烧结熔剂用转炉渣中磷元素去除研究

Study on Phosphorus Removal from Converter Slag for Sintering Flux

转炉渣中的磷元素给烧结系统以及炼钢脱磷应用带来不利的因素。岩相及化学分析表明:转炉渣中的难磨相成因与MgO (Fe)和CaFeO3含铁元素高低有关。难磨相中大部分为硅酸二钙,硅酸三钙含量偏少,导致转炉渣早期水化速度慢、强度低,而后期强度高。而磷元素主要赋存于铁酸钙中,其次在石灰石中,同时,TFe与P含量相背驰。转炉渣中铁元素含量增加,磷含量随之减少,通过细粒级的选别将磷元素从含铁料中去除,低磷转炉渣能更好地应用于冶炼烧结系统中去。

Phosphorus in converter slag is bad for sintering system and dephosphorization in steelmaking. The petrographic and chemical analysis shows that the genesis of tough phase in converter slag is related to the iron content of MgO(Fe) and CaFeO3. Most of the tough phases are dicalcium silicate while tricalcium silicate content is low, which lead to the low hydration speed,low strength in the early stage and high strength in later stage of converter slag. However,phosphorus mainly occurs in calcium ferrite, followed by limestone. At the same time, the content of TFe is opposite to that of P. With the increase of iron content in converter slag, phosphorus content will decrease. Phosphorus will be removed from iron bearing materials by fine-grained separation. Low phosphorus converter slag can be better used in smelting and sintering system.