The Dynamics Model Of Desulphurization By Mg-injection In Hot Metal Ladle

With the rapid development of modern industrial production and technology, customers have higher requirements on the quality of steel, hot metal desulphurization has gradually become an important link in modern iron and steel production. Hot metal desulphurization by magnesium has many merits such as high desulphurization rate, high desulfurization efficiency, short processing time, less slag quantity, low iron loss, little temperature drop, deep desulphurization, less environmental pollution and lower cost, it has become an essential technical measure to produce low sulfur steel.This dissertation is based on Tangshan Guofeng iron and Steel Co.'s desulfurization station's operating parameters, through numerical simulation and theoretical calculation, to develop the dynamics model that could predict the sulfur content in hot metal in different time, and then, to explore suitable technological conditions and parameters. Therefore, this dissertation studies three aspects.(1) Numerical simulation of flow field under the desulphurization by Mg-injection in hot metal ladleIn this part, flow state of hot metal will be simulated under the different N2 inje-ction rates and the different lance heights, via large commercial software ANSYS CF-X, using Eulerian-Eulerian multiphase model, thereby exploring the influence of vario-us flow states to the actual production.(2) Numerical simulation of temperature drop of the hot metal ladleIn this part, temperature drops of standing process and injection process of hot metal will be simulated considering convective and radiant heat transfer of hot metal with external environment, chemical reactions heat in the hot metal ladle, physical heat-absorbing of the adding material and so on. Then, the average temperature drop expression will be regressed for the dynamics model.(3) The dynamics model of desulphurization by Mg-injection in hot metal ladleThe dynamics model of desulphurization by Mg-injection in hot metal ladle is built by comprehensive consideration on the transport dynamics, macrokinetics and temperature change. Then, using Visual Basic 6.0 language and the fourth stage fourth order Runge-Kutta method, this dynamics model will be programmed. At last, under the different N2 injection rates, lance heights, initial temperatures, Mg-injection rates, initial Sulfur contents, initial masses of the hot metal, this dynamics model calculates the Sulfur content varying with the time in hot metal. At last, comparing the prediction results with the actual production data, a good match will be found.