Analysis Method Research On The Purity Of The By-products SiCl₄ Recycled From The Production Of Sponge Titanium

The silicon tetrachloride is the organic compound, it mainly used in the chemical industry and military production. High pure SiCl₄ is the main material for the quartz correspondence optical fiber, which is also the basic raw material of the electron level polycrystalline silicon at home and abroad for many years. However, the purity of SiCl₄ was controlled strictly. The by-products SiCl₄ from the Zunyi Titanium Factory was disposed and recycled, and this technology was a new one. The production under the technology contains complex impurities. Therefore, a set of effective analysis method for silicon tetrachloride purity was established in this paper. In view of the new recycling craft of silicon tetrachloride, the analysis method of metal impurities, the silicon content and the organic impurities in the silicon tetrachloride was researched separately. The purpose is to provide the reference for analysis of the silicon tetrachloride.The results indicated that the method was available. The samples were taken to a plastics bottle which was heated at 57℃by hermetic injection, connecting dry gas N₂ at the same time in order to make the SiCl₄ out till no SiCl₄ liquid was left in the plastics bottle. Ti,V,Cr,Co,Ni,Cu,Pb,Zn,Mn was riched and analyzed by ICP-MS . The result showed that the determination limits for 9 elements were in the range of 0.009～0.05ug/L ;and the RSD were0.9%～3.7%;linearity correlation r > 0.999,with 98.15～102.0% recoveries. Fe,Mg was analyzed by Flame Atom Absorption Spectrophotometer. The determination limits is 0.002ug/ml, 0.0004ug/ml; The linear scope was 0.002～20 ug/ml; 0.0004～16 ug/ml respectively; the standard deviation is 0.05, with 94.5%～98.7% recoveries. K₂SiF₆ Volumetric Method was carried out to analyze the content of silicon in silicon tetrachloride. The standard uncertainty is0.31% and the expansion uncertainty is±0.93%, which demonstrated it was a reliable method .The organic functional group in silicon tetrachloride was analyzed by FT-IR Spectrophotometer. Experimentally determined absorptivity was reported for quantitative determinations of -OH content.The purity of silicon tetrachloride raw material and the high pure silicon tetrachloride production was determined quantitatively by Gas chromatography. These results show the method is simple effective for silicon tetrachloride analysis.