Maximizing the exploitation of phosphogypsum wastes using soaking technique with citric acid, recovering rare-earth and residual phosphate contents

Abstract

Phosphogypsum (PG), the main by-product of phosphoric acid production industries, is considered one of the most important secondary sources of rare earth elements (REEs). The current study focuses on the recovery of REEs content and the residual phosphate content existing in the PG with preserving on the CaSO₄ skeleton to be used in other various applications. These attainments are carried out using citric acid leaching process via soaking technique. Several dissolution parameters for REEs using citric acid were studied, including soaking time, soaking temperature, citric acid concentration, solid-to-liquid ratio, and recycling of the citrate leaching solutions in the further REEs dissolution experiments. The best-operating conditions were 14 d of soaking time, 7.5% citric acid concentration, and the solid-to-liquid ratio of 1/5 at ambient temperature. About 79.57% dissolution efficiency of REEs was achieved using the optimal conditions. Applying four soaking stages by mixing different fresh PG samples with the same citrate solution sequentially, cumulative dissolution efficiency for REEs was found to be 64.7% under optimal soaking conditions. REEs were recovered using Dowex 50X8 resin from citrate solutions with 96% extraction efficiency. Dissolution kinetics proved the pseudo-first-order nature, reversible reactions, and two activation energies for all REEs.

Keywords

phosphogypsum / rare earths / citric acid / dissolution / soaking / Dowex 50X8 / pre-concentration

References

[1] JorjaniE, BagheriehA H, ChelganiS C. Rare earth elements leaching from Chadormalu apatite concentrate: Laboratory studies and regression predictions [J]. Korean Journal of Chemical Engineering, 2011, 28(2): 557-562

[2] El HadyS M. A novel procedure for processing of the xenotime mineral concentrate of southwestern Sinai [J]. Korean Journal of Chemical Engineering, 2017, 34(7): 2049-2055

[3] RoyS, BasuS, AnithaM, et al. . Synergistic extraction of Nd(III) with mixture of 8-hydroxyquinoline and its derivative with di-2-ethyl hexyl phosphoric acid in different diluents [J]. Korean Journal of Chemical Engineering, 2017, 34(6): 1740-1747

[4] YoonH S, KimC J, ChungK W, et al. . Leaching kinetics of neodymium in sulfuric acid of rare earth elements (REE) slag concentrated by pyrometallurgy from magnetite ore [J]. Korean Journal of Chemical Engineering, 2014, 31(10): 1766-1772

[5] AsadollahzadehM, TorkamanR. Extraction of dysprosium from waste neodymium magnet solution with ionic liquids and ultrasound irradiation procedure [J]. Korean Journal of Chemical Engineering, 2022, 39(1): 134-145

[6] JohanssonN, KrookJ, EklundM, et al. . An integrated review of concepts and initiatives for mining the technosphere: Towards a new taxonomy [J]. Journal of Cleaner Production, 2013, 55: 35-44

[7] KhawassekY M, EliwaA A, HaggagE S A, et al. . Adsorption of rare earth elements by strong acid cation exchange resin thermodynamics, characteristics and kinetics [J]. Applied Sciences, 2018, 1(1): 1-11

[8] KhawassekY M, EliwaA A, GawadE A, et al. . Recovery of rare earth elements from El-Sela effluent solutions [J]. Journal of Radiation Research and Applied Sciences, 2015, 8(4): 583-589

[9] BinnemansK, JonesP T, BlanpainB, et al. . Towards zero-waste valorisation of rare-earth-containing industrial process residues: A critical review [J]. Journal of Cleaner Production, 2015, 99: 17-38

[10] RutherfordP M, DudasM J, SamekR A. Environmental impacts of phosphogypsum [J]. Science of the Total Environment, 1994, 149(1–2): 1-38

[11] RICHARDSON S G, JOHNSON C D, PATEL S K. Establishing vegetation cover on phosphogypsum in Florida [R]. FIPR, Bartow, FL., 1995: Publication No. 01-086-116. u]https://fiprf.loridapolye.du/publications/establishing-vegetation-cover-on-phosphogypsum-in-florida.php.

[12] RutherfordP M, DudasM J, ArocenaJ M. Radioactivity and elemental composition of phosphogypsum produced from three phosphate rock sources [J]. Waste Management & Research, 1995, 13(5): 407-423

[13] TayibiH, ChouraM, LópezF A, et al. . Environmental impact and management of phosphogypsum [J]. Journal of Environmental Management, 2009, 90(8): 2377-2386

[14] EnamoradoS, AbrilJ M, MasJ L, et al. . Transfer of Cd, Pb, Ra and U from phosphogypsum amended soils to tomato plants [J]. Water, Air, and Soil Pollution, 2009, 203(1–4): 65-77

[15] PÅLSSON BI, MARTINSSON O, WANHAINEN C, et al. Unlocking rare earth elements from European apatite-iron ores [C]// ERES 2014, 1st European Rare Earth Resources Conference. Milos Island, Greece, 2014: 211–220.

[16] HabashiF. The recovery of the lanthanides from phosphate rock [J]. Journal of Chemical Technology and Biotechnology Chemical Technology, 1985, 35(1): 5-14

[17] WalawalkarM, NicholC K, AzimiG. Process investigation of the acid leaching of rare earth elements from phosphogypsum using HCl, HNO₃, and H₂SO₄ [J]. Hydrometallurgy, 2016, 166: 195-204

[18] JarosińskiA, KowalczykJ, MazanekC. Development of the Polish wasteless technology of apatite phosphogypsum utilization with recovery of rare earths [J]. Journal of Alloys and Compounds, 1993, 200(1–2): 147-150

[19] PrestonJ S, ColeP M, CraigW M, et al. . The recovery of rare earth oxides from a phosphoric acid byproduct. Part 1: Leaching of rare earth values and recovery of a mixed rare earth oxide by solvent extraction [J]. Hydrometallurgy, 1996, 41(1): 1-19

[20] PrestonJ S, Du PreezA C. The recovery of a mixed rare-earth oxide and the preparation of cerium, europium and neodymium oxides from a South African phosphoric acid sludge by solvent extraction [J]. Mineral Processing and Extractive Metallurgy Review, 1998, 18(2): 175-200

[21] LOKSHIN E P, VERSHKOVA J A, KALINNIKOV V T, et al. Method of recovering rare-earth minerals from phosphogypsum: Patent No. RU2225892 (C1) [P]. 2004.

[22] LOKSHIN E P, KALINNIKOV V T, IVLEV K G, et al. Method of recovering rare-earth elements from phosphogypsum: Patent No. RU2293781 (C1) [P] 2007.

[23] ABRAMOV Y K, VESELOV M, ZALEVSKY V M, et al. Method for extracting rare earth elements from phosphogypsum: United States Patent No. 2012/0114538A1 [P]. 2012.

[24] Al-ThyabatS, ZhangP. REE extraction from phosphoric acid, phosphoric acid sludge, and phosphogypsum [J]. Mineral Processing and Extractive Metallurgy, 2015, 124(3): 143-150

[25] El-DidamonyH, AliM M, AwwadN S, et al. . Treatment of phosphogypsum waste using suitable organic extractants [J]. Journal of Radioanalytical and Nuclear Chemistry, 2012, 291(3): 907-914

[26] El-DidamonyH, GadoH S, AwwadN S, et al. . Treatment of phosphogypsum waste produced from phosphate ore processing [J]. Journal of Hazardous Materials, 2013, 244–245: 596-602

[27] ParkH, JungK, AlorroR D, et al. . Leaching behavior of copper, zinc and lead from contaminated soil with citric acid [J]. Materials Transactions, 2013, 54(7): 1220-1223

[28] JossoP, RobertsS, TeagleD A H, et al. . Extraction and separation of rare earth elements from hydrothermal metalliferous sediments [J]. Minerals Engineering, 2018, 118: 106-121

[29] AstutiW, HirajimaT, SasakiK, et al. . Comparison of atmospheric citric acid leaching kinetics of nickel from different Indonesian saprolitic ores [J]. Hydrometallurgy, 2016, 161: 138-151

[30] McdonaldR G, WhittingtonB I. Atmospheric acid leaching of nickel laterites review: Part I. Sulphuric acid technologies [J]. Hydrometallurgy, 2008, 91(1–4): 35-55

[31] Health Canada. Canadian guidelines for the management of naturally occurring radioactive materials (NORM) [M]. Government of Canada, 2000: 47.

[32] PotgieterJ H, PotgieterS S, MccrindleR I, et al. . An investigation into the effect of various chemical and physical treatments of a South African phosphogypsum to render it suitable as a set retarder for cement [J]. Cement and Concrete Research, 2003, 33(8): 1223-1227

[33] ZengC-X, GuanQ-J, SuiY, et al. . Kinetics of nitric acid leaching of low-grade rare earth elements from phosphogypsum [J]. Journal of Central South University, 2022, 29(6): 1869 1880

[34] LiS-C, MalikM, AzimiG. Extraction of rare earth elements from phosphogypsum using mineral acids: Process development and mechanistic investigation [J]. Industrial & Engineering Chemistry Research, 2022, 611102-114

[35] YangX-S, SalvadorD, MakkonenH T, et al. . Phosphogypsum processing for rare earths recovery—A review [J]. Natural Resources, 2019, 10(9): 325-336

[36] CánovasC R, ChapronS, ArrachartG, et al. . Leaching of rare earth elements (REEs) and impurities from phosphogypsum: A preliminary insight for further recovery of critical raw materials [J]. Journal of Cleaner Production, 2019, 219: 225-235

[37] SHAPIRO L, BRANNOCK W W. Rapid analysis of silicate, carbonate, and phosphate rocks [R]. US Geological Survey, 1962. DOI: https://doi.org/10.3133/b1144a.

[38] MarczenkoZ. Spectrophotometric determination of elements [J]. Analytica Chimica Acta, 1977, 91(2): 427-428

[39] CamposM P, CostaL J P, NistiM B, et al. . Phosphogypsum recycling in the building materials industry: Assessment of the radon exhalation rate [J]. Journal of Environmental Radioactivity, 2017, 172: 232-236

[40] RashadA M. Phosphogypsum as a construction material [J]. Journal of Cleaner Production, 2017, 166: 732-743

[41] HagagM S, MorsyA M A, AliA H, et al. . Adsorption of rare earth elements onto the phosphogypsum a waste byproduct [J]. Water, Air & Soil Pollution, 2019, 230(12): 1-14

[42] LeonS P, InoueN, ShinanoH. Effect of acetic and citric acids on the growth and activity (VB-N) of pseudomonas sp. and moraxella sp [J]. Bull Fac Fish Hokkaido Univ, 1993, 44(2): 80-85

[43] Sánchez-ClementeR, IgeñoM I, PoblaciónA G, et al. . Study of pH changes in media during bacterial growth of several environmental strains [C]// Environment, Green Technology, and Engineering International Conference. Basel, Switzerland: MDPI, 2018, 21297

[44] AbbasiliasiS, TanJ S, Tengku IbrahimT A, et al. . Fermentation factors influencing the production of bacteriocins by lactic acid bacteria: A review [J]. RSC Advances, 2017, 7(47): 29395-29420

[45] ThabetO B D, GtariM, SghaierH. Microbial diversity in phosphate rock and phosphogypsum [J]. Waste and Biomass Valorization, 2017, 8(7): 2473-2483

[46] TRIFI H. Characterization and bioremediation potential of phosphate solubilizing bacteria isolated from Tunisian phosphogypsum [R]. Biology, Faculty of Sciences and National Center for Nuclear Sciences and Technology. Tunis, 2011.

[47] MuyzerG, StamsA J M. The ecology and biotechnology of sulphate-reducing bacteria [J]. Nature Reviews Microbiology, 2008, 6(6): 441-454

[48] CONNORS K. chemical kinetics, chemical kinetics: The study of reaction rates in solution [M]. VCH Publishers, 1990.

[49] EliwaA A, GawadE A, MubarkA E, et al. . Intensive studies for modeling and thermodynamics of fusion digestion processes of Abu rusheid mylonite rocks [J]. JOM, 2021, 73(11): 3419-3429

[50] PERROT P. A to Z of thermodynamics [M]. Oxford University Press, 1998.