高磷铁水脱磷渣枸溶性

Solubility in citric acid of dephosphorization slags from high phosphorus hot metal refining

参照实际转炉脱磷炉渣,配制了不同F、P2O5、FeO和MgO含量及碱度的渣样,用化学分析方法测试了不同组分对渣中磷的枸溶率的影响规律.结果表明:当脱磷渣中含有F时,P主要与F形成氟磷灰石,使得磷的枸溶率随渣中F含量的升高而急剧降低,当不含氟时枸溶率可达92.5%,当氟质量分数达到0.5%时枸溶率已降低到50%以下;随碱度增加,由于渣中Ca2+含量增加,破坏了硅氧网络结构,使得枸溶率有所上升;渣中MgO含量升高,由于Mg2+在熔融冷却过程中会抑制β--Ca3(PO4)2晶体的析出,而β--Ca3(PO4)2中磷不易为质量分数为2%的柠檬酸液溶出,而使枸溶率有所升高;随渣中P2O5含量升高,由于P5+与O2-形成络离子,P5+位于O2-密集形成的间隙中,不易溶出,使得枸溶率有所下降;渣中FeOn升高,枸溶率随之降低.

Consulting a practical dephosphorization slag in the converter, samples with different levels of F, P2O5 , FeO, MgO and basicity were prepared in laboratory, and the effect of composition on their solubility in citric acid was analyzed by chemical analysis methods. The results show that when the slag contains fluorine, P and F mainly form fluorapatite, and the solubility in citric acid of the slag sharply decreases when the fluorine content increases in the slag. if there is no any fluorine in the slag, the solubility in citric acid can be reached up to 92.5% , but when the mass fraction of fluorine in the slag reaches to 0.5% , the solubility in citric acid drops to less than 50%. The solubility in citric acid is improved with the increase of basicity, for increasing Ca^2＋ can destroy the Si-O network structure. With the increase of MgO content, the solubility in citric acid increases since in the process of cooling, Mg^2＋ inhibits the precipitation of β-Ca3 （ PO4 ） 2 crystals in which P can not be dissolved easily in the 2% citric acid. The solubility in citric acid decreases with the increase of P2O5 content, for p^5＋. is formed as PO4^3- complex ions with O^2- , p^5＋ locates in intensive gaps formed by O^2- , and the complex ions can not dissolved easily in the 2% citric acid. The solubility in citric acid will be decreased with the increase of FeOn.