Pure titanium metal

Alternatively, the TiCl may be reduced using hydrogen, sodium, or magnesium. It follows that TiCl2 is the first stage in the KroU process for the production of titanium metal from titanium tetrachloride. A process for recovery of scrap titanium involving the reaction of scrap metal with titanium tetrachloride at >800° C to form titanium dichloride, collected in a molten salt system, and followed by reaction of the dichloride with magnesium to produce pure titanium metal, has been patented (122,123). 

Titanium tetraiodide can be prepared by direct combination of the elements at 150—200°C it can be made by reaction of gaseous hydrogen iodide with a solution of titanium tetrachloride in a suitable solvent and it can be purified by vacuum sublimation at 200°C. In the van Arkel method for the preparation of pure titanium metal, the sublimed tetraiodide is decomposed on a tungsten or titanium filament held at ca 1300°C (152). There are frequent hterature references to its use as a catalyst, eg, for the production of ethylene glycol from acetylene (153). 

C04-0111. The element titanium is commonly found as the ore ilmenite, F eTi03. Much of the world reserves of titanium is found in Canada. At a particular mine, a sample of earth was found to contain 15% ilmenite by mass. What mass of pure titanium metal can be isolated from 1.00 x 10 metric tons of earth, if the extraction process is 95% efficient ... 

Very highly pure titanium metal can be prepared in small amounts by decomposition of pure titanium tetraiodide, (Tih) vapor on a hot wire under low pressure (Van Arkel-de Boer method). 

Starting with rutile (Ti02), explain how you would obtain pure titanium metal. Hint First convert Ti02 to TiCl4. Next, reduce TiC with Mg. Look up physical properties of TiCl4, Mg, and MgCl2 in a chemistry handbook.)... 

An ingot of pure titanium metal is heated at 1000 °C in an atmosphere of ammonia, so that nitrogen atoms diffuse into the bulk. The diffusivity of nitrogen in /3-titanium, the stable structure at 1000 °C, is 5.51 x 10 m at this temperature. What is the thickness of the surface layer of titanium that contains a concentration of nitrogen atoms greater than 0.25 at% after heating for 1 hour ... 

The sodium chloride can then be easily washed away using water, leaving the pure titanium metal. 

Pure titanium metal sponge is now manufactured on a scale of thousands of tons per annum, in a number of countries, by the magnesium reduction... 

For decorative purposes, the anodizing of chemically pure titanium metal parts made of ASTM grades 2 and 4 can be conducted as follows. 

Pure titanium metal is produced by reacting titanium(IV) chloride with magnesium metal. The equation for the reaction is... 

Klaproth and many contemporary chemists tried in vain to isolate titanium metal, but in 1825 Berzelius succeeded in reducing potassium hexafluorotitanate K TiF with metallic potassium. The titanium metal obtained, however, was very impure. The same method was used two decades later by Friedrich Wohler and Sainte-Claire Deville. They got a powder with a metallic luster and thought at first that their prepa-rahon was pure titanium metal, until they found that the reaction product was rich in nitrides. Welders of htanium components today recognize the situation. Even under a protective atmosphere of argon or helium, the slightest traces of nitrogen lead to the formahon of yellow titanium nitride. 

In 1887, two scientists in Uppsala University introduced a new technique with which they could prepare pure titanium metal. Their method was a forerunner of the Kroll process, the large-scale technique for titanium production today. 

In 1925 the two Dutchmen van Arkel and de Boer succeeded in preparing perfectly pure titanium metal with their iodide dissociation process, described in Chapter 19 Zirconium. 

Pure titanium metal is produced from TiC by metallothermic processes using sodium metal (Hunter process) or magnesium metal (Kroll process) as reductive agents at temperatures of 800-850 °C... 

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