In the eighties, Kawasaki Steel Corp. developed the KTB process, combining the RH TOP lance oxygen blowing function with the new idea of putting heating energy into the RH vessel by using the post-combustion effect, burning CO emerging from the liquid steel to CO2. Using the oxygen supplied by the TOP lance, forced decarburisationas well as chemical heating of the liquid steel by aluminium combustion became standard practices in many steel

plants. This process proved to be most suitable for mass production of ultra low carbon steel with consistently high quality. Consequently, many RH degassers built by SMS Mevac have since been using this technology.

In the nineties, lance types with multiple functions were developed to incorporate further features with new operational benefits.
Such features include:

• short lances, blowing from a large distance onto the liquid steel, thus simplifying the equipment installed and allowing the installation of TOP lances even in steel shops with restricted headroom above the RH
• powder blowing for decarburisation, desulphurisation or dephosphorisation
• gas heating for adjustment of proper vessel refractory temperature and skull removal

More than 20 TOP lances have been installed so far, many of them incorporating the multiple function design.