Preparation Of High Purity Vanadium Carbide And The Application In Hard Alloy

Vanadium carbide is one of the most important functional material in transition carbide metal. It has a series of excellent performance such as high strength, high hardness, high temperature resistant, acid and alkali resistant, wear resistance, low density,good stability, superior electric,thermal conductivity and so on. Vanadium carbide can improve mechanical properties of steel and has been widely used in the steel industry. vanadium carbide has another important purpose which is as additive or coating of hard alloy to improve surface hardness of alloy. At home and abroad, in order to improve the strength and hardness of the hard alloy,it often adds vanadium carbide as particles strengthening phase in hard alloy. Vanadium carbide has been also widely used in mechanical processing, metallurgical mineral, aerospace, microelectronics, catalysis, etc.Now,at home and abroad, the main raw materials of vanadium carbide are V2O5or V2O3adding the corresponding carbon sources to reduction and carbonization. The purity of vanadium carbide adding in hard alloy is higher than in steel. If using the V2O5of metallurgical industry, its purity isn’t high enough and would influence the performance of hard alloy,which is harm to the development of hard alloy. In our country, vanadium carbide in hard alloy is using the sold metallurgy level V2O5(V2O5=98%～99%) as raw material, then dissolving vanadium acid sodium solution, purification, filtering, precipitation and roasting to get high purity of V2O5. This method has shortcomings such as complex process, large auxiliary materials dosage, low vanadium recovery and high product cost (the production cost as much as450000yuan/ton).This paper based on the shortcomings of the production of vanadium carbide and rich vanadium resources in panzhihua, presents a new method to prepare high purity V2O5using partial vanadium acid ammonium. The research is mainly using the method of hydrometallurgy, purifying the ammonium poly-vanadate, preparation the high purity ammonium meta-vanadate, using ammonium meta-vanadate preparation high-purity vanadium carbide directly for hard alloy by secondary reduction carbonization method. In order to decreasing production cost, improving product quality and the efficiency of the production, it’s not using the present method of making vanadium carbide by V2O5and saving the procedure of roasting partial vanadium acid into V2O5.Through the research, getting the optimum process conditions of preparation high-purity ammonium meta-vanadate and vanadium carbide, and technical indexes of vanadium carbide reach the highest standard of the domestic industry. The vanadium carbide applied to hard alloy that has obtained good effect and can be widely used in hard alloy industry.In the future, it needs to make further research on wastewater treatment, process conditions and consider development of hard alloy based on vanadium carbide.