摘要:
采用四酸(盐酸-硝酸-氢氟酸-高氯酸)溶矿、三酸(氢氟酸-硝酸-硫酸)溶矿及氢氧化钠碱熔法3种前处理方法对铝土矿样品进行分解,电感耦合等离子体发射光谱法(ICP-AES)测定样品中的镓。结果表明,四酸溶矿法的分解产物中存在较多的不溶物,镓与盐酸生成GaCl3导致挥损,镓的测定结果严重偏低;三酸溶矿法的分解产物中也存在较多的不溶物,导致测定结果严重偏低;氢氧化钠碱熔法处理铝土矿样品,酸化后所得溶液清澈透明,由于大量NaCl的存在,镓不会挥损,测定值准确度高。采用氢氧化钠碱熔,盐酸酸化提取,ICP-AES法测定镓的准确度高,精密度好,方法检出限为3.21 μg/g,相对标准偏差(RSD,n=11)小于5%。经国家一级和二级标准物质分析验证,测定结果与标准值基本一致。
Abstract:
The bauxite ores were digested by three different pretreatments as HCl-HNO3-HF-HClO4 mixed acids, HF-HNO3-H2SO4 mixed acids and alkali fusion. The Ga was measured by Inductively Coupled Plasma-Atomic Emission Spectrometry(ICP-AES). The HCl-HNO3-HF-HClO4 mixed acids incompletely dissolved the bauxite ores with a large amount of residues. Due to the Ga reacts with HCl to form GaCl3 which is easy to volatilize from the solution system, the measured Ga concentration is much lower than the certified value. The bauxite ores also were incompletely dissolved by HF-HNO3-H2SO4 mixed acids with lower concentration for Ga. Nevertheless, the bauxite ores were completely digested by alkali fusion with clear solution. The NaCl in solution can protect Ga lossing by volatilization to obtain accurate result. The method of alkali fusion, HCl extraction and measurement by ICP-AES produces high precision and accurate result for Ga with detection limit of 3.21 μg/g and less than 5% RSD (n=11). The obtained result is generally consistent with certified value of both first and second grade national standard reference materials.
下载:
京公网安备 11010202008159号