高频燃烧-红外吸收法测定铜中硫

研究了高频燃烧 红外吸收法测定铜中硫的最佳实验条件。通过正交试验确定了试样量、氧气压力和氧气流量最佳条件分别为3 g、15 bar和150 L/min。试样尺寸和坩埚位置分别影响SO2的释放曲线峰位和峰值，从而影响测定结果的准确度和精密度。试验表明，当试样尺寸约为1 cm×05 cm×02 cm，坩埚位于线圈的底部，测定结果最好。为了减少熔样过程中熔渣飞溅与起泡对测定的影响，采用在样品表面加盖15 g左右惰性覆盖物的方法，覆盖物的最佳尺寸大约在3 mm ×3 mm ×3 mm。实验选用BY0211 2紫铜标准样（w (S)= 0006 4%）和阴极铜内控样（w (S)= 0000 4%）进行仪器校正，并测定了方法检出限为0000 03%。采用本方法测定粗铜内控样和紫铜标准样，测定结果与参考值或者认定值一致，相对标准偏差（RSD ，n=11）小于27%。

Determination of sulfur in copper by high frequency combustion-infrared absorption method

The optimal experimental conditions for the determination of sulfur in copper by high frequency combustion-infrared absorption method were studied.The optimal conditions obtained by orthogonal test were as follows: the sampling amount,oxygen pressure and flow rate were 3 g,1.5 bar and 150 L/min,respectively.The release curve peak position and value of SO2 were affected by sample size and crucible position,consequently,influencing the accuracy and precision of determination results.The results showed that the determination results were best when the sample size was about 1 cm×0.5 cm×0.2 cm and the crucible was located on the bottom of coil.In order to reduce the influence of cinder splashing and bubbling in sample fusion on determination,1.5 g of inert mantles was covered on the surface of sample.The optimal dimension of mantle was about 3 mm ×3 mm ×3 mm.In this study,the instrument was corrected using BY0211-2 red copper standard sample(w(S)= 0.006 4%) and cathode copper internal control standard sample(w(S)= 0.000 4%).The detection limit of method was 0.000 03%.The proposed method was applied to the determination of crude copper internal control sample and red copper standard sample.The found results were consistent with the reference values or certified values.The relative standard deviation(RSD,n=11) was less than 2.7%.