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Effects of contaminant metal ions on precipitation recovery of rare earth elements using Oxalic acid

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Journal of Rare Earths 2022年第3期40卷 482-490,I0005页

作者： Wencai Zhang Aaron Noble Bin Ji Qi Li Department of Mining and Minerals Engineering Virginia Polytechnic Institute and State UniversityBlacksburgVA24061USA

Solution equilibrium calculations were performed in this study to understand the impact of contaminant metal ions on the precipitation efficiency of selected rare earth elements(Ce^(3+),Nd^(3+),and Y^(3+))using Oxalic acid as a precipitant.Trivalent metal ions,Al^(3+) and Fe^(3+),are found to considerably affect the precipitation efficiency of REEs.When Al^(3+) and Fe^(3+)concentrations are increased by 1×10^(−4) mol/L,in order to achieve an acceptable cerium recovery of 93%from solutions containing 1×10^(−4) mol/L Ce^(3+),oxalate dosage needs to increase by 1.2×10^(−4) and 1.68×10^(−4) mol/L,respectively.Such great impacts on the required oxalate dosage are also observed for Nd^(3+) and Y^(3+),which indicates that Oxalic acid consumption and cost will be largely increased when the trivalent metal ions exist in REE-concentrated solutions.Effects of the divalent metal ions on the oxalate dosage are minimal.Furthermore,solution equilibrium calculation results show that the precipitation of Fe^(3+) and Ca^(2+)(e.g.,hematite and Ca(C_(2)O_(4))∙H_(2)O(s))likely occurs during the oxalate precipitation of REEs at relatively high pH(e.g.,pH 2.5),which will reduce rare earth oxalate product purity.In addition to the metal ions,anionic species,especially SO_(4)^(2-),are also found to negatively affect the precipitation recovery of REEs.For example,when 0.1 mol/L SO_(4)^(2-) occurs in a solution containing 1×10^(−4) mol/L Ce^(3+) and 4×10^(−4) mol/L oxalate,the pH needs to be elevated from 2.0 to 3.3 to achieve the acceptable recovery.Overall,findings from this study provide guidance for the obtainment of high-purity rare earth products from solutions containing a considerable amount of contaminant metal ions by means of Oxalic acid precipitation.

关键词： Rare earth elements Oxalic acid Precipitation Contaminant metal ions

Electrocatalytic production of glycolic acid via Oxalic acid reduction on titania debris supported on a TiO_(2)nanotube array

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Journal of Energy Chemistry 2022年第5期31卷 669-678页

作者： Francesco Pio Abramo Federica De Luca Rosalba Passalacqua Gabriele Centi Gianfranco Giorgianni Siglinda Perathoner Salvatore Abate Department of ChiBioFarAM(Industrial Chemistry) University of MessinaERIC aisbl and INSTM/CASPEV.le F.Stagno d’Alcontres 31Messina 98166Italy University of Calabria Department of Environmental EngineeringLaboratory of Industrial Chemistry and Catalysis Via P.Bucci87036 RendeCSItaly

Electrodes prepared by anodic oxidation of Ti foils are robust and not toxic materials for the electrocatalytic reduction of Oxalic acid to glycolic acid, allowing the development of a renewable energy-driven process for producing an alcoholic compound from an organic acid at low potential and room temperature. Coupled with the electrochemical synthesis of the Oxalic acid from CO_(2),this process represents a new green and low-carbon path to produce added value chemicals from CO_(2). Various electrodes prepared by anodic oxidation of Ti foils were investigated. They were characterized by the presence of a TiO_(2) nanotube array together with the presence of small patches, debris, or TiO_(2) nanoparticles. The concentration of oxygen vacancies, the amount of Ti^(3+) measured by X-ray photoelectron spectroscopy(XPS) and the intensity of the anodic peak measured by cyclic voltammetry, were positively correlated with the achieved Oxalic acid conversion and glycolic acid yield. The analysis of the results indicates the presence of small amorphous TiO_(2) nanoparticles(or surface patches or debris) interacting with TiO_(2) nanotubes, the sites responsible for the conversion of Oxalic acid and glycolic acid yield. By varying this structural characteristic of the electrodes, it is possible to tune the glycolic acid to glyoxylic acid relative ratio. A best cumulative Faradaic efficiency(FE) of about 84% with FE to glycolic acid around 60% and oxalic conversion about 30% was observed.

关键词： Oxalic acid TiO_(2)nanotubes Glyoxylic acid Glycolic acid Electrocatalysis

Oxalic acid cross-linked sodium alginate and carboxymethyl chitosan hydrogel membrane for separation of dye/NaCl at high NaCl concentration

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Chinese Chemical Letters 2022年第4期33卷 1951-1955页

作者： Wenbin Xie Kongyin Zhao Lijing Xu Ningning Gao Hui Zhao Zelong Gong Linan Yu Jun Jiang State Key Laboratory of Separation Membranes and Membrane Processes/National Centre for International Joint Research on Separation Membranes Tiangong UniversityTianjin 300387China SINOPEC Research Institute of Petroleum Processing Beijing 100083China

Dye desalination is a challenge in the treatment of textile wastewater with high salt concentration. It is imperative to develop salt resistance membrane that is from sustainable materials to effectively treat dye/salt mixtures. And most polymer membrane materials are non-renewable petrochemical resources.In this paper, a green hydrogel membrane(CMCS-OA-Na Alg) was prepared by non-metallic ions of Oxalic acid(OA) cross-linking of two natural macromolecules of sodium alginate(Na Alg) and carboxymethyl chitosan(CMCS). The membrane showed excellent anti-swelling at high salt concentration(swelling rate less than 8.0% in 10.0 wt% Na Cl solution) and good anti-fouling performance. The membrane exhibited a rejection higher than 95.0% for dyes(bright blue, direct black, direct red, and Congo red) and lower than7.0% for Na Cl, which can achieve better dye/Na Cl separation performance. This study provides a promising membrane material for high salt textile wastewater treatment only using water and carbohydrates as raw materials without any organic solvents.

关键词： Hydrogel filtration membranes Oxalic acid Sodium alginate High salt wastewater Salt resistance

High-efficiency simultaneous extraction of rare earth elements and iron from NdFeB waste by Oxalic acid leaching

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Journal of Rare Earths 2021年第3期39卷 323-330,I0004页

作者： Qingsheng Liu Tao Tu Hao Guo Huajin Cheng Xuezhong Wang Faculty of Materials Metallurgy and Chemitry Jiangxi University of Science and TechnologyGanzhou 341000China Science School Jiangxi University of Science and TechnologyGanzhou 341000 China College of Materials Science and Engineering Jiangsu UniversityZhenjiang 212013China

Iron can not be recovered at high value because only rare earth elements are effectively recovered from NdFeB waste via oxidation roasting-hydrochloric acid leaching process.In this study,a new method for leaching NdFeB waste with Oxalic acid was developed.The high-efficiency,simultaneous and high-value recovery of rare earth elements and iron was realized to simplify the process and improve the economic benefit.Results of the Oxalic acid leaching experiments show that under the optimum leaching conditions at 90℃ for 6 h in the aqueous solution of Oxalic acid(2 mol/L) with a liquid-solid ratio of60 mL/g,the iron leaching efficiency and precipitation rate of rare earth oxalate reach 93.89% and 93.17%,respectively.Rare earth oxalate and Fe(C_(2)O_(4))3^(3-) were left in the residue and the leaching solution,respectively.The leaching mechanism was further analyzed by characterising the leach residues obtained through X-ray powder diffraction(XRD) and scanning electron microscopy-energy dispersive X-ray spectroscopy(SEM-EDS).Results of the leaching kinetics study indicate that the process of Oxalic acid leaching follows the shrinking nucleus model,and the leaching kinetics model is controlled by the mixed factors of diffusion and chemical reaction.The leaching residue was calcined at 850℃ for 3 h and then decomposed into rare earth oxide,which can be directly used to prepare rare earth alloy via molten salt electrolysis.For the leaching solution,ferric oxalate solution was reduced using Fe powder to prepare the ferrous oxalate(FeC_(2)O_(4)-2H_(2)O).

关键词： NdFeB waste Oxalic acid Orthogonal experiment Leaching kinetics Reduction precipitation Rare earths

Removal of Vand Fe from spent denitrification catalyst by using Oxalic acid:Study of dissolution kinetics and toxicity

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Green Energy & Environment 2021年第5期6卷 660-669页

作者： Wenfen Wu Chenye Wang Xingrui Wang Huiquan Li CAS Key Laboratory of Green Process and Engineering National Engineering Laboratory for Hydrometallurgical Cleaner Production TechnologyInstitute of Process EngineeringChinese Academy of SciencesBeijing100190China College of Chemical and Engineering University of Chinese Academy of SciencesBeijing100049China

The selective dissolution of V and Fe from spent denitrification catalyst(SDC)with Oxalic acid was investigated to minimise their environmental effects.The dissolution kinetics of different elements from SDC by using 0.1–1.5 mol L^(-1) Oxalic acid concentration was studied at 60℃–90℃.V and Fe were preferentially released(65%and 81%)compared with Al,Ti and W within 5 min due to the redox reactions of Oxalic acid.The dissolved fractions of Fe,V,Al,Wand Ti increased with the increase of Oxalic acid concentration and reaction temperature.The dissolution kinetic experiments were analysed and controlled diffusion with n0.92).The Arrhenius parameters of the Ea values of Ti,W,V,Fe and Al from SDC with Oxalic acid were 30,26,20,19 and 11 kJ mol^(-1),respectively.The obtained Avrami equation of V and Fe was successfully used to predict their leaching behaviour in Oxalic acid.Toxicity characteristic leaching procedure revealed that the toxicity risk of Vand Fe metals from SDC after leaching with Oxalic acid decreased to below 5 mg kg^(-1) residua.Overall,the leaching residua by Oxalic acid indicated its safety for the environment.

关键词： Spent denitrification catalyst Oxalic acid Dissolution kinetic Avrami model

Reductive leaching of indium from the neutral leaching residue using Oxalic acid in sulfuric acid solution

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International Journal of Minerals,Metallurgy and Materials 2021年第3期28卷 373-379页

作者： F.Maddah M.Alitabar H.Yoozbashizadeh Department of Materials Science and Engineering Sharif University of TechnologyTehran 11155-9466Iran

The present study evaluates the reductive leaching of indium from indium-bearing zinc ferrite using Oxalic acid as a reducer in sulfuric acid solution.The effect of main factors affecting the process rate,including the oxalic-acid-to-sulfuric-acid ratio,stirring rate,grain size,temperature,and the initial concentration of synergic acid,was precisely evaluated.The results confirmed the acceptable efficiency of dissolving indium in the presence of Oxalic acid.The shrinking-core model with a chemical-reaction-controlled step can correctly describe the kinetics of indium dissolution.On the basis of an apparent activation energy of 44.55 kJ/mol and a reaction order with respect to the acid concentration of 1.14,the presence of Oxalic acid was found to reduce the sensitivity to temperature changes and to increase the effect of changes in acid concentration.Finally,the equation of the kinetic model based on the factors under study is presented.

关键词： Oxalic acid reductive leaching indium

Immobilization of lead in anthropogenic contaminated soils using phosphates with/without Oxalic acid

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Journal of Environmental Sciences 2015年第2期27卷 64-73页

作者： Xiaojuan Su Jun Zhu Qingling Fu Jichao Zuo Yonghong Liu Hongqing Hu Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River) Ministry of Agriculture College of Resources and Environment Huazhong Agricultural University

Understanding the effects of Oxalic acid（OA） on the immobilization of Pb（Ⅱ） in contaminated soils by phosphate materials, has considerable benefits for risk assessment and remediation strategies for the soil. A series of phosphate amendments with/without Oxalic acid were applied to two anthropogenic contaminated soils. We investigated the immobilization of Pb（Ⅱ） by KH2PO4, phosphate rock（PR）, activated phosphate rock（APR） and synthetic hydroxyapatite（HAP） at different phosphate：Pb（P：Pb） molar ratios（0, 0.6, 2.0 and 4.0） in the presence/absence of 50 mmol Oxalic acid/kg soil, respectively. The effects of treatments were evaluated using single extraction with deionized water or Ca Cl2, Community Bureau of Reference（BCR） sequential extraction and toxicity characteristic leaching procedure（TCLP）methods. Our results showed that the concentration of water extractable, exchangeable and TCLP-Pb all decreased with incubation time. The concentration of water-extractable Pb after120 days was reduced by 100% when soils were amended with APR, HAP and HAP ＋ OA, and the TCLP-Pb was 〈5 mg/L for the red soil at P：Pb molar ratio 4.0. Water-soluble Pb could not be detected and the TCLP-Pb was 〈5 mg/L at all treatments applied to the yellow-brown soil. BCR results indicated that APR was most effective, although a slight enhancement of water-soluble phosphate was detected at the P：Pb molar ratio 4.0 at the beginning of incubation. Oxalic acid activated phosphates, and so mixing insoluble phosphates with Oxalic acid may be a useful strategy to improve their effectiveness in reducing Pb bioavailability.

关键词： Soil lead remediation Toxicity characteristics leaching procedure（TCLP） Phosphorous materials Oxalic acid Lead fraction

Oxalic acid Promoted Hydrolysis of Sodium Borohydride for Transition Metal Free Hydrogen Generation

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Journal of Wuhan University of Technology(Materials Science) 2020年第4期35卷 1011-1015页

作者： PENG Yuanting ZENG Hui SHI Yu XU Jinrong 谢镭陈均 ZHENG Jie LI Xingguo Wuhan Institute of Marine Electric Propulsion Wuhan 430064China Sunan Institute for Molecular Engineering Peking UniversityChangshu Hi-Tech Industrial Development ZoneChangshu 215500China Institute of Materials China Academy of Engineering PhysicsJiangyou 621908China Beijing National Laboratory for Molecular Sciences(BNLMS) College of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

We reported an inexpensive and high-efficiency hydrogen generation method from NaBH4 hydrolysis promoted by Oxalic acid.NaBH4 and H2C2O4 were premixed and hydrogen generation was initiated by adding water into the solid mixture.H2C2O4 was selected as the acid promotor due to its solid state and low mass per proton.The effect of reactant ratio on the hydrogen yield and hydrogen storage density was investigated.With optimized reactant ratio,high gravimetric hydrogen storage up to 4.4wt%based on all the reactants can be achieved with excellent hydrogen generation kinetics.

关键词： hydrogen generation sodium borohydride Oxalic acid hydrolysis

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A Facile Recovery Process for Cathodes from Spent Lithium Iron Phosphate Batteries by Using Oxalic acid

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CSEE Journal of Power and Energy Systems 2018年第2期4卷 219-225页

作者： Li Li Jun Lu Longyu Zhai Xiaoxiao Zhang Larry Curtiss Yi Jin Feng Wu Renjie Chen Khalil Amine School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081China Chemical Sciences and Engineering Division Argonne National LaboratoryIL 60439USA Material Science Division Argonne National LaboratoryIL 60439USA State Key Laboratory of Operation and Control of Renewable Energy and Storage Systems China Electric Power Research Institute.Beijing 100192China

A simplistic and novel leaching process is developed to dispose spent lithium iron phosphate(LiFePO_(4))batteries.In this paper,Oxalic acid is selected as a leaching reagent to recover lithium as a resource and remove phosphorus from LiFePO_(4) batteries,benefiting from its low natural effects.The physical properties of spent cathode materials(before leaching)and residues(after leaching)are identified by X-ray diffraction(XRD)and scanning electronic microscopy(SEM)with energy dispersive X-ray spectroscopy(EDS).The total amounts of Li and Fe are analyzed by inductively coupled plasma-atomic emission spectroscopy(ICP-AES).The process occurs under conditions of a 0.3 mol·L^(-1) Oxalic acid concentration,a temperature of 80℃,a reaction time of 60 min and a solid/liquid ratio of 60 g·L^(-1).It can effectively precipitate92%ferrum in terms of FeC_(2)O_(4)·2H_(2)O from LiFePO4,with the leaching efficiency of Li achieving up to 98%.This method demonstrates a new strategy for dealing with spent lithium iron phosphate batteries with a low cost and low environmental impact.

关键词： Leaching Oxalic acid precipitation spent lithium-ion batteries