Extraction of Rare Earth Elements from Aqueous Solutions by Using Hydrometallurgical Techniques
Date
2024-04-16
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ORCID
0000-0002-9437-557X
Type
Thesis
Degree Level
Masters
Abstract
Rare earth elements (REEs) are essential in today's applications due to their unique characteristics. The growing ecological consciousness of developing nations has resulted in a considerable move away from conventional energy sources due to an increasing demand for environmentally friendly technologies that depend on essential elements like REE. Within hydrometallurgy, the solvent extraction (SX) method plays a crucial part in the purification of rare earth elements (REE) from concentrated solutions through efficient elemental extraction and high purity. Due to its remarkable extraction capacity and straightforward implementation, the SX technique is extensively employed in the industry. However, there are several difficulties encountered when utilizing conventional techniques for the treatment of REE solutions. These difficulties encompass environmental damage, substantial capital investments, and increased energy consumption. The disadvantages associated with using conventional extraction techniques have prompted a specific focus on innovative approaches. Solvent extraction methods stand out by creating a lower-energy process, higher selectivity and less environmental damage.
The purpose of this thesis is to report the results of five different parameters, such as extraction time, temperature, aqueous to organic ratio (A/O), lixiviant (HNO3) concentration, and D2EHPA concentration on extraction efficiency. It involves an SX process using D2EHPA in kerosene as an extractant with isodecanol modifier and presents an overview of the process of extracting specific rare earth elements (REE), such as cerium (Ce), neodymium (Nd), lanthanum (La), praseodymium (Pr), and yttrium (Y), from mixed solutions using the solvent extraction technique.
When performed under specific conditions, including an aqueous-organic ratio (A/O) of 1, an extraction time of 120 minutes, and a temperature of 25°C, the extraction rates of La, Ce, Pr, Nd, and Y were determined to be 54.5%, 45.33%, 51.33%, 55.33%, and 97.33%, respectively, using their optimal lixiviant concentrations and D2EHPA concentrations. These conditions were identified as 2M HNO3 lixiviant and 25% D2EHPA concentration for La, Ce, Pr, and Nd, while for Y, the optimal conditions were 1M HNO3 lixiviant and 30% D2EHPA concentration.
Description
Keywords
Rare earth elements, solvent extraction
Citation
Degree
Master of Science (M.Sc.)
Department
Chemical and Biological Engineering
Program
Chemical Engineering