快速测定硅铁中的硅量

Rapid Determination of Silicon In Fe-Si

试样以硝酸、氢氟酸溶解 ,在 3mol/ L硝酸介质中 ,加入饱和硝酸钾 ,使硅酸生成氟硅酸钾沉淀 ;经过滤、洗涤 ,除去大部分游离酸 ,在硝酸钾 -乙醇混合液存在下 ,用氢氧化钠中和残余游离酸 ,加入沸水使氟硅酸钾沉淀水解 ;以溴百里香酚蓝 -酚红为指示剂 ,用氢氧化钠标准溶液滴定计算硅量。本方法操作简单 ,容易掌握 ,可大大节约分析时间 。

The sample was dissolved in nitric acid and hydrofluoric acid,then in 3mol/L nitric acid medium saturation KNO\-3 was added to form acid kalium\|fluosilicate deposit.After filtration and washing most dissociated acid was removed.In the existence of niter\|ethanol solution,sodium hydroxide was used to neutralize remains of acids,then impour boiling water was added to make kalium\|fluosilicate precipitate and hydrolyze.Using bromthymol blue phenol red was used as indicator and tetrated with sodium hydroxide.The method is easy and rapid with satisfactory results.