AT THE HEART OF STEEL REFINING
In secondary metallurgy, the slag design is the key to metallurgical efficiency: it guarantees the quality and cleanliness of the steel in addition to consistent performance. The selection of the flux used in the process, and especially its origin, purity and consistency, has a considerable impact on the control of slag composition and formation. Thanks to its special physical and chemical properties, synthetic calcium aluminate flux achieves rapid slag formation and efficient steel refining in secondary metallurgy as well as in continuous casting tundish and in foundries.
Kerneos invented the first calcium aluminate in 1908 and also developed the related fusion manufacturing process. It was also the first company to study the use of calcium aluminate as a metallurgical flux. Many steelmakers use these products today with great success. They offer considerable practical advantages such as improved steel cleanness, high productivity, environmental protection and cost optimisation.
A FLEXIBLE AND CREATIVE SLAG COMPONENT
Synthetic calcium aluminate flux are designed by steelmakers and metallurgists in order to meet their specific needs for better efficiency in steel mills. Excellent results are also obtained in foundries and for the production of certain ferrous alloys.
The properties of calcium aluminate flux, its purity and unique consistency make it valuable in various applications in the metallurgy industry, especially in secondary metallurgy which is oriented towards quality steel production. Calcium aluminates flux are often used when improved performance is sought: cost reduction, improved quality and productivity, environmental protection.
The permanent quest for higher process efficiency and for improved steel quality leads steelmakers to develop new metallurgical tools and to revisit their slag formation process. Introducing a new reagent makes it possible for steelmakers to optimise the slag formation and its composition and to obtain the desired improvement in performance. The use of calcium aluminate flux leads to the improvement of traditional slag practices and the achievement of superior performance:
Rapid slag formation
Thanks to their low melting point (< 1 325 – 1 375 °C), calcium aluminate flux melts upon contact with steel and can dissolve other reagents like lime if additions are carefully performed. It is thus possible to obtain a fluid and homogenous slag as soon as the ladle is filled at the end of tapping.
Improved desulphurisation kinetics
The rapid formation of slag enables the initiation of desulphurisation reactions as soon as the ladle is filled. The observed increase of desulphurisation kinetics can either achieve lower sulphur content and therefore higher steel quality or higher productivity thanks to shorter treatment time or costs savings thanks to the use of cheaper raw materials containing more sulphur.
Steel cleanliness
The composition of calcium aluminate flux is similar to the final slag composition. So it can start trapping non-metallic inclusions as soon as the ladle is filled. It is therefore possible to remove these impurities when they are formed and to reduce the need for subsequent treatment.
Increased productivity
The consistency of calcium aluminate flux increases predictability and reproducibility of performance. Thus, the majority of the reagents is added during tapping, allowing the rapid formation of a fluid and homogeneous slag. By this way, the refining process starts earlier, is much faster and thus the overall processing time is reduced.
Cost reduction
Better alloys yields and globally optimised reagent additions, reduced corrosion of the refractory lining thanks to the elimination of fluoride flux and a shorter processing time represent substantial cost savings which make the operation very profitable for steelmakers.
Increased durability for refractory materials
Thanks to its high magnesia content (13%), the OPTIMET™ product line contributes to the optimisation of the ladle lining lifetime as well as the increased efficiency of secondary metallurgy.
PROVEN METALLURGICAL FLUX
On the basis of its expertise and the detailed studies on slag processing carried out with metallurgists, Kerneos has developed specialised lines of metallurgical flux available worldwide in bulk or in various packaging suited to the needs of its customers:
LDSF®: a range of fused calcium aluminate flux
LDSF® has been used for over 25 years by many steelmakers in steel production, with all types of metallurgical production equipment. It is a proven product in the metallurgy industry, with LDSF® RG, our standard flux and LDSF® LT , a low titanium / low impurities flux.
OPTIMET™: a range of sintered calcium magnesium aluminate flux
Kerneos has designed the patented OPTIMET™ product line, flux with a high MgO (13 %) content to improve the refractory lining lifetime and to give the benefit of a calcium aluminate flux.
