CaO基含TiO2和Al2O3半钢渣系脱磷能力的热力学

Thermodynamics of dephosphorization capacity of containing TiO2 and Al2O3 of CaO-based semi-steel slag

以共存理论和冶金脱磷原理为基础,建立了脱磷热力学模型,并对CaO基含TiO2、Al2O3半钢渣系的脱磷能力进行热力学研究,得到CaO基含TiO2、Al2O3半钢脱磷渣系的磷分配比和磷容量热力学模型。研究结果表明,渣中TiO2和Al2O3均会使炉渣的脱磷能力降低,尤其是在低温低碱度条件下影响较为明显,两种氧化物在质量分数相同的情况下,TiO2比Al2O3的影响更大;随着炉渣碱度的增加,炉渣的磷分配比和磷容量均先升高而后持平;随着渣中w（（Fe O））的增加,炉渣的磷分配比和磷容量均先升高而后降低;随着w（（Mg O））的降低,炉渣的磷分配比和磷容量逐渐降低。采用半钢化渣球冶炼半钢,渣中w（（TiO2）＋（Al2O3））和w（（Fe O））升高,w（（Mg O））稍有降低,在Fe O和Mg O的共同作用下,半钢渣系的磷分配比和磷容量有所升高。控制炉渣碱度为4.0左右,w（（Fe O））≤20.0%时,炉渣不仅具有较高的磷分配比和磷容量,并且可以弱化TiO2和Al2O3对磷分配比和磷容量的影响,确定半钢化渣球的加入比例为总渣量的15.0%-20.0%。

A dephosphorization thermodynamic model was established based on the coexistence theory and the principle of metallurgical dephosphorization. The thermodynamic study on the phosphorus distribution ratio and phosphate capacity of Ca O-based steel slag which contained TiO2 and Al2O3 was carried out,and the thermodynamic model of phosphorus distribution ratio and phosphorus capacity of containing TiO2 and Al2O3 of Ca O-based semi-steel slag were obtained.The calculated results indicate that the ability of dephosphorization would be reduced with the increase of w（（TiO2）） and w（（Al2O3））,especially under the low temperature and low alkalinity conditions. The effect of TiO2 is greater than that of Al2O3 with the same content of the two oxides. The phosphorus distribution ratio and phosphate capacity increase first and then are almost invariant with the increase of alkalinity,increase first and then decreased as w（（Fe O）） increasing,and decrease with the w（（Mg O）） increasing. Semi-steel is smelted by semi-steel slag ball,and the w（（TiO2）＋（Al2O3）） and w（（Fe O）） increase as semi-tempered slag ball isused,and w（（Mg O）） decreases. On accounting of the synergistic action of Fe O and Mg O,the phosphorus distribution ratio and phosphate capacity increase. It is better for the increase of the phosphorus distribution ratio and phosphate capacity and weakening the influence of w（（TiO2）＋（Al2O3）） when the basicity of slag is about 4.0 and w（（Fe O））≤ 20.0%,and the proportion of semi-tempered slag ball is 15.0 %-20.0 % of total slag.