Preparation Of Ferrovanadium Nitride From Ammonium Vanadate Polymer

The steel contains a certain amount of vanadium and nitrogen,and the grain could be strengthened and refined,and the wear resistance and fatigue resistance of the steel could be improved.On the premise of ensuring the strength of steel,the increase of nitrogen content in steel can reduce the amount of vanadium and the cost.In actual production,vanadium nitride is the main carrier of vanadium and nitrogen added to steel,but the high melting point of vanadium nitride and low apparent density have many limitations.This paper will study the vanadium nitride which is better than the vanadium nitride.At present,the production process of nitrided ferrovanadium and vanadium oxide use vanadium as raw material,however the raw material source for ammonium polyvanadate compounds such as vanadium,complex process,high cost.In order to save the cost,this paper will study the preparation of nitrided ferrovanadium by using vanadium polymers directly.In this study,the traditional vanadium nitride production process is combined,the vanadium polymer,Fe2O3 powder are used as raw material,and the toner is used as the reductant,and ferrovanadium is prepared in the electric resistance furnace.The basic operation process:the weighing of raw material,mixing with water,briquetting,drying,and then the raw material is put into the resistance furnace,high temperature under the nitrogen atmosphere reduction nitridation reaction time,cooling,detection and analysis of nitrided ferrovanadium.The carbon content,temperature,heating time and nitrogen flow,densification temperature and densification time,nitrogen content of nitrided ferrovanadium apparent density and impurity distribution are studied by means of metallographic microscope,scanning electron microscope,X-ray diffraction,DSC thermal analysis to obtain the optimal conditions of the process.Through the study,the results are as followed:(1)Through exploration,the best process conditions are:holding temperature is 1450℃,holding time is 120 min,carbon percentage is 10%,densification temperature is 1570℃,densification time is 60 min,and the nitrogen flow is 0.8 L/min.In this case,the content of nitrogen is 11.4%,the content of vanadium is 57.5%,the content of iron is 22.14%,and the density is 4.7 g/cm3,which has reached the expected requirement.(2)The elemental scanning on the surface of the sample shows that there is an obvious boundary between the elements Fe and V.The nitrogen and vanadium elements are completely overlapped and combined into VN phase.The carbon element is evenly distributed,which indicated that carbon is distributed at Fe and VN phase simultaneously,(3)Through the thermal analysis of the synthesized vanadium nitride and existing vanadium nitride,and it can be seen that the DSC curves have the same change rule during the heating process.Simultaneously,endothermic peak and exothermic peak is basically the same.Therefore,it can be judged that the vanadium nitride samples obtained in this study can be used in the production of steel smelting.