稀土镁硅铁合金中稀土总量、硅、镁的联合测定

The Content Determination for the Magnesium ,Silicon and Rare-earth Amount of the Balling-Mg-ferrosilicon-rare-earth Alloy

针对球墨铸铁生产中的球化剂———稀土镁硅铁合金中的稀土总量、硅、镁含量的测定,提出了1种经济简便、快速准确的测定方法,传统测量方法是在铂金皿中加碱熔融试样后,用沉淀重量法测定,其操作不易掌握,且成本高。本法是在塑料烧杯中用硝酸、氢氟酸溶解试样,定容后分取不同体积母液,调节不同pH值,用偶氮氯膦Ⅲ与稀土元素显色、钼酸铵与硅显色、偶氮氯膦Ⅰ与镁显色,利用分光光度计比色,测得其质量分数,其结果具有较好的准确度和精密度,适合在工厂实验室推广应用。

In view of the content determination for the Magnesium , Silicon and rare-earth amount of the balling-Mg-ferrosilicon-rare-earth alloy in production of the nodular cast iron, a simple and convenient, quick and accurate method of determination is put forward in this article.The usual weight-precipitation method by adding the alkalis into the platinum container for melting the test samples is uneasy for operation and costly.In the method of this article called the spectro-photometry, the content is determined by taking the nitric acid and hydrofluoric acid into the plastic beaker for dissolution and then extracting the mother liquor of the different volume and adjusting the different pH value; the color display is fulfiled by azo-chlorophsphine Ⅲ and rare-earth element ,ammonium molybdate and Silicon, azo-chlorophsphine and Magnesium; the colorimetric analysis is done by spectrophotometer. This is a method of high accuracy and precission and is suited to apply to and popularize for the laboratories of factories.