EXTRACTION OF LANTHANUM AND CERIUM FROM A BASTNASITE ORE BY DIRECT ACIDIC LEACHING

Madencilik, 2020, 59(2), 85-92 Mining, 2020, 59(2), 85-92 Orijinal Araştırma / Original Research EXTRACTION OF LANTHANUM AND CERIUM FROM A BASTNASITE ORE BY DIRECT ACIDIC LEACHING DİREKT ASİT LİÇİ İLE BASTNAZİT CEVHERİNDEN LANTANYUM VE SERYUM KAZANIMI Sait Kursunoglua,* , Soner Topa,** , Shokrullah Hussainib,*** , Hasan Serkan Gokcenb,**** , Mahmut Altinerc,***** , Safak Ozsaracd,****** , Muammer Kayab,******* a Abdullah Gul University, Engineering Faculty, Materials Science and Nanotechnology Engineering Department, Kayseri, TURKEY Eskisehir Osmangazi University, Faculty of Engineering and Architecture, Mining Engineering Department, Eskisehir, TURKEY c Cukurova University, Engineering Faculty, Mining Engineering Department, Adana, TURKEY d Batman University, Faculty of Engineering and Architecture, Geological Engineering Department, Batman, TURKEY b Geliş Tarihi / Received : 21 Kasım / November 2019 Kabul Tarihi / Accepted : 01 Mayıs / May 2020 Keywords: Lanthanum, Cerium, Direct acidic leaching, Bastnasite ore. Anahtar Sözcükler: Lantanyum, Seryum, Direkt asit liçi, Bastnazit cevheri. ABSTRACT The extraction of lanthanum (La) and cerium (Ce) from a bastnasite ore by direct acidic leaching was investigated. The effects of acid concentration and leaching temperature on the extraction of La and Ce from the ore were tested. Using nitric (NHO3), more than 85% of the La and Ce were simultaneously extracted into leach solution whereas the La and Ce dissolutions were determined as less than 85% by using sulfuric acid (H2SO4). The La dissolution exceeded 90% by using hydrochloric acid (HCl); however, the Ce dissolution remained below 85% under the following conditions: solid-to-liquid ratio of 20% (w/v), the acid concentration of 20%, leaching temperature of 25 °C and leaching time of 1 h. The result revealed that HNO3 could be used as a solvent for the maximum simultaneous extraction of the La and Ce from the bastnasite ore. The leaching temperature had no crucial effect on the dissolution of La and Ce when HNO3 or HCl solutions were preferred as a solvating agent. However, the leaching temperature had a slight positive effect on the dissolutions of La and Ce when H2SO4 was used as a solvent. ÖZ Direkt asit liçi ile bir bastnazit cevherinden lantanyum (La) ve seryum (Ce) ekstraksiyonu araştırılmıştır. Bastnazit cevherinden La ve Ce ekstraksiyonuna asit konsantrasyonu ve liç sıcaklığının etkileri test edilmiştir. Nitrik asit (NHO3) kullanarak La ve Ce’un %85’ten fazlası liç çözeltisine alınmıştır ancak çözünme değerleri sülfürik asit (H2SO4) kullanıldığında %85’ten az olarak belirlenmiştir. La çözünümü hidroklorik asit (HCl) kullanımıyla %90’ı geçmiştir fakat Ce çözünümü %20 (g/L) katı-sıvı oranı, %20 asit konsantrasyonu, 25 °C liç sıcaklığı ve 1 saat liç süresi şartları altında %85’in altında kalmıştır. Sonuçlar bastnazit cevherinden eş zamanlı olarak maksimum La ve Ce çözünümüne ulaşılabilmek için çözücü olarak HNO3 kullanılabileceğini ortaya koymuştur. Çözücü olarak HNO3 ve HCl tercih edildiğinde liç sıcaklığının La ve Ce çözünümüne önemli bir etki yapmadığı belirlenmiştir. Fakat çözücü olarak H2SO4 kullanılmasıyla liç sıcaklığının La ve Ce çözünmeleri üzerine hafif bir pozitif etkisi saptanmıştır. * Sorumlu yazar / Corresponding author: • https://orcid.org/0000-0002-1680-5482 ** • https://orcid.org/0000-0003-3486-4184 *** • https://orcid.org/0000-0003-0287-0061 **** • https://orcid.org/0000-0001-5093-6769 ***** • https://orcid.org/0000-0002-7428-5999 ****** • https://orcid.org/0000-0002-8319-9275 ******* • https://orcid.org/0000-0001-5260-2589 85 S. Kursunoglu, et al / Scientific Mining Journal, 2020, 59(2), 85-92 INTRODUCTION The unique properties of rare earth make their usage inevitable for the high technological fields. Rare earth elements (REEs) are mainly used in the production of ceramics, automobile catalytic converters, fluid shredder catalysts, glass additives and polishing, metallurgical alloys, neodymium magnets, lasers, and rechargeable battery alloys (Jha et al., 2016; Swain and Mishra, 2019; Huang et al., 2019). Lanthanides are erbium (Er), cerium (Ce), ytterbium (Yb), dysprosium (Dy), gadolinium (Gd), praseodymium (Pr), holmium (Ho), lanthanum (La), europium (Eu), promethium (Pm), neodymium (Nd), samarium (Sm), scandium (Sc), lutetium (Lu), terbium (Tb), thulium (Tm), and yttrium (Y) elements, whose atomic numbers are in the range of 57-71 in the periodic table (Chen, 2011). Lanthanides exist as carbonate, oxide, phosphate, and silicates in rock form. REEs are classified as light rare earth (LREE) and heavy rare earth (HREE) minerals (Zhang et al., 2018). The atomic numbers of LREEs are in the range of 57-64. HREEs have atomic numbers between 6571. The difference is because LREEs have a nonpair 4f electron layer. The HREEs have a double electron in the 4f layer. Although scandium (Sc) is the lightest element that differs from its status as a metal, it has a transitive property and is neither in the heavy nor light category. Yttrium (Y) is another transitive metal, chemically similar to lanthanides. Although approximate 250 minerals are containing REEs, most of the world’s rare earth reserves include bastnasite (La(CO3)F) and monazite ((Ce,La,Nd,Th)PO4) minerals (Gupta and Krishnamurthy, 2005; Demol et al., 2018). Xenotime (Y(PO4)) is the other important REE mineral resource (Chelgani et al., 2015). Alkali digestion and sulfuric acid baking processes followed by water leaching are used for REE beneficiation from high and low-grade monazite ores, respectively (Lucas et al., 2014). Water leaching after sulfuric acid baking is also applied to the bastnasite and xenotime minerals to extract the REEs (Demol et al., 2019). Under the influence of several chemicals, physical and biological processes, rare earth elements, which are separated from the primary rock and adsorbed to clay minerals, form weathered 86 crust elution-deposited rare earth ores. Column leaching with ammonium sulfate and ammonium formate was successfully applied for the recovery of REEs from these ores (Feng et al., 2018; Zhou et al., 2019). Coal fly ashes and bottom ashes as secondary resources, which are a by-product of coal-burning thermal power plants, can be utilized for the extraction of REEs. REEs were successfully obtained by direct leaching or alkali fusion-leaching methods from these combustion products (Peiravi et al., 2017; Tang et al., 2019; Tuan et al., 2019). The recovery of REEs from waste materials, such as scraps, cathode ray tubes, magnets, and glasses are of increasing importance (Yin et al., 2018; Jowitt et al., 2018; Liu et al., 2019). The main objective is to investigate the extraction of La and Ce from a bastnasite ore using inorganic acids through a direct acidic leaching process under the atmospheric conditions. By applying the direct acidic leaching method, physical mineral processing techniques such as attrition scrubbing, screening, and des (...truncated)