论文部分内容阅读
硅铁中钙的测定一般有草酸钙重量法、原子吸收法、络合滴定法及偶氮胂Ⅰ光度法等。但国内至今仍无一个统一的化学分析方法。这大概是由于硅铁中钙含量较低、干扰元素较多、分离中较易损失及络合滴定的终点较难确定所致。为了解决这一实际困难,笔者试验用偶氮氯膦Ⅲ光度法测定硅铁中钙:即用氢氟酸—硝酸分解试样;高氯酸冒烟赶氟;铜试剂分离Fe、Cr、Mn和Ni等干扰元素;调节酸度至pH2～3;以EDTA作掩蔽剂,
The determination of calcium in ferrosilicon calcium oxalate gravimetric method, atomic absorption method, complexometric titration and arsenazo Ⅰ luminosity method. However, there is still no unified chemical analysis method in China. This is probably due to the lower calcium content in ferrosilicon, more interference elements, the more easily lost in the separation and the complexation titration end point is difficult to determine. In order to solve this practical difficulty, the author experiment with chlorophosphonazo Ⅲ spectrophotometric determination of calcium in ferrosilicon: ie hydrofluoric acid - nitric acid decomposition of samples; perchloric acid smoke and fluoride; copper reagent separation of Fe, Cr, Mn And Ni and other interference elements; adjust the acidity to pH2 ~ 3; EDTA as masking agent,