100t 转炉留渣双渣法冶炼高硅高磷铁水试验

针对钢厂铁水硅和磷含量较高的特点,采用转炉留渣双渣冶炼工艺以获得稳定的铁水脱磷率。吹炼3 min后加入石灰和污泥球等造渣材料,供氧强度0～3 min时为2.5m³/（t·min）,3～4.5 min时为3.2m³/（t·min）,温度控制在约1320℃。转炉一次倒渣后,继续吹炼,加入后期造渣料,待一氧化碳体积分数稳定时,适当提高氧枪枪位,促进化渣,并进行终点碳控制。试验结果表明:脱磷期铁水平均脱磷率为58.09%,脱碳期钢水平均脱磷率为85.56%;当半钢温度为1320℃炉渣碱度为2.0,炉渣TFe含量为18%时,在脱磷期能获得较好的铁水脱磷效果;当转炉钢水一倒温度为1580℃,终渣碱度为3.5,炉渣TFe含量为20%时,在脱碳期能够获得较好的脱磷效果;转炉终点P]_e/P]_r为0.90;试验中得到脱磷期和脱碳期炉渣的岩相组成适合铁水脱磷。

Test of High Silicon and High Phosphorus Hot Metal Smelted by Retaining Slag and Double Slag Method at 100 t BOF

In view of the high silicon and phosphorus content of hot metal in a steel works, a converter slag-retaining double-slag smelting process is used to obtain a stable dephosphorization rate of hot metal. The specific process is to add slag-forming materials such as lime and sludge balls after the start of the blowing process for 3 min. The oxygen supply intensity is 2. 5 m³ (t ·min) at 0 ~ 3 min, and 3. 2 m³/( t ·min) at 3 ~ 4. 5 min. The temperature is controlled at about 1320 °C. After the converter has first deslagging, it starts to blow and adds the late slag forming material. When the carbon monoxide in the furnace rises to a stable level, the oxygen lance position is raised appropriately to improve slagging and control the end-point carbon. The test results show that the average dephosphorization rate of hot metal in the dephosphorization period is 58.09% ,and the average dephosphorization rate of molten steel in the decarburization period is 85. 56% ； When the temperature of the semi-steel is 1320 °C ,the basicity of the slag is 2.0,and the TFe content in the slag is 18% ,a better dephosphorization effect can be obtained in the dephosphorization period. When the molten steel temperature of the converter liquid after first deslagging is 1580 °C ,the basicity of the final slag is 3. 5,and the TFe content in the final slag is 20%, a better dephosphorization effect can be obtained in the decarburization period. P]_e/P]_r ratio at the end of the converter is 0. 90. The petrographic composition of the slag during dephosphorization and decarburization poriod from the experiment is suitable for dephosphorization of hot metal.