Preparation of crystalline rare earth carbonates with large particle size from the lixivium of weathered crust elution-deposited rare earth ores

Abstract

Crystalline rare-earth (RE) carbonates having large particle size were prepared from the lixivium of weathered crust elution-deposited rare-earth ores using the precipitation method with ammonium bicarbonate as the precipitant. Their chemical composition was studied using elemental and thermogravimetric analyses (TGA), and their structure and morphology were characterized using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results demonstrate that the crystalline rare-earth carbonate is a hydrated basic carbonate or oxycarbonate and not astable intermediate carbonate in the process of thermal decomposition. The particle size of crystalline rare-earth carbonates with large particle size is in the range of 50–200 µm. With an RE₂O₃ content of up to 95wt%, the quality of crystalline rare-earth carbonates is higher compared to the Chinese National Standard (GB/T 28882-2012). The quality of the product is superior to the Chinese National Standard.

Keywords

rare-earth ores / precipitation / crystalline rare-earth carbonate / large particle size

References

[1] Moldoveanu GA, Papangelakis VG. An overview of rare-earth recovery by ion-exchange leaching from ion-adsorption clays of various origins. Mineral. Mag., 2016, 80(1): 63.

[2] Kanazawa Y, Kamitani M. Rare earth minerals and resources in the world. J. Alloys Compd., 2006, 408–412, 1339.

[3] Goodenough KM, Wall F, Merriman D. The rare earth elements: Demand, global resources, and challenges for resourcing future generations. Nat. Resour. Res., 2018, 27(2): 201.

[4] Chi RA, Tian J, Li ZJ, Peng C, Wu YX, Li SR, Wang CW, Zhou ZJ. Existing state and partitioning of rare earth on weathered ores. J. Rare Earths, 2005, 23(6): 756.

[5] He LY, Feng TZ, Fu SY, Zhu DX. Study on process of extraction of rare earths from the ion-adsorption type rare earth ore ore by (NH₄)₂SO₄ leaching. Chin. Rare Earths, 1983, 4(3): 1.

[6] Moldoveanu GA, Papangelakis VG. Recovery of rare earth elements adsorbed on clay minerals: I. Desorption mechanism. Hydrometallurgy, 2012, 117–118, 71.

[7] Chi RA, Tian J. Weathered Crust Elution-Deposited Rare Earth Ores, 2008, Inc., New York, Nova Science Publishers

[8] Bazin C, El-Ouassiti K, Ouellet V. Sequential leaching for the recovery of alumina from a Canadian clay. Hydrometallurgy, 2007, 88(1–4): 196.

[9] Li YX, He XB, Gu ZY, Hu PG. Precipitation reaction of RECl₃ with NH₄HCO₃ and co-precipitation behavior of accompanying impurity lons. Chin. Rare Earths, 1999, 20(2): 19.

[10] Tian J, Yin JQ, Chen KH, Rao GH, Jiang MT, Chi RA. Extraction of rare earths from the leach liquor of the weathered crust elution-deposited rare earth ore with non-precipitation. Int. J. Miner. Process., 2011, 98(3–4): 125.

[11] Chi R, Zhou Z, Xu Z, Zhu G, Xu S. Solution-chemistry analysis of ammonium bicarbonate consumption in rare-earth-element precipitation. Metall. Mater. Trans. B, 2003, 34(5): 611.

[12] Chi R, Xu Z. A solution chemistry approach to the study of rare earth element precipitation by oxalic acid. Metall. Mater. Trans. B, 1999, 30(2): 189.

[13] Leng ZY, Liu SZ, Ma Y, Xu YH, Wang WB, Hao XK, Bai Y, Fan MY, Huang JM, Wu Z. Crystalline rare earth carbonate precipitating from leaching solution of sulfuric acid calcinating concentrate of rare earth. J. Rare Earths, 2000, 21(2): 26.

[14] China Ministry of Environmental Protection, Chinese National Standard GB 26451-2011: Emission Standards of Pollutants from Rare Earths Industry, 2011.

[15] Li DQ. Chemical engineering problems in hydrometallurgical industry of rare earths. Prog. Chem., 1995, 7(3): 209.

[16] Luo XP, Zou LP, Ma PL, Luo CG, Xu J, Tang XK. Removing aluminum from a low-concentration lixivium of weathered crust elution-deposited rare earth ore with neutralizing hydrolysis. Rare Met., 2017, 36(8): 685.

[17] Yu ZH, Wang M, Wang LS, Zhao LS, Feng ZY, Sun X, Huang XW. Preparation of crystalline mixed rare earth carbonates by Mg(HCO₃)₂ precipitation method. J. Rare Earths, 2020, 38(3): 292.

[18] Michiba K, Tahara T, Nakai I, Miyawaki R, Matsubara S. Crystal structure of hexagonal RE(CO₃)OH. Z. Kristallogr., 2011, 226(6): 518.

[19] Yu QH, Li XB. Study on the formation of crystalline rare earth carbonates from rare earth ore leaching liquors. J. Rare Earths, 1993, 11(3): 223.

[20] Yin JQ, Lu SL. Preparation of crystalline carbonate rare earth from the controlled-flow rate elution leach liquid of the weathered crust elution-deposited rare earth ore. Hydrometallurgy, 1995, 14(4): 9.

[21] Liu YH, Chen J, Li DQ. Application and perspective of ionic liquids on rare earths green separation. Sep. Sci. Technol., 2012, 47(2): 223.

[22] Tian J, Yin JQ, Chi RA, Rao GH, Jiang MT, Ouyang KX. Kinetics on leaching rare earth from the weathered crust elution-deposited rare earth ores with ammonium sulfate solution. Hydrometallurgy, 2010, 101(3–4): 166.

[23] Xu ZY, Zhang YJ, Fang ZY, Yin XB, Zhu W. Controllable synthesis and optical properties of NdOHCO₃ dodecahedral microcrystals. Mater. Res. Bull., 2010, 45(1): 74.

[24] General Administration of Quality Supervision, Inspection and Quarantine of the People’s Republic of China, Chinese National Standard GB/T 18882.1-2002: Chemical Analysis Methods for Mixed Rare Earth Oxide of Ion-absorpted Type RE Ore-Determination of Total Rare Earth Contents-Oxalate Gravimetric Method, 2002.

[25] Tian J, Yin JQ, Tang XK, Chen J, Luo XP, Rao GH. Enhanced leaching process of a low-grade weathered crust elution-deposited rare earth ore with carboxymethyl sesbania gum. Hydrometallurgy, 2013, 139, 124.

[26] Ali AB, Maisonneuve V, Houlbert S, Silly G, Buzaré JY, Leblanc M. Cation and anion disorder in new cubic rare earth carbonates Na₂LiLn(CO₃)₃ (Ln = Eu-Er, Yb, Lu, Y); synthesis, crystal structures, IR, Raman and NMR characterizations. Solid State Sci., 2004, 6(11): 1237.

[27] Refat MS. A novel method for the synthesis of rare earth carbonates. Synth. React. Inorg. Met.-Org. Chem., 2004, 34(9): 1605.

[28] Sheu HS, Shih WJ, Chuang WT, Li IF, Yeh CS. Crystal structure and phase transitions of Gd(CO₃)OH studied by synchrotron powder diffraction. J. Chin. Chem. Soc., 2010, 57(4B): 938.

[29] Want B. Single crystal growth and characterization of lanthanum-neodymium oxalate octahydrate. J. Cryst. Growth, 2011, 335(1): 90.

[30] Liu S, Ma RJ. Preparation of crystalline precipitation of mixed rare earth carbonates. Chin. J. Nonferrous Met., 1998, 8(2): 331.

[31] Gu FB, Wang ZH, Han DM, Guo GS, Guo HY. Crystallization of rare earth carbonate nanostructures in the reverse micelle system. Cryst. Growth Des., 2007, 7(8): 1452.

[32] Zhang YJ, He HM, Yang XZ, Zheng A, Fan Y. Morphology-controlled synthesis, characterization, growth mechanism of SmOHCO₃ with high uniform size and photoluminescence property of SmOHCO₃:Eu³⁺. Powder Technol., 2012, 224, 175.

[33] Frost RL, Xi YF, Scholz R, Belotti FM, Filho MC. Infrared and Raman spectroscopic characterization of the carbonate mineral weloganite-Sr₃Na₂Zr(CO₃)₆·3H₂O and in comparison with selected carbonates. J. Mol. Struct., 2013, 1039, 101.

[34] Bushuev NN, Zinin DS. Thermal decomposition features of calcium and rare-earth oxalates. Russ. J. Inorg. Chem., 2016, 61(2): 161.

[35] Zhan G, Yu JX, Xu ZG, Zhou F, Chi RA. Kinetics of thermal decomposition of lanthanum oxalate hydrate. Trans. Nonferrous Met. Soc. China, 2012, 22(4): 925.

[36] Yin SH, Lin G, Li SW, Peng JH, Zhang LB. Application of response surface methodology for optimization of parameters for microwave heating of rare earth carbonates. High Temp. Mater. Processes, 2016, 35(8): 813.

[37] General Administration of Quality Supervision, Inspection and Quarantine of the People’s Republic of China, Standardization Administration of the People’s Republic of China, Chinese National Standard GB/T 28882-2012: Rare Earth Carbonate of lon-absorpted Type Rare Earth Ore, 2012.