Abstract: Based on the floatation and sinking data of lignite from the Tunlan Mine coal processing plant, the integrated yield maximization problem subject to multiple product constraints at the same time was investigated using the equal incremental product quality method. The optimum separation densities of heavy media water bath (DMB) and heavy media cyclone (DMC) for coarse (130~18 mm) and fine (18 ±0.5 mm) grains were determined by solvent method and Mathcad software method, respectively, and the incremental product quality method was analyzed for four different cases. For a target composite ash of 18.26% with a sulfur content of 0.98%, the composite yield reached a maximum of 87.45% when the incremental ash was equalized by Solver; by solvent equilibrating the incremental sulfur, the yield reached a maximum of 76.55% with a target sulfur content of 0.83% and an ash content of 14.65%; and multiple product qualities (ash and sulfur) were solved by Solver Simultaneous use of multiple product qualities (ash and sulphur) was used and the yield reached a maximum value of 66.87% when the ash and sulphur contents were 11.12% and 0.74%, respectively; Multiple constraints for yield maximization were achieved simultaneously using Mathcad software and the yield reached a maximum value of 66.33% when the ash and sulphur contents were 11.00% and 0.74%, respectively. Based on simultaneous satisfaction of multiple product quality (ash and sulfur) constraints and single product quality constraints, yield maximization was successfully achieved using Solver and Mathcad software.