Patent GB-763731-A (GB)
Title: Process for the manufacture of metallic titanium
IPC: C22B34/12
Filed: 1953-09-01
Abstract: A low valency titanium halide, e.g. chloride, is produced by reduction of a titanium tetrahalide with a titanium alloy preferably containing at least 10 per cent by weight Ti in such amounts that the weight of titanium in the alloy exceeds the third part of the weight of titanium in the tetrahalide and then disproportionated at an elevated temperature to produce metallic titanium.  The titanium tetrahalide obtained in the disproportionaion reaction may be continuously recycled, fresh titanium tetrachloride being added thereto, and then passed in counter-flow through the titanium alloy. The additional titanium tetrahalide may be sprayed into the recycling gas which should have a temperature not lower than 150 DEG C. at any point.  Iron, silicon, carbon, nitrogen, oxygen, copper and aluminium are cited as alloy constituents, aluminium being particularly useful as an accelerator for the process, but virtually all alloys can be used: in the examples alloys of 40 per cent titanium, 20 per cent iron, and 40 per cent silicon and of titanium with 3 per cent oxygen, 4 per cent nitrogen and 5 per cent carbon are used.  Aluminium may alternatively be present e.g. in the titanium tetrachloride vapour as aluminium trichloride.  In one method of operation, the tetrahalide is continuously evaporated and passed either in vacuo or in the presence of hydrogen or an inert protective gas (e.g. argon) at atmospheric pressure, into a reaction furnace heated to 250 to 1100 DEG C. e.g. by induction, indirectly by means of gas or by resistance heating e.g. of the alloy itself, wherein it reacts with the preferably pre-heated alloy either in liquid or solid form and the resultant gases are passed into the decomposition chamber preferably pre-heated to above 1100 DEG C. by high or low frequency heating or by an electric arc, where a disproportionation takes place.  Before recycling the heat from the resulting tetrahalide may be used e.g. to evaporate or preheat the tetrahalide starting material.  In the examples the alloy is disintegrated to below 1 millimetre, pressed to form moulded pieces with water glass and treated in a shaft furnace. The resultant gases are then passed through an electric arc and the titanium produced falls into a bath of molten titanium heated by high frequency.ALSO:Metallic titanium of high purity is obtained from a low valency titaniumhalide, e.g. chloride produced by reduction of a titanium tetrahalide with a titanium alloy in such amounts that the weight of titanium in the alloy exceeds the third part of the weight of titanium in the tetrahalide, which is then disproportioned at an elevated temperature, e.g. above 1100 DEG C. Iron, silicon, carbon, nitrogen, oxygen, copper and aluminium are cited as alloy constituents, aluminium being particularly useful as an accelerator for the process, but virtually all alloys can be used: in the examples alloys of 40 per cent titanium, 20 per cent iron, and 40 per cent silicon and of titanium with 3 per cent oxygen, 4 per cent nitrogen and 5 per cent carbon are used. Alternatively aluminium may be present e.g. in the titanium tetrachloride vapour as aluminium trichloride.  In the examples the alloy is disintegrated to below 1 millimeter, pressed to form moulded pieces with water glass and treated with TiCl4 vapour in a shaft furnace.  The resultant gases are then passed through an electric arc and the titanium produced falls into a bath of molten titanium heated by high frequency.