scholarly journals Effects of contaminant metal ions on precipitation recovery of rare earth elements using oxalic acid

Author(s):  
Wencai Zhang ◽  
Aaron Noble ◽  
Bin Ji ◽  
Qi Li
2018 ◽  
Vol 929 ◽  
pp. 171-176 ◽  
Author(s):  
Eny Kusrini ◽  
Zakaria Jaka Bahari ◽  
Anwar Usman ◽  
Arif Rahman ◽  
Eko Adi Prasetyanto

The present work describes the extraction of lanthanide (rare earth elements, REE) from low grade bauxite using acid leaching method. The aim of this study is to obtain the best condition for extraction of lanthanides from low grade bauxite. The effect of different parameters such as temperatures and concentration of oxalic acid in leaching process were investigated. The content of La, Ce and Y elements were determined using ICP-OES. The experimental result shows that the efficiencies of lanthanide leaching are the temperature-dependent. Increasing leaching temperature from 45°C to 85°C did not improve recoveries of lanthanides. The most optimum condition was found at oxalic acid leaching of 1 mol/L, leaching temperature at 40°C, and time for 2 hours. The obtained results show that the lanthanides can be leached using oxalic axid. This finding may lead to more effective and economical method to separate lanthanides from low grade bauxite.


2014 ◽  
Vol 875-877 ◽  
pp. 2229-2237 ◽  
Author(s):  
Tomonori Kawano

Paramecium bursaria is an unicellular organism that lives widely in fresh water environments such as rivers and ponds. Recent studies have suggested that in vivo cellular robotics using the cells of P. bursaria as micro-machines controllable under electrical and optical stimuli, has a variety of engineering applications such as transport of micro-sized particles in the capillary systems. The present study aimed to test if the swimming cells of P. bursaria, implementable in capillaries or on chips, are applicable for detection of metal ions. For model assays, rare earth elements (REEs) were chosen as target chemicals. In P. bursaria, LC50 values for REE ions ranged between 2.0 and 62.7 µM. Among them, Sc was shown to be most toxic. In addition to the lethal impacts of REE ions, most of REE ions at sub-lethal concentrations at around 10 - 30 µM, showed inhibitory action against the motility of the cells during the electrically forced motility known as galvanotaxisis. In conclusion, in the non-lethal ranges of REE concentration, swimming cells of P. bursaria report the presence of REE ions, by lowering the motility.


Author(s):  
T.K. Jumadilov ◽  
◽  
Kh. Khimersen ◽  
B. Totkhuskyzy ◽  
J. Haponiuk ◽  
...  

Rare earth elements play an important role in the production, energy, and high technology. Due to the rapid development of industry, the demand for rare earth metals is rising every day. Therefore, it is necessary to improve the extraction of rare earth metals from various sources to meet the demand for these elements. Currently, pyro- and hydrometallurgical technologies are used to extract rare earth metals from an ore and other secondary sources (industrial wastewater, acid drainage mines, etc.). Hydrometallurgical technologies include precipitation, extraction, adsorption, and ion exchange methods. Adsorption is one of the most effective methods for the extraction and separation of rare earth elements. Adsorption methods are highly selectivity to metal ions and have low emissions. However, not all adsorbents are effective in producing the same metal ions. This study provides an overview of the different adsorbents that can be used to extract rare earth elements from aquatic systems. Hydrogels and molecular polymers have been found to be cost-effective methods for high-grade rare earth metals. Further research is needed to ensure the performance of these systems.


Author(s):  
Marco Fontani ◽  
Mariagrazia Costa ◽  
Mary Virginia Orna

In 1794, Finnish scientist Johan Gadolin discovered the first of the rare earth elements in some ore deposits at Ytterby, Sweden. He called the oxide of the new element that he had isolated ytterbia and ytterbite the ore from which he had extracted it. Three years later, Anders Gustaf Ekeberg verified Gadolin’s discoveries and proposed the name of yttria (or yttric earths) for the oxide and gadolinite for the ore. For many years, chemists, among them L. N. Vauquelin, J. J. Berzelius, and M. H. Klaproth, wrestled with the problem that perhaps Gadolin’s yttrium was not a simple body but in reality contained other elements. In 1842, the Swedish chemist C. G. Mosander described how, by means of the fractional precipitations of the oxalates from dilute solutions of oxalic acid and by treatment of the hydroxides with dilute ammoniacal solutions, he seemed to have succeeded in extracting three new elements. The first was yttrium, the most basic; the second was erbium, the least basic; and the intermediate fraction he called terbium. The names terbium, erbium, and ytterbium derive from the name of the town, Ytterby. The names that Mosander gave to the three elements derived from the sequence in which they were separated: the name yttrium was not changed out of respect for Gadolin. The first element that he extracted, Mosander called terbium, and the following one he called erbium. He removed a letter from the word terbium because he had isolated it later. In the following years, it was discovered that both erbium and terbium were not single elements but mixtures of elements yet unknown. A practice developed that we might call an entente cordiale: when a discoverer split a presumed element into its constituents, one element retained the name already given by its preceding discoverer. This usage was respected by everyone, including Urbain, who, in 1907, presented his discoveries with the names neo-ytterbium and lutecium. Only Auer von Welsbach, a renowned Austrian chemist, did not respect this tacit “gentlemen’s agreement” and called the elements with atomic numbers 70 and 71 aldebaranium and cassiopeium.


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