Experimental Study on Preparation of Vanadium Carbonitride by Vanadium Pentoxide

Vanadium carbonitride was prepared by vanadium pentoxide and carbon powder in laboratory conditions.Six temperature curves and seven different carbon contents were adopted to determine the optimum reaction temperature and carbon addition.The results show that the content of vanadium and nitrogen in the sample obtained by temperature system 5 are both higher than those of samples by other temperature systems.With the increase of carbon addition,the content of vanadium in the sample increases slightly but the content of nitrogen decreases slightly,and the residual carbon content increases in the sample.When the carbon addition is 29% and 30%,vanadium carbonitride with 76% of V and 18% of N can be obtained.According to the reaction mechanism for carbon reduction of V₂O₅ and nitrogen addition,the whole process is divided into three stages including VO₂ formation through thermal decomposition of V₂O₅,VC（VN） formation and nitriding,respectively.The more suitable temperature regime was obtained at 30 ℃/min of heating speed in the first stage,6.8 ℃/min of heating speed in the second stage,1 250℃ for 1 h of heat preservation,and 10 ℃/min of cooling rate to 800 ℃ in the third stage.