摘要
风化壳淋积型稀土矿床是很重要的一种矿床类型。作者采用水析法提取了梧州市区风化壳淋积型稀土矿床中的粘土矿物，并进行了钕和镱的吸附实验研究。实验结果表明，在不同的实验体系中，吸附反应达到平衡的时间是不同的，２％ＨＣＩ至少１２ｈ，１％ＨＣＩ至少０．１ｈ。影响粘土吸附稀土的物理化学因素有：溶液浓度、溶液酸碱度（ｐＨ值）、离子强度、固液比和温度等。在ｐＨ值较低的相同实验条件下，轻稀土的吸附效率要明显高于重稀土。在较低的ｐＨ值条件下，重稀土的吸附效率很低，而在较高的ｐＨ值条件下则相反。根据实验结果对Ｌａｎｇｍｕｉｒ吸附模型和计量置换吸附模型在粘土吸附稀土的适用性进行了讨论。在上述实验的基础上，提出了酸性淋滤和粘土吸附反应的耦合作用是风化壳淋积型稀土矿床的成矿机理。
Weathering crust-leaching REE deposits in southern China are experimentally studied. The clays that are used for adsorption experiments of Nd and Yb are extracted from the weathering crust-leaching REE ore deposits in the Wuzhou area using the standard sedimentation method. The results show that the equilibrium time of Yb adsorption varies with electrolytic system.It needs 12 hours for the 2% HCI system, and 0.2 hours for the 1% HCI system.The physicochemical factors that affect REE adsorption by clays include electrolytic concentration of the solution,pH value, ionic strength,temperature,and the solid/liquid ratio.The adsorption of Nd is more effective than that of Yb at low PH conditions.The amount of Yb adsorption by clays considerably increases with increasing PH value.The Langmuir isotherm model and Geng’s isotherm equation are discussed based on experimental observations,and a model of acidic infiltration coupled with the adsorption of REE by clays is proposed to explain the metallogenetic mechanism of the weathering crustleaching REE ore deposits.
出处
《地球化学》
CAS
CSCD
北大核心
1994年第2期189-198,共10页
Geochimica
关键词
稀土元素矿床
成矿机理
风化壳
weathering crust-leaching REE deposit, physicochemical condition
metallogenetic mechanism
