Abstract: Calcium aluminate desulphurization flux for RH process was designed to avoid the corrosion and storage problem of CaO-CaF2 flux. The Al2O3 content was set a range of 33 %-37 % in accordance with slagsteel sulphur ratio and melting time, the residual slag inside chamber was also taken into consideration. The optimized range of particle size was between 3-5 mm. The flux was put into production trials and the result was evaluated. It was concluded that the desulphurizing effect had a strong correlation with initial sulphur content and volume of flux addition. The regression analysis showed that deep desulphurization is easier to be achieved if the initial sulphur content is lower than 30×10^-6, or it will be much harder on the contrary.  Compared to  CaO-CaF2 flux, the alloy yield has been improved when using calcium aluminate desulphurization flux. 

Key words: calcium aluminate, RH refining, deep desulphurization, dynamic analysis for desulphurization