Minerals which could not be differentiated with existing technologies, such as color-sorting, X-ray transmission or near-infrared sensors, can now be identified and separated. The new ore sorting technology enables the user to define and apply a greater number of sorting criteria, and thus sort with much greater precision. The laser identification technology consists of a multi-channel laser scanning system with high-resolution imaging, and cutting-edge color and textural selectivity. Multiple material characteristics such as brightness, color, size, shape and surface texture are processed simultaneously.
The new multi-channel laser sorter is based on TOMRA´s compact PRO series, which has a well-proven track record of performance in the mining industry. The chute sorter has been equipped with two multi-channel laser systems placed opposite each other at an angle of 180°. This allows for the detection of material from two sides and maximizes the capture of information about the structure of material surfaces. This is particularly important for sorting material with contact zones because they are typically only detectable on one side of the ore. The machine can be quickly optimized for each required sorting task by selecting a sorting program and making appropriate sensitivity adjustments.
TOMRA´s patented multi-channel sorting technology measures reflection, absorption and fluorescence and utilizes the scattering effect of multiple lasers inside a detector unit.
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.