【摘要】 稀土资源已成为现代工业化建设的战略性资源，白云鄂博稀土精矿采用硫酸高温焙烧进行稀土的冶炼分离，期间砷的存在会降低产品质量、造成环境污染，因此有必要建立稀土硫酸焙烧冶炼工艺流程白云鄂博稀土精矿及水浸渣中砷的测定方法。实验采用盐酸-硝酸-氢氟酸酸溶体系并使用微波消解法消解样品，向消解液中加入盐酸、硫脲-抗坏血酸混合溶液，使用氢化物发生-原子荧光光谱法(HG-AFS)测定砷，从而建立了微波消解-HG-AFS测定白云鄂博稀土精矿及水浸渣中砷的方法。实验对载流浓度和硼氢化钾质量浓度进行了优化：确定了载流浓度为5%(盐酸),硼氢化钾质量浓度为20 g/L。砷在质量浓度为0.50～50.00 ng/mL时与其对应的荧光强度呈良好的线性关系，校准曲线的线性相关系数r=0.999 9;方法中砷的检出限为0.02μg/g。实验方法用于测定白云鄂博稀土精矿及水浸渣中砷，结果的相对标准偏差(RSD,n=6)分别为4.1%和10%;加标回收率为94%～105%;与电感耦合等离子体串联质谱法(ICP-MS/MS)的比对结果表明两种方法的测定结果无显著性差异。更多还原

【Abstract】 Rare earth resources have become the strategic resources for modern industrialization construction. Bayan Obo rare earth concentrate is smelted and separated by high-temperature roasting with sulfuric acid, during which the presence of arsenic will reduce the product quality and cause environmental pollution. Therefore, it is necessary to establish a method for the determination of arsenic in Bayan Obo rare earth concentrate and water leaching residue in rare earth sulfuric acid roasting and smelting process. In experiments, the sample was dissolved by microwave digestion method in hydrochloric acid-nitric acid-hydrofluoric acid system. The mixture of hydrochloric acid, thiourea and ascorbic acid was added into the digestion solution. The content of arsenic was determined by hydride generation-atomic fluorescence spectrometry(HG-AFS). Consequently, a method for determination of arsenic in Bayan Obo rare earth concentrate and water leaching residue by microwave digestion-hydride generation-atomic fluorescence spectrometry was established. The carrier concentration and potassium borohydride mass concentration were optimized: the carrier concentration was 5%(hydrochloric acid), and the mass concentration of potassium borohydride was 20 g/L. The mass concentration of arsenic in range of 0.50-50.00 ng/mL showed good linear relationship with the corresponding fluorescence intensity, and the linear correlation coefficient of calibration curve was r=0.999 9. The limit of detection of arsenic in this method was 0.02 μg/g. The contents of arsenic in Bayan Obo rare earth concentrate and water leaching residue were determined according to the experimental method. The relative standard deviations(RSD, n= 6) of the results were 4.1% and 10%, respectively. The spiked recoveries were between 94% and 105%. The results were compared with those obtained by inductively coupled plasma tandem mass spectrometry(ICP-MS/MS), and it was found that the determination results of two methods had no significant difference.更多还原