-specific. Furnace geometry, capacity, scrap mix, available pump wells, maintenance access, operator burden, metal loss and compatibility with existing controls all shape the business case. No payback periods, independent lifecycle comparisons or standardized energy data across technologies are presented. The strongest evidence is application-specific: stirring references at NZAS and Boyne, a seven-week pumping trial at TST, and a chip-submergence installation at Neuman. These are useful operational data points, but they are limited in number and largely reported by the supplier or the adopting company.
The broader signal is that recycled feedstock is becoming more varied and harder to handle. Light scrap and chips can carry low bulk density and poor submergence characteristics, and conventional charging can struggle to introduce them efficiently. Non-contact magnetic systems may become more relevant where they can demonstrate repeatable recovery, stable melt quality and low interruption rates. They will not displace established equipment by default. Zmag's challenge is to convert a clear technical proposition into validated, repeatable casthouse results that operators can compare with familiar alternatives.