高频红外吸收法测定工业硅中碳

Determination of carbon in industrial silicon by high frequency-infrared absorption method

研究了高频红外吸收法测定工业硅中碳含量的主要影响因素,包括坩埚选择、氧气纯度、助熔剂选择及加入方式、样品量、助熔剂与样品的混合方式以及质量配比等方面,确定了最佳的检测条件.结果表明,采用经过预处理的超低碳硫分析专用坩埚、高纯氧气和钨锡铁复合助熔剂,样品燃烧充分,碳释放完全,分析结果稳定,空白值最低为0.001 0％.采用实验方法对实际样品进行分析,结果的相对标准偏差为2.5％～4.4％;对工业硅标准样品分析时测量值与认定值一致.

The main factors affecting the determination of carbon in industrial silicon by high frequencyinfrared absorption method was tested to obtain the optimal determination conditions, such as selection of crucible, oxygen purity, selection and addition sequence of flux, sample amount, mixed manner and mass ratio of flux with sample. It was found that, when ultra-low carbon-sulfur specific cruci- ble after pretreatment was used for sample fusion with high purity oxygen and tungsten-tin-iron complex flux, sample combustion was sufficient with complete carbon release and the analytical results were stable with minimal blank value of 0. 001 0%. Actual samples were analyzed with the proposed method. The relative standard deviation （RSD） was 2.5%-4.4%. The determination results of industrial silicon standard sample were consistent with certified values.