Role of minerals properties on leaching process of weathered crust elution-deposited rare earth ore
Role of minerals properties on leaching process of weathered crust elution-deposited rare earth ore
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DOI：
10.1016/s1002-0721(14)60454-3
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发表时间：
2015-05-01
影响因子：
4.9
通讯作者：
Wu Wenyuan
中科院分区：
文献类型：
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作者：
Xiao Yanfei;Liu Xiangsheng;Wu Wenyuan
花岗岩为侵入岩，火山岩为喷出岩。它们的风化程度和矿物化学成分可能有许多差异。研究了龙南稀土矿区花岗岩风化壳淋溶沉积型稀土矿（LN矿）和六塘稀土矿区火山岩风化壳淋溶沉积型稀土矿（LT矿）的矿物学特征和淋溶机理。采用X射线衍射（XRD）、傅里叶变换红外光谱（FT-IR）等方法对稀土矿进行物相分析。本文还介绍了矿石的粒度分布和主要成分。用不同的动力学模型分析了两种稀土矿的浸出机理，并用收缩核模型进行了描述。它们都是内扩散控制的浸出过程。LN矿石的浸出动力学方程可表示为：1-2/3 eta（LN）-（1-η（LN））（2/3）=0.106r（0）（-0.377）e（-1.096x104/8.314T）t，LT矿的浸出动力学方程为1-2/3 eta（LT）-（1-η（LT））（2/3）=8.33x10（-3）r（0）（-0411）e（-4.640 × 10 ~ 3/8.314T）t，在相同条件下，LT矿的稀土浸出率始终较低，达到相同的稀土浸出率需要更长的时间和更高的（NH 4）（2）SO 4消耗量，氨氮污染更严重。因此，提出镁盐作为去除氨氮污染的淋洗剂，并进行了进一步的研究。
Granite belonged to intrusive rock and volcanic was extrusive rock. There may be many differences in their degree of weathering and mineral chemical composition. The present study investigated the minerals properties and the leaching mechanism of the granitic weathered crust elution-deposited rare earth ore from Longnan Rare Earth Mine area (LN ores) and volcanic weathered crust elution-deposited rare earth ore from Liutang Rare Earth Mine area (LT ores). The X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) were used to characterize the phase of rare earth ores. The particle size distributions and main composition of the ore were also presented in this paper. The leaching mechanisms of two kinds of rare earth ores were analyzed with different kinetics models and could be described by the shrinking-core model. They were all inner diffusion-controlled leaching processes. The leaching equation of the kinetics of the LN ores could be expressed as:1-2/3 eta(LN)-(1-eta(LN))(2/3) =0.106r(0)(-0.377)e(-1.096x104/8.314T)t, leaching equation of kinetics of LT ores was 1-2/3 eta(LT)-(1-eta(LT))(2/3)=8.33x10(-3)r(0)(-0411)e(-4.640x103/8.314T)t.The rare earth leaching rate of LT ores was always lower in the same condition, and it would need more time and more (NH4)(2)SO4 consumption to achieve the same rare earth leaching efficiency, which would lead to more serious ammonia-nitrogen pollution. Therefore, magnesium salt was proposed as the leaching agent to eliminate ammonia-nitrogen pollution and further studies would be taken in the future.