Understanding of the separation mechanism of Knelson concentrators at particle scale and investigation of the effects of different feed properties and operating parameters helps process engineers to design, control and optimize these particulate solids processing units. This article reports findings of an investigation on separation performance of laboratory Knelson concentrator using an open-source Discrete Element Method (DEM) solver 'LIGGGHTS'. An available standard 7.5-cm (300) laboratory Knelson concentrator with five collecting rings was numerically simulated. The effects of feed properties including feed mass, feed type, feed grade, feed particles size, feed particle population and operating parameters including centrifugal force intensity, feeding rate and concentration cycle time on separation performance of laboratory Knelson concentrator were studied. Results of DEM simulations are expressed qualitatively and quantitatively in terms of performance indices, i.e., concentrate grade and total recovery. For validation of simulation predictions, the authors carried out several experimental tests on synthetic samples of pure quartz and magnetite mixtures under the same conditions used in simulation environment. A close agreement between simulation predictions and laboratory measurements for concentrate grade and total recovery was observed which validates DEM simulations. (C) 2017 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.