A dynamic mathematical model of the vacuum circulation process for ste
el decarburization was developed, It comprises the process parts of st
eel circulation, decarburization reaction, adjustment of vessel pressu
re with its influence on the carbon equilibrium content, and the oxyge
n pickup from the ladle slag. The model allows to simulate the behavio
ur of all important process values with good accuracy and can be used
for optimization of plant construction and operation as well as for im
provement of process control.