Demand For Rare Earth Elements Research Articles

Proposal of Method for Evaluating Measures to Reduce Domestic Rare Earth Demand

Proposal of Method for Evaluating Measures to Reduce Domestic Rare Earth Demand

The Mutual Separation of Rare Earth Elements Utilizing the Reaction of Corresponding Complexes Coordinated by Tris(2-aminoethyl)amine with 3-Ethoxysalicylaldehyde

The demand for rare earth elements (REEs) has been increasing with the advance of the industrialized world, whereas worldwide supply of REEs is diminishing. The establishment of an efficient recycling technology of REEs from the industrial wastes and scraps is a pressing need to maintain a stable supply of these elements. The purpose of this work is to develop a novel separation process for the recovery of REEs form the standpoint of an environmental-friendly and green chemistry. In the reaction of dysprosium(III) ion coordinated by tris(2-aminoethyl)amine (tren) with 3-ethoxysalicylaldehyde in methanol, a product was precipitated as a mononuclear complex with a heptadentate Schiff-base ligand N[CH2CH2N=CH(2-OH-3-OEtC6H3)]3·(H3L1). On the other hand, the reaction of neodymium(III) ion afforded no precipitation under the same synthetic condition as that of dysprosium(III) complex. This result made it possible to obtain dysprosium(III) complex as the main product from the methanolic solution containing both of dysprosium(III) and neodymium(III) ions (Dy3+/Nd3+ = 50/50). A solution of tren (4 mmol) was added to a hot solution (40–50 °C) of a mixture of dysprosium(III) triflate (1 mmol) and neodymium(III) triflate (1 mmol) in methanol (20 cm3) and stirred for 1 min at 40–50 °C. Then a solution of 3-ethoxysalicylaldehyde (6 mmol) in methanol (25 cm3) was added and stirred for 15 min at 40–50 °C. The product was precipitated on cooling. The product was filtered off, washed with cold methanol and dried. The metallic distribution Dy3+/Nd3+ in the product was 91.0/9.0. Recrystallization from N,N-dimethylformamide gave clear crystals. The metallic distribution Dy3+/Nd3+ in the crystals was found to be 99.2/0.8. This method was also applied to the mutual separation of terbium(III) and europium(III) ions.

Interactions of microorganisms with rare earth ions and their utilization for separation and environmental technology

In recent years, rare earth elements (REEs) have been widely used in various modern technological devices and the global demand for REE has been increasing. The increased demand for REEs has led to environmental exposure or water pollution from rare earth metal mines and various commercial products. Therefore, the development of a safe technology for the separation and adsorption of REEs is very important from the perspective of green chemistry and environmental pollution. In this review, the application and mechanisms of microorganisms for the removal and extraction of REEs from aqueous solutions are described. In addition, the advantages in using microorganisms for REE adsorption and future studies on this topic are discussed.

Rare Earth Mineralization in Igneous Rocks: Sources and Processes

Deposits of rare earth elements (REEs) in igneous rocks have played an instrumental role in meeting the growing industrial demand for these elements since the 1960s. Among the many different igneous rocks containing appreciable concentrations of REEs, carbonatites and peralkaline silicate rocks are the most important sources of these elements, both historically and for meeting the anticipated growth in REE demand. The contrasting geochemical and mineralogical characteristics of REE mineralization in carbonatites, peralkaline feldspathoid rocks, and peralkaline granites reflect different sources and evolutionary pathways of their parental magmas, as well as differences in the extent of postmagmatic reworking of primary REE minerals by hydrothermal fluids.

Structural and Magnetic Properties of Nd(Fe,Mo)12Nx, Compounds Produced by Strip-Casting Method

The strip casting (SC) technique is employed to fabricate Nd(Fe,Mo)12Nx magnets. The crystallographic structure, intrinsic and permanent magnetic properties, as well as the microstructures of the compound are investigated. There are prominent advantages for the SC Nd-Fe-Mo alloys and their nitrides when compared with the samples prepared by the conventional casting (CC) method: (1) SC technique rebounds to the formation of the compounds crystallizing in a ThMn12-type structure. A single-phased host alloy Nd(Fe,Mo)12 can be directly prepared by strip casting without any isothermal annealing. Accordingly, lower energy cost and less rare earth demand notablely benefit the manufacture processing from a point of economizing. (2) The intrinsic magnetic properties, such as Curie temperature Tc, saturation magnetization Ms and anisotropy field Ha of the SC sample exceed the CC sample due to a phase forming condition with less-Mo-depended. (3) The microstructure studies also demonstrate that the SC compound contains finer grains, better-proportioned phase distribution than the CC compound. Optimized final particles are observed aligned in their easy axis and the energy product of powder sample is up to (BH)max ∼ 22 MGOe (176kJ/m3).

中国の輸出政策の変更と希土類の価格変化の関係について

This paper analyzes relations between China's export restrictions and rare earth prices in recent years.China has decreased the rates of Value Added Tax (VAT) rebates on rare earths raw materals (ores, metals and compounds) since 2004. It has also increased the rates of export duties on the same items since 2006. It appears that China has taken such measures to restrict outflows of rare earth raw materials, and these measures have been taken several times in recent years. Rare earth prices generally soared for the last several years. For example, price of dysprosium, one of the rare earth elements, has increased by about six times between June 2003 and June 2008.We analyzed relations between China's measures for export restrictions and prices of ten rare earth metals between June 2003 and June 2008 by using regression models. The findings of this analysis are as follows.(1) There is a strong tendency in which rare earth metal prices increase significantly soon after enforcement of an export restriction by China.(2) As China repeats measures for export restrictions, length of time between enforcement of such a measure and occurance of price increase has become shorter.This paper also mentions the possibility that demand for rare earths will be less price elastic in the near future. It is highly probable that growing needs to tackle global warming will require people to buy a greater number of eco-frindly products including hybrid vehicles. In such a situation, demand for rare earths, which are raw materials for essential parts of such products, would increase substantially. In addition, manufacturers of such products would have no choice other than procuring certain amount of rare earths regardless of their prices, since there is few alternative raw materials for these products. Under such circumstances, demand for rare earths would be less price elastic, and thus, rare earth prices in the future are likely to be more volatile.

Studies on Separation of Samarium(III) Nitrate Complexes from Neodymium(III) on Strongly Basic Anion Exchangers

With the development of new branches of industry like optoelectronics, power metallurgy, and modern techniques of raw material or plastics admixture, there is greater demand for rare earth elements of high purity. This paper presents the selective separation of neodymium(III) microquantities from samarium(III) macroquantities in the 90% v/v polar organic solvent–10% v/v 1 or 7 M HNO3 system on strongly basic anion exchangers of various types. Weight and bed distribution coefficients as well as the number of theoretical plates were determined. It is shown that the neodymium(III) content in purified samarium(III) decreases to a value below 10−3% under optimal conditions.

Supply and Demand of Rare Earths in Japan

Supply and Demand of Rare Earths in Japan