2017 Volume 57 Issue 4 Pages 706-712
Aimed at the pretreatment for hot metal with varied phosphorus contents, by applying the indirect approach, the distribution ratio of phosphorus between multi phase slags with 6% to 13% P2O5, whose melting points were close to the hot metal temperature, and carbon-saturated molten iron at 1573 K, , were measured. The results demonstrated was determined by the composition of multi phase slags and that at different levels of the P2O5 content, the combination of the (FeO) content and the mass ratio of solid particles to molten slag with which reached the maximum was different. In correspondence with high-P content hot metal, under the condition of about 13% P2O5, a decrease in (%FeO) and a simultaneous increase in solid particles/molten slag mass ratio was benefit to the increase of , and the maximum reached 130. However, when P2O5 content was about 10% and 6%, could only reach 107.98 and 60.7 at most, respectively. The results of microcosmic measurements showed that in quenched multi phase slags, there exist two kinds of precipitates with different phosphorus contents, i.e. the low-P phase (6C2S-mC3P, m=0.6294~1.3400) and the high-P phase (C2S-nC3P, n=1.1064~1.4303), and also 2CaO·SiO2 phase with no phosphorus and CaO–SiO2–FetO slag.