基于浸取pH依赖性的离子吸附型稀土分类及高效浸取方法
Classification and High Efficient Leaching of Ion Adsorption Rare Earth Based on Its pH Dependence
作者单位E-mail
许秋华 南昌大学稀土与微纳功能材料研究中心, 南昌 330031
南昌航空大学环境与化学工程学院, 南昌 330063 
 
杨丽芬 南昌大学稀土与微纳功能材料研究中心, 南昌 330031  
张丽 南昌大学稀土与微纳功能材料研究中心, 南昌 330031  
李翠翠 南昌大学稀土与微纳功能材料研究中心, 南昌 330031  
王大山 南昌大学稀土与微纳功能材料研究中心, 南昌 330031  
周新木 南昌大学稀土与微纳功能材料研究中心, 南昌 330031  
周雪珍 南昌大学稀土与微纳功能材料研究中心, 南昌 330031  
李永绣 南昌大学稀土与微纳功能材料研究中心, 南昌 330031 yxli@ncu.edu.cn 
摘要: 研究了稀土及主要杂质离子被硫酸铵浸出的pH依赖性。结果证明稀土和钙镁等离子的浸取率在低酸度范围内随酸度增大有明显提高,继续提高酸度并不会进一步提高浸取率,而铝、铁、钪等易水解金属离子的浸取率随酸度增大而持续增加。据此,基于离子吸附型稀土的定义及浸取所需pH值的范围,将离子吸附型稀土进一步区分为易浸稀土和难浸稀土,其中难浸稀土是需要在弱酸性条件(pH ≤ 4)下才能浸取的被胶体等强吸附剂吸附的稀土离子。由于在不同地区和不同矿层及不同粒级的样品中所含强吸附剂的量以及磨蚀pH(pHd)和交换pH(pHt)的不同,这两类离子吸附型稀土的比例不同。对于pHd和pHt值较高的矿样,适当提高浸取酸度可以显著提高稀土浸取率。为此,提出了分阶段浸取稀土并增加石灰水护尾工序来保证稀土浸取率和尾矿安全稳定性的原则流程。
关键词: 离子吸附型稀土  浸取效率  pH依赖性  电解质
基金项目: 国家自然科学基金(No.21161014,51274123)和科技部973课题(No.2012VBA01204)资助项目。
Abstract: The pH value dependence of leaching efficiency (LE) of ion adsorbed rare earth (IARE) and the main co-existing impurity ions leached by ammonium sulfate is studied. The results show that the LE of IARE and calcium magnesium increases with increasing acidity in the range of low acidity; however, no further significant increase is observed when employing high concentration of acid solution. While the LE of some easily hydrolyzed metal ions such as Al, Fe, Sc increases continuously with the increase of acidity. Therefore, based on the definition of ion adsorption rare earth and the range of pH value needed for leaching different kinds of IARE, the IARE is further divided into two types:easy leaching and hard leaching. The hard leaching IARE is absorbed by strong absorbents such as colloid particles and 2:1 type clay minerals, and could only be leached under weak acidity condition (pH ≤ 4). The ratio of these two types of adsorbed rare earth ions is different due to the amount of strong adsorbent contained in samples from different regions and different deposit layers as well as different particle levels, and depending on the abrasive pH(pHd) and exchange pH(pHt) of mineral sample. For the samples with high pHd and high pHt value, the LE of IARE can be significantly improved by increasing the leaching acidity. Accordingly, a sequence leaching process by adding an acid leaching process and a washing process with water and lime solution after general ammonium sulphate leaching was proposed to ensure the LE of IARE and the safety of tailing.
Keywords: ion adsorption rare earth  leaching efficiency  pH dependence  electrolyte
投稿时间:2017-10-22 修订日期:2017-11-24
摘要点击次数:  118
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许秋华,杨丽芬,张丽,李翠翠,王大山,周新木,周雪珍,李永绣.基于浸取pH依赖性的离子吸附型稀土分类及高效浸取方法[J].无机化学学报,2018,34(1):112-122.
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