Study On New Reagent Of Removing Vanadium From Raw Titanium Tetrachloride On Producing Sponge Titanium

Titanium tetrachloride(TiCl₄)is a semifinished product of titanium sponge production and titanium dioxide production which is producted by chlorination.Crude TiCl₄(chloridize liquid)is a muddy red color liquid,which contains many harmful impurities,and its composition is very complicated.These impurities have a direct impact on the quality of titanium sponge and titanium white,so it is necessary to refine the crude TiCl₄.The vanadium impurities in the crude TiCl₄ is mainly vanadium oxychloride(VOCl₃) and a small number of vanadium tetrachloride(VCl₄),and their existence bring on TiCl₄ showing yellow.The purpose of refining and removing vanadium is not only to decolorization,but also to deoxidize.This is an extremely important aspect of the process of refining TiCl₄.The difference of boiling point(only 9℃)and relative volatility(α=1.22)between TiCl₄ and VOCl₃ is relatively small,to achieve the required separation requirements,the circumfluence ratio and the theoretic back plate number are great,so in industrial production the chemical method is used to remove vanadium,rather than distillation method(that is the physical method of removing vanadium).Chemical method is to add a kind of chemical reagents into rough TiCl₄,so that VOCl₃ impurities are selective deoxidized or selective deposited,and the insoluble resultant is mutual separated with TiCl₄.At present,the following four methods are applied in industrial production,such as copper method,aluminum powder method,hydrogen sulfide method and organic matter method.Organic matter method is a relatively ideal way of removing vanadium,fremdness has widely applied this approach.In this paper,a new reagent of removing vanadium-NR reagents is developed,through experiments on the reaction of removing vanadium its impact on the various factors is discussed and the optimal experimental conditions is determined.Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) analysis show that:When the amount of NR reagent is 0.8 percent of raw materials,and temperature 130～140℃,and reaction time 60 min,the vanadium content of chlorination solution(from Zunyi Titanium Company) is ruduced from 0.14 %to 0.0003%to 0.0005%,and the colourmetric purity is less than 5mgK₂Cr₂O₇/L, which have reached the industrial standards of purificatory TiCl₄(vanadium content≤0.0007%),the effect of removing vanadium is relatively good.And the equipment is simple,waste is less,vanadium is easy to handle and recovery;NR reagent-source raw materials,cheap,removing vanadium low cost.In this paper,the physical characteristics of chlorination solution composition and the characteristics and method of treatment of mainly impurities is expatiated.The principles of organic matter method and the separation methods are analysed and discussed.The advantages and disadvantages and the applications of the four industrial methods of removing vanadium is compared and evaluated,calculating the feasibility of the redox reaction in theory,also the V-analysis method is made a detailed introduction.