عنوان

Liquid-liquid extraction of some rare earth metal ions by polyoxyalkylene systems

Number

TLpq304347315

.Language of Text, Soundtrack etc

انگلیسی

Title Proper

Liquid-liquid extraction of some rare earth metal ions by polyoxyalkylene systems

General Material Designation

[Thesis]

First Statement of Responsibility

A.-E. A. Al-Naser

Name of Publisher, Distributor, etc.

King Fahd University of Petroleum and Minerals (Saudi Arabia)

Date of Publication, Distribution, etc.

1996

Specific Material Designation and Extent of Item

146

Dissertation or thesis details and type of degree

M.S.

Body granting the degree

King Fahd University of Petroleum and Minerals (Saudi Arabia)

Text preceding or following the note

1996

Text of Note

Polyoxyalkylene systems, namely, polypropylene glycol(PPG-1025), polyethylene glycol(PEG-600) and polybutadieneoxide(PBDO-700) dissolved in either nitrobenzene or 1,2-dichloroethane have been tested as prospective extractants for some lanthanide metal ions usd\rm(Pr\sp{3+},\ Eu\sp{3+},usd and Er from their aqueous solutions in the presence of picrate lipophilic anions. The metal ions were quantified before and after extraction using inductively coupled plasma emission spectrophotometry technique. The percent extraction and the distribution coefficient have indicated that pH of the aqueous phase, picrate concentration and the organic solvent are the major parameters that affect the extraction efficiency of the metal ions. The optimum pH range was found to be 3.5 to 5.5 and the picrate concentration should be as high as possible, however a picrate concentration of about 0.05M proved to be adequate for a near quantitative extraction. In all cases, nitrobenzene enhanced a higher percent extraction compared to 1,2-dichloroethane. The efficiency of the polyoxyalkylene systems to extract certain lanthanide metal ions was in the order PBDO-700 > PPG-1025 > PEG-600 when nitrobenzene was the organic solvent and in the order PPG-1025 > PBDO-700 > PEG-600 when 1,2-dichloroethane that has a lower dielectric constant, used as the solvent in the organic phase. The extractability of PPG-1025 towards the lanthanide metal ions was in the order usd\rm Pr\sp{3+}>Eu\sp{3+}>Er\sp{3+}usd irrespective of the organic solvent used. The stoichiometry of the extracted polyoxyalkylene ion-pair with the lanthanide metal ions has been estimated. Each mole of the metal ions is associated with three moles of picrate anions and 13 to 14 moles of the propyleneoxide units in the case of PPG-1025, and about 10 moles of ethyleneoxide units in the case of PEG-600 and 10 moles of butadieneoxide units in the case of polybutadieneoxide-700.

Chemistry

erbium

europium

Organic chemistry

praseodymium

Pure sciences

A.-E. A. Al-Naser

Electronic name

p

[Thesis]

276903

a

Y