Numerical Simulation And Experimental Study On Desulfurization Of Calcined Dolomite Hot Meta

With the development of China’s industry,steel production and consumption has jumped to the front of the world.However,many kinds of special steel such as coldrolled thin strip(plate),electrical steel strip(plate),galvanized strip(plate),coated strip(plate)and some stainless steel strip(plate)and so on are still difficult to produce in China.As a result,it still needs a lot of imports every year.Therefore,China’s demand for upgrading the technology level of the metallurgical industry is still very urgent.As one of the harmful elements in steel,it is valuable to study how to economically remove it to a very low level.This research is based on the subject of dolomite in-situ desulfurization,that is,the low-cost dolomite raw material and aluminum powder are directly put into the molten iron to be desulfurized,and the magnesium produced by the high-temperature decomposition of dolomite and thermal reduction of aluminum is directly used for desulfurization.Compared with the traditional passivated magnesium desulfurization method,the use of dolomite in desulfurization not only simplifies the process and achieves deep desulfurization at a lower cost.But also reduces pollution and realizes green metallurgy.In this research,the numerical simulation of computational fluid dynamics including chemical reactions is carried out based on the previous in situ desulfurization of dolomite.Due to the complexity of the actual reaction process,there is a contradiction between the computer’s arithmetic power and the huge calculation volume.Based on the thermodynamic and kinetic analyses,as well as the analysis of the reaction process in the experiment,the reaction conditions were reasonably simplified.With the experimentally obtained parameters and appropriate adjustments,the desulfurization process of dolomite was successfully simulated,and the sulfur content change curve was fitted relatively close.The simulation results indicate that the reaction is controlled by the diffusion of Al,S and Mg,and the whole process is a tandem reaction.Among the two forms of magnesium,dissolved Mg is the main form of desulfurization while Mg vapor desulfurization accounts for less.The kinetic model of in situ desulfurization of dolomite was established by kinetic analysis.In order to analyze the law of magnesium bubble desulfurization,study the variation law of bubble growth and uplift,and obtain the coupling relationship model between bubble uplift and mass transfer,a water model experimental study was carried out.Saturated clarified lime water and carbon dioxide gas were used as the working mass,and the relationship between the size of bubbles and microporous size and flow rate was measured by high-speed camera photography and image pro-plus software.The coupling relationship between bubble uplift and mass transfer was modeled by analyzing the coupled bubble boundary layer mass transfer equation for the forces on the bubble in water.