| Electromagnetic levitation technology applied in pyrometallurgy enables the metal material levitated in the air,avoiding the crucible's pollution when metals smelting at high temperature,meanwhile,it provides good thermodynamic and dynamic conditions for metal smelting.This research takes ferrosilicon alloy and metallurgical grade silicon as the research object,and conducts thermodynamic and experimental research through its impurity removal process.The purpose is to discuss the principle of removing impurities in the electromagnetic levitation process of metal,and provide a theoretical reference for electromagnetic levitation melting technology.In this study,thermodynamic calculation,theoretical analysis and related experimental methods were used to explore the process of dephosphorization of ferrosilicon alloy and metallurgical grade silicon by electromagnetic levitation refining technology.The main research results are shown below:?1?Thermodynamic analysis and calculation of droplets of Si-Fe-P ternary metal in electromagnetic levitation refining under pure Ar gas conditions.The calculation and analysis of the refining temperature of 1723K-2123K,Si-Fe-P ternary system in ferrosilicon alloy and metallurgical grade silicon in the temperature range of the activity trend,temperature mainly affects the activity coefficient and then the change in activity.The calculation results show that in the temperature range from 1723K to2123K,the activity of Si will increase gradually and then stabilize,and the activities of Fe and P are positively correlated with temperature,showing an increasing trend.?2?Thermodynamic analysis and calculation of droplets of Si-Fe-P ternary metal in electromagnetic levitation refining under Ar-H2 mixed atmosphere.The calculation shows that the Gibbs free energy and enthalpy change of P and H2 reaction exist when refining ferrosilicon alloys and metallurgical grade silicon in a mixed atmosphere of Ar-H2 mixed atmosphere.The results show that the volatilization of phosphorus in molten metal is in the form of P2 and P.After the introduction of H2,it will react with P to form phosphine compounds.This process is an exothermic reaction.At high temperatures of 1723K-2123k,the phosphine compounds generated on the surface of the droplets exist in the form of PH,PH2,PH3.Hydrogen is a gas with good thermal conductivity.With the continuous introduction of H2,the PH and PH2 will change to PH3 when the temperature drops below 1723K,and the dephosphorization effect is achieved in the form of PH3.?3?By exploring the temperature and atmosphere conditions during the electromagnetic suspension refining test,it is shown that different atmosphere flows and atmosphere types will affect the dephosphorization process of ferrosilicon alloys and metallurgical silicon,among which 50%Ar-50%H2,100%H2 and 100%Ar The results of Ar comparison test show that increasing the flow rate of the atmosphere within a certain range is conducive to the removal of impurity phosphorus,and the dephosphorization effect of ferrosilicon alloy and metallurgical silicon increases significantly with the increase of H2 content.When the the refining temperature is1823K,atmosphere is 100%H2,the gas flow rate is 1.5L/min,the dephosphorization rate of ferrosilicon alloy is 89.9%,and the metallurgical grade silicon dephosphorization rate is 90.3%. |
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