An Efficient NTAamide(n-Oct) Extraction Resin for High-Purity Thorium Preparation

Area of Science:

• Materials Science
• Nuclear Chemistry
• Separation Science

Background:

• High-purity thorium is crucial for producing key radioactive nuclides, including uranium-233 (233U) and actinium-225 (225Ac).
• Separating trace uranium and rare earth impurities from crude thorium products presents a significant challenge in obtaining high-purity thorium.

Purpose of the Study:

• To develop an efficient extraction resin for isolating high-purity thorium from nitric acid solutions containing uranium and rare earth elements.
• To characterize the adsorption properties and separation capabilities of the novel NTAamide(n-Oct)@CG71M resin for thorium.

Main Methods:

• Batch adsorption studies were conducted to evaluate the resin's selectivity and capacity for thorium (Th(IV)).
• Adsorption kinetics and isotherms were analyzed using pseudo-second-order and Langmuir models, respectively.
• Thermodynamic parameters were determined to understand the nature of the adsorption process.
• Dynamic separation experiments were performed using commercial thorium nitrate and simulated monazite leach liquor.

Main Results:

• The NTAamide(n-Oct)@CG71M resin demonstrated high selectivity and strong adsorption for thorium over a wide acidity range (0.10-8.0 mol/L HNO3).
• The maximum Th(IV) adsorption capacity (qmax) was 79.9 mg/g, following pseudo-second-order kinetics and Langmuir adsorption isotherm.
• Dynamic separation successfully yielded 99.99% pure thorium nitrate from commercial reagents and achieved 99.4% recovery of high-purity thorium from simulated leach liquor.
• The resin exhibited good reusability in separation experiments.

Conclusions:

• The developed NTAamide(n-Oct)@CG71M extraction resin is highly effective for preparing high-purity thorium nitrate.
• This resin offers a reliable technical solution for thorium purification, with significant potential for industrial applications in radioactive nuclide production.