【摘要】 华南稀土花岗岩风化壳主要可分为腐植层、全风化层和半风化层。在岩石的风化淋滤过程中，稀土以水合或羟基水合离子吸附在全风化层中的主要矿物埃洛石和高岭石等粘土矿物上。这些层状粘土矿物具有取代结构和断面余键两个吸附活性中心。量子化学计算表明两个吸附活性中心对不同稀土的吸附能力为：Ｌａ^３＋＞Ｃｅ^３＋＞Ｐｒ^３＋＞Ｎｄ^３＋＞Ｓｍ^３＋＞Ｅｕ^３＋＞Ｇｄ^３＋＞Ｔｂ^３＋＞Ｄｙ^３＋＞Ｈｏ^３＋＞Ｙ^３＋＞Ｅｒ^３＋＞Ｔｍ^３＋＞Ｙｂ^３＋＞Ｌｕ^３＋，再加上Ｃｅ^３＋的不稳定易形成ＣｅＯ＿２，导致了稀土在迁移富集中分异，出现了风化壳矿体上层轻稀土和下层重稀土稍高的现象。风化壳矿石有四个主要物理化学性质：含水多样性、对酸碱的缓冲性、吸附稀土的相对稳定性和可交换性。更多还原

【Abstract】 The weathering crust of REE granites in southern China can be divided into humic layer,completely weathering layer and partly weathering layer. In the completely weathering layer, rare earth elements are adsorped on the clay minerals (mainly halloysite and kaolinite) in hydrous complex or hydroxy and hydrous complex during the weathering leaching process. The layered clay minerals have two active adsorptive centers, i.e. the replacing structure and the residual bond on fractured surface. The order of adsorbility of these two centers is as follows: La3+>Ce3+>Pr3+>Nd3+>Sm3+>Eu3+>Gd3+>Tb3+>Dy3+>Ho3+>Y3+>Er3+>Tm3+>Yb3+>Lu3+ based on quantum chemical calculating, and Ce3+ is unstable and easily form CeO2, which leads to the fractionation of REE during their migration and enrichment. Therefore, the light rare earths are slightly more enriched at the upper layer and the heavy those at the bottom of the ore body of the weathering crust.The ores of the weathering crust type have four main physicochemical properties:the variety of contained water, the bufferity to resist the change of acid and base,the relative chemical stability of adsorbed rare earth ions and the exchangeability of ions absorbed on the clay minerals.更多还原