Abstract: The tailings from Meishan iron ore dressing plant is characterized by fine grain xize and difficult settlement.With growth of treatment capacity and change of process flowsheet,the output of Meishan tailings increases remarkably.As a consequence,tailings often run out from the chickener pond.To solve the problem,the dressing plant has conducted tests of high effective thickening in cooperation with Changsha Minerals % Metallurgy Research Institute and achieved satisfactcry results which can be used as basis for technical improvement of the dressing plant.