In addition to chemical impurities vanadium titanium tube

Vanadium and  titanium tubing grades  and a small amount of impurities mainly VOCl3 discretion VCI4, their presence makes TC4 titanium tube yellow. In addition to the purpose of refining vanadium, not only for bleaching but also for oxygen. This is an extremely important part of the refining process.
     TC Titanium  and vanadium impurities ask discretion tube boiling point difference and relative volatility are relatively small, such as a two-component system titanium tube -VOCl3 boiling point difference is 10 ℃, the relative volatility of d = 1.22; and TC4 titanium alloy tube -VCl4 two lines boiling point difference of 14 degrees Celsius. Nevertheless, in theory, the use of physical methods are possible in addition to vanadium impurities, such as efficient use of the rectification column in addition to vanadium. The advantage of this method is that without the use of chemicals, refined enough continuous production process, easy to automate, isolated VCl4 VOCl3 and can be used directly. The disadvantage is that the energy consumption, large investment in equipment, but also need to address the structure of power kettle, put have not been applied in industry.
    In addition, TC4 titanium tube -V0Cl3 freezing point line two quite different points, a difference of about 54 degrees Celsius, and therefore can be used in addition to freezing crystallization VOCI3 but the energy consumption is frozen
Large, so it did not get industrial applications.
    For this reason is often used in addition to chemical vanadium. Vanadium is a chemical method in addition to adding a chemical reagent in a titanium tube, so VOCl3 (or VCl4) impurity selective reduction or selective precipitation alum form insoluble compounds and TC4 titanium alloy tube separated from each other or the selective adsorption of VoCl3 ( or VCl4), vanadium impurities and TC4 titanium alloy tube separated from each other; or selective dissolution of VOCl2, so alum 7icld impurities and separated from each other. We can say that a low-technology equipment simply better long costs, labor conditions are good, but easy to achieve continuous operation in addition to vanadium process has not been established. This is also the TC4 titanium tube refining process requires study.