Abstract An experimental test is carried out on the 70t converter in Masteel to study the law of middle period dephosphorization in the smelting period. It is found that the dephosphorization rate is slow in the early and middle period of smelting and the content of the final P in steel cannot reach the standard due to the low oxidation of slag. The content of the final P in steel can be controlled within 0.02% by adding ore to the molten bath in the middle period and raising the lance position. The experimental test shows that the dephosphorization can still be achieved by a large margin if appropriate slag conditions are maintained in the middle period when the C and O reactions are strong. By theoretical calculation, it is concluded that the slag content should be controlled between 15 and 23%, and the basicity of slag should be between 2.5 and 2.8 in the middle period of production. Through the observation of experimental slag by SEM, it is found that the limiting factor of dephosphorization in the middle period under the test conditions is that the dephosphorization speed is too slow due to the low oxidation, rather than the solidification of phosphorus.

中文翻译：

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70t转炉中期脱磷研究

摘要 在马钢70t转炉上进行了实验试验，研究了冶炼中期脱磷规律。发现冶炼前期和中期脱磷速度慢，钢中最终P含量达不到标准，原因是炉渣氧化率低。通过中段向熔池中加入矿石并提高枪位，可将钢中最终P的含量控制在0.02%以内。实验测试表明，在C和O反应强烈的中期，如果保持适当的渣条件，仍然可以实现较大的脱磷。通过理论计算得出炉渣含量应控制在15～23%之间，炉渣碱度应控制在2之间。5和2.8在生产中期。通过扫描电镜对实验渣的观察发现，试验条件下中期脱磷的限制因素是氧化低导致脱磷速度过慢，而不是磷的凝固。