Abstract: For some problems such as low filling slurry concentration，high cement consumption and lack of tailings capacity of classified tailings cemented backfill in a gold mine in China，a co-disposal scheme of unclassified-tailings paste filling and stockpiling based on the deep cone thickener was proposed to improve and optimize existing filling system.During the operation of filling system post-improvement，all unclassified tailings from dressing plant were pumped into the deep cone thickener by first or multistage pumping station.When filling is required，thickener underflow is mixed with cement by two-stage horizontal mixer to produce paste which flow by gravity or pumped to stope.When filling is not required，underflow is transported to tailing pond for paste stockpiling by piston pump.The calculation and practice showed that the reforming scheme can save 13.99 million yuan filling cost and 10.4 million yuan tailings discharge cost per year.And，tailings discharge concentration was increased from 35% to 68% which contributes to increase the tailings stockpiling angle and prolong the service life of tailings pond.The co-disposal scheme of unclassified-tailings paste filling and stockpiling，according with the conception of “Green Mining”，can simultaneously realize goaf filling and tailings stockpiling.

Key words: Filling system, Unclassified-tailings paste backfill, Tailing paste stockpiling, Co-disposal, Optimized reform