硅钼蓝分光光度法测定氟化稀土中二氧化硅

发布时间：2018-05-11 12:40

本文选题：氟化稀土 + 二氧化硅　；参考：《冶金分析》2017年04期

【摘要】：氟化稀土是一种用途广泛的材料,其中二氧化硅的含量是衡量产品品质的一个关键指标,直接影响生产合金的工艺和产品的质量。实验采用碳酸钠-硼酸混合熔剂(m_(碳酸钠)∶m_(硼酸)=4∶1)熔融试样,经盐酸酸化,加入0.4mL硫酸(1+5)控制显色体系的pH≈1,正硅酸与钼酸铵沸水浴保温时间为3~5s时形成硅钼杂多酸,用草酸-硫酸混合酸破坏磷、砷等干扰元素,抗坏血酸还原硅钼杂多酸为硅钼蓝,建立了光度法测定氟化稀土中二氧化硅含量的方法。试验表明,显色液中二氧化硅质量浓度在0.04~2.0μg/mL范围内符合比尔定律,方法中二氧化硅的检出限和测定下限分别为0.002 8%和0.010%(质量分数)。方法用于3个氟化稀土实际样品中二氧化硅量的测定,结果的相对标准偏差(RSD,n=10)为2.3%~5.2%;测定值与电感耦合等离子体原子发射光谱法(ICP-AES)的测定结果一致。
[Abstract]:Rare-earth fluoride is a widely used material, in which the content of silicon dioxide is a key indicator of the quality of the product, which directly affects the process and quality of the production of the alloy. The experiment uses the sodium carbonate boric acid mixed flux (m_ (sodium carbonate): m_ (boric acid) =4: 1) melting sample, acidification by hydrochloric acid, and 0.4mL sulfuric acid (1+5) control display PH 1 of color system, silicon molybdenum heteropoly acid is formed when the time of boiling water bath of ammonium molybdate and orthosilic acid and ammonium molybdate is 3~5s. The interference elements such as phosphorus, arsenic and so on are destroyed by oxalic acid sulphuric acid mixed acid and silicon molybdenum heteropoly acid is reduced by ascorbic acid as silicon molybdenum blue, a spectrophotometric method for the determination of silicon dioxide content in rare earth fluoride is established. The experiment shows that silica in the chromogenic solution is used. The mass concentration in the range of 0.04~2.0 mu g/mL accords with Bill's law. The detection limit and the lower limit of the determination of silica are 0.0028% and 0.010% (mass fraction). The method is used for the determination of silica in 3 real samples of rare earth fluoride, the relative standard deviation (RSD, n=10) of the results is 2.3%~5.2%; the determination value and inductively coupled plasma The results of ICP-AES are consistent.

【作者单位】：瑞科稀土冶金及功能材料国家工程研究中心有限公司;包头稀土研究院;包头轻工职业技术学院;
【分类号】：TQ133.3;O657.3

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