TITLE:
Modeling Preparative Chromatographic Separation of Heavy Rare Earth Elements and Optimization of Thulium Purification
AUTHORS:
Mark Max-Hansen, Hans-Kristian Knutson, Christian Jönsson, Marcus Degerman, Bernt Nilsson
KEYWORDS:
Rare Earth Elements, Chromatography, Model Calibration, Optimization, Multi-Objective, HDEHP
JOURNAL NAME:
Advances in Materials Physics and Chemistry,
Vol.5 No.5,
April
29,
2015
ABSTRACT: Rare Earth Elements
are in growing demand globally. This paper presents a case study of applied mathematical
modeling and multi objective optimization to optimize the separation of heavy
Rare Earth Elements, Terbium-Lutetium, by means of preparative solid phase
extraction chromatography, which means that an extraction ligand, HDEHP, is
immobilized on a C18 silica phase, and nitric acid is used as an eluent. An
ICP-MS was used for online detection of the Rare Earths. A methodology for
calibration and optimization is presented, and applied to an industrially
relevant mixture. Results show that Thulium is produced at 99% purity, with a
productivity of 0.2 - 0.5 kg Tm per m3 stationary phase and second,
with Yields from 74% to 99%.