In this study, the beneficiation of two lignite tailings by Multi Gravity Separator (MGS) was investigated. The tailings samples from the Tuncbilek/Kutahya and Soma/Manisa regions have ash contents of 66.21% and 52.65%, respectively. Significant operational parameters of MGS such as solid ratio, drum speed, tilt angle, shaking amplitude, wash water rate, and feed rate were varied. Empirical equations for recovery and ash content were derived by a least squares method using Minitab 15. The equations, which are second-order response functions, were expressed as functions of the six operating parameters of MGS. The results showed that it is possible to produce a coal concentrate containing 22.83% ash with a recovery of 49.32% from Tuncbilek coal tailings, and a coal concentrate containing 22.89% ash with a recovery of 60.01% from Soma coal tailings. (C) 2010 Elsevier Ltd. All rights reserved.