Inline NMR Detection of Li⁺ in Aqueous Solutions Using a Cryogen-Free Magnet at 4.7 T

Area of Science:

• Analytical Chemistry
• Materials Science
• Electrochemistry

Background:

• Lithium is crucial for battery technology, necessitating efficient and eco-friendly extraction methods.
• Inline-compatible analytical techniques are vital for optimizing lithium extraction processes.
• Nuclear Magnetic Resonance (NMR) is a proven analytical method with existing inline applications.

Purpose of the Study:

• To evaluate the suitability of ⁷Li NMR for inline flow measurements.
• To define the limitations and potential applications of a specific NMR measurement setup for lithium analysis.
• To investigate the impact of internal pre-polarization on ⁷Li NMR measurements.

Main Methods:

• Utilized a cryogen-free magnet with a variable magnetic field (4.7 T) for ⁷Li NMR measurements.
• Conducted spin echo measurements to analyze the influences of flow velocity, repetition time, and lithium concentration.
• Explored the possibilities of internal pre-polarization for enhanced signal detection.

Main Results:

• The study demonstrated that the developed NMR method and setup are well-suited for inline flow measurements of ⁷Li.
• Investigated parameters like flow velocity, repetition time, and lithium concentration to establish measurement limitations.
• Internal pre-polarization was explored as a method to potentially improve sensitivity.

Conclusions:

• The ⁷Li NMR flow measurement setup shows significant promise for inline analysis in lithium extraction.
• The findings provide a basis for defining the operational parameters and application scope of this analytical technique.
• This technology has the potential to enhance the efficiency and environmental sustainability of lithium resource management.