Characteristics and provenances of rare earth elements in the atmospheric particles of a coastal city with large-scale optoelectronic industries

2019 ◽  
Vol 214 ◽  
pp. 116836 ◽  
Author(s):  
Yu Yan ◽  
Rui-lian Yu ◽  
Gong-ren Hu ◽  
Shan-shan Wang ◽  
Hua-bin Huang ◽  
...  
2018 ◽  
Vol 14 (1) ◽  
pp. 195
Author(s):  
Diana Hendrati ◽  
Erianti Siska Purnamasari ◽  
Syulastri Effendi ◽  
Santhy Wyantuti

<p>Gadolinium (Gd) merupakan salah satu logam tanah jarang, dimana logam tanah jarang dapat diekstrak dari mineral salah satunya mineral monasit. Logam Gd biasanya digunakan sebagai bahan dasar <em>contrast agent</em> dalam dunia kesehatan. Ligan dibutilditiokarbamat mampu membentuk senyawa kompleks dengan cara mengikat logam sehingga membentuk khelat yang dapat digunakan untuk ekstraksi. Tujuan dari penelitian ini adalah memantapkan sintesis ligan dibutilditiokarbamat berdasarkan desain eksperimen dan karakterisasi kompleks antara Gd(III) dengan ligan dibutilditiokarbamat hasil sintesis. Penelitian ini diawali dengan pembuatan desain eksperimen untuk sintesis ligan dan ekstraksi Gd(III) dengan ligan, kemudian proses sintesis dan ekstraksi dilakukan sesuai dengan desain eksperimen, hasil sintesis dan ekstraksi dikarakterisasi menggunakan metode spektroskopi serta diuji kelarutannya dalam pelarut organik. Data yang diperoleh menunjukkan bahwa sintesis ligan dibutilditiokarbamat optimal pada suhu 4 °C, perbandingan dibutilamin dan karbondisulfida yaitu 1 : 3 dengan perbandingan mol ammonia terhadap dibutilamin yaitu 1 : 4, sedangkan kondisi optimal untuk ekstraksi Gd(III) dengan ligan yaitu pada pH 6, dengan perbandingan mol Gd(III) dan ligan yaitu 1 : 4 dan lama ekstraksi 60 menit. Oleh karena itu ligan dibutilditiokarbamat hasil sintesis berpotensi digunakan sebagai ekstraktan untuk ekstraksi Gd(III). Hasil prediksi ligan berdasarkan desain eksperimen yaitu sebesar 56,12% sedangkan prediksi ekstraksi Gd(III) dengan ligan hasil sintesis diperoleh sebesar 78,41%. Kesimpulan dari penelitian ini bahwa sintesis ligan dibutilditiokarbamat  berdasarkan desain eksperimen dapat dikembangkan untuk sintesis skala besar.</p><p>Gadolinium (Gd) is one of the rare-earth elements, whereas rare-earth elements can be extracted from monazite. Gd is usually used as raw material for synthesizing contrast agent<em> </em>in medicine field. Dibuthyldithiocarbamate ligand can form a complex compound with metal. This ligand will bind a metal and then forming chelate which is used for extraction. The purpose of this research is to ensure procedure of dibuthyldithiocarbamate ligand synthesis based on the design of experiment and to study the characterization of reaction result between Gd(III) and dibuthyldithiocarbamate ligand which this ligand is synthesis result. This research begins with making design of experiment for ligand synthesis and Gd(III) extraction with ligand, then perform the process of synthesis and extraction according to the design of experiment, the result of synthesis and extraction were characterized by spectroscopy method and solubility tested in organic solvent. The data was collected indicate that the optimal condition of dibuthyldithiocarbamate ligan synthesis at 4 °C (temperature), the ratio of di-n-butylamine and carbon disulphide is 1:3 with the mole ratio of ammonia to the di-n-butylamine 1:4, while the optimal conditions for gadolinium extraction with ligand at pH 6, the mol ratio of gadolinium and ligand is 1:4 and 60 minutes extraction time. Hence, dibuthyldithiocarbamate ligand can be used as extractan for extracting Gd(III). The prediction of ligand based on the experimental design is 56.12% while the prediction of Gd(III) extraction with ligand of the synthesis result is obtained equal to 78.41%. The conclusion of this research is that the synthesis of dibuthyldithiocarbamate ligand based on the experimental design can be developed for large-scale synthesis.</p>


2018 ◽  
Vol 14 (2) ◽  
pp. 219
Author(s):  
Diana Hendrati ◽  
Erianti Siska Purnamasari ◽  
Syulastri Effendi ◽  
Santhy Wyantuti

<p>Gadolinium (Gd) merupakan salah satu logam tanah jarang, dimana logam tanah jarang dapat diekstrak dari mineral salah satunya mineral monasit. Logam Gd biasanya digunakan sebagai bahan dasar <em>contrast agent</em> dalam dunia kesehatan. Ligan dibutilditiokarbamat mampu membentuk senyawa kompleks dengan cara mengikat logam sehingga membentuk khelat yang dapat digunakan untuk ekstraksi. Tujuan dari penelitian ini adalah memantapkan sintesis ligan dibutilditiokarbamat berdasarkan desain eksperimen dan karakterisasi kompleks antara Gd(III) dengan ligan dibutilditiokarbamat hasil sintesis. Penelitian ini diawali dengan pembuatan desain eksperimen untuk sintesis ligan dan ekstraksi Gd(III) dengan ligan, kemudian proses sintesis dan ekstraksi dilakukan sesuai dengan desain eksperimen, hasil sintesis dan ekstraksi dikarakterisasi menggunakan metode spektroskopi serta diuji kelarutannya dalam pelarut organik. Data yang diperoleh menunjukkan bahwa sintesis ligan dibutilditiokarbamat optimal pada suhu 4 °C, perbandingan dibutilamin dan karbondisulfida yaitu 1 : 3 dengan perbandingan mol ammonia terhadap dibutilamin yaitu 1 : 4, sedangkan kondisi optimal untuk ekstraksi Gd(III) dengan ligan yaitu pada pH 6, dengan perbandingan mol Gd(III) dan ligan yaitu 1 : 4 dan lama ekstraksi 60 menit. Oleh karena itu ligan dibutilditiokarbamat hasil sintesis berpotensi digunakan sebagai ekstraktan untuk ekstraksi Gd(III). Hasil prediksi ligan berdasarkan desain eksperimen yaitu sebesar 56,12% sedangkan prediksi ekstraksi Gd(III) dengan ligan hasil sintesis diperoleh sebesar 78,41%.</p><p><strong>The Consolidation of Dibutyldithiocarbamate (DBDTC) Synthesis as Gadolinium Metal Extraction Based On Experimental Design. </strong>Gadolinium (Gd) is one of the rare-earth elements, whereas rare-earth elements can be extracted from monazite. Gd is usually used as raw material for synthesizing contrast agent<em> </em>in medicine field. Dibuthyldithiocarbamate ligand can form a complex compound with metal. This ligand will bind a metal and then forming chelate which is used for extraction. The purpose of this research is to ensure procedure of dibuthyldithiocarbamate ligand synthesis based on the design of experiment and to study the characterization of reaction result between Gd(III) and dibuthyldithiocarbamate ligand which this ligand is synthesis result. This research begins with making design of experiment for ligand synthesis and Gd(III) extraction with ligand, then perform the process of synthesis and extraction according to the design of experiment, the result of synthesis and extraction were characterized by spectroscopy method and solubility tested in organic solvent. The data was collected indicate that the optimal condition of dibuthyldithiocarbamate ligan synthesis at 4 °C (temperature), the ratio of di-n-butylamine and carbon disulphide is 1:3 with the mole ratio of ammonia to the di-n-butylamine 1:4, while the optimal conditions for gadolinium extraction with ligand at pH 6, the mol ratio of gadolinium and ligand is 1:4 and 60 minutes extraction time. Hence, dibuthyldithiocarbamate ligand can be used as extractan for extracting Gd(III). The prediction of ligand based on the experimental design is 56.12% while the prediction of Gd(III) extraction with ligand of the synthesis result is obtained equal to 78.41%. The conclusion of this research is that the synthesis of dibuthyldithiocarbamate ligand based on the experimental design can be developed for large-scale synthesis.</p>


Minerals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 80 ◽  
Author(s):  
Nan Ju ◽  
Yun-Sheng Ren ◽  
Sen Zhang ◽  
Zhong-Wei Bi ◽  
Lei Shi ◽  
...  

The Saima deposit is a newly discovered niobium deposit which is located in the eastern of Liaoning Province, NE China. Its mineralization age and geochemical characteristics are firstly reported in this study. The Nb orebodies are hosted by the grey–brown to grass-green aegirine nepheline syenite. Detailed petrographical studies show that the syenite consists of orthoclase (~50%), nepheline (~30%), biotite (~15%) and minor arfvedsonite (~3%) and aegirine (~2%), with weak hydrothermal alteration dominated by silicification. In situ LA-ICP-MS zircon U-Pb dating indicates that the aegirine nepheline syenite was emplaced in the Late Triassic (229.5 ± 2.2 Ma), which is spatially, temporally and genetically related to Nb mineralization. These aegirine nepheline syenites have SiO2 contents in the range of 55.86–63.80 wt. %, low TiO2 contents of 0.36–0.64 wt. %, P2O5 contents of 0.04–0.11 wt. % and Al2O3 contents of more than 15 wt. %. They are characterized by relatively high (K2O + Na2O) values of 9.72–15.51 wt. %, K2O/Na2O ratios of 2.42–3.64 wt. % and Rittmann indexes (σ = [ω(K2O + Na2O)]2/[ω(SiO2 − 43)]) of 6.84–17.10, belonging to the high-K peralkaline, metaluminous type. These syenites are enriched in large ion lithophile elements (LILEs, e.g., Cs, Rb and Ba) and light rare earth elements (LREEs) and relatively depleted in high field strength elements (HFSEs, e.g., Nb, Zr and Ti) and heavy rare earth elements (HREEs), with transitional elements showing an obvious W-shaped distribution pattern. Based on these geochronological and geochemical features, we propose that the ore-forming intrusion associated with the Nb mineralization was formed under post-collision continental-rift setting, which is consistent with the tectonic regime of post-collision between the North China Craton and Paleo-Asian oceanic plate during the age in Ma for Indosinian (257–205 Ma). Intensive magmatic and metallogenic events resulted from partial melting of lithospheric mantle occurred during the post-collisional rifting, resulting in the development of large-scale Cu–Mo mineralization and rare earth deposits in the eastern part of Liaoning Province.


2015 ◽  
Vol 1130 ◽  
pp. 543-546 ◽  
Author(s):  
A.J. Murray ◽  
Sarah Singh ◽  
M.R. Tolley ◽  
L.E. Macaskie

Rare earth elements (REEs) are highly valuable due to the complex nature of their extraction from primary and secondary sources. A key feature is that REEs often co-occur with uranium and thorium which, being radioactive, increase the hazard and complexity of REE recovery. A bioprocess which utilizes enzymatically-generated inorganic phosphate to precipitate REEs from solution as their phosphate biominerals is highly effective in the recovery of REEs, effecting rapid recovery onto immobilized bacterial biofilm at high flow-through rates. This also bioprecipitates U and Th. The metal recovery process requires addition of an organic phosphate substrate, e.g. glycerol 2-phosphate (G2P), the cleavage of which provides the inorganic phosphate source for REE biomineralization. G2P is expensive, precluding its large scale use, but early work using uranium showed that tributyl phosphate (TBP) can be used as an alternative phosphate donor molecule. The potential for substitution of G2P by TBP for biorecovery of neodymium is described and a new approach is proposed for enhancing the metal selectivity for REEs against uranium.


2021 ◽  
Author(s):  
Emmanuel Ohene Opare ◽  
Amin Mirkouei

Abstract Over 40 million tons of electronic devices (e.g., computers, laptops, notebooks, and cell phones) became obsolete in 2020, and this estimate is expected to grow exponentially, mainly due to the decreasing lifespan of electronics. Most of the electronics replaced end up in municipal landfills. Electronic waste (e-waste) has raised concerns because many components in these products are not biodegradable and are toxic. Some of the toxic materials and chemicals include rare earth elements (REEs), which are currently experiencing supply constraints. This study focuses on generated e-wastes from households due to the high amount of these wastes. Technologies for e-waste mining must be tailored to household needs rather than large-scale industrial processes. The use of portable e-waste recovery systems may produce win-win outcomes where industry, households, and regulatory bodies could benefit, and this will incentivize e-waste mining for all stakeholders. This study investigates the sustainability benefits of employing a portable e-waste recycling and REEs recovery, using techno-economic and life cycle assessment methods. The results indicate that the proposed approach in this study mitigates environmental impacts when maleic acid is used as one of the key ingredients in recovering and separating REEs and other metals. It is concluded that when adopted globally, this technology can significantly address the e-waste challenge while improving the availability of REEs for high-tech applications.


Minerals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1059
Author(s):  
Miao He ◽  
Qing Liu ◽  
Quanlin Hou ◽  
Jinfeng Sun ◽  
Quanren Yan

The South China Block had experienced a significant tectonic transition during the Mesozoic in response to the subduction of the Paleo- and the Pacific Ocean. Large-scale granitic intrusions with massive mineralization are widespread in South China, and their tectonic settings are not defined. The Xitian intrusion is ideal for probing the geodynamic setting and mineralization in South China because they comprise an abundance of microgranular enclaves (MEs) and diverse types of granite associated with mineralization. Age determined by zircon U-Pb dating suggests that the MEs and their host granites are coeval within error, of ca. 152 Ma. The MEs have a similar initial Hf-O isotopic composition as host granites, and the rapid cooling mineral textures indicate that they are autoliths. Geochemical data show that the host granites are high-K, calc-alkaline, and transitional from metaluminous to peraluminous, slightly enriched in light rare earth elements (LREEs) relative to heavy rare earth elements (HREEs), with obvious negative Eu anomalies, belonging to I-type. The Nb/Ta and Zr/Hf ratios indicate the volatile penetrates the magmatic-forming process, and the fluid with abundant volatile could extract metal element effectively from the mantle.


2020 ◽  
Vol 22 (12) ◽  
pp. 2398-2405
Author(s):  
Haijun Zhou ◽  
Xi Chun ◽  
Changwei Lü ◽  
Jiang He ◽  
Dagula Du

Smelting is one of the main sources of rare earth elements (REEs) in large scale smelting regions that have been neglected before.


2019 ◽  
Vol 19 (1) ◽  
pp. 92-102 ◽  
Author(s):  
Gongren Hu ◽  
Shanshan Wang ◽  
Ruilian Yu ◽  
Zongwei Zhang ◽  
Xiaoming Wang

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