Titanium tubes, hydriding

Titanium hydride is used as a source for Ti powder, alloys, and coatings as a getter in vacuum systems and electronic tubes as a sealer of metals and as a hydrogen source. 

Fig. 89. Preparation of very pure hydrogen from titanium hydride, a) quartz reactor tube ) molybdenum boat containing Ti c) heating winding d) radiation shield e) radiation shields for protection of stoppers f) glass wool g) apparatus for conducting reactions with the very pure hydrogen product the tube contains a boat for the reactants and is surroimded by an electric furnace. This part may be omitted if the hydrogen product is to be used elsewhere m) pressure-sensing switch r) relay.

Titanium metal is hydrt enated at 600-700°C (see section on Titanium). It is then placed in a small nickel boat s, which in turn is inserted into the horizontal nickel tube o (closed at one end), and the hydride is fluorinated with gaseous HF (see Fig. 136). The open end of the tube has a cooling jacket and is sealed with piceln to a copper cover b. Two copper tubes are silver-soldered into the cover and serve as inlet and outlet for the hydrogen in addition. 

M is the analyte and m may be equal to n or not (for example, As and As are both reduced to AsHs). Hydrides were collected in U-tubes in a nitrogen trap or in rubber balloons. Titanium(iii) chloride—hydrochloric acid and magnesium-zinc reductants were used to extend the hydride method to bismuth, antimony, and tellurium. For some elements, especially tin, lead, and tellurium, the hydride formation reaction is relatively slow and hence the collection vessel is necessary. In addition, arsenic(v) must be reduced to arsenic(iii) by tin(ii) chloride or potassium iodide before the actual hydride generation when a metal-acid reduction is employed. 

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