Determination of sulfur in copper by high frequency combustion-infrared absorption method
高频燃烧-红外吸收法测定铜中硫

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%.