氮,氮,氮′,氮′-四辛基-3-氧戊二酰胺色谱柱分离-电感耦合等离子体质谱法测定混合稀土氧化物中重稀土

电感耦合等离子体质谱法(ICP-MS)测定稀土元素时,轻稀土元素Ce、Nd、Sm的氧化物等复合离子严重干扰重稀土元素Tb、Dy、Ho、Er的测定,因此对混合稀土中重稀土元素进行测定前一般需要先对其分离富集。实验在样品溶解后,将N,N,N′,N′-四辛基-3-氧戊二酰胺(TODGA)用硅藻土吸附后装柱,以0.1 mol/L HNO₃为样品溶液介质上柱,通过控制洗脱液的种类、酸度以及洗脱液流速,实现了轻稀土元素La、Ce、Pr、Nd与重稀土元素Tb、Dy、Ho、Er、Tm、Yb、Lu的分离和富集,建立了ICP-MS测定混合稀土氧化物中重稀土元素的方法。实验表明:控制洗脱流速为2.0 mL/min,用pH 2.0的HNO₃淋洗至淋洗体积约为500 mL,继续收集洗脱液,并用ICP-MS检测其中Nd₂O₃含量,直至洗脱液中Nd₂O₃的质量浓度小于200 ng/mL,可将轻稀土元素La、Ce、Pr、Nd及少量Y、Sm、Gd洗脱;再改用350 mL 1 mol/L HCl洗脱重稀土元素,可实现重稀土元素与La、Ce、Pr、Nd及部分Y、Sm、Gd的分离;通过选择¹⁵⁹Tb、¹⁶³Dy、¹⁶⁵Ho、¹⁶⁷Er、¹⁶⁹Tm、¹⁷²Yb、¹⁷⁵Lu为测定同位素可消除质谱干扰。将实验方法应用于混合稀土氧化物中重稀土元素的测定,加标回收率在93%～110%之间,相对标准偏差(RSD,n=8)在1.1%～10%之间。     

Efficient extraction and stripping of Nd(III), Eu(III) and Er(III) by membrane dispersion micro-extractors

The extraction of low concentration rare earth elements at high phase ratio was investigated. The traditional extraction set-up, such as mixer-settler, have drawbacks of easy emulsification, difficult separation and low efficiency if operated at the above condition. Membrane dispersion micro-extractor, owing to its well-dispersed, high surface-to-volume ratio and fast mass transfer rate, was employed in our work. Nd(III), Eu(III), Er(III) were chosen to represent light, medium, heavy rare earth elements (REEs). The extraction process of REEs with 2-ethylhexyl phosphoric acid-2-ethylhexyl ester (P507) was investigated by membrane dispersion micro-extractors. Firstly, the extraction equilibrium of these three elements was explored in the stirred conical flasks, and it is indicated that the extraction efficiencies can be 0.95, 0.97 and 0.98, respectively within 40 min at phase ratio of 100:1. Then the effects of operational conditions such as the residence time, organic and aqueous flow rates on extraction efficiency were also explored in micro-extractors. The results indicate that the efficiency decreases and then increases if increasing aqueous phase flow rate, residence time and droplets' diameter are the key factors of this process. Increasing the phase ratio reduces the extraction efficiency significantly. When the REEs solution has an initial pH of 4.00, the flow rates of continuous and dispersed phase are 40 and 1.6 mL/min, respectively, and 90 mg/L Nd (III), Eu(III) and Er(III) is extracted by 1 mol/L P507 at the out-let length of 8 m. The extraction efficiencies are 0.978, 0.983 and 0.991, respectively. Finally the stripping process was also studied with the micro-extractor. The stripping efficiencies of Nd(III), Eu(III) and Er(III) can reach 0.99, 0.96 and 0.91, respectively when the out-let length is 8 m and the concentration of hydrochloric acid is 1 mol/L. The developed approach offers a novel and simple strategy on the fast extraction and enrichment of low concentration rare earth elements from waste water.     

有机次膦酸在硝酸体系下提取稀土研究

本文采用溶剂萃取法,用有机次磷酸萃取剂从富含稀土元素镧(La）、钕(Nd）、钇(Y)、铈(Ce）的硝酸溶液中提取稀土。选择盐酸为反萃剂。考察了酸度、萃取剂浓度、相比和萃取时间对萃取率和反萃率的影响,结果表明,二异丁基膦酸萃取稀土的最佳条件为：室温,酸度0.2mol/l,萃取剂浓度40%,A/O比1:5,萃取时间15min,镧（La）、钕（Nd）,铈（Ce）和钇（Y）分别为41.68%、81.30%、81.29%和100%。当利用盐酸作为反萃实验的反萃剂时其最佳条件为：室温,初始水相稀土溶液为0.3 mol/L,反萃剂盐酸为6 mol/L,负载有机相与反萃剂盐酸溶液的体积比为1:6,将反萃的震荡时间改变为5min,应用上述条件的镧(La）、钕(Nd）、铈(Ce）、钇(Y)的反萃率分别为92.45%、94.88%、95.76%、93.34%。有机次膦酸对稀土元素（La）、钕（Nd）、铈（Ce）和钇（Y）的萃取效率不同。钇的提取率高于镧、钕和铈。它是一种有机次膦酸,对轻稀土元素亲和力低,对重稀土元素亲和力强。     

Hydrometallurgical Process for Copper Recovery from Waste Printed Circuit Boards (PCBs)

Present paper focuses on the selective recovery of copper from the enriched ground printed circuit boards (PCBs) using leaching and solvent extraction. The metal-enriched ground sample obtained from the beneficiation of the sized PCBs in a laboratory scale column type air separator contained mainly 49.3% Cu, 3.83% Fe, 1.51% Ni, 5.45% Sn, 4.71% Pb, and 1.85% Zn. The leaching of the enriched sample with 3.5 mol/L nitric acid dissolved 99% copper along with other metals at 323 K temperature and 120 g/L pulp density in 1 h time. The composition of the leach liquor with wash solution was found to be 42.11 g/L Cu, 2.12 g/L Fe, 4.02 g/L Pb, 1.58 g/L Zn, and 0.4 g/L Ni. The McCabe–Thiele plot indicated the requirements of three counter-current stages for maximum extraction of copper from the leach liquor at pH 1.5 using 30, 40, and 50% (v/v) LIX 984 N at the phase ratios (A/O) of 1:3, 1:2, and 1:1.5, respectively. The counter-current simulation studies show the selective extraction of 99.7% copper from the leach liquor feed of 1.5 pH in three stages with 50% LIX 984 N at A/O phase ratio of 1:1.5. The stripping of copper from the loaded organic with sulfuric acid produced copper sulfate solution from which copper metal/powder could be recovered by electrolysis/ hydrogen reduction.     

Separation and recovery of associated rare earths from the Zhijin phosphorite using hydrochloric acid

The separation and extraction of associated rare earths from the Zhijin phosphorite mine is of great interest. Based on previous studies, the hydrolysis of phosphate ore using hydrochloric acid was systematically studied through extensive testing. Experiments were conducted to separate and recover the rare earths from the hydrolysis solution. Kinetic studies on the acidolysis of phosphorite using hydrochloric acid show that the use of hydrochloric acid in the acidolysis of phosphorite is mainly controlled by a chemical reaction and is also a diffusion-controlled reaction. When 210 L of HCL per 100 kg of phosphorite was used at 30 ℃ for 360 min, 96.1% of the P_2 O_5 and 95.0% of the rare earths are leached from the phosphorite. After defluorination and purification, the pH of the phosphate-acid solution is adjusted to 2.1 using sodium hydroxide, and a rare earth concentrate with rare earth content of 1.76 wt%is obtained; i.e., 90.1% of the rare earths are recovered. The rare earth content is increased to more than5 wt% through multiple enrichment processes, with a total yield of 59.5%.     

环烷酸萃取脱除废旧稀土荧光粉酸浸液中铁铝

研究了废旧稀土荧光粉酸浸液在环烷酸萃取过程中关于铁、铝杂质的除杂效果,考察环烷酸对于铁、铝、稀土的选择性;有机相组成、氨水浓度、温度对分离效果的影响;水洗温度、水洗相比对水洗效果的影响;盐酸浓度、相比、反萃时间对反萃效果的影响.结果表明:选择环烷酸:异辛醇:磺化煤油体积比为20:20:60、氨水浓度为2 mol/L、温度为20 ℃、氨水滴加速度为3 mL/min时,分离效果较优;水洗温度为40 ℃、相比（A/O）为2时,铁铝稀土的洗脱率分别为1.5%、4.2%和26.4%;反萃剂盐酸浓度为3 mol/L、反萃相比（A/O）为1、反萃时间为20 min时,铁、铝、稀土萃取率分别高达99.5%、99.8%和99.8%.      

PMBP-苯溶剂萃取-ICP-AES快速测定化探样品中15种稀土元素

建立了在p H=5.5的酸度下,使用PMBP-苯溶剂定量萃取化探样品中15种稀土元素,然后用甲酸-8-羟基喹啉溶液反萃取稀土元素,分离后ICP-AES同时测定的新方法。成功解决了盐酸、硝酸、氢氟酸、高氯酸消解后ICP-AES直接测定稀土元素基体成分复杂,质谱干扰严重,方法检出限高等问题,试样用过氧化钠-氢氧化钾熔融后,水提取,过滤,滤渣酸溶,经过沉淀和溶剂萃取等分离富集,对稀土组份进行全分析。方法快速、准确、易操作,其检出限为0.003~0.068 ug/m L,精密度RSD2%。     

Recovering REEs from NdFeB wastes with high purity and efficiency by leaching and selective precipitation process with modified agents

A leaching and selective precipitation approach is proposed in this work to recover rare earth elements (REEs) from NdFeB magnet wastes collected from industry. Hydrochloric acid and oxalic acid were employed as the leaching and precipitation agents, respectively. Hexamethylenetetramine (HMTA) or tartaric acid was used as the chelating agent during leaching. Both leaching and precipitation processes were optimized individually. For leaching process, the effects of two different chelating agents, the concentrations of leaching agent, chelating agent, and temperature on the extraction and recovery yields were investigated. The optimized process based on the factorial experiment was determined to be the hydrochloric acid concentration of 6 mol/L, the tartaric acid concentration of 50 g/L, and the temperature of 313 K, by which the extraction yields of Fe and REEs up to 67.99% and 99.27%, respectively, are obtained. For the precipitation process, the optimized oxalic acid dosage and pH value were also determined. The produced RE oxide products have the purity and recovery yield up to 95.83% and 90.18%, respectively. These results indicate that the present method with low acid consumption and high product purity has advantages over many other approaches for REE recovery.     

萃取分离基体-电感耦合等离子体质谱法测定高纯二氧化锆中痕量稀土杂质

建立了1-苯基-3-甲基-4-苯甲酰基-吡唑酮[5](PMBP)萃取分离基体-电感耦合等离子体质谱法(ICP-MS)测定高纯二氧化锆中痕量稀土杂质的方法。结果表明,在2 mol/LHNO3介质中,基体锆的萃取率为99.7%,而待测稀土元素则完全留在水相中。考察了影响萃取和测定的主要因素。在优化实验条件下,方法的测定下限为1.8~5.7 ng/g,回收率在89.0%~110%之间,相对标准偏差(RSD)小于14%。     

Decomposition of mixed rare earth concentrate by NaOH roasting and kinetics of hydrochloric acid leaching process

A new clean extraction technology for the decomposition of Bayan Obo mixed rare earth concentrate by NaOH roasting is proposed.The process mainly includes NaOH roasting to decompose rare earth concentrate and HCl leaching roasted ore.The effects of roasting temperature,roasting time,NaOH addition amount on the extraction of rare earth and factors such as HCl concentration,liquid-solid ratio,leaching temperature and leaching time on the dissolution kinetics of roasted ore were studied.The experimental results show that when the roasting temperature is 550℃ and the roasting time is 60 min,the mass ratio of NaOH:rare earth concentrate is 0.60:1,the concentration of HCl is 6.0 mol/L,the ratio of liquid to solid(L/S) 6.0:1.0,and the leaching temperature 90℃,leaching time 45 min,stirring speed 200 r/min,and the extraction of rare earth can reach 92.5%.The relevant experimental data show that the process of HCl leaching roasted ore conforms to the shrinking core model,but the control mechanism of the che mical reaction process is different when the leaching temperature is different.When the leaching temperature is between 40 and 70℃,the chemical reaction process is controlled by the diffusion of the product through the residual layer of the inert material.The average surface activation energy of the rare earth element is E_a=9.96 kJ/mol.When the leaching temperature is 75-90℃,the chemical reaction process is controlled by the interface transfer across the product layer(product layer interface mass transfer) and diffusion.The average surface activation energy of rare earth elements is E_a=41.65 kJ/mol.The results of this study have certain significance for the green extraction of mixed rare earth ore.     

Recovery of thorium and rare earths from leachate of ion-absorbed rare earth radioactive residues with N1923 and Cyanex® 572

Ion-absorbed rare earth ores radioactive residues (IREORR) are a class of waste residue from the production of rare earth elements (REEs). Because of its radioactive dose, IREORR are usually stored in waste warehouses. IREORR are difficult to be disposed of. However, it contains relatively high concentrations of REEs, which can be considered as a valuable secondary resource. In this paper, a novel process is developed for the separation of thorium (Th) and recovery of REEs from IREORR hydrochloric acid leachate with primary amine N1923 and Cyanex® 572, respectively. The effects of sulfate concentration, extractant concentration and pH on N1923 extraction in hydrochloric acid solution were investigated in detail. The results show that the extraction capacity of N1923 can be improved by adding sulfate to the solution and increasing the concentration of N1923. Acidity has little effect on the extraction of Th when pH is higher than 1. As for the stripping, REEs are more easily stripped from loaded organic phase than Th, and nitric acid is a better stripping agent than hydrochloric acid. Combined with the extraction of Cyanex® 572 for REEs, a fractional extraction experiment for separating Th and enriching of REEs was performed. The yield of Th is higher than 99.9% and the concentration of REEs is enriched to 183.84 g/L.     

氧化铝赤泥盐酸浸出稀土元素研究

在用盐酸浸出氧化铝赤泥提取氧化钪的过程中,稀土元素镧,铈,钕也一同浸出,进入到浸出液中。研究了拜耳法赤泥盐酸浸出稀土元素镧,铈,钕的过程。研究了浸出温度、酸度、液固比和浸出时间对稀土元素浸出率的影响。研究结果表明,影响稀土浸出率的因素依次是浸出温度,盐酸浓度,配料液固比,和浸出时间。当接近沸点109℃浸出时,镧、铈、钕浸出率提高最快。盐酸酸度在4～5 mol.L-1时,浸出率升高较快,5～7 mol.L-1时,缓慢提高,当超过7 mol.L-1时,镧、铈、钕的浸出率基本不变化。当液固比为4.0时,镧、铈、钕元素的浸出率较低,仅为60%～75%之间,当液固比提高到5.0时,稀土元素的浸出率升高较快。随着浸出时间的延长,氧化稀土的浸出率从60～180 min时,缓慢提高,在180 min时达到最大值,超过180 min后,变化不大。在温度为沸点(109℃),液固比6.0,时间180 min。盐酸浓度7 mol.L-1的条件下浸出,赤泥中La,Ce,Nd的浸出率能达到95%以上。     

Trace detection of Ce3+ by adsorption strip voltammetry at a carbon paste electrode modified with ion imprinted polymers

To develop a convenient method for sensitive and selective determination of Ce3+ in aqueous phase with complicated matrices, a carbon paste electrode(CPE) modified with ion imprinted polymers(IIPs) were fabricated. The polymers were prepared by precipitation polymerization using Ce3+ as template, allyl phenoxyacetate(APA) as monomer, ethylene glycol dimethacrylate(EGDMA) as crosslinker and azobisisobutyronitrile(AIBN) as initiator under the molar ratio of Ce3+, APA and EGDMA as 1:4:40, respectively. Ce~(3+) was detected directly by differential pulse adsorptive stripping voltammetry(DPASV) and its oxidation peak appears at about 0.93 V. All parameters affecting the sensor's response are optimized and a calibration curve is plotted at a linear range of 1.0 × 10~(-6)-1.0 x 10~(-5) mol/L and 1.0×10~(-5)-2.0 × 10~(-4)mol/L with the detection limit of 1.5 × 10~(-7) mol/L. All other rare earth ions have no interference with the determination of Ce~(3+) even at a concentration 500 times higher than that of Ce~(3+).This sensor was successfully applied to determination of Ce~(3+) in two catalyst sample solutions with RSD≤3.3%(n = 5)and recoveries in the range of 99.2%-106.5% at our optimal conditions.     

Recovery of yttrium from deep-sea mud

Deep-sea mud rich in rare earth yttrium has received lots of attention from the international community as a new resource for Y. A novel process, which mainly includes acid leaching, solvent extraction, and oxalic acid precipitation-roasting, is proposed for recovery of Y from deep-sea mud. A series of experiments were conducted to inspect the impacts of various factors during the process and the optimum conditions were determined. The results show that the Y of deep-sea mud totally exists in apatite minerals which can be decomposed by hydrochloric acid and sulfuric acid solution. The highest leaching efficiency of Y is 94.53% using hydrochloric acid and 84.38% using sulfuric acid under the conditions of H~+concentration 2.0 mol/L, leaching time 60 min, liquid-solid ratio 4:1 and room temperature 25 ℃(only in case of sulfuric acid, when using hydrochloric acid, the leaching temperature should be 60 ℃). Because of the much lower leaching temperature, sulfuric acid leaching is preferred. The counter current extraction and stripping tests were simulated by a cascade centrifugal extraction tank device. Using 10 vol% P204,15 vol% TBP and 75 vol% sulfonated kerosene as extractant, 98.79% Y~(3+) and 42.60% Fe~(3+) are extracted from sulfuric acid leaching liquor(adjusted to pH = 2.0) after seven-stage counter current extraction with O/A ratio of 1:1 at room temperature, while other metals ions such as Al~(3+), Ca~(2+), Mg~(2+)and Mn~(2+) are almost not extracted. The Y~(3+) in loaded organic can be selectively stripped using 50 g/L sulfuric acid solution and the stripping efficiency reaches 99.86% after seven-stage counter current stripping with O/A ratio of 10:1 at room temperature, while only 2.26% co-extracted Fe~(3+) is stripped. The Y~(3+) of loaded strip liquor can be precipitated by oxalic acid to further separate Y~(3+) and Fe~(3+). The precipitation efficiency of Y~(3+) in loaded strip liquor can be 98.56% while Fe~(3+) is not precipitated under the conditions of oxalic acid solution concentration 200 g/L, quality ratio of oxalic acid to Y of 2, and precipitation time 0.5 h. And the precipitate was roasted at 850 ℃ for 3 h to obtain the oxide of Y in which the purity of Y_2 O_3/REO is 79.02% and the contents of major non-rare earth impurities are less than 0.21%.Over the whole process included acid leaching, solvent extraction, and oxalic acid precipitation-roasting,the yttrium yield is 82.04%.     

酸性萃取剂负载Cr（Ⅲ）的碱反萃取研究

针对酸性萃取剂负载的Cr（Ⅲ）高酸难反萃、反萃不完全的问题,根据不同酸度条件下Cr（Ⅲ）与OH-络合形态的差别,进行了碱作为反萃取剂从负载Cr（Ⅲ）的酸性萃取剂中回收铬实验研究.结果表明,碱反萃取P204负载有机相时的优化条件为0.5 mol/L氢氧化钠、相比为1、常温、反萃取反应为10 min,经四级逆流反萃取,反萃取率达到98.3%;碱反萃取P507负载有机相时的优化条件为2 mol/L氢氧化钠、相比为1、常温、反萃取反应为20 min,经四级逆流反萃取,反萃取率达到98.8%.     

电感耦合等离子体质谱法测定钇铁合金中14种稀土杂质

采用硝酸-双氧水处理钇铁合金样品,以0.3mol/L硝酸为测定介质,选用¹⁰³Rh和¹⁸⁵Re作为内标元素对基体效应和测量信号进行补偿和校正,实现了电感耦合等离子体质谱法(ICP-MS)对钇铁合金中14种稀土杂质元素的测定。通过选择合适的同位素和干扰校正方程消除了质谱干扰;通过选择稀释因子为2000,即控制基体质量浓度为0.5mg/mL进行测定消除了基体效应的影响。在优化的实验条件下,14种稀土元素的校准曲线线性相关系数都在0.9999以上,各元素的检出限为0.003~0.020μg/L。将实验方法应用于钇铁合金样品中稀土杂质的测定,测定结果的相对标准偏差(RSD,n=11)介于0.97%~6.5%之间,加标回收率为96%~104%。采用实验方法对钇铁合金样品进行测定,同时采用基体匹配结合电感耦合等离子体原子发射光谱法(ICP-AES)进行方法对照试验,两种方法测定结果基本一致。     

Rare earth recovery from fluoride molten-salt electrolytic slag by sodium carbonate roasting-hydrochloric acid leaching

Fluorinated rare earth molten-salt electrolytic slag contains a considerable amount of rare earth elements,as well as a variety of heavy metals and fluorides that cause environmental pollution.Therefore,it is of great importance to fully utilise this resource.In this study,the transformation mechanism of fluorinated rare earth molten-salt electrolytic slag roasted with sodium carbonate,and the regulation mechanism of rare earth leaching under different roasting conditions were investigated with ...     

Migration behavior,separation and recycling of rare earth during thermal decomposition of Zhijin phosphorus ore

Zhijin phosphorus ore is a moderate and low-grade phosphorus rare-earth ore contained in mines. The separation and extraction of associated rare earth are important research topics. In this study,the migration behavior of rare earth during the thermal decomposition of Zhijin phosphorus ore and the separation and extraction of rare earth in phosphorus slag are discussed systematically. During the thermal decomposition process of phosphorus ore, almost all of the associated rare earth enters into the phosphorus slag phase but does not enter into the ferrophosphorus or gas phases. Amorphous calcium metasilicate and calcium fluosilicate are major components of phosphorus slag, and rare earth mainly exists as a calsil solid solution. Hydrochloric acid was used for acidolysis of the phosphorous slag.Under the following conditions, 96% of the rare earth in the phosphorous slag can be dissolved in the acidolysis solution: acid excess coefficient of 1.5, reaction time of 50 min and reaction temperature of 50℃. The rare earth in the acidolysis solution was separated and recycled using oxalic acid as a precipitator and NaOH as a pH modifier. At pH of 1.7, rare-earth-enriched matter with rare-earth content of 2.1 wt% was obtained, and the recovery of the rare earth was 88%.     

Effect of Ca and Rare Earth Additions on the Texture,Microhardness, Microstructure and Structural Properties of As-Cast Mg–4Al–2Sn Alloys

In this work, alloys with nominal composition of Mg–4Al–2Sn–xRE–yCa (where RE = rare earth, x = 0, 1, 3 and y = 0, 1) have been prepared using tilt casting method. Prepared as-cast samples have been investigated by X-ray diffractometry, optical microscopy and scanning electron microscopy techniques as well as hardness measurement. The texture, microstructure and structural parameters of samples were also refined from X-ray diffraction patterns utilizing the Rietveld method and generalized spherical-harmonic model. It was found that with addition of rare earth and calcium elements, intermetallic phases of γ-Mg₁₇Al₁₂ and β-Mg₂Al₃ disappeared in cast alloys while small amount of Al₁₁RE₃ and CaMgSn intermetallics phases are formed. The texture factor of α-Mg as a main phase of samples was decreased with addition of rare earth up to 1 % and increased with more addition of rare earth elements. According to the results, with addition of rare earth elements, texture of Mg phase changes from 〈112〉 direction to 〈100〉 and 〈002〉 directions while Ca addition causes the texture in 〈002〉 direction. The microhardness of Mg–4Al–2Sn alloy was enhanced with addition of rare earth and calcium elements which is in agreement with the expected trend based on computed phase fraction of the samples. Addition of 1 wt% of calcium causes a dramatic change in the morphology and chemical composition of intermetallic phases, from acicular shape with composition of Al₁₁RE₃ into fine feather of CaMgSn intermetallic phase which accumulated in cluster morphologies in interdendritic regions.     

Rapid recovery of rare earth elements in industrial wastewater by CuFe2O4 synthesized from Cu sludge

This study systematically evaluates the recovery of rare earth elements (REEs) from aqueous solution and industrial wastewater using magnetic nanoparticles CuFe₂O₄. The industrially manufactured CuFe₂O₄ displays a nonlinear isotherm for REEs adsorption, suggesting limiting binding sites on the CuFe₂O₄ surface. The recovery of REEs increases significantly from 0.1% to 99.99% with increasing pH (2.29–8.15). At room temperature, the maxima recovery rates of Nd, La, and Ce are observed to be in a high capacity of 51.02, 42.02, and 40.16 mg/g, respectively. No significant attenuation of REE adsorption is observed with increasing NaCl concentration from 0.001 to 1.0 mol/L, showing high selectivity of REEs even in such high NaCl concentration matrix. In addition, desorption efficiency increases with the increasing concentration of HNO₃ in the range of 0.005–0.05 mol/L. When HNO₃ concentration is over 0.05 mol/L, the desorption efficiency can reach almost 100% in each batch experiment. Importantly, our results show that REEs can be sorbed and recycled from liquid crystal display (LCD) polishing wastewater, suggesting that CuFe₂O₄ may be a good candidate in the efficient and rapid recovery of REEs from industrial wastewater.