硅钼蓝光度法测定硅铬合金中硅含量  

Determination of Sillicon in Ferrosilicochromium with Molybdenum Blue Photometric Method

作　　者：夏培民 

机构地区：[1]腾达西北铁合金有限责任公司,甘肃永登730334

出　　处：《甘肃冶金》2013年第4期63-64,73,共3页Gansu Metallurgy

摘　　要：将经典的氟硅酸钾碱滴定法改为硅钼蓝光度法快速测定硅。试样用硝酸和氢氟酸溶解,多余的氢氟酸用饱和硼酸溶液配合,在一定酸度下,加入钼酸铵与硅酸生成黄色的硅钼杂多酸,再加入草酸以破坏磷等与钼酸铵形成的杂多酸并络合三价铁,最后加入硫酸亚铁铵将硅钼黄还原为硅钼蓝,然后用分光光度法测定硅含量的方法。实验结果表明,在0.1～0.6mol/L的酸度下,正硅酸与钼酸铵生成硅钼杂多酸,选择硅钼蓝的吸收波长在660nm处,表观摩尔吸光系数为ε=8.69×103L·mol-1·cm-1,Si的浓度在0～500mg/100mL范围内符合比尔定律,相关系数r=0.9998。本方法应用于硅铬合金中硅含量的测定,方法选择性强,且缩短了分析周期。l： The classical potassium fluosilicate precipitated alkali titration method was changed to silicon-molybdenum blue photometry for fast determination of silicon. After the sample was dissolute with nitric acid and hydrofluoric acid, excess hydrofluoric acid was neutralized with saturated borate solution. At certain acidity, the silicic acid reacted with ammonium molybdate to form soluble silicon molybdenum heteropolyacid. By adding oxalic acid to destroy the heteropoly formed by phosphorus and ammonium molybdate and complex formation of trivalent iron, and finally adding ammonium ferrous sulfate to reduce molybdisilicic to molybdenum blue. Experiment resuh shows that in at acidity of 0.1 - 0.6 mol/l HNO, TEOS reacted with ammonium molybdate to form yellow silicon molybdate heteropoly acid. The apparent molar absorptivity is 8.69 ×10^3L·mol^-1·cm^-1 at 660 nm,Sig density was in accord with the Bcer＇s law in the range of 0 -5001~g/100mL. This approach was applied to determination of silicon content of silicochromium with good selectivity and cutting down in the analytical cycle

关 键 词：硅铬合金 硅 硅钼蓝光度法 

分 类 号：O657.32[理学—分析化学]