Compton scattering internal standard correction extended by FP method and applied to metal element analysis of ore and concentrate samples

Compton scattering provides an internal reference signal that is generated naturally during XRF measurement, eliminating the need to add an external internal standard to the sample. Because the Compton peak responds to changes in the sample's bulk absorption characteristics, it can compensate for many matrix effects while keeping sample preparation simple. This makes the technique particularly attractive for routine analysis of geological powders and mining materials.

The traditional method assumes a relatively stable relationship between the analyte signal and the Compton scattering intensity. At high analyte concentrations, however, absorption effects from abundant coexisting elements become much stronger, causing deviations that cannot be fully corrected by the conventional approach. Elements such as calcium in iron ores can significantly influence iron X-ray intensity, reducing calibration accuracy unless additional matrix corrections are included.

The FP method calculates theoretical matrix correction coefficients based on X-ray physics rather than relying entirely on empirical calibration data. Incorporating these coefficients into the Compton scattering correction accounts more effectively for absorption and enhancement effects caused by other elements in the sample. The result is accurate calibration over much wider concentration ranges, including major elements present at tens of weight percent.

The FP-derived correction produces alpha coefficients that are roughly an order of magnitude smaller than those used in conventional matrix correction methods. Smaller coefficients reduce the propagation of errors arising from uncertainties in coexisting element concentrations, making analytical results more robust. This also minimizes the impact of particle size differences and mineralogical heterogeneity that are common in pressed powder samples.

The technique has been demonstrated for iron ores, copper ores and concentrates, nickel oxide ores, and nickel sulfide ores. It supports accurate determination of both major components, such as iron, copper, and nickel, and numerous accompanying elements including sulfur, silicon, calcium, magnesium, aluminum, zinc, cobalt, lead, arsenic, and others that influence ore quality and commercial value.

Mining laboratories often need to analyze hundreds or thousands of samples per day to control extraction and mineral processing. Pressed pellet preparation is significantly faster and less expensive than fused bead preparation, but traditionally sacrifices some analytical accuracy. The improved Compton scattering correction recovers much of that accuracy while preserving the speed, simplicity, and low operating cost required for high-throughput production environments.

Yes. The correction was successfully demonstrated on both sequential and simultaneous wavelength-dispersive XRF spectrometers. Comparable calibration performance across different instrument configurations indicates that the correction approach is broadly applicable rather than being limited to a single hardware design.