In addition to general efficiency gains from temperature harmonisation, EMS has an additional benefit; namely, full power stirring that facilitates the use of ‘hard’ alloys with a high melting point for alloying. This has been implemented successfully by one of ABB’s customers in Northern Europe.
The customer is a primary melter with a very small percentage of titanium in its products. Their furnace previously used a master alloy containing 5-10% titanium and then switched to a cheaper harder master alloy with an 80% titanium content.
This alloy has a very high melting point of around 1,600°C, compared to the melting point of 660–700°C for aluminium. The customer found that its mechanical ‘robot’ stirrer was resulting in the master alloy dissolving very slowly.
Frustrated by the limitations of the mechanical stirrer – which required extensive maintenance – the company replaced it with an ABB AL-EMS solution. This resulted in a much faster dissolve of the 80% titanium alloy in the furnace, with associated cost savings due to the significantly lower cost of the titanium master alloy.
Recent research summarised in my paper ‘Optimized Electromagnetic Stirring in Melting and Holding Furnaces’ recently published in the journal Light Metals, demonstrates that stronger stirring power in aluminium furnaces allows for more cost-effective alloying with hard, and traditionally cheaper, master alloys, as well as a safer and more consistent alloying praxis, with improved analysis accuracy.