Abstract: Effect of alumina on hot metal desulphurization has been investigated by hot metal desulphurization experiment using CaO based desulphurization flux with various Al2O3 contents. The results indicated that the desulphurization ratio and apparent desulphurization rate constant increased with increasing the Al2O3 contents, following by a decrease with further increasing the Al2O3 contents. The utilization of lime increased with the increase of the Al2O3 contents. The melting point of the lime and desulphurization production, which was covered the surface of the lime particle, was lower with the increase in the Al2O3 contents. An excess of alumina should reduce the ratio of the CaO content, which was the main desulphurization component, and weaken the beneficial effect of CaF2 in the desulphurization flux. It is suggested that the Al2O3 mass fraction in desulphurization flux should be 10 % to get better desulphurization effect and higher utilization ratio of the flux.

Key words: CaO based desulphurization flux, alumina, hot metal desulphurization, desulphurization rate