转炉吹炼不同阶段炉渣黏流特性变化

To clarify the variation mechanism of furnace slag viscous flow characteristics in different stages of converter blowing. According to typical converter slag compositions during different stages, the effects of basicity, FeO, MgO, MnO and Al₂O₃On the viscosity of CaO-SiO₂-FeO-MgO-MnO-Al₂O₃ converter slag was studied by u-sing Factsage thermodynamic simulation software. The suitable basicity of converter slag, reasonable FeO, MgO, MnO and Al₂O₃ contents in converter slag during different stages were given in combination with production practice. The results showed that the viscosity of converter slag decreased gradually with the increase of temperature under different alkalinity conditions, and the viscosity of converter slag increased first and then decreased with the increase of alkalinity under different temperature conditions. The viscosity of furnace slag is greatly affected by the content of FeO, MgO and Al₂O₃, while the content of MnO had relatively little effect on the viscosity of furnace slag. The fluidity of furnace slag is mainly related to the polymerization degree of furnace slag structure and the mass fraction of solid phase in furnace slag. The increase of FeO, MgO and Al₂O₃ content could destroy the network structure of silicate polymer in slag, and excess MgO could easily lead to the precipitation of high melting point solid phase in slag. When the content of Al₂O₃ is low, it exists in furnace slag in the form of complex tetrahedral structure A10:|~, which is easy to form high melting point substances such as calcium aluminate, thus changing the fluidity of furnace slag. The actual production considered that in the early stage of converter smelting, the basicity of slag is controlled at about 1. 4-1. 5, the content of FeO, MgO, MnO and Al₂O₃ was controlled at about 20%, about 6%-8%, above 6% and about 3%-5%, respectively. The viscosity of slag is suitable and the fluidity of slag was well. In the middle and later stages of converter smelting, the basicity of slag should be controlled at about 3. 0-3. 5, the content of FeO, MgO, MnO and Al₂O₃ should be controlled about 15%-20%, about 6%-8%, about 3%-6% and below 3%, respectively. The furnace slag has well fluidity.