| 摘要 |
<p>Chlorides of iron, aluminium, beryllium, titanium, zirconium and boron are prepared by chlorinating a sintered source material and a carbonaceous material, which prior to sintering have been ground to pass a 140 mesh sieve (United States Standard Sieve Series), the individual grains of source material having been sintered together such that they are also in good contact with the carbonaceous material. The process is of particular use in producing titanium tetrachloride, in which case the source material may be rutile or ilmenite, or a slag produced by the partial reduction of ilmenite, for example sorel slag or sodium or boric acid containing slags. The carbonaceous material may be charcoal, coke, for example petroleum or natural coke, coal, or carbon obtained from carbonaceous gases, for example carbon monoxide or hydrocarbons, at low temperatures. The carbonaceous material is preferably employed in less than the stoichiometric amount, and the mixture of the source and carbonaceous materials may be extruded, briquetted, or pelleted. A flux, for example boric acid, borax, fluorspar or phosphates, salts or oxides of alkali or alkaline earth metals, may be added to the material to be sintered, which sintering may be effected between 600 DEG C. and 1400 DEG C., preferably in a non-oxidising or inert atmosphere, for example, nitrogen, carbon monoxide or argon. In the preparation of titanium tetrachloride, the source material may be treated to set up stresses therein, for example by rapid cooling. A source of silica, for example clay, may be incorporated in the mixture prior to sintering to increase the strength of the chlorination residue, which residue may be leached with water and re-sintered for further chlorination, which may be effected in static or fluidised beds, preferably at 600-1100 DEG C.</p> |
