攀钢半钢冶炼转炉脱磷工艺技术研究

Research on dephosphorization technology by semi-steel steelmaking converter of Pan Gang

针对攀钢半钢冶炼时辅料消耗大、终渣氧化性高且脱磷效果不佳的问题,通过对转炉脱磷理论以及冶炼过程脱磷规律的研究,确定了前期脱磷率偏低、中期返干是影响脱磷率的主要因素。通过对终渣岩相的进一步分析,确定了磷在渣中的主要富集相,解释了后期依靠提高炉渣氧化性和增加辅料消耗不能显著提高脱磷率的原因。通过采用"留渣加料"、含铝复合造渣剂造渣以及降低冶炼后期枪位等技术措施,转炉成渣时间由4. 3 min缩短到3. 2 min,返干比例由由56%显著降低到18%,在总渣料消耗平均减少5. 69 kg/t的情况下转炉冶炼全程脱磷率由79. 4%提高到84. 1%,终渣TFe质量分数平均降低2. 49%。通过对脱磷工艺参数的优化,在提高转炉脱磷效率的同时,降低了转炉冶炼成本。

To solve the problem of high slagging materials consumption, high oxidablitiy of slag and low dephosphorization effect, theory of dephosphorization and dephosphorization rules were researched and factors affected dephosphorization rate were confirmed. And according to the lithofacies of slag, enriched phase of phosphorous in slag was found out, reasons of why dephosphorization rate couldn＇t be improved remarkable by high slagging materials consumption and high oxidablitiy were explained. By adopting the measures of ＂slag-remaining charging material＂, aluminiferous-slag former and lower the lance position,slag-forming time was reduced from 4.3 min to 3.2 min, ration of re-dry was reduced remarkably from 56 % to 18 %, total dephosphorization rate was improved from 79.4 % to 84.1% under the condition that total material consumption was reduced by 5.69 kg/t. In addition,TFe content of slag was reduced by 2.49 % on average. According to optimization of dephosphorization parameters,dephosphorization rate was improved and cost of BOF refining was reduced as well.