Abstract: The paper starts with a summary of the progress so far made in the study of reconcentration of flotation tailings. The fat coal flotation tailings of Guobei Plant is taken as the object to investigate the properties of the tailings through sieve and float-and-sink analysis. Based on analysis, the tailings in-depth reflotation system consisting of the following processes is proposed: pre-desliming of tailings + preremoval of high-ash mineral particles with spiral separator + liberation of intergrown constituents through grinding + flotation. Through laboratory study of the effect of grinding time on flotation result and screening and timed-release flotation tests, the optimum rod mill grinding time is 5 minutes.