高频燃烧红外吸收法测定铜铅锌矿石中硫

铜铅锌矿石是冶炼钢铁的重要原材料,而其中硫含量的高低会直接影响钢铁的脆性、流动性等性能。因此,准确快速测定铜铅锌矿石中硫含量对于冶炼此类矿石意义重大。选取与实际样品具有相似化学性质的多个铜铅锌矿石标准物质建立校准曲线以消除基体效应,以铁助剂和钨锡助剂为助熔剂,实现了高频燃烧红外吸收法对铜铅锌矿石中质量分数为0.106%～10.76%硫的测定。探讨了称样量、钨锡助剂用量、比较器水平、分析时间、坩埚是否需要加盖等因素对硫测定结果的影响,确定最佳实验条件如下:称样量为0.1000g、钨锡助剂用量为1.6g、比较器水平为1%、分析时间为50s、坩埚不加盖。结果表明,校准曲线线性相关系数为0.9999,方法检出限为0.0264%,定量限为0.106%。采用实验方法对不同铜铅锌矿石标准物质进行多次测定,相对误差均小于根据DZ/T 0130—2006《地质矿产实验室测试质量管理规范》得到的相对误差允许限。按照实验方法对铜铅锌矿石实际样品中硫平行测定11次,测定结果与燃烧碘量法、硫酸钡重量法结果无显著差异,相对标准偏差(RSD)在0.50%～4.6%之间。

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

Copper-lead-zinc ore was an important raw material for steel smelting, and its sulfur content would directly affect these properties such as of steel brittleness and fluidity. Therefore, the accurate and rapid determination of sulfur content in copper-lead-zinc ore was of great significance for the smelting of copper-lead-zinc ore. Several certified reference materials of copper-lead-zinc ores with similar chemical properties as the actual sample were selected to establish the calibration curve for eliminating the matrix effect. Thus, a determination of sulfur content with mass fraction in range of 0.106%-10.76% in copper-lead-zinc ore was realized by high frequency combustion infrared absorption method with iron and tungsten-tin as flux. The effect of determination conditions such as sample mass, the mass of tungsten-tin flux, comparator level, analysis time and crucible covered or not were discussed. The optimum analytical conditions were obtained as follows: the sample mass was 0.1000g; the mass of tungsten-tin flux was 1.6g; the comparator level was 1%; the analysis time was 50s; the crucible was not covered. The results showed that the linear correlation coefficient of calibration curve was 0.9999. The limit of detection was 0.0264%, and the limit of quantification was 0.106%. Different certified reference materials of copper-lead-zinc ore were determined according to the experimental method. The relative errors were all less than the allowance limit of relative error obtained in accordance with The specification of testing quality management for geological laboratories of DZ/T 0130-2006. The content of sulfur in actual sample of copper-lead-zinc ores was determined parallel for 11 times according to the experimental method. The results were compared with those obtained by combustion iodine method and barium sulfate gravimetry. The relative standard deviation (RSD, n=11) were between 0.50% and 4.6%.