| Phosphorus is one of the main deleterious elements in steel. Researching on the ultra-low phosphor steel production technology is one important direction for the production of clean steel. In this paper, the main purpose is to achieve dephosphorization deeply under the condition of less slag smelting.The high-temperature simulation dephosphorization experiments were carried out with analyses of thermodynamics and kinetics. The effects of slag basicity, mass fraction of FeO and slag quality on the dephosphorization were mainly researched. One kinetics model of dephosphorization was established on the basis of double film theory, and was validated using the experiment results. The main results are as follows:(1) The kinetics model is as follows: The validated results show better agreement with the experimental results. It can be used for forecasting the dephosphorization process of molten steel.(2) According to the experiment results, the calculation formula of phosphorus distribution ratio which established by Kunisada K, et al. was modified, and the new calculation formula established suit for the experiment condition of this paper is:(3) The main dephosphorization task can be accomplished within 15min. After 15min, the dephosphorization speed decreases and the rephosphoration phenomenon could be happened with the prolong of time. The less of basicity and the lower of w(FeO), the more serious of the rephosphoration phenomenon.(4) Under the condition of w(FeO) of 10% and slag quantity of 25kg/t steel, the terminal phosphorus mass fraction of molten steel decrease with the increasing of basicity, and then increase. When basicity is 5, the phosphorus mass fraction of 0.002% is the minimum.(5) Under the condition of basicity of 4 and slag quantity 25kg/t steel, the terminal phosphorus mass fraction of molten steel decrease with the increasing of w(FeO), when w(FeO)> 15%,the dephosphorization effect does not change obviously with it. |
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