Titanium metal is hydrogenated at 600-700°C. It is then placed in a small nickel boat and inserted into the horizontal nickel tube (closed at one end). The hydride is fluorinated with gaseous HF. The open end of the tube has a cooling jacket and is sealed with picein to a copper cover. Two copper tubes are silver-soldered into the cover and serve as an inlet and outlet for the hydrogen; the inlet tube also contains a concentric silver tube for introducing HF. The output gases pass through an empty polyethylene bottle, a bubble counter filled with paraffin oil and a polyethylene trap to freeze excess HF gas. The closed end of the reaction tube is placed in a tubular furnace. The temperature is measured externally. After thoroughly flushing the apparatus with Hs, fluorination followed with a 1 4 mixture of H2 and HF for four to five hours. The HF flow is first started at a temperature above 200°C. The water temperature in the cooling jacket should be higher than 20°C to prevent condensation of the HF. After completion of the fluorination, the product is left to cool in a stream of hydrogen. The yield is 90%.
