Desulphurisation with dispersed in-situ phases induced by composite ball explosive reaction during ultra-low carbon steel production in RH degasser

A novel desulphurization technology has been put forward using a dispersed in-situ phases induced by an explosive reaction of a composite ball. A composite ball with this function has been designed and prepared using a laboratory model batch type balling disc (at 12 rev min-1) and the composite ball has been fed at the end of Ruhrstahl-Heraeus refining. The plant trials have been carried out in ANSTEEL and the ruling factors have been analyzed. The results indicate that feeding composite ball in RH degasser is a novel technology and the sulphur in the molten steel can be removed from 30 ×10-6~50 ×10-6 to less than 10 ×10-6~20 ×10-6 with desulphurization rate more than 50%. The desulphurization effect is perfect and stable. There is few carbon pick up in molten steel. The feeding amount of the composite ball is about 5kg per ton steel. It is suitable for deep desulphurization in RH degasser.