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العنوان
Investigations on the Recovery of Certain f-Block
Elements from Liquid Solution /
المؤلف
Abou ELgoud, EL Sayed Mustafa EL Sayed.
هيئة الاعداد
باحث / EL Sayed Mustafa EL Sayed Abou ELgoud
مشرف / Saad Abdelwahab Mohamed
مشرف / Hisham Fouad Aly
مناقش / Yasser Abdel-Mohsen El-Nadi
تاريخ النشر
2019.
عدد الصفحات
237 P. :
اللغة
الإنجليزية
الدرجة
الدكتوراه
التخصص
Physical and Theoretical Chemistry
تاريخ الإجازة
1/1/2019
مكان الإجازة
جامعة عين شمس - كلية العلوم - قسم الكيمياء
الفهرس
Only 14 pages are availabe for public view

from 237

from 237

Abstract

The f-block elements in the periodic table consists of the lanthanide and actinide series. The lanthanides consist of the elements lanthanum (La, Atomic number=57) to lutetium (Lu, Atomic Number =71). The actinides consist of the elements from actinium (Ac, atomic number = 89) to lawrencium (Lr, atomic number = 103). Within the objectives of this thesis is the recovery and separation of the 4f lanthanide elements and its chemistry analogue yttrium (III), known as rare earth elements, (REEs). Phosphate ores can be a potential resource of rare earth elements (REEs). Therefore, the recovery of these elements from the aqueous solution obtained from the leaching of phosphate rock and phosphogypsum is important. In this thesis, the first part is directed to investigation the liquid-liquid extraction for the extraction and separation of Ce (IV), La (III), Pr (III), Er (III) and Y(III) from citric acid medium using acidic organophosphorus extractants, di-2-ethylhexyl phosphoric acid (D2EHPA). The different parameters affecting the liquid-liquid extraction process of these metals have been separately studied in terms of shaking time, citric acid concentration, D2EHPA concentration, pH, temperature, and phase ratio. The thermodynamic parameters associated with the extraction process were determined and discussed. The extraction equilibrium for the extraction was modeled in terms of a conditional extraction constant dependency on di-2-ethylhexyl phosphoric acid and citric acid concentration. The model given was found to verify the experimental results.
In the second part, the feasibility of using a macroporous strongly acidic cation exchange resin (SQS-6) as an adsorbent for Ce (IV),
La (III), Pr (III), Nd (III), Er (III) and Y(III) from concentrated phosphoric acid medium was carried out using batch and column techniques. In batch technique, various parameters affecting the uptake of these metal ions such as volume to mass ratio, acid concentration and the metal ion concentration were separately studied. Effect of temperature on the equilibrium distribution values was also studied to evaluate the changes in standard thermodynamic quantities. Experimental results of the investigated metal ions were found to fit the Langmuir and Freundlich isotherm models over the entire studied concentration range studied. The elution of the investigated metals from the loaded resin was performed with 1.0 mol/L citric acid at pH 4.0. In column technique, the different parameters affecting the breakthrough of these metals have been separately studied in terms of initial metal concentrations, bed depths and flow rates. The experimental data resulting from column technique was found to obey the Thomas and Yoon -Nelson models.
Key words: Extraction; REEs; Citric acid; D2EHPA; Separation ;
Sorption; SQS-6; phosphoric acid.