TOMRA´s patented multi-channel sorting technology measures reflection, absorption and fluorescence and utilizes the scattering effect of multiple lasers inside a detector unit. Typically, the focused laser beam, which is a monochromatic light source, hits a rock or mineral and is absorbed or reflected. This provides data concerning its color. When this laser beam hits a larger, translucent crystal – for example quartz – the laser beam enters the crystal and is reflected, refracted and scattered inside the crystal. The beam then returns as a blurry glow which is of relatively low intensity. Large translucent crystals will scatter more efficiently than smaller ones. This differentiated visual behavior is captured in high-resolution by high-sensitivity tools inside the new sorting system.
High purity quartz has a monocrystalline structure. As this structure is translucent, a laser beam diffuses inside the rock
where it characteristically illuminates the core. Microcrystalline or opaque rocks will only reflect the light beam.