稀土分析检测方法标准述评

从稀土矿、稀土精矿、稀土金属及其氧化物、稀土深加工产品等方面概述我国稀土分析国家标准体系.其中稀土配分、三氧化二铝、稀土总量、水分、灼减量等参数的检测,是稀土交易和萃取分离工艺过程中重要的技术指标;而钕铁硼、灯用稀土三基色荧光粉、稀土硅铁合金等分析标准,对于稀土磁性材料、稀土发光材料、稀土合金等稀土深加工产品的生产都有重要的指导意义;稀土产品及分析方法的建立,完善了稀土国家标准体系,满足了稀土生产和贸易的需要,促进了稀土行业持续健康发展.      

能量色散X荧光法快速测定装置在稀土分析中的应用

本文描述了一套由清华大学设计的能量色散ｘ荧光法快速测定装置，介绍了它在高纯稀土分离工业性试验基地的应用情况。该装置可同时测定多个稀土元素，其性能可以满足稀土分离厂中控分析的一般需要。在试验基地两年的应用表明，该装置具有投资少，操作、维护简便，分析精度高等特点，能够比较准确地反映各工艺段的运行状况，在国内各稀土厂有一定的应用前景。     

轻稀土萃取分离中稀土总量和分量的同时在线测定

用放射性同位素源Am-241激发萃取分离过程的轻稀土样品La、Ce、Pr和Nd,样品经放射源激发后产生特征KX-射线和康普顿散射线,由固体探测器接收,多道能谱仪分析和处理特征KX-射线和康普顿散射线,确定总稀土浓度和各稀土元素含量,实现轻稀土分量和总量的在线同时测定。     

影响分馏萃取稀土产品纯度的主要因素初探

影响酸性磷类试剂分馏萃取稀土产品纯度的主要因素有原料组成、分离系数、混合萃取比、流量波动和分离流程。采用理论分析和计算机动态仿真研究了这些因素对稀土分离产品纯度的影响。研究结果表明,分馏萃取法制备纯度高于99.999%的稀土分离产品时,应选择目标元素纯度≥99%的稀土原料,采用先AB/C分离后接有机进料A/B分离的工艺流程来分离原料中的稀土杂质,尽可能减小流量的随机波动,以及适当降低水相酸度。     

X射线荧光光谱法在线测定稀土冶炼分离过程中钬铒铥镱

我国稀土冶炼分离过程复杂,但多数稀土企业仍依靠实验室离线分析指导工艺,导致分析结果严重滞后,因此现迫切需要一种高效稳定的稀土在线分析方法。实验应用稀土配分在线分析仪,建立了一种在线测定稀土冶炼分离过程中Ho、Er、Tm、Yb配分含量的方法。将采样管置于串级萃取槽水相分隔室内,在蠕动泵作用下将样品输送至分析区域,通过X射线荧光光谱法(XRF)进行检测和数据记录。实验将XRF测试条件优化为电压40 kV、电流600 μA、测试时间60 s,模拟现场工况条件下优化蠕动泵泵速为250 r/min,并采用基本参数法消除元素间吸收增强效应。样品11次测定结果的相对标准偏差(RSD)小于0.4%,实验室模拟及现场在线测试结果与电感耦合等离子体原子发射光谱法(ICP-AES)的离线分析结果吻合较好,测试结果滞后时间短,完全能够满足稀土冶炼分离过程工艺动态控制的测定需要。     

稀土萃取分离技术现状分析

文章深入地分析了稀土萃取分离技术的现状,详细介绍了目前萃取分离工艺上采用的新技术、新方法,对稀土萃取分离工艺的优化设计和技术改造有着良好的指导意义。     

氧化铽中微量稀土杂质元素的化学光谱测定

本文采用强酸型阳离子交换树脂以α—羟基异丁酸淋洗分离镝和铽、铽和钆,可将氧化铽中稀土杂质富集进行光谱测定。本法对稀土杂质的富集分离比较快速有效,可分析高纯氧化铽中十一个稀土杂质元素。对单一稀土氧化物的产品分析有实用和参考价值。     

从废稀土荧光粉回收稀土

稀土荧光粉广泛应用于发光材料行业,并且用量每年都在不断增长,同时产生的废旧稀土荧光粉也越来越多.因此,从中回收稀土不仅有利于保护环境,而且有利于资源的充分利用.物理方法难以从废旧稀土荧光粉中分离得到高纯度单一稀土,化学方法则可以获得单一高纯稀土.而它的瓶颈在于浸出和分离的高效性及经济性.本文对废稀土荧光粉回收稀土技术的现状进行了分析,认为已具有从废旧稀土荧光粉中提取单一、高纯稀土的成套新技术.     

从废稀土荧光粉回收稀土

稀土荧光粉广泛应用于发光材料行业,并且用量每年都在不断增长,同时产生的废旧稀土荧光粉也越来越多。因此,从中回收稀土不仅有利于保护环境,而且有利于资源的充分利用。物理方法难以从废旧稀土荧光粉中分离得到高纯度单一稀土,化学方法则可以获得单一高纯稀土。而它的瓶颈在于浸出和分离的高效性及经济性。本文对废稀土荧光粉回收稀土技术的现状进行了分析,认为已具有从废旧稀土荧光粉中提取单一、高纯稀土的成套新技术。     

基于蝴蝶突变离子型稀土冶炼分离过程危险性分析

离子型稀土冶炼分离生产工艺流程包含:酸溶、萃取、沉淀、灼烧等,研究分析稀土冶炼分离过程中使用的危险物质的特点,指出生产工艺中存在中毒、灼烧、机械伤害等危险性以及萃取厂房的耐火等级偏低,防火分区不符合安全要求等问题.分析生产过程中存在的危险有害因素,利用蝴蝶型突变理论,建立离子型稀土冶炼分离企业的安全生产保障体系、危险程度界定和突变级数分级模型,对稀土冶炼分离企业管理和生产具有深远的现实意义.      

Impact of backmixing of the aqueous phase on two-component rare earth separation process

Solvent extraction based on mixer-settler is the major industrial method of rare earth (RE) separation. In the mixer-settler extraction process, due to the insufficient settling time in normal circumstances, backmixing of the aqueous phase could have significant impact on the process of RE extraction separation. Therefore on the basis of the extraction equilibrium and mass balance of the mixer-settler extraction process, here we developed a mathematic expression of the aqueous phase backmixing in a two-component separation process, and obtained a quantitative analysis of the backmixing effect on the purification process by the approximations according to certain hypotheses. Two extraction systems of La/Ce and Pr/Nd separation were chosen as the examples to analyze the backmixing effect, and the results showed that the aqueous backmixing had greater influence in the scrubbing segment than in the extraction segment, especially in the system with a high separation factor such as La/Ce separation. Therefore it was suggested that the aqueous backmixing effect should be well attended in the design and application of RE extraction separation.     

Separation of aluminum from rare earth by solvent extraction with 4-octyloxybenzoic acid

Leaching method is usually used to extract rare earth(RE) elements from ion adsorbed RE ores.In the leaching process,some impurities such as aluminum(Al) enter the leaching solution.The separation of Al from RE by carboxylic acid extractant 4-octyloxybenzoic acid(POOA) was studied in this article.By changing the pH value,temperature,solvent,saponification degree and other parameters,the extraction and separation performance of POOA in chloride system was systematically studied.Through specific e...     

Clean separation technologies of rare earth resources in China

After a review on the conventional separation process of rare earths (RE), hyperlink extraction technology was introduced and a potential process was proposed for clean separation of RE. A great amount of acid, base and water was consumed in the conventional RE separation process which included the procedures of raw material dissolving, extraction separation and precipitation. Therefore hyperlink extraction technology had been developed, by which the repeated consumption of acid and base could be avoided during the extraction process. And based on the theory and successful applications of the hyperlink extraction technology, we proposed the integral hyperlink process in which the intermediate acid resulted in individual procedures would be recycled and reused after being treated. The proposed process would make it feasible to consume no chemicals except for oxalic acid, and so could be a promising clean separation technology with a significant reduction on consumption and emission.     

Adjacent stage impurity ratio in rare earth countercurrent extraction process

Impurity components decrease stage by stage in a cascade of rare earth (RE) extraction separation, and adjacent stage impurity ratio (ASIR) which is defined as the ratio of an impurity’s contents in the aqueous/organic phase of two adjacent stages can be used to evaluate the capacity of impurity removal for the two stages. On the basis of extraction equilibrium and mass balance, the ASIR in a two-component extraction separation was deducted and its simplified expressions were given for different process sections according to reasonable assumptions. The calculation simulation was then carried out to obtain the ASIR distribution in the cascade. The results showed that in both the extraction and scrubbing sections the ASIR principally increased with the decrease of the molar proportion of the impurity but along with a flat appearing in the purification zone located in the middle of the cascade. The ASIR intuitively exhibits the running status of RE extraction separation and purification, which could provide a theoretic guide for investigating the influence factors of RE extraction separation process in practical industry.     

三代酸法稀土分离工艺改进和发展过程

本文介绍稀土分离三代酸法工艺改进发展过程，主要针对工艺的技术、设备、质量、产量、收率。完善优化工艺过程，研究开发新产品，提高技术经济指标。     

等效分离系数及多组分稀土串级萃取分离工艺设计

以多元稀土串级萃取体系的状态方程为基础，引入等效分离系数，将多元串级萃取体系描述为对分离系数进行修正后的等效双组分分离体系；提出了等效分离系数的计算方法，并对多元串级革取的分高工艺进行设计计算．计算机仿真结果表明，等效分离系数为萃取体系槽级中的最小有效分离系数．     

Separation chemistry and clean technique of cerium（IV）： A review

The separation method of changeable valence RE element of cerium(Ce) was reviewed in this paper. Solvent extraction is the most effective and efficient method to separate Ce(IV) from RE(Ⅲ), usually accompanied with fluorine(F) and phosphor(P) from bastnaesite and monazite etc. By roast or wet-air oxidation, Ce(Ⅲ) of bastnaesite and monazite was oxidized into Ce(IV), and Cyanex923 and [A336][P507] have been investigated to co-extract and recover Ce(IV), F and P from H2SO4 leaching liquor, leading to favorable conditions for the subsequent separation of Th(IV) and RE(Ⅲ). The interaction of Ce(IV) and F and/or P enhances the roasting, leaching and extraction of Ce(IV) due to increasing of the stability of Ce(IV), and the formation of CeF3 and CePO4 after reductive stripping will benefit the utilization of F and P. For dealing with RE ores of high-content Ce, the clean process of oxidation roasting and Ce(IV)-F separation for Sichuan bastnaesite highlights the advantages of Ce(IV) based clean technique, which firstly demonstrates the comprehensive utilization of Ce(IV), Th(IV), F and RE(Ⅲ) and prevention of environmental pollution from fountainhead. A preliminary flowsheet of two-step oxidation and extraction of Ce(IV) for Bayan Obo mixed ores was further proposed to process the oxidation and extraction of Ce(IV) in presence of both F and P, indicating the possibility of similar effects with clean process of Sichuan bastnaesite. Ce(IV) separation chemistry and clean technique will open up new realms for light RE resources utilization, meeting "Emission Standards of Pollutants from Rare Earths Industry" promulgated by China's Ministry of Environment Protection(MOP) in 2011.     

江西离子型稀土冶金分离技术的发展与进步

简要介绍了江西离子型稀土冶金分离技术的发展历程及其在国内外的影响和地位，指出萃取技术仍然是稀土元素分离提纯的首选工业方法。同时对“十一五”期间江西稀土冶金分离技术领域科技开发的重大课题提出了建议。     

CL－5709萃淋树脂色层分离重稀土元素

本文研究了用ＣＬ－５７０９萃淋树脂－梯度淋洗技术色层分离Ｄｙ、Ｈｏ、Ｅｒ。研究表明，淋洗液酸度、工作温度、色层柱高度及淋洗速度对分离效果有重要影响。实验得出了使Ｄｙ、Ｈｏ、Ｅｒ互相分离的最适合的工艺参数。利用该条件可以有效地分离不含钇的Ｄｙ、Ｈｏ、Ｅｒ混合物，还用红外光谱研究了萃淋树脂吸附稀土离子的机理。