高频燃烧红外吸收法测定铜精矿中硫的助熔剂探讨

称取0.040 0 g试样,将试样置于灼烧过并铺有0.3 g五氧化二钒助熔剂的坩埚内,加入0.2 g锡粒,再覆盖0.15 g五氧化二钒助熔剂和 1.4 g钨粒,以硫酸钾绘制校准曲线,建立了高频燃烧红外吸收法测定铜精矿中硫质量分数为5.00%～40.00%的方法。实验表明,以积分面积为横坐标,硫绝对含量为纵坐标绘制校准曲线。校准曲线的线性方程为Y=37.02X－1.52,线性相关系数R=0.999 8。方法检出限为0.017%。采用实验方法对铜精矿实际样品中硫含量进行测定,所得结果与重量法或燃烧-滴定法基本一致。采用实验方法对铜精矿标准样品进行测定,测定值与认定值基本一致。对铜精矿实际样品和标准样品6次平行测定结果的相对标准偏差(RSD,n=6)为0.41%～0.72%。

Discussion on the flux in determination of sulphur in copper concentrate by high frequency combustion infrared absorption method

0.040 0 g of sample was transferred into crucible (which had been burned before) containing 0.3 g of vanadium pentoxide flux. Then, 0.2 g of tin particles was added followed by covering with 0.15 g of vanadium pentoxide flux and 1.4 g of tungsten particles. The calibration curves were prepared with potassium sulfate. Thus,a determination method of sulpfur with mass fraction of 5.00%-40.00% in copper concentrate was established by high frequency combustion infrared absorption method. The results showed that the calibration curves could be prepared with integral area as horizontal ordinate and absolute sulfur content as vertical coordinate. The linear equation of calibration curve was Y=37.02X－1.52 with linear correlation coefficient of R=0.999 8. The detection limit of method was 0.017%. The proposed method was applied to the determination of sulfur content in copper concentrate actual sample. The results were consistent with those obtained by gravimetric method or combustion-titration method. The certified reference material of copper concentrate was determined according to the experimental method, and the results were consistent with the certified values. The actual samples and certified reference material of copper concentrate were determined for six times. The relative standard deviations (RSD, n=6) were between 0.41% and 0.72%.