稀土 单个稀土金属及其化合物中稀土含量的测定 重量法

[中文适用范围]： 本文件规定了用重量法测定 11 种稀土金属（镧、铈、镨、钕、钐、铕、钆、铽、镝、钬和钇）及其化合物，例如氧化物、碳酸盐、氢氧化物、草酸盐、氯化物和氟化物中稀土含量的测定方法。稀土含量的测定范围（质量分数）如下： — 稀土金属：98.0%（质量分数）至 99.5%（质量分数）； — 稀土氧化物：95.0%（质量分数）至 99.8%（质量分数）； — 稀土草酸盐：95.0%（质量分数）至 99.8%（质量分数）； — 稀土氟化物：75.0%（质量分数）至90.0%（质量分数）； — 其他化合物（即稀土氢氧化物、稀土氯化物和稀土碳酸盐）：40.0%（质量分数）至70.0%（质量分数）。当a）样品的基质为铒、铥、镱和镥时；b）样品中钍或铅的含量按质量分数大于0.1%时，本标准不适用于单个稀土金属及其化合物。 [外文原描述]： This document specifies a gravimetric method for the determination of rare earth content in 11 kinds of individual rare earth metals (lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium and yttrium) and their compounds, such as oxides, carbonates, hydroxides, oxalates, chlorides and fluorides. The determination ranges for the rare earth content in mass fraction are as follows: — rare earth metal: 98,0 % (mass fraction) to 99,5 % (mass fraction); — rare earth oxide: 95,0 % (mass fraction) to 99,8 % (mass fraction); — rare earth oxalate: 95,0 % (mass fraction) to 99,8 % (mass fraction); — rare earth fluoride: 75,0 % (mass fraction) to 90,0 % (mass fraction); — other compounds (i.e. rare earth hydroxide, rare earth chloride and rare earth carbonate): 40,0 % (mass fraction) to 70,0 % (mass fraction). It does not apply to individual rare earth metals and their compounds when: a) the matrixes of the sample are erbium, thulium, ytterbium and lutetium; b) the content of thorium or lead in the sample is greater than 0,1 % in mass fraction.