硅铁中锰、磷、铬的联合测定

Combined determination of manganese,phosphorus and chromium in ferrosilicon

采用一次称样、硝酸和氢氟酸溶样、水浴加热的方法制成母液后,分别用分光光度法测定了硅铁中锰、磷元素含量,滴定法测定了硅铁中铬元素含量。通过试验确定了溶样方式,氢氟酸加入量等溶样条件;进行了锰和铬之间的相互干扰试验,结果表明,样品中的铬不干扰锰含量的测定,采用亚硝酸钠和尿素可消除锰对铬测定的干扰。按此方法对4批次硅铁样品进行了分析,其测定值与国标法测定的结果相一致,测定锰、磷、铬3元素的相对标准偏差(n=6)依次为1.0%～1.4%、0.1%～0.5%和0.8%～1.5%,适用于工厂实验室的日常分析。

After once weighting, the sample was dissolved by nitric acid and hydrofluoric： acid with heating in water bath to preparemother solution. The content of manganese and phosphorus in ferro- silicon was determined by spectrophotometry, and the content of chromium in ferrosilicon was deter- mined by titrimetry. The conditions for sample dissolution such as sample dissolution method and hydrofluoric acid dosage were obtained through experiments. The mutual interference test between manganese and chromium was conducted. The results showed that, chromium in the sample did not interfere with the determination of manganese content, and the interference of manganese with chro- mium could be eliminated using sodium nitrate and urea. Four batches of ferrosilicon samples were an- alyzed by this method, and the results were consistent with those obtained by national standard meth- od. The relative standard deviations （RSD, n=6） of manganese, phosphorus and chromium were 1.0 %-1.4 %, 0.1%-0.5% and 0.8 %-1.5 %, respectively. The proposed method was applicable for the routine analysis in factory laboratory.