【摘要】 以V₂O₅粉末为原料,C粉末为还原剂,对碳热还原氮化法制备VN的机理进行研究,重点讨论了配碳量和温度对产物的影响.结果表明,V₂O₅为逐级还原,存在直接和间接还原;配碳量（C/V₂O₅）为28%（ω）时,产物氮含量最高;800¹ 000℃发生碳化反应生成VC_1-x,1000¹200℃同时发生碳化和氮化反应,主要生成V（C,N）;温度超过1 300℃,V（C,N）向VC_1-x转化.随温度升高,产物氮含量逐渐降低,钒含量逐渐升高,产物之间发生团聚甚至熔蚀形成球状,大部分颗粒粒径约为1μm.采用本工艺进行实际生产,产品氮含量>17%,钒含量为79%,碳含量<2%,表观密度约为3.5 g/cm³,符合国家标准.更多还原

【Abstract】 The reduction and nitridation mechanism for preparation of VN with V₂O₅ as raw material and carbon powder as reductant was studied,the effects of mass ratio of C to V₂O₅ and temperature were examined,and the products analyzed.The results show that the reduction of V₂O₅ is successive,and indirect reduction occurs along with direct reduction.When the mass ratio of C/V₂O₅ is 28%,the nitrogen content in products is maximum.From 800 to 1000℃,carbonization reaction takes place,and the product is VC_1-x.From 1000 to 1200℃,carbonization and nitridation reactions take place simultaneously,and the main phase is V（QN）.When the temperature is higher than 1300℃,V（C,N） is transformed gradually into VC_1-x with the increase of temperature,the nitrogen content decreases and the vanadium content increases,the products will agglomerate even fuse each other and are composed of spherical particles with the average diameter of 1 μm.Using the above process to prepare VN,the nitrogen content of products can reach more man 17%,vanadium content more than 79%,and carbon content less man 2%,and the apparent density is about 3.5 g/cm³ which accords with national standard.更多还原