Effect Of Nitric Acid Concentration Research Articles

Effect of nitric acid concentration on corrosion behavior of CrFeCoNi high entropy alloy

CrFeCoNi high entropy alloy (HEA) was prepared by the method of vacuum melting. Its corrosion behavior in HNO3 solution with different concentrations was studied. The electrochemical test results indicated that the corrosion resistance firstly increased with increasing HNO3 concentration from 0.1 M to 4 M, and then decreased with further increasing HNO3 concentration to 6 M. The CrFeCoNi HEA exhibited the best corrosion resistance in 4 M HNO3 solution. The discrepancy of corrosion property in different concentration of HNO3 solutions could be attributed to the different protection of passive film formed on HEA. XPS results indicated that the content of Cr2O3 in the passive film initially increased with increasing HNO3 concentration from 0.1 M to 4 M, and then decreased with further increasing HNO3 concentration to 6 M. Higher content of Cr2O3 in the passive film was responsible for better corrosion property.

Effect of Nitric Acid Concentration on the Properties of Bentonite Clay

Effect of Nitric Acid Concentration on the Properties of Bentonite Clay

Effect of process variables on leaching behavior and kinetics of silver element from waste photovoltaic modules

In order to achieve efficient leaching of silver, in waste photovoltaic panels, the leaching process using nitric acid was investigated. The effects of nitric acid concentration, leaching time, solid–liquid ratio, and leaching temperature on the silver leaching rate were examined. The response surface method was used to establish an experimental model for analyzing and optimizing the leaching experiment. The results showed that the nitric acid concentration had the most significant effect on the leaching rate. The leaching rate of 98.02% was achieved under the following optimal leaching conditions: a nitric acid concentration of 18%, a leaching time of 32 min, a solid–liquid ratio of 1:30, and a leaching temperature of 60 °C. According to the shrinkage nuclear model, the leaching kinetics of silver using nitric acid followed a chemical reaction-controlled process with an apparent activation energy of 42.26 kJ/mol. Scanning electron microscopy–energy-dispersive x-ray spectrometry results of minerals before and after leaching confirmed the efficient recovery of silver in waste photovoltaic cells.

Targeted production of aromatics from corn stover and high-density polyethylene composite pyrolysis over nitric acid modified biochar catalyst

The pore structure and active functional groups of biochar play a critical role in determining its catalytic performance. In this study, coconut shell-derived biochar underwent modification with nitric acid to serve as a catalyst in the pyrolysis of a corn stover/high-density polyethylene composite (CHC) in a fixed bed reactor. The effects of nitric acid concentration, treatment time, and temperature on the catalytic performance of biochar were investigated, specifically targeting the production of aromatics during the CHC pyrolysis process. The results revealed that a higher modification temperature, a longer treatment time, and a lower concentration of nitric acid effectively enhanced the catalytic performance of biochar in producing aromatics, while simultaneously reducing the formation of aliphatics and oxygenates. The highest yield of aromatic hydrocarbons (56.1 %) was obtained under the conditions of a modification temperature of 90 °C, a modification time of 10 h, and a nitric acid concentration of 1.0 mol/L. Furthermore, the nitric acid-modified biochar catalyst promoted the production of CO and CH4 during the CHC pyrolysis process, indicating that the decarbonylation and end-chain breaking reactions were enhanced due to the presence of abundant oxygen-containing functional groups introduced by nitric acid oxidation.

Mild Nitric Acid Treatments to Produce Nitrocellulose from Kapok Fiber (Ceiba Pentandra)

Kapok (Ceiba pentandra) is one of the natural fibrous sources with a high content of cellulose. The natural kapok used contains 54.3% of cellulose, 11.3% of hemicellulose, and 19.11% of lignin. Kapok is a potential material to be explored by isolating the fiber, then converting into nitrocellulose. The effect of nitric acid concentration on the nitration process and characterization of material were investigated. Kapok fiber was isolated by delignification and bleaching process. Delignification was done in the presence of 5% (w/v) of NaOH and 30% (v/v) of H2O2 for alkaline and acid hydrothermal treatment, respectively. Kapok was washed until neutral pH and dried in an oven at 100 oC for 4 h to get kapok fiber (CK). For the nitration process, CK 5% (w/w) was added to a solution of 15% (v/v) phosphoric acid and variation of 15%, 20%, and 25% of nitric acid. The mixture was stirred at 10 oC, 300 rpm, for 30 min. The solid CK was separated and poured into hot water for 5 min and continuously washed with demineralized (DI) water and sodium hydrogen carbonate until neutral pH. The nitrocellulose (KN) was produced after the material dried. The smooth surface of fiber and diameter around 14.5-19.1 µm was changed into a plat fiber of 13.3-21.2 µm after hydrothermal treatment. The crystallinity index (CrI) of CK was increased up to 58.17% based on X-Ray Diffraction (XRD) observation. The degree of substitution (DS) was calculated by data spectra of Fourier Transform-Infra Red (FT-IR) analysis of a specific functional group for N-O and C-O stretching vibrations. The DS optimum value was achieved at about 0.885 at concentration of 20% nitric acid (NK20). The synthesis of nitrocellulose kapok fiber-based has potential as a functional material.

Kinetic study on arsenopyrite dissolution in nitric acid media by the rotating disk method

The kinetics of arsenopyrite compact samples dissolution in nitric acid media was investigated using the full factorial experiment model (FFEM). The effects of nitric acid concentration (2–5 M), temperature (303–348 K), disk rotation frequency (3.33–10 rps) on the arsenopyrite dissolution rate were studied. Nitric acid concentration and temperature have a significant effect, and disk rotation frequency does not. With an increase in nitric acid concentration from 4 M to 5 M and temperature from 318 K to 333 K, the dissolution rates of iron and arsenic increase by 30.1–30.4 times, from 0.26–0.27 × 10–6 mol dm−2 s−1 to 7.83–8.21 × 10–6 mol dm−2 s−1. Increasing temperature to 348 K does not lead to a significant increase in the dissolution rate. The data obtained were processed using the FFEM to obtain kinetic equations (R2 = 0.95): WFe=0.04CHNO31.8e-4419Tω0.1, WAs=0.04CHNO31.8e-4420Tω0.1. Using SEM–EDS and XPS analyses, the mechanism of arsenopyrite passivation was determined. Under mild conditions (nitric acid concentration of 3 M and temperature of 303 K), local conglomerates containing iron polysulphides (Fe2Sx) are formed on the arsenopyrite surface. They do not create diffusion difficulties when dissolving arsenopyrite. Under harsh conditions (nitric acid concentration of 5 M and temperature of 333 K), polysulphides begin to aggregate. It leads to the formation of the passivating film containing elemental sulphur. The film is thin (20–30 μm) and porous. While the arsenopyrite dissolution rate is high. Further increase of parameters leads to thickening and compaction of the passivating film and decrease in the arsenopyrite dissolution rate.

Extraction of Nickel from Morowali Laterite Ore with Nitric Acid

Nickel extraction from Morowali laterite ore has been carried out with nitric acid as the solvent. This study aims to determine the effect of nitric acid concentration, temperature, and stirring time on nickel content in laterite ore originating from Morowali. Morowali laterite seeds were extracted using the leaching method using nitric acid as the solvent with various concentrations of 0.5, 1, and 2, temperatures of 30, 60, and 95, and stirring times of 3, 6, and 12. Taguchi analysis was used in this study to obtain the effect of the three parameters used. The results showed that the optimum conditions were obtained at a concentration of 2 molars nitric acid, a temperature of 95°C, and a stirring time of 12 hours, with a nickel content of 16.469 ppm and a nickel recovery percent of 3.88%.

Separation of palladium and silver from E-waste leachate: effect of nitric acid concentration on adsorption to Thiol scavenger

The development of recovery techniques for metals present in low concentrations in E-waste, such as silver and palladium, is important from the aspect of the circular economy. Adsorption of palladium and silver was studied in detail in a batch process with silica-based Thiol scavenger from nitric acid leachate of waste printed circuit boards (PCBs). High adsorption efficiencies of Pd(II) and Ag(I), >97%, were reached in nitric acid concentrations below 3 mol L−1. At higher acid concentrations, adsorption efficiency of Ag(I) decreased drastically which enables the separation of Ag(I) and Pd(II) based on nitric acid concentration in sample solution. Pd(II) and Ag(I) followed pseudo 2nd order kinetical model with fast adsorption with contact times of 60 and 30 min, respectively, in all studied acid concentrations. Adsorption followed Langmuir isotherm reaching highest loading capacities of 199 mg g−1 for Ag(I) and 105 mg g−1 for Pd(II) in 1 mol L−1 nitric acid media, after which loading capacities decreased while nitric acid concentration increased. Thiourea-based desorption agents were most effective for desorption with >80% desorption efficiencies for Ag(I) and 55 - 88% efficiencies for Pd(II) in a one-step desorption. However, separation of Pd(II) and Ag(I) is not entirely possible in desorption step, hence the highest separation between Pd(II) and Ag(I) was found with two-step adsorption in which Pd(II) and Ag(I) were separated initially at adsorption step based on nitric acid concentration, followed by desorption step with acidic thiourea solution.

Pyridine-di-phosphonates as chelators for trivalent f-elements: kinetics, thermodynamic and interfacial study of Am(III)/Eu(III) solvent extraction.

The fractionation of high-level radioactive waste from nuclear power plants simplifies the handling of its components, and facilitates the reduction of radiotoxic effects on the environment. The search and study of new ligands for solvent extraction, as one of the methods in fractionation, remains a complex and important research task. In this work, four pyridine diphosphonate ligands were synthesized. These ligands are part of the class of the N,O-donor extractants, which are selective towards Am(III). The separation factor SF(Am/Eu) for the best extractant reached values up to 10. The influence of the substituents on the efficiency of extraction and complexation of trivalent f-elements, the kinetics of extraction, and the behavior of the ligand at the interface were described. The effect of nitric acid concentration on the extraction was shown. The stoichiometry of the complexes was determined by slope analysis in solvent extraction experiment and verified by spectrophotometric titration in acetonitrile. Liquid tension experiments with a pendant drop method revealed the interfacial properties of the ligands in "F-3 solvent/H2O" and "F-3 solvent/HNO3" systems. The relationship between the surface activity and the ligand structure was shown. Studies of the extraction kinetics were performed in a modified Lewis cell. The effect of the ligand structure on the extraction rate was shown. The DFT calculation with the B3LYP density functional was used to explain the extraction properties of the ligands, including selectivity. The calculation of the pre-organization energy of the ligands explained the kinetics and extraction patterns for the studied series.

Effects of nitric acid concentration for nitration of fused [1,2,5]oxadiazolo[3,4-d]pyrimidine-5,7-diamine.

Nitration reactions are very often used for the selective synthesis of novel, high performing nitramine-based materials. Now nitration reactions of the fused 5,7-diamino pyrimidine derivative 1, under different nitric acid concentrations were examined. Concentrated nitric acid gave selectively N-(5-amino-4,5-dihydro-[1,2,5]oxadiazolo[3,4-d]pyrimidin-7-yl)nitramide, 2, while the fused ring nitrate salt, 4, and ring open nitrate salt, 3 were obtained using low concentrations of nitric acid (<70%). In addition, the cesium salt of the fused nitramine derivative 5 was synthesized. All new compounds were isolated in high yields and comprehensively characterized by NMR, FTIR spectroscopy, and elemental analyses. The molecular structures of 2, 3, and 5 were analyzed by single X-ray crystallographic data. These compounds have high calculated heats of formation and high crystal densities. Detonation properties for compounds 2 and 3 were calculated using EXPLO5 software. Fused ring compound 2 (vD, 8549 m s-1; P, 29.62 GPa), and nitrate salt, 3 (vD, 8392 m s-1; P, 29.37 GPa) have superior detonation properties compared with TNT (vD, 7303 m s-1; P, 21.30 GPa). In addition, electrostatic potentials, two-dimensional (2D)-fingerprints, and Hirshfeld surface analysis were used to predict the sensitive properties of compounds 2 and 3. The experimental sensitives suggest possible applications with insensitive energetic applications.

Influence of silicon, boron and rare-earth metals on corrosion resistance of austenitic chromium-nickel steel

The effect of silicon (in range 0.14 – 0.78 wt. %), boron, and rare-earth metals (REM) on the corrosion resistance of low-carbon austenitic chromium-nickel steel of 03Kh18N11 (AISI 304L) grade was studied. It is shown that all steels in quenched state when tested in boiling 56 and 65 % HNO3 solutions have comparable corrosion rates, which do not exceed the critical norm (0.5 mm/year) in accordance with GOST 6032 – 2017 (State Standard). Testing samples in boiling 27 % HNO3 + 4 g/l Cr+6 solution are susceptible to intergranular corrosion (IGC). The corrosion rate and the penetration depth of IGC increase with increasing silicon concentration from 0.14 to 0.78 wt. %. Study of the effect of nitric acid concentration and test temperature has shown that steel with 0.78 wt. % Si has significant corrosion losses exceeding the critical ones when testing in 56 and 65 % HNO3 solutions with temperature of 120 and 130 °С. But steel with high silicon content (0.78 wt. %) and low carbon concentration (0.020 – 0.022 %) after quenching in a range of 1080 – 1150 °C and tempering at 650 °C does not exceed the critical norm on average corrosion rate. Only 0.01 wt. % increase in carbon concentration leads to a significant (more than 30 times) increase in corrosion rate of sensitized steel. It is shown that microalloying with REM does not impair corrosion resistance of sensitized steel. In contrast to REM, alloying chromium-nickel steel with even a small addition of boron (0.0015 %) reduces steel corrosion resistance by an order of magnitude. Corrosion rate inverse dependence on quenching temperature is observed when, with increasing temperature, corrosion rate of 02Kh18N11GS0.38R steel increases. The effect of silicon (in range 0.14 – 0.78 wt. %), boron, and rare-earth metals (REM) on the corrosion resistance of low-carbon austenitic chromium-nickel steel of 03Kh18N11 (AISI 304L) grade was studied. It is shown that all steels in quenched state when tested in boiling 56 and 65 % HNO3 solutions have comparable corrosion rates, which do not exceed the critical norm (0.5 mm/year) in accordance with GOST 6032 – 2017 (State Standard). Testing samples in boiling 27 % HNO3 + 4 g/l Cr+6 solution are susceptible to intergranular corrosion (IGC). The corrosion rate and the penetration depth of IGC increase with increasing silicon concentration from 0.14 to 0.78 wt. %. Study of the effect of nitric acid concentration and test temperature has shown that steel with 0.78 wt. % Si has significant corrosion losses exceeding the critical ones when testing in 56 and 65 % HNO3 solu tions with temperature of 120 and 130 °С. But steel with high silicon content (0.78 wt. %) and low carbon concentration (0.020 – 0.022 %) after quenching in a range of 1080 – 1150 °C and tempering at 650 °C does not exceed the critical norm on average corrosion rate. Only 0.01 wt. % increase in carbon concentration leads to a significant (more than 30 times) increase in corrosion rate of sensitized steel. It is shown that microalloying with REM does not impair corrosion resistance of sensitized steel. In contrast to REM, alloying chromium-nickel steel with even a small addition of boron (0.0015 %) reduces steel corrosion resistance by an order of magnitude. Corrosion rate inverse dependence on quenching temperature is observed when, with increasing temperature, corrosion rate of 02Kh18N11GS0.38R steel increases.

Selective separation of zirconium(IV) from uranium(VI) using dioxoamide ligand present in ammonium based ionic liquid: An application towards spent metallic fuel reprocessing

The alloy of an actinide (U or Pu) with zirconium (6%) has been proposed as metallic fuel. The removal of zirconium from the dissolver solution is required prior to the separation of actinides during reprocessing. In this context, the extraction behavior of zirconium was studied in a solution of 2-ethylhexyl- and the decyl-derivative of benzodioxodiamide, abbreviated as BD and BDD, respectively, in ionic liquid medium. Instead of the conventional imidazolium ionic liquid that displayed several drawbacks, strongly hydrophobic ionic liquids such as methyltributylammonium bis(trifluoromethylsulfonyl)imide ([N1444][NTf2]) and methyltrioctylammonium bis(trifluoro-methylsulfonyl)imide ([N1888][NTf2]) have been employed, as a diluent, in conjunction with the BD and BDD ligands for the extraction of Zr(IV). The effect of nitric acid concentration in aqueous phase, duration of equilibration, interference of uranium and the effect of temperature on the extraction of Zr(IV) in BD present in ionic liquid was studied. The number of BD-ligands involved in the extraction of zirconium was determined. The results showed the possibility of removing zirconium from the bulk quantity of uranium present in the dissolver solution.

Potential application of graphene oxide membranes in high-level liquid waste treatment

The drawbacks of current high-level liquid waste (HLLW) separation processes would bring some adverse effects on the sustainable and clean utilization of nuclear power. In this work, a novel separation method for HLLW treatment based on graphene oxide membranes (GOMs) was investigated. Effects of nitric acid concentration and membrane thickness on the permeation behaviors of typical ions through GOMs were systematically investigated. On the whole, the permeation rates were in the order: hydrogen ion, cesium ion > sodium ion > strontium ion > europium ion, uranyl ion > thorium ion, which could be well explained by size exclusion and chemical interaction. As the nitric acid concentration decreased, strong coordination cations were generally restrained from migrating through GOMs due to cations hydrolysis and deprotonation of graphene oxide sheets. Ions permeation was supposed to be a two-step process which included entrance to the membrane and intramembrane migration. Based on the favorable rejection of f-block elements, GOMs separation showed promising potential in HLLW treatment. Furthermore, a new technical route for HLLW separation was proposed which showed superiority of simplified process, low running cost, less secondary radioactive waste production.

Liberation of Gold Using Microwave-Nitric Acid Leaching and Separation-Recovery of Native Gold by Hydro-Separation

The purpose of this study was to liberate gold from sulfide minerals in a gold concentrate through microwave-nitric acid leaching and to separate the light minerals in an insoluble residue using a hydro-separation process. The representative sulfide minerals in the gold concentrate were pyrite with minor galena. Mineralogical characterization was conducted on the gold concentrate using 1715.20 g/t based on lead-fire assays. During the leaching experiment, the effect of nitric acid concentration was studied. The results indicated that the metal leaching rate of the gold concentrate increased with increasing nitric acid concentration. After the microwave-nitric acid leaching, the resulting main feature was consistent with the increased exposure to reactive sulfide minerals and decrease in weight. Characterization techniques such as X-ray diffraction (XRD), scanning electron microscope energy dispersive spectroscopy (SEM-EDS) and scanning electron microscope backscattered electron imaging (SEM-BSE) were performed to characterize the minerals in the insoluble residue using microwave-nitric acid leaching and the hydro-separation process. The XRD patterns of the insoluble residues were compared. The intensities of the pyrite peak decreased and disappeared under different nitric acid concentrations, whereas intensities of the quartz peak increased. The hydro-separation process focused on the separation of heavy (e.g., native gold) and light (e.g., quartz) minerals from the insoluble residues. After the hydro-separation treatment process, the heavy minerals exhibited typical diffraction lines of gold, as obtained using the XRD analysis.

Liquid-liquid extraction of Co(II) from nitrate solution using TOA

Cobalt has widespread industrial applications but if present in excess amounts it may cause several noxious effects. Liquid-liquid extraction process can be useful in cleaning the environment from harmful chemical pollutants. Solvent extraction of cobalt using cobalt nitrate as the feed solution and trioctylamine (TOA) as the extractant in toluene was carried out where the effects of nitric acid concentration, equilibration time, concentration of the extractant and cobalt ions had been investigated. The percentage extraction of Co(II) decreased upon increasing the concentration of acid. A time of 15 min was needed to achieve the extraction equilibrium. Highest percentage extraction of cobalt was achieved using 0.1 M TOA which is 99%. Cobalt loading increased with increase in metal ion concentration. Presence of nitrate ions had almost no significance in the extraction process. The loaded organic phase was stripped using different stripping agents and 99.15% back extraction was achieved with 0.1 mol/L (NH4)2CO3. The extraction mechanism was proposed from the FTIR and slope measurement.

Effect of nitric acid concentration on the optical and surface morphology of zinc oxide (ZnO) thin films

This present study reports on the fabrication of porous zinc oxide (ZnO) by wet chemical etching so that the ZnO can be applied in the optoelectronic devices. ZnO thin films were deposited by radio frequency (RF) sputtering technique on the glass substrate. The etchants concentrations tested in the present study were 0.01%, 0.05% and 0.1% of nitric acid (HNO3). ZnO was etched at various etching time which at 5 s, 20 s and 35 s. Then, the samples were characterized by UV–visible (UV–vis) spectrophotometer, Fourier Transform Infra-Red (FTIR) spectrophotometer, optical microscope (OM), scanning electron microscope (SEM), atomic force microscope (AFM) and x-ray diffraction (XRD) spectrometer to access their optical properties, surface morphology and phase structure. All analyses revealed the best combination of etchant concentration and etching time was 0.1% of HNO3 and 35 s.

A facile preparation of dicyclohexano-18-crown-6 ether impregnated titanate nanotubes for strontium removal from acidic solution

In the present work, dicyclohexano-18-crown-6 impregnated titanate nanotubes composite (TNTs@DCH18C6) was prepared as an adsorbent for the selective separation of Sr2+ from acidic medium solution. Samples were specified with TEM, FTIR, and TGA. Effects of nitric acid concentration, adsorbent dosage, ionic strength, initial Sr2+ concentration and contact time were investigated with batch experiments. The results indicated that the adsorption was faster in the first 5 min and equilibrium was achieved after 180 min in the media of 6 mol L−1 HNO3. The adsorption data at equilibrium state were successfully described by the Freundlich isotherm. The kinetics adsorption was well described by the pseudo-second-order model. Results demonstrated that the as-synthesized hybrid composite is highly stable in harsh acidic medium, indicating its promise as an effective adsorbent for the removal of Sr2+ from acidic solution.

Optimization of HNO3 leaching of copper from old AMD Athlon processors using response surface methodology

The present study investigates the optimization of HNO3 leaching of Cu from old AMD Athlon processors under the effect of nitric acid concentration (%), temperature (°C) and ultrasonic power (W). The optimization study is carried out using response surface methodology with central composite rotatable design (CCRD). The ANOVA study concludes that the second degree polynomial model is fitted well to the fifteen experimental runs based on p-value (0.003), R2 (0.97) and Adj-R2 (0.914). The study shows that the temperature is the most significant process variable to the leaching concentration of Cu followed by nitric acid concentration. However, ultrasound power shows no significant impact on the leaching concentration. The optimum conditions were found to be 20% nitric acid concentration, 48.89 °C temperature and 5.52 W ultrasound power for attaining maximum concentration of 97.916 mg/l for Cu leaching in solution.

Process optimization and kinetics for leaching of cerium, lanthanum and neodymium elements from iron ore waste's apatite by nitric acid

The leaching of rare earth elements (REEs) including cerium, lanthanum and neodymium from apatite concentrate obtained from iron ore wastes by nitric acid was studied. The effects of nitric acid concentration, solid to liquid ratio and leaching time on the recoveries of Ce, La and Nd were investigated using response surface methodology. The results showed that the acid concentration and solid to liquid ratio have significant effect on the leaching recoveries while the time has a little effect. The maximum REE leaching recoveries of 66.1%, 56.8% and 51.7% for Ce, La and Nd, respectively were achieved at the optimum leaching condition with 18% nitric acid concentration, 0.06 solid to liquid ratio and 38 min leaching time. The kinetics of cerium leaching was investigated using shrinking core model. It was observed that the leaching is composed of two stages. In the first stage a sharp increase in cerium leaching recovery was observed and at the longer time the leaching became slower. It was found that in the first stage the diffusion of reactants from ash layer is the rate controlling mechanism with an apparent activation energy of 6.54 kJ/mol, while in the second stage the mass transfer in the solution is the controlling mechanism.

TEHDGA, DMDOHEMA and Mixed Sorbents: Characterization and Am(III) Uptake Properties

The Atalante research facility produces radioactive waste that have to be managed according to specific rules. In particular, solid and liquid wastes need to be transferred to another facility in Marcoule to be evaporated with an alpha activity limit of 16.65 GBq/m3. The radioactive aqueous nitric acid wastes produced in Atalante must be first decontaminated by removing U, Pu and minor actinides and therefore a dedicated decontamination program for radioactive aqueous nitric acid wastes is implemented in Atalante. In particular, the recovery of americium and curium is obtained by extraction chromatography. TEHDGA (N, N, N’, N’-tetra-2-ethylhexyl-3-oxopentane-1,5-diamide), DMDOHEMA ((N,N’-dimethyl-N,N’-dioctylhexyloxyethyl malonamide) and a mixture of both extractants were impregnated on silica gel and studied.Batch experiments were made to determine the performances of such a process. The weight distribution coefficients (Dw) were determined for Am and Nd. Different kinetic behavior was found with both complexants. An effect of nitric acid concentration was observed. For three solids, the americium's uptake increases with acidity. Loading capacities by isotherm and Langmuir isotherm are obtained (between 48mg.g-1 and 94mg.g-1). After determining various parameters in batch extraction experiments, the performances of the solid supports were studied in columns. The breakthrough and elution curves were obtained with neodymium (respectively between 12mg.g-1 and 21mg.g-1; 0.17 and 0.27 L.g-1). Capacity and recovery were optimized with the mixture of DMDOHEMA and TEHDGA.