中文摘要：

稀土元素在矿石中有多种不同的赋存形式，主要有离子吸附型和矿物晶格型，稀土不同赋存形态对其本身准确分析测定有很大的影响。本文从稀土元素在矿石中不同赋存形态的角度出发，探讨了不同前处理方法对稀土准确测试结果的影响，采用盐酸-硝酸-氢氟酸-高氯酸（四酸）敞开酸溶、盐酸-硝酸-氢氟酸-高氯酸-硫酸（五酸）敞开酸溶、氢氟酸-硝酸封闭压力酸溶、氢氧化钠-过氧化钠碱熔四种方法对离子吸附型和矿物晶格型两类赋存类型的稀土矿石样品进行前处理，电感耦合等离子体发射光谱法测定其中的15种稀土元素。结果表明：对于离子吸附型的稀土矿石标准物质（GBW07161、GBW07188），四酸敞开酸溶法测定的结果明显偏低，15种稀土元素大都偏低10％～20％，五酸敞开酸溶法、封闭压力酸溶法和碱熔法的测定值与标准值吻合；而对于稀土以离子化合物及类质同象置换的形式赋存于矿物晶格中的白云鄂博轻稀土矿石样品，三种酸溶法结果较碱熔法均偏低，其中四酸敞开酸溶法偏低最多，约偏低20％左右，五酸敞开酸溶法和封闭压力酸溶法偏低5％～15％。本文提出，对于离子吸附型稀土矿，五酸敞开酸溶法和封闭压力酸溶法可以代替传统操作复杂的碱熔法，但对于稀土以离子形式赋存于矿物晶格型的稀土矿．目前最合适的前处理法是传统的碱熔法。

英文摘要：

Rare earth elements （REEs） in ore have many different forms, mainly ion adsorption and mineral lattice types. The occurrence state of rare earth elements has a great impact on accurate analysis. In this study, the effects of different pretreatment methods in REEs analysis are discussed from the perspective of REEs occurrence states in ore. Four pretreatment methods including HC1-HNO3-HF-HC104 under normal pressure （the open acid digestion） , HC1-HNO3-HF-HC104-H2SO4 under normal pressure （the open acid digestion, adding sulfuric acid） , HF-HNO3 in confining pressure （the pressurized acid digestion） as well as NaOH-Na2O2 alkali fusion were conducted for REEs ores. 15 rare earth elements were determined by Inductively Coupled Plasma-Atomic Emission Spectrometry （ICP-AES）. The results of the open HC1-HNO3-HF-HC104 acid digestion for the two National Standard Substances （GBW 07161, GBW 07188） which are ion adsorption-type rare earth ores, are significantly lower, mostly 10% - 20% lower than certified values. Meanwhile, the results from the pressurized acid digestion, the open HC1-HNO3- HF-HClO4-H2 SO4 acid digestion and alkaline fusion are in agreement with certified values. For the two Baiyun Ebo REEs ore samples （SS-1 and BY-1 ） which are mineral lattice-type, results from all three acid digestions are lower than those from alkaline fusion. The results of the open HC1-HNO3-HF-HC104 acid digestion are the lowest, approximately 20% lower than those from alkaline fusion, and results of the open HC1-HNO3-HF-HClO4-H2 SO4 acid digestion and the pressurized acid digestion essentially are as low as approximately 5% -15%. In summary, for ion adsorption-type rare earth ores, the the open HC1-HNO3-HF-HClO4-H2SO4 acid digestion and pressurized acid digestion could replace the traditional alkaline fusion, while for mineral lattice-type rare earth ores, the most suitable pretreatment method is still alkaline fusion.