Processamento metalúrgico de minério de terras-raras por conversão hidrotérmica alcalina e controle do ferro
Metallurgical processing of rare earths ore by alkaline hydrothermal conversion and control of iron
Marisa Nascimento; Bruna Malvar Castello Branco; Paulo Sergio Moreira Soares
Resumo
O trabalho examina a conversão hidrotérmica alcalina para a extração de terras raras a partir da monazita e o comportamento do ferro como principal contaminante, empregando uma solução de hidróxido de sódio seguida de lixiviação clorÃdrica. Inicialmente foram construÃdos diagramas Eh-pH, para a identificação das regiões de estabilidade das espécies formadas na etapa de conversão. Ensaios iniciais identificaram a concentração de NaOH, a temperatura e a razão sólido-lÃquido como as mais importantes variáveis nesse processo. Ensaios complementares confirmaram que maiores percentuais de extração de lantânio no licor clorÃdrico são alcançados com a conversão alcalina a 140 o C e com o aumento da concentração de NaOH. A variação da razão sólido-lÃquido apresentou pequeno efeito na extração de lantânio para o licor clorÃdrico. Os melhores resultados para a combinação de extração de lantânio e seletividade frente ao ferro foram obtidos a 140 o C (46,4% La e 1,5% Fe), razão sólido-lÃquido de 0,16 g/ml (65,5% La e 34,5% Fe) e [NaOH] igual ou inferior a 60g/100 ml (52,1% La e 4,5% Fe)
Palavras-chave
Abstract
The study examines alkaline hydrothermal conversion for the extraction of rare earth elements from monazite and the behavior of iron as main contaminant, using a sodium hydroxide solution followed by hydrochloric leaching. Initially, Eh-pH diagrams were constructed to identify the stability regions of the species formed during the conversion step. Initial tests identified the concentration of NaOH, temperature, and solid-liquid ratio as the most important variables in this process. Further experiments confirmed that higher percentages of lanthanum extraction in the hydrochloric liquor are achieved with alkaline conversion at 140 °C and an increased concentration of NaOH. Variation in the solid-liquid ratio had a minimal effect on lanthanum extraction to the hydrochloric liquor. The best results for a combination of lanthanum extraction and selectivity against iron were obtained at 140 °C (46.4% La e 1.5% Fe), solid-liquid ratio 0.16 g/ml (65.5% La e 34.5% Fe), and NaOH concentration equal or less than 60g/100 ml (52.1% La e 4.5% Fe).
Keywords
References
1 Jha M, Kumari A, Panda R, Kumar J, Yoo K, Lee J. Review on hydrometallurgical recovery of rare earth metals. Hydrometallurgy. 2016;165:2-26. http://doi.org/10.1016/j.hydromet.2016.01.003.
2 Krishnamurthy N, Gupta CK. Extractive metallurgy of rare earths. 2nd ed. Boca Raton: CRC Press; 2015.
3 Lapidus GT, Doyle FM. Selective thorium and uranium extraction from monazite: II. Approaches to enhance the removal of radioactive contaminants. Hydrometallurgy. 2015;155:161-167. http://doi.org/10.1016/j. hydromet.2015.03.015.
4 Lapidus GT, Doyle FM. Selective thorium and uranium extraction from monazite: I. Single-stage oxalate leaching. Hydrometallurgy. 2015;154:102-110. http://doi.org/10.1016/j.hydromet.2015.04.006.
5 Alves RC, Nascimento M, Paulino JF, Afonso JC. Selection of a hydrometallurgical process for rare earths extraction from a Brazilian monazite. Hydrometallurgy. 2021;200. http://doi.org/10.1016/j.hydromet.2021.105556.
6 Berry L, Galvin J, Agarwal V, Safarzadeh MS. Alkali pug bake process for the decomposition of monazite concentrates. Minerals Engineering. 2017;109:32-41. http://doi.org/10.1016/j.mineng.2017.02.007.
7 Berry L, Agarwal V, Galvin J, Safarzadeh M. Decomposition of monazite concentrate in sulphuric acid. Canadian Metallurgical Quarterly. 2018;57:422-433. http://doi.org/10.1080/00084433.2018.1478490.
8 Demol J, Ho E, Senanayake G. Sulfuric acid baking and leaching of rare earth elements, thorium and phosphate from a monazite concentrate: Effect of bake temperature from 200 to 800 °C. Hydrometallurgy. 2018;179:254-267. http://doi.org/10.1016/J.HYDROMET.2018.06.002.
9 Purwanti T, Setyadji M, Astuti W, Perdana I, Petrus HTBM. Phosphate Decomposition by Alkaline Roasting to Concentrate Rare Earth Elements from Monazite of Bangka Island, Indonesia. Journal of Mining Science. 2020;56:477-485. http://doi.org/10.1134/S1062739120036763.
10 Nascimento M, Lemos F, Guimarães R, Sousa C, Soares P. Modeling of REE and Fe extraction from a concentrate from Araxá (Brazil). Minerals (Basel). 2019;9. http://doi.org/10.3390/min9070451.
11 Abdel-Rehim AM. An innovative method for processing Egyptian monazite. Hydrometallurgy. 2002;67:9-17. http:// doi.org/10.1016/S0304-386X(02)00134-2.
12 Habashi F. Extractive metallurgy of rare earths. Canadian Metallurgical Quarterly. 2013;52:224-233. http://doi.org/1 0.1179/1879139513Y.0000000081.
13 Kumari A, Panda R, Jha M, Lee J, Kumar J, Kumar V. Thermal treatment for the separation of phosphate and recovery of rare earth metals (REMs) from Korean monazite. Journal of Industrial and Engineering Chemistry. 2015;21:696-703. http://doi.org/10.1016/j.jiec.2014.03.039.
14 El-Nadi YA, Daoud JA, Aly HF. Modified leaching and extraction of uranium from hydrous oxide cake of Egyptian monazite. International Journal of Mineral Processing. 2005;76:101-110. http://doi.org/10.1016/j. minpro.2004.12.005.
15 Calkins GD, Filbert RB Jr, Bearse AE, Clegg JW. Recovery of thorium and uranium from monazite sand. Vol. 1. Columbus, Ohio: Battelle Memorial Inst.; 1950.
16 de Rohden N-SC, Beaumontel MP. Treatment of Monazite. US Patent 2783125, 1957.
17 Mukherjee TK. Development of rare earths technology in India. In: Chidambaram R, Banerjee S, editors. Materials research: current scenario and future projections. 1st ed. New Delhi: Allied Publishers Pvt. Limited; 2003.
18 Zelikman AN, Krein OE, Samsonov GV. Metallurgy of rare metals. 2nd ed. Jerusalem: Israel Program for Scientific Translations; 1966.
19 Witharana WPWS, Prabath DHL, Madushanka RS, Rohitha LPS, Dissanayake DMDK. Extraction of rare earths from monazite in pulmoddai deposit. In: Proceedings of ISERME 2021; 2021; Moratuwa, Sri Lanka. Moratuwa: Department of Earth Resources Engineering, University of Moratuwa; 2021. p. 135-42.
20 Issa A Fo, Riffel BF. Some aspects of the mineralogy of CBMM niobium deposit and mining and pyrochlore ore processing - Araxá - MG/Brazil. In: Proceedings of International Symposium Niobium 2001; 2001; Orlando. Orlando: Niobium 2001 Limited/TMS (The Minerals, Metals & Materials Society); 2001. p. 1-15.
21 Lapido-Loureiro FEV. Terras-Raras no Brasil: depósitos, recursos identificados, reservas. Vol. 21. Rio de Janeiro: CETEM/MCT; 1994.
22 Neumann R, Medeiros EB. Comprehensive mineralogical and technological characterisation of the Araxá (SE Brazil) complex REE (Nb-P) ore, and the fate of its processing. International Journal of Mineral Processing. 2015;144:1-10. http://doi.org/10.1016/j.minpro.2015.08.009.
23 Silva MCN, Matiolo E. Estudo de concentração de monazita em uma amostra de carbonatito friável brasileiro. Anais da XXIV Jornada de Iniciação CientÃfica - CETEM, Rio de Janeiro: CETEM/MCTIC; 2016. p. 76-80.
24 Kim E, Osseo-Asare K. Aqueous stability of thorium and rare earth metals in monazite hydrometallurgy: Eh-pH diagrams for the systems Th-, Ce-, La-, Nd- (PO 4)-(SO 4)-H 2O at 25°C. Hydrometallurgy. 2012;113-114:67-78. http://doi.org/10.1016/j.hydromet.2011.12.007.
25 Yang X, Rozelle PL, Pisupati SV. The effect of caustic soda treatment to recover rare earth elements from secondary feedstocks with low concentrations. Minerals Engineering. 2021;173. http://doi.org/10.1016/j.mineng.2021.107184.
26 Toyoda S, Ito K, Tokuda M. Decomposition of Rare Earth Containing Ores by Alkaline Hydrothermal Process. In: Proceedings of International Symposium on the Extraction and Applications of Zinc & Lead; 1995; Sendai. Sendai: The Mining & Materials Processing Institute of Japan ans The Metallurgical Society of CIN; 1995, p. 500-504.
Submitted date:
02/01/2024
Accepted date:
10/16/2024
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