Abstract: In order to solve the problem of the instability of slag quantity and end slag composition in the aluminium killed steel production process with LF in some factory, a deoxidation slagging model was proposed based on mass balance in SPHC production and aluminum deoxidization process. The model was written as offline test software by VB6.0, and it was run to test the result with input the field smelting data of SPHC. The results showed that, the stability of materials quantity and end slag composition was promoted greatly, and the stable refining process and good molten steel quality were well. The mass of slag calculated kept stable since the mean square deviation was decreased to 0.93 from 2.95. The mass of slag formed per ton of steel could reduce 2.41 kg in the calculation when compared with the factory.

Key words: LF, slag-forming model, secondary refining, deoxidization process