Calderys created a dedicated product range, ALKON®, to solve the problems associated with wear conditions specific to primary and secondary aluminium furnaces. Our deep understanding of the corundum formation with new modern alloys (containing magnesium, zinc, strontium, etc.) has led to the development of a product range with specific non-wetting additives.
The major impact on the lining in Aluminium furnaces with Aluminium contact are corundum formation, by oxidation and/or corrosion, and mechanical abuse.
Corundum formation by oxidation
At the surface of the bath, molten Aluminium oxidizes with oxygen in the atmosphere: 4/3 Al2 + O2 => 2/3 Al2O3
Liquid aluminium and its alloys react with the refractories to form corundum by a reduction of the silica: 4 Al + 3SiO2 => 2Al2O3+ 3Si
Aluminium reduces the silica in refractories, as well as all other reducible oxides like MgO, with the formation of internal and external corundum. Internal corundum expands and destroys the lining. External corundum decreases the capacity of the furnace and can lead to a complete stoppage. Modern aluminium alloys contain magnesium, silicon, zinc, copper and other elements such as strontium. These additional elements accelerate the corrosion of refractories with corundum growth (for example, unstable alumina-magnesia spinel).
The botoom of the furnace is impacted by the chargiing of big ingots. Prior to working, the surface of the bath as well as the bottom are rackled and cleaned to take away the dross. This mechanical operation with heavy mobile machinery induce, as the chargining, high mechanical abuse.
With the ALKON® range, Calderys has engineered a worldwide best-selling refractory product range with anti-wetting properties and high mechanical strength. Thanks to special additives, these low porosity dense castables are not wetted by modern alloys. They also demonstrate high mechanical strength to withstand the mechanical abuse during charging, cleaning, and de-drossing of the metal.If you want to know more, contact our Aluminum Industry Expert!
Our mission is to help you meet your ever increasing production and productivity targets, whilst protecting the safety of your people and the integrity of your equipment. Our focus is to deliver safe, reliable and high performing refractory solutions customized to your needs. Our international production and sales facilities allow us to develop and deliver customized solutions based on monolithic and ready shape monolithic refractory materials worldwide in a fast, efficient, and safe manner.
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