Solidification Behaviour of Slags: The Single Hot Thermocouple Technique

Abstract

With the Single Hot Thermocouple Technique the solidification behaviour of metallurgical slags has been studied, building TTT and CCT diagrams, with in situ observation for melting and solidification under various thermal conditions. Slags in the system CSTNA were studied, analysing the kinetics of crystals growth. Following findings are reported: (i) for the slag CS (%CaO/%SiO 2 = 0.7) no crystal is observed during contin uous cooling even to low cooling rates, but on the other hand intense crystallisation is obtained when increas ing the temperature after reaching a particular range of lower temperatures; (ii) it was observed that the longer the duration of the superheating is, the longer the incu bation times for a slag CST (41 %CaO, 29 %SiO 2 , 30 %TiO 2 ) becomes; (iii) the addition of Na 2 O into the CST slag system shortens intensely the crystals incubation times at TTT diagrams to the range of seconds.