Patent GB-784697-A (GB)
Title: An improved process for the reduction of the free carbon content in titanium carbide
Inventor: RANSLEY CHARLES ERIC
IPC: C25C3/16
Filed: 1952-04-15
Abstract: Titanium carbide of low carbon content is prepared either by heating a titanium carbide of higher carbon content with alumina or by preparing titanium carbide from titanium oxide, e.g. as rutile, and carbon in the presence of alumina.  The treatment is carried out in vacuo or in a protective gas atmosphere, e.g. hydrogen or carbon monoxide produced in the reaction.  2-3 per cent of alumina based on the titanium carbide may be used.  The alumina is preferably calcined.  The mixture may be ground before the heating operation. Heating may be effected at a temperature of about 2200 DEG  C.  The mixture heated may be in compacted form so as to form a sintered product, or in loosely packed form and the product finely ground. Specification 784,696 also is referred to.ALSO:Titanium carbide of low carbon content is prepared either by heating a titanium carbide of higher carbon content with alumina or by preparing titanium carbide from titanium oxide, e.g. as rutile, and carbon in the presence of alumina, the mixture heated being in compacted form so as to form a sintered product.  The treatment is carried out in vacuo or in a protective gas atmosphere, e.g. hydrogen or carbon monoxide produced in the reaction 2-3 per cent of alumina based on the titanium carbide may be used.  The alumina is preferably calcined. The mixture may be ground before the heating operation.  Heating may be effected at a temperature of above 1600 DEG C. and preferably above 2200 DEG C.  In one example commercial TiC powder and 2-3 per cent of powdered alumina are reduced to 1-2m , moistened with a binder, e.g. 1 per cent paraffin wax in benzene, heated to melt the wax, and compacted at 0.5-5 tons p.s.i. at either high or ordinary temperature or alternatively extruded with the desired shape.  It is then sintered at about 2200 DEG C. in a stream of hydrogen or in a vacuum.  Suitable powder for sintering may be produced by coarse-grinding (to pass 200 mesh B.S.S.) the commercial carbide, heating with calcined alumina in a hydrogen stream at 2200 DEG C. for 5-10 minutes, or at about 1600 DEG C. in a vacuum, and grinding the product.  In a third example a ground mixture of rutile alumina and coke was mixed with molasses as binder, extruded into pills and calcined for about 7 hours at about 800 DEG C.  After cooling the charge was heated to about 2200 DEG C. in an atmosphere of carbon monoxide produced by the reaction.  Specification 784,696 also is referred to.ALSO:Titanium carbide of low carbon content is prepared either by heating a titanium carbide of higher carbon content with alumina or by preparing titanium carbide from titanium oxide, e.g. as rutile, and carbon in the presence of alumina.  The treatment is carried out in vacuo or in a protective gas atmosphere, e.g. hydrogen or carbon monoxide produced in the reaction.  2-3 per cent of alumina based on the titanium carbide may be used.  The alumina is preferably calcined.  The mixture may be ground before the heating operation. Heating may be effected at a temperature of about 2200 DEG C.  The mixture heated may be in compacted form so as to form a sintered product or in loosely packed form and the product finely ground. Specification 784,696 also is referred to.