کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
626860 1455458 2008 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Supercritical direct extraction of neodymium using TTA and TBP
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی تصفیه و جداسازی
پیش نمایش صفحه اول مقاله
Supercritical direct extraction of neodymium using TTA and TBP
چکیده انگلیسی

Extraction of a metal ion from its oxide using ligand assisted supercritical carbon dioxide (SC CO2) comprises namely ionisation of metal oxide, in-situ chelation of metal cation with the ligand to form metal chelate/adduct and subsequently its extraction. Understanding of the mass transfer of chelate/adduct is very important in deciding the overall performance of the in-situ supercritical fluid extraction (ISCFE) process. For the present study neodymium (Nd) is selected as a model metal ion for its extraction from oxide using a mixed ligand system containing thenoyl tri-fluoroacetone (TTA) and tri-butylphosphate (TBP). Extraction studies have been performed at 35 MPa and 60°C for the prepared Nd-TTA-TBP adduct as well as for neodymium oxide (Nd2O3). The rate of dissolution starting from oxide and TTA-TBP adduct of Nd have been calculated and compared with the equilibrium values based on dissolution studies at the same conditions of temperature and pressure. During the extraction starting from oxide, the ligands TTA and TBP are also co-extracted with the adduct as these are highly soluble in SC CO2. Mass transfer coefficient has also been estimated for the steady state during the dynamic extraction. It is observed that the rate of extraction and mass transfer coefficient increase with flow rate of SC CO2.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Desalination - Volume 232, Issues 1–3, 30 November 2008, Pages 91-101