Stirring up efficiencies for new arc furnaces
Partnering is vital to ongoing development of metallurgical processes, says Yang. Because parts of the processes take place at such high temperatures — 1,500 degrees Celsius or more — “you cannot imagine everything that is going on at that temperature.” He says, “You are unaware of a lot of phenomena that are occurring, or of their physical parameters, so a lot of the technology is developed on the basis of experience”. ABB’s database enables a high order of accuracy in its simulations, but still, “every new invention has to be installed somewhere to be proved before you can go further,” says Yang.
Today, steel, aluminum and other metals manufacturers are under multiple pressures: to increase the quality of their products, and reduce the carbon emitted during production, while maintaining competitive pricing. ABB’s electromagnetic stirrers have been developed for a wide variety of furnaces and processes, to increase the energy efficiency and output of metal production and give manufacturers control over their processes which in turn facilitates production of new and stronger alloys.
The greening of steel
The latest electric arc furnaces, for example, show great promise for producing significant volumes of so-called “green steel”. Powered by electricity, they can be run on energy from renewable generation; and traditionally, they have transformed scrap metals into new steel products, taking advantage of steel’s recyclability and lighting the way towards a circular economy for this essential material.
ABB Ability™ Optimold Monitor enables real-time visualization of mold temperature in continuous casting.
In 2022, ABB’s long collaboration with EAF furnace manufacturer Tenova achieved the milestone of final acceptance from steelmaker Acciaieria Arvedi for a record-breaking melting unit with a furnace tapping size of 300 metric tons.
Tenova’s Consteel EAF required an innovative adaptation of ABB’s ArcSave electromagnetic stirring technology, the latest generation of EAF-EMS, to complement its continuous scrap charging system. “We worked together to develop a new concept of how to configure the stirrer for their particular furnace,” says Yang.
The jointly designed product is known as the Consteerrer, which has resulted in a 3.6% reduction in electrical energy consumption (which translates into a 38,000-tonne annual reduction in the plant’s CO2 emissions) at Acciaieria Arvedi; and a 5% productivity increase, alongside a 17% reduction in final oxygen content of the produced steel. Other benefits include increased yield from scrap metals and reduced carry-over slag.
True green steel is produced using direct-reduced iron, which is formed by applying green hydrogen or biogas to draw oxygen out of iron ore, where this process was previously achieved using coke (high-carbon coal). Among ABB Metallurgy’s current R&D projects, says Yang: “We are developing EMS processes that enable us to work efficiently with this new raw material for the arc furnace.”