Efficient Mining of Tantalum, Niobium, and Tin Using Handheld XRF Analyzers

Most mining operators are familiar with the importance of tantalum, niobium, and tin in today’s tech-driven world. Tantalum is used in electronics like mobile phones and computers due to its high melting point, making it ideal for capacitors. Niobium is essential in the steel industry and for creating super-alloys and superconductors. Tin, known for its low melting point, has been used for thousands of years in various applications, especially in soldering. However, the demand for these metals is growing faster than the supply, making effective mining and exploration methods crucial.

Role of Handheld XRF Analyzers in Mining

X-ray fluorescence spectroscopy (XRF) is a non-destructive analytical technique used to determine the elemental composition of materials. XRF analyzers work by measuring the fluorescent (or secondary) X-rays emitted from a sample when excited by a primary X-ray source. Each of the elements present in a sample produces a set of characteristic fluorescent X-rays, or “unique fingerprints.” These fingerprints are distinct for each element, making XRF analysis an excellent tool for quantitative and qualitative measurements. Accuracy is a key factor in the evaluation of ore concentrates, particularly due to their high trading values. (Download free ebook for more information on X-ray fluorescence spectroscopy.)

Handheld X-ray fluorescence (XRF) analyzers have revolutionized mining by providing fast and accurate elemental analysis with minimal sample preparation. These portable devices are versatile enough to be used at different stages of mining—from initial exploration to ore grade control and even environmental assessments. They offer real-time data, enabling miners to make quick, informed decisions on-site, increasing efficiency and reducing the need for time-consuming lab analyses.

Geological Background

Tantalum, niobium, and tin are typically found in late-stage magmatic rocks such as pegmatites and high-temperature veins. The common minerals containing these elements include tantalite ((FeMn)Ta₂O₆), columbite ((FeMn)Nb₂O₆), and cassiterite (SnO₂). Tantalite often occurs with columbite, forming coltan. These dense minerals can be eroded and transported by water, accumulating in placer deposits. These deposits are significant sources of tantalum, niobium, and tin in various countries, making them prime targets for mining.

Methodology and Results

We conducted a study to show that handheld XRF analyzers can produce results comparable to traditional laboratory methods, making them reliable for on-site analysis. We prepared some high-grade samples and analyzed them using both a handheld XRF analyzer and traditional laboratory methods such as ICP (Inductively Coupled Plasma) and AAS (Atomic Absorption Spectroscopy) for comparison. The handheld XRF analyzer was set to “Mining mode,” which uses a fundamental parameters algorithm to quantify over 30 elements without requiring user calibrations. However, for even better accuracy, a simple post-calibration adjustment can be made using pre-characterized lab samples.

The study found a high correlation between the data from the handheld XRF analyzer and the laboratory methods. The coefficient of determination (R² value) was close to 1, indicating a strong correlation. This means that the handheld XRF analyzer can accurately identify high- and low-grade concentrates of coltan samples within seconds. Figures in the study showed that the results for elements like tantalum (Ta), niobium (Nb), and tin (Sn) were very close to the lab values, proving the effectiveness of the handheld device.

You can see more details, including results screens, correlation diagrams, types of instruments, and analyses in the application note: Exploration and mining of tantalum-niobium (coltan) and tin with handheld XRF analyzers.

Summary

Handheld XRF analyzers are highly effective for quickly and accurately analyzing the elemental composition of minerals like coltan. They are useful across all stages of the mining workflow, from exploration to extraction and processing. Given their efficiency and accuracy, these devices are essential for meeting the growing demand for tantalum, niobium, and tin in various high-tech applications.