scholarly journals Solvent Extraction of Thorium(IV) by Didodecylphoric Acid

Author(s):  
Fawwaz I. Khalili ◽  
Khaled M. Mousa ◽  
Ehsan I. Soudani

Solvent extraction of Thorium (VI) ion from perchlorate solution using didodecylphosphoric acid, DDPA, in chloroform diluent was studied. The effects of stripping hydrochloric acid concentration, stripping time, extraction time, DDPA concentration, pH, ionic strength, supporting electrolyte and temperature on the extraction processes have been studied. From the distribution coefficient values at different temperatures,the enthalpy, the free energy and the entropy changes associated with the extraction processes were determined. The composition of the complex formed was established to be Th(ClO4)4-nRn(HR)5-n where, n=1 or 2 and (HR)2 represents the dimer of DDPA.  

Author(s):  
Khaled Mousa ◽  
Fawwaz Khalili

Solvent extraction of uranium(Vl) ion from perchlorate solution using didodecylphosphorie acid, DDPA, in toluene diluent was studied. The effects of stripping nitric acid concentration, stripping time, extraction time, DDPA concentration, pH, ionic strength, supporting electrolyte and temperature on the extraction processes have been studied. From the distribution coefficient values at different temperatures, the enthalpy, the free energy and the entropy changes associated with the extraction processes were determined. The composition of the complex formed was established to be UO2(CLO4)(HR2)(HR)2 where, (HR)2 represents the dimer of DDPA.


2011 ◽  
Vol 366 ◽  
pp. 330-333
Author(s):  
Jun Jun Wu ◽  
Hai Feng Chen ◽  
Shi Jiang Zhao ◽  
Bin Li

Pyrophyllite was the cheap, environmentally friendly alumina silicate clay minerals. This paper studied optimization of conditions for extraction of acid-soluble Al2O3 from pyrophyllite. Qualitative tests had been performed in studying pyrophyllite crystal at different temperatures by using scanning electron microscopy. Dissolution experiments showed that after thermal activation the behavior of alumina in acid the dissolution was different, which was affected by hydrochloric acid concentration, heat activation temperature and acid leaching time. When the calcinations temperature was 700 °C and hydrochloric acid concentration was 25%, the dissolution amount of alumina largest. The fit results indicated that the research for the relationship between dissolution and time by Using Exponential function series Asymptotic1 model to fitting match was the best. So the above function could be used to estimate each time the dissolution of alumina from pyrophyllite in hydrochloric acid.


2013 ◽  
Vol 734-737 ◽  
pp. 1033-1036
Author(s):  
Gui Fang Zhang ◽  
Peng Yan ◽  
Qing Rong Yang

Based on the benefication of the complex silicate ore containing scandium, the research about aid-leaching agent used in the leaching of the scandium concentrate was been conducted. And the suitable leaching agent and aid-leaching agent which the useful ions entered into leaching liquid and the harmful ions were kept in leaching residue were been found according to the experiment results. For the scandium of sample existed various complex silicate ore as isomorphism form, the research has adopted hydrochloric acid with aid-leaching agent to dissociate the silicate ore and make scandium entering into solution. The research results has shown that the scandium leaching rate could reach 92.06% under the optimal conditions which the hydrochloric acid concentration is 22.8%, the dosage of aid leaching agent is 6%, liquid solid ratio is 4:1, particle size of leaching material totally is less than 0.15mm and leaching time is 8h.


Polymer ◽  
1997 ◽  
Vol 38 (20) ◽  
pp. 5247-5250 ◽  
Author(s):  
Gustavo M. Morales ◽  
Marcos Llusa ◽  
Maria C. Miras ◽  
Cesar Barbero

2009 ◽  
Vol 97 (7) ◽  
Author(s):  
Claire Le Naour ◽  
M. V. Di Giandomenico ◽  
Y. Zhao ◽  
M. Mendes

AbstractSolvent extraction in the conditions of tracer scale chemistry was used to study protactinium(V) complexation with sulphate, chloride, oxalate and diethylene-triamine-pentaacetate. Extraction experiments were conducted using the chelating agent thenoyltrifluoroacetone (TTA) in toluene at constant ionic strength and temperature. Information on the species involved in partition equilibria relative to protactinium(V) complexation were deduced from a systematic study of the variations of distribution coefficient of Pa(V) as function of ligands, protons and TTA concentration.


1977 ◽  
Vol 30 (10) ◽  
pp. 2297
Author(s):  
BB Misra ◽  
SR Mohanty

The extraction of iron(III) from hydrochloric acid solution by the series of sulphoxides (R2SO) from dipentyl to didecyl sulphoxide in 1,1,2-trichloroethane has been studied. At a given strength of the extractant, extraction increases initially with increase in the acid concentration to a maximum at 8 M and decreases thereafter. Increase in H+ at constant Cl- strength or increase in Cl- at a given H+ increases the extraction. Under otherwise identical conditions, extraction increases with increase in the extractant concentration. The extracted species would appear to be HFeCl4,2R2SO. A mixture of two sulphoxides or of a sulphoxide and tributyl phosphate extracts the metal ion more than the sum of extractions due to the individual components.


2013 ◽  
Vol 78 (1) ◽  
pp. 93-100 ◽  
Author(s):  
J.H. Yang ◽  
Y. Cui ◽  
G.X. Sun ◽  
Y. Nie ◽  
G.M. Xia ◽  
...  

The extraction behavior of Sm(III) and Nd(III) with N,N,N?,N?-tetrabutyl-3-oxa-diglycolamide (TBDGA) in 70% kerosene-30% n-octanol from hydrochloride acid wasstudied. The effect of hydrochloric acid concentration, extractant concentration,and temperature on the distribution of rare earth elementswas investigated. The extraction mechanism was established and the stoichiometry of the main extracted species was confirm to be SmCl3?2TBDGA and NdCl3?2TBDGA for Sm(III) and Nd(III), respectively. The extraction distribution ratio decreases with an increase in temperature, which demonstrates that the extraction reaction is exothermic. The IR spectra of the loaded organic phase and free extractant were recorded and discussed.


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