MR imaging of ore for heap bioleaching studies using pure phase encode acquisition methods.

Area of Science:

• Geophysics
• Chemical Engineering
• Materials Science

Background:

• Imaging aqueous flow in low-grade copper ore is crucial for understanding heap leaching hydrology.
• Traditional MRI techniques can introduce image distortions, limiting their application.
• Developing robust imaging methods is essential for optimizing mining processes.

Purpose of the Study:

• To evaluate various MRI techniques for imaging aqueous flow fields in copper ore.
• To compare the performance of Single Point Imaging Multiple Point Acquisition (SPI-MPA) and Spin Echo Single Point Imaging (SESPI).
• To determine the most suitable MRI method for studying copper ore heap leaching hydrology.

Main Methods:

• Application of SPI-MPA and SESPI MRI techniques at 2 T and 4.7 T magnetic field strengths.
• Direct comparison of MRI images with X-ray tomographic images for distortion assessment.
• Analysis of signal-to-noise ratios (SNRs) and performance across different particle sizes and flow conditions.

Main Results:

• Both SPI-MPA and SESPI produced distortion-free images of ore packings at 2 T.
• SESPI demonstrated superior SNRs compared to SPI-MPA for equivalent acquisition times, linked to NMR relaxation.
• SESPI maintained image quality across various particle sizes, while SPI-MPA performance degraded with smaller particles.

Conclusions:

• SESPI is the most robust MRI method for imaging copper ore heap leaching hydrology.
• The superior performance of SESPI is attributed to its ability to handle varying particle sizes and magnetic field strengths.
• SESPI's reliability makes it a valuable tool for optimizing copper ore processing and water management.