P2O5对炼钢炉渣中石灰溶解过程的影响

在1400℃下，将平均尺寸φ15 mm?10 mm的石灰块投入CaO?SiO2?FeO及CaO?SiO2?FeO?P2O5两组渣系中，研究了静态条件下石灰在两组渣系中的溶解行为。结果表明，两组渣系在反应界面周围形成四个区域，即基体渣层、C2S渗透层、铁酸钙渗透层和石灰层。渗透层为石灰中的Ca2+与液渣中的Fe2+相互渗透所形成的一个多相共存区域，存在致密固相层影响石灰的溶解。渗透层中的铁酸钙层逐渐被C2S层取代，C2S层厚度不断增加最终溶解于液相渣中。5~60 s两组渣系石灰溶解速度相近，60~80 s含磷渣系石灰溶解速度显著加快。当渣中加入P2O5时，磷会固溶于C2S中形成C2S?C3P固溶体层，该层的形成会排挤FeO进入渣中，提高渣的渗透能力，加速石灰溶解。

Effect of P2O5 on lime dissolution process in steelmaking slag

The dissolution behavior of lime in two groups of slag systems under static conditions was studied by introducing lime blocks with an average size of φ15 mm?10 mm into CaO?SiO2?FeO and CaO?SiO2?FeO?P2O5 slag at 1400℃. The results showed that four areas were formed along reaction interface around in two slag, namely base slag layer, C2S permeable layer, calcium ferrite permeable layer and lime layer. C2S permeable layer and calcium ferrite permeable layer were formed by the interpenetration of Ca2+ in lime and Fe2+ in liquid slag. The presence of a dense solid phase layer in the permeable layer affected the dissolution of lime. The calcium ferrite layer in the permeable layer was gradually replaced by C2S layer. The thickness of C2S layer increased and reached maximum. Finally C2S layer was dissolved in liquid slag. The dissolution rate of lime in the two groups of slag was similar in reaction time of 5~60 s, and the dissolution rate of lime in phosphorus-containing slag was significantly accelerated in reaction time of 60~80 s. When P2O5 was added to the slag, phosphorus was dissolved in C2S to form a C2S?C3P solid solution layer. The formation of this layer will displace FeO into the slag, improve the permeability of the slag, and accelerate the dissolution of lime.