Principle of Optical Sorting

Optical Sorting is a method where physical properties like color, shape, geometry and size of minerals are measured, analized and separated according to predetermined criterias. So value bearing minerals can be separated from non valuable minerals.

Optical sorting is applied in

• Pre-concentration of plant feed
• Intermediate product preparation
• Final product preparation

Optical sorting can help to overcome problems in some most critical areas of modern mining and mineral processing

• Energy consumption
• Mineral reserves
• Water consumption
• Environmental impact
• Quality improvement

Principle of Optical Sorting

Optical sorting is a single particle sorting method. Every particle is examined on an individual basis. 

First the to be sorted material will be conditioned which comprises screening to a appropriate size distribution and cleaning of material surface by scrubbing, humidifying and/or washing.

Next step is to generate a monolayer and presentation of the single (isolated) particles to a sensor i.e. a CCD-Line Scan Camera.

Generating of the required monolayer is done using a belt -Belt sorters are operated with a speed of 1.5-6m/s - or by vibro feeder with a chute -Chute or Gravity Sorter-. On the chute the material is accelerated. The detection (scanning) takes place immediately after the material has left the belt or the chute.

The data of the sensor are sent to an evaluation system (lndustrial PC) where a sorting decision is generated according to predetermined criteria such as color, shape, geometry and/or size.

The evaluation system activates an array of high- speed air valves to reject the relevant objects.