X-Ray Transmission (XRT) and X-Ray Fluorescence (XRF) sorters identify materials based on atomic density and elemental composition. They complement NIR by separating materials that optical spectroscopy cannot distinguish — heavy metals, glass, stones, ceramics, and dark materials.
X-Ray Transmission (XRT)
Identifies materials by atomic density difference. An X-Ray source passes through the material and the detector measures attenuation. This enables separating aluminum from heavy materials, removing glass and stones from recyclable fractions, and classifying metals by density.
X-Ray Fluorescence (XRF)
Identifies elemental surface composition. Distinguishes copper from brass, zinc from aluminum, stainless steel from carbon steel — separation impossible by conventional magnetic or optical means. Applied in non-ferrous metal recycling where purity determines the selling price.
When to consider
X-Ray sorting is justified when the price differential between pure and mixed fractions offsets the investment. In fine non-ferrous recycling (below 30 mm), XRF separation can add 30-50% in value when selling pure copper, brass, and zinc versus a generic mix.
Viability depends on volume, composition, and market value of the fractions.