The Gel Route to Yttrium Oxide

1988 ◽  
Vol 121 ◽  
Author(s):  
F. Ribot ◽  
C. Sanchez ◽  
J. Livage
Keyword(s):  
Rare Earth ◽  
Light Scattering ◽  
Anion Exchange ◽  
Yttrium Oxide ◽  
Close Agreement ◽  
Chemical Nature ◽  
Exchange Resin ◽  
Anion Exchange Resin ◽  
Sol Gel ◽  
Sol Gel Process

ABSTRACTSynthesis of pure Y2O3 Powders have been performed through the sol-gel process. Stable colloids in the range of 500 Å to 2000 Å have been obtained by hydroxylation of yttrium-aquo ions performed through an anion exchange resin.The chemical nature of these sols and gels investigated by GTA, DTA and EXAFS is in close agreement with Y(OH)3nH2O. Scattering experiments (S.A.N.S, S.A.X.S, light scattering) show that these colloids are made of anisotropie particles, that can be described as platelets 30 Å thick, 500 Å large and a few thousand Angstroms long.This synthesis can be extended to other rare earth colloids.

scholarly journals Sorption of rare earth coordination compounds

2020 ◽  
Vol 244 ◽  
pp. 474-481
Author(s):  
Olga Cheremisina ◽  
Elizaveta Cheremisina ◽  
Maria Ponomareva ◽  
Аleksander Fedorov
Keyword(s):  
Rare Earth ◽  
Ion Exchange ◽  
Anion Exchange ◽  
Coordination Compounds ◽  
Exchange Resin ◽  
Anion Exchange Resin ◽  
Equilibrium Constants ◽  
Mass Action ◽  
Dynamic Capacity ◽  
Nitrate Solutions

Rare earth elements (REEs) are valuable and strategically important in many high-technology areas, such as laser technology, pharmacy and metallurgy. The main methods of REE recovery are precipitation, extraction and sorption, in particular ion exchange using various sorbents, which allow to perform selective recovery and removal of associated components, as well as to separate rare earth metals with similar chemical properties. The paper examines recovery of ytterbium in the form of coordination compounds with Trilon B on weakly basic anion exchange resin D-403 from nitrate solutions. In order to estimate thermodynamic sorption parameters of ytterbium anionic complexes, ion exchange process was carried out from model solutions under constant ionic strength specified by NaNO3, optimal liquid to solid ratio, pH level, temperatures 298 and 343 K by variable concentrations method. Description of thermodynamic equilibrium was made using mass action law formulated for ion exchange equation and mathematically converted to linear form. Values of equilibrium constants, Gibbs free energy, enthalpy and entropy of the sorption process have been calculated. Basing on calculated values of Gibbs energy, a sorption series of complex REE ions with Trilon B was obtained over anion exchange resin D-403 from nitrate solutions at temperature 298 K. Sorption characteristics of anion exchange resin have been estimated: total capacity, limiting sorption of complex ions, total dynamic capacity and breakthrough dynamic capacity.

PEMODELAN MATEMATIS ADSORPSI CO2 DENGAN STRONG BASE ANION EXCHANGE RESIN SEBAGAI ADSORBEN UNTUK PURIFIKASI BIOGAS

2015 ◽  
Vol 5 (1) ◽  
pp. 11
Author(s):  
Anies Mutiari ◽  
Wiratni Wiratni ◽  
Aswati Mindaryani
Keyword(s):  
Anion Exchange ◽  
Pilot Plant ◽  
Exchange Resin ◽  
Anion Exchange Resin ◽  
Scale Up ◽  
Sum Of Squares ◽  
Strong Base ◽  
Model Transfer ◽  
Plant Parameter

Pemurnian biogas telah banyak dilakukan untuk menghilangkan kadar CO2  dan meningkatkan kandungan CH4  yang terkandung di dalamnya. Kandungan CH4 yang tinggi akan memberikan unjuk kerja yang lebih baik. Model  matematis proses adsorpsi CO2 disusun berdasarkan teori lapisan film antar fasa, dimana pada proses yang ditinjau terdapat tiga fase yaitu gas, cair dan padat. Model matematis dari data eksperimental   kecepatan dan kesetimbangan proses adsorpsi CO2 melalui mekanisme pertukaran ion di suatu kolom adsorpsi telah dibuat. Model ini dibuat untuk mencari konstanta yang dapat dipergunakan pada proses scale up data laboratorium ke skala pilot plant. Parameter proses kecepatan yang dicari nilainya adalah koefisien transfer massa massa volumetris CO2 pada fase cair (kLa), koefisien transfer massa volumetris CO2 pada fasegas (kGa) dan tetapan laju reaksi (k1 dan k2). Pada hasil penelitian ini ditunjukkan bahwa nilai parameter yang diperoleh sesuai hasil fitting data dengan model matematis yang digunakan, yaitu model transfer massa pada lapisan film antar fase secara seri: adalah kGa, kla, k1 dan k2  dengan nilai Sum of Squares Error (SSE) rata-rata 0,0431. Perbandingan nilai kGa hasil simulasi dan teoritisnya memberikan kesalahan rata-rata 18,79%. Perbandingan nilai kLa hasil simulasi dan teoritis memberikan kesalahan rata-rata 7,92%.Kata kunci: model matematis, adsorpsi CO2, pemurnian biogas

Catalysis of the Photodecomposition of Chloroform by a Polystyrene Anion Exchange Resin

2013 ◽  
Vol 2 (2) ◽  
pp. 79-87 ◽  
Author(s):  
Laura A. Pena ◽  
Alissa M. Chan ◽  
Larissa R. Cohen ◽  
Karen Hou ◽  
Brent M. Harvey ◽  
...  
Keyword(s):  
Anion Exchange ◽  
Exchange Resin ◽  
Anion Exchange Resin
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